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gerrit-public.fairphone.software / toolchain / llvm-project / e635c529a03bbec7255c4d8964fa06df66718790 / . / 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>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]56 </ol>
57 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]58 <li><a href="#typesystem">Type System</a>
59 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]60 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]61 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]62 <ol>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]63 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]64 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]65 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]66 <li><a href="#t_void">Void Type</a></li>
67 <li><a href="#t_label">Label Type</a></li>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]68 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]69 </ol>
70 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]71 <li><a href="#t_derived">Derived Types</a>
72 <ol>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]73 <li><a href="#t_aggregate">Aggregate Types</a>
74 <ol>
75 <li><a href="#t_array">Array Type</a></li>
76 <li><a href="#t_struct">Structure Type</a></li>
77 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]78 <li><a href="#t_vector">Vector Type</a></li>
79 </ol>
80 </li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]81 <li><a href="#t_function">Function Type</a></li>
82 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]83 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]84 </ol>
85 </li>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]86 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]87 </ol>
88 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]89 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]90 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]91 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]92 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]93 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
94 <li><a href="#undefvalues">Undefined Values</a></li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]95 <li><a href="#trapvalues">Trap Values</a></li>
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]96 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]97 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]98 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]99 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]100 <li><a href="#othervalues">Other Values</a>
101 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]102 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]103 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]104 </ol>
105 </li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]106 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
107 <ol>
108 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]109 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
110 Global Variable</a></li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]111 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
112 Global Variable</a></li>
113 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
114 Global Variable</a></li>
115 </ol>
116 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]117 <li><a href="#instref">Instruction Reference</a>
118 <ol>
119 <li><a href="#terminators">Terminator Instructions</a>
120 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]121 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
122 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]123 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]124 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]125 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]126 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]127 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]128 </ol>
129 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]130 <li><a href="#binaryops">Binary Operations</a>
131 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]132 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]133 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]134 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]135 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]136 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]137 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]138 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
139 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
140 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]141 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
142 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
143 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]144 </ol>
145 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]146 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
147 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]148 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
149 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
150 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]151 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]152 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]153 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]154 </ol>
155 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]156 <li><a href="#vectorops">Vector Operations</a>
157 <ol>
158 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
159 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
160 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]161 </ol>
162 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]163 <li><a href="#aggregateops">Aggregate Operations</a>
164 <ol>
165 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
166 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
167 </ol>
168 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]169 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]170 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]171 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]172 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
173 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
174 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]175 </ol>
176 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]177 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]178 <ol>
179 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
180 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
181 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
182 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
183 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]184 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
185 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
186 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
187 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]188 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
189 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]190 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]191 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]192 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]193 <li><a href="#otherops">Other Operations</a>
194 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]195 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
196 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]197 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]198 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]199 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]200 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]201 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]202 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]203 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]204 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]205 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]206 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]207 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
208 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]209 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
210 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
211 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]212 </ol>
213 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]214 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
215 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]216 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
217 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
218 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]219 </ol>
220 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]221 <li><a href="#int_codegen">Code Generator Intrinsics</a>
222 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]223 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
224 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
225 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
226 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
227 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
228 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohmane58f7b32010-05-26 21:56:15 +0000[diff] [blame]229 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]230 </ol>
231 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]232 <li><a href="#int_libc">Standard C Library Intrinsics</a>
233 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]234 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
235 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
236 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
237 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
238 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]239 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
240 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
241 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohmane635c522011-05-27 00:36:31 +0000[diff] [blame^]242 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
243 <li><a href="#int_log">'<tt>llvm.log.*</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
Jakob Stoklund Olesen74bb06c2010-02-06 01:16:28 +0000[diff] [blame]1167 <dt><tt><b>inlinehint</b></tt></dt>
1168 <dd>This attribute indicates that the source code contained a hint that inlining
1169 this function is desirable (such as the "inline" keyword in C/C++). It
1170 is just a hint; it imposes no requirements on the inliner.</dd>
1171
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1172 <dt><tt><b>naked</b></tt></dt>
1173 <dd>This attribute disables prologue / epilogue emission for the function.
1174 This can have very system-specific consequences.</dd>
1175
1176 <dt><tt><b>noimplicitfloat</b></tt></dt>
1177 <dd>This attributes disables implicit floating point instructions.</dd>
1178
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1179 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1180 <dd>This attribute indicates that the inliner should never inline this
1181 function in any situation. This attribute may not be used together with
1182 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1183
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1184 <dt><tt><b>noredzone</b></tt></dt>
1185 <dd>This attribute indicates that the code generator should not use a red
1186 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1187
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1188 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1189 <dd>This function attribute indicates that the function never returns
1190 normally. This produces undefined behavior at runtime if the function
1191 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1192
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1193 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1194 <dd>This function attribute indicates that the function never returns with an
1195 unwind or exceptional control flow. If the function does unwind, its
1196 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1197
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1198 <dt><tt><b>optsize</b></tt></dt>
1199 <dd>This attribute suggests that optimization passes and code generator passes
1200 make choices that keep the code size of this function low, and otherwise
1201 do optimizations specifically to reduce code size.</dd>
1202
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1203 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1204 <dd>This attribute indicates that the function computes its result (or decides
1205 to unwind an exception) based strictly on its arguments, without
1206 dereferencing any pointer arguments or otherwise accessing any mutable
1207 state (e.g. memory, control registers, etc) visible to caller functions.
1208 It does not write through any pointer arguments
1209 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1210 changes any state visible to callers. This means that it cannot unwind
1211 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1212 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1213
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1214 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1215 <dd>This attribute indicates that the function does not write through any
1216 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1217 arguments) or otherwise modify any state (e.g. memory, control registers,
1218 etc) visible to caller functions. It may dereference pointer arguments
1219 and read state that may be set in the caller. A readonly function always
1220 returns the same value (or unwinds an exception identically) when called
1221 with the same set of arguments and global state. It cannot unwind an
1222 exception by calling the <tt>C++</tt> exception throwing methods, but may
1223 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1224
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1225 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1226 <dd>This attribute indicates that the function should emit a stack smashing
1227 protector. It is in the form of a "canary"&mdash;a random value placed on
1228 the stack before the local variables that's checked upon return from the
1229 function to see if it has been overwritten. A heuristic is used to
1230 determine if a function needs stack protectors or not.<br>
1231<br>
1232 If a function that has an <tt>ssp</tt> attribute is inlined into a
1233 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1234 function will have an <tt>ssp</tt> attribute.</dd>
1235
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1236 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1237 <dd>This attribute indicates that the function should <em>always</em> emit a
1238 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1239 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1240<br>
1241 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1242 function that doesn't have an <tt>sspreq</tt> attribute or which has
1243 an <tt>ssp</tt> attribute, then the resulting function will have
1244 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1245</dl>
1246
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1247</div>
1248
1249<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1250<h3>
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1251 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1252</h3>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1253
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1254<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1255
1256<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1257 the GCC "file scope inline asm" blocks. These blocks are internally
1258 concatenated by LLVM and treated as a single unit, but may be separated in
1259 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1260
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1261<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1262module asm "inline asm code goes here"
1263module asm "more can go here"
1264</pre>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1265
1266<p>The strings can contain any character by escaping non-printable characters.
1267 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]1268 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1269
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1270<p>The inline asm code is simply printed to the machine code .s file when
1271 assembly code is generated.</p>
1272
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1273</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1274
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1275<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1276<h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1277 <a name="datalayout">Data Layout</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1278</h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1279
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1280<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1281
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1282<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1283 data is to be laid out in memory. The syntax for the data layout is
1284 simply:</p>
1285
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1286<pre class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1287target datalayout = "<i>layout specification</i>"
1288</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1289
1290<p>The <i>layout specification</i> consists of a list of specifications
1291 separated by the minus sign character ('-'). Each specification starts with
1292 a letter and may include other information after the letter to define some
1293 aspect of the data layout. The specifications accepted are as follows:</p>
1294
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1295<dl>
1296 <dt><tt>E</tt></dt>
1297 <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]1298 bits with the most significance have the lowest address location.</dd>
1299
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1300 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1301 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1302 the bits with the least significance have the lowest address
1303 location.</dd>
1304
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1305 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1306 <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]1307 <i>preferred</i> alignments. All sizes are in bits. Specifying
1308 the <i>pref</i> alignment is optional. If omitted, the
1309 preceding <tt>:</tt> should be omitted too.</dd>
1310
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1311 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1312 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1313 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1314
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1315 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1316 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1317 <i>size</i>.</dd>
1318
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1319 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1320 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesence522852010-05-28 18:54:47 +0000[diff] [blame]1321 <i>size</i>. Only values of <i>size</i> that are supported by the target
1322 will work. 32 (float) and 64 (double) are supported on all targets;
1323 80 or 128 (different flavors of long double) are also supported on some
1324 targets.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1325
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1326 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1327 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1328 <i>size</i>.</dd>
1329
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1330 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1331 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1332 <i>size</i>.</dd>
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1333
1334 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1335 <dd>This specifies a set of native integer widths for the target CPU
1336 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1337 "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]1338 this set are considered to support most general arithmetic
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1339 operations efficiently.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1340</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1341
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1342<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]1343 default set of specifications which are then (possibly) overridden by the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1344 specifications in the <tt>datalayout</tt> keyword. The default specifications
1345 are given in this list:</p>
1346
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1347<ul>
1348 <li><tt>E</tt> - big endian</li>
Dan Gohman8ad777d2010-02-23 02:44:03 +0000[diff] [blame]1349 <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]1350 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1351 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1352 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1353 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1354 <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]1355 alignment of 64-bits</li>
1356 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1357 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1358 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1359 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1360 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1361 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1362</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1363
1364<p>When LLVM is determining the alignment for a given type, it uses the
1365 following rules:</p>
1366
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1367<ol>
1368 <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]1369 specification is used.</li>
1370
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1371 <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]1372 smallest integer type that is larger than the bitwidth of the sought type
1373 is used. If none of the specifications are larger than the bitwidth then
1374 the the largest integer type is used. For example, given the default
1375 specifications above, the i7 type will use the alignment of i8 (next
1376 largest) while both i65 and i256 will use the alignment of i64 (largest
1377 specified).</li>
1378
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1379 <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]1380 largest vector type that is smaller than the sought vector type will be
1381 used as a fall back. This happens because &lt;128 x double&gt; can be
1382 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1383</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1384
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1385</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1386
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1387<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1388<h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1389 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1390</h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1391
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1392<div>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1393
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1394<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1395with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1396is undefined. Pointer values are associated with address ranges
1397according to the following rules:</p>
1398
1399<ul>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1400 <li>A pointer value is associated with the addresses associated with
1401 any value it is <i>based</i> on.
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1402 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1403 range of the variable's storage.</li>
1404 <li>The result value of an allocation instruction is associated with
1405 the address range of the allocated storage.</li>
1406 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1407 no address.</li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1408 <li>An integer constant other than zero or a pointer value returned
1409 from a function not defined within LLVM may be associated with address
1410 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1411 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1412 allocated by mechanisms provided by LLVM.</li>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1413</ul>
1414
1415<p>A pointer value is <i>based</i> on another pointer value according
1416 to the following rules:</p>
1417
1418<ul>
1419 <li>A pointer value formed from a
1420 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1421 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1422 <li>The result value of a
1423 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1424 of the <tt>bitcast</tt>.</li>
1425 <li>A pointer value formed by an
1426 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1427 pointer values that contribute (directly or indirectly) to the
1428 computation of the pointer's value.</li>
1429 <li>The "<i>based</i> on" relationship is transitive.</li>
1430</ul>
1431
1432<p>Note that this definition of <i>"based"</i> is intentionally
1433 similar to the definition of <i>"based"</i> in C99, though it is
1434 slightly weaker.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1435
1436<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1437<tt><a href="#i_load">load</a></tt> merely indicates the size and
1438alignment of the memory from which to load, as well as the
Dan Gohman4eb47192010-06-17 19:23:50 +0000[diff] [blame]1439interpretation of the value. The first operand type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1440<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1441and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1442
1443<p>Consequently, type-based alias analysis, aka TBAA, aka
1444<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1445LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1446additional information which specialized optimization passes may use
1447to implement type-based alias analysis.</p>
1448
1449</div>
1450
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1451<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1452<h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1453 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1454</h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1455
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1456<div>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1457
1458<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1459href="#i_store"><tt>store</tt></a>s, and <a
1460href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1461The optimizers must not change the number of volatile operations or change their
1462order of execution relative to other volatile operations. The optimizers
1463<i>may</i> change the order of volatile operations relative to non-volatile
1464operations. This is not Java's "volatile" and has no cross-thread
1465synchronization behavior.</p>
1466
1467</div>
1468
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1469</div>
1470
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1471<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1472<h2><a name="typesystem">Type System</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1473<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1474
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1475<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1476
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1477<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1478 intermediate representation. Being typed enables a number of optimizations
1479 to be performed on the intermediate representation directly, without having
1480 to do extra analyses on the side before the transformation. A strong type
1481 system makes it easier to read the generated code and enables novel analyses
1482 and transformations that are not feasible to perform on normal three address
1483 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1484
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1485<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1486<h3>
1487 <a name="t_classifications">Type Classifications</a>
1488</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1489
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1490<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1491
1492<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1493
1494<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1495 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1496 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1497 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1498 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1499 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1500 </tr>
1501 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1502 <td><a href="#t_floating">floating point</a></td>
1503 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1504 </tr>
1505 <tr>
1506 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1507 <td><a href="#t_integer">integer</a>,
1508 <a href="#t_floating">floating point</a>,
1509 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1510 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1511 <a href="#t_struct">structure</a>,
1512 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1513 <a href="#t_label">label</a>,
1514 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1515 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1516 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1517 <tr>
1518 <td><a href="#t_primitive">primitive</a></td>
1519 <td><a href="#t_label">label</a>,
1520 <a href="#t_void">void</a>,
Tobias Grosser4c8c95b2010-12-28 20:29:31 +0000[diff] [blame]1521 <a href="#t_integer">integer</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1522 <a href="#t_floating">floating point</a>,
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1523 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1524 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1525 </tr>
1526 <tr>
1527 <td><a href="#t_derived">derived</a></td>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1528 <td><a href="#t_array">array</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1529 <a href="#t_function">function</a>,
1530 <a href="#t_pointer">pointer</a>,
1531 <a href="#t_struct">structure</a>,
1532 <a href="#t_pstruct">packed structure</a>,
1533 <a href="#t_vector">vector</a>,
1534 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1535 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1536 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1537 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1538</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1539
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1540<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1541 important. Values of these types are the only ones which can be produced by
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1542 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1543
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1544</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1545
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1546<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1547<h3>
1548 <a name="t_primitive">Primitive Types</a>
1549</h3>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1550
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1551<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1552
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1553<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1554 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1555
1556<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1557<h4>
1558 <a name="t_integer">Integer Type</a>
1559</h4>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1560
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1561<div>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1562
1563<h5>Overview:</h5>
1564<p>The integer type is a very simple type that simply specifies an arbitrary
1565 bit width for the integer type desired. Any bit width from 1 bit to
1566 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1567
1568<h5>Syntax:</h5>
1569<pre>
1570 iN
1571</pre>
1572
1573<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1574 value.</p>
1575
1576<h5>Examples:</h5>
1577<table class="layout">
1578 <tr class="layout">
1579 <td class="left"><tt>i1</tt></td>
1580 <td class="left">a single-bit integer.</td>
1581 </tr>
1582 <tr class="layout">
1583 <td class="left"><tt>i32</tt></td>
1584 <td class="left">a 32-bit integer.</td>
1585 </tr>
1586 <tr class="layout">
1587 <td class="left"><tt>i1942652</tt></td>
1588 <td class="left">a really big integer of over 1 million bits.</td>
1589 </tr>
1590</table>
1591
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1592</div>
1593
1594<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1595<h4>
1596 <a name="t_floating">Floating Point Types</a>
1597</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1598
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1599<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1600
1601<table>
1602 <tbody>
1603 <tr><th>Type</th><th>Description</th></tr>
1604 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1605 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1606 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1607 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1608 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1609 </tbody>
1610</table>
1611
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1612</div>
1613
1614<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1615<h4>
1616 <a name="t_x86mmx">X86mmx Type</a>
1617</h4>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1618
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1619<div>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1620
1621<h5>Overview:</h5>
1622<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>
1623
1624<h5>Syntax:</h5>
1625<pre>
Dale Johannesenb1f0ff12010-10-01 01:07:02 +0000[diff] [blame]1626 x86mmx
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1627</pre>
1628
1629</div>
1630
1631<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1632<h4>
1633 <a name="t_void">Void Type</a>
1634</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1635
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1636<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1637
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1638<h5>Overview:</h5>
1639<p>The void type does not represent any value and has no size.</p>
1640
1641<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1642<pre>
1643 void
1644</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1645
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1646</div>
1647
1648<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1649<h4>
1650 <a name="t_label">Label Type</a>
1651</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1652
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1653<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1654
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1655<h5>Overview:</h5>
1656<p>The label type represents code labels.</p>
1657
1658<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1659<pre>
1660 label
1661</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1662
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1663</div>
1664
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1665<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1666<h4>
1667 <a name="t_metadata">Metadata Type</a>
1668</h4>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1669
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1670<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1671
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1672<h5>Overview:</h5>
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1673<p>The metadata type represents embedded metadata. No derived types may be
1674 created from metadata except for <a href="#t_function">function</a>
1675 arguments.
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1676
1677<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1678<pre>
1679 metadata
1680</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1681
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1682</div>
1683
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1684</div>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1685
1686<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1687<h3>
1688 <a name="t_derived">Derived Types</a>
1689</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1690
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1691<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1692
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1693<p>The real power in LLVM comes from the derived types in the system. This is
1694 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1695 useful types. Each of these types contain one or more element types which
1696 may be a primitive type, or another derived type. For example, it is
1697 possible to have a two dimensional array, using an array as the element type
1698 of another array.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1699
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1700
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1701<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1702<h4>
1703 <a name="t_aggregate">Aggregate Types</a>
1704</h4>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1705
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1706<div>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1707
1708<p>Aggregate Types are a subset of derived types that can contain multiple
1709 member types. <a href="#t_array">Arrays</a>,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]1710 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1711 aggregate types.</p>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1712
1713</div>
1714
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1715<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1716<h4>
1717 <a name="t_array">Array Type</a>
1718</h4>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1719
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1720<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1721
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1722<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1723<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1724 sequentially in memory. The array type requires a size (number of elements)
1725 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1726
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1727<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1728<pre>
1729 [&lt;# elements&gt; x &lt;elementtype&gt;]
1730</pre>
1731
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1732<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1733 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1734
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1735<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1736<table class="layout">
1737 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1738 <td class="left"><tt>[40 x i32]</tt></td>
1739 <td class="left">Array of 40 32-bit integer values.</td>
1740 </tr>
1741 <tr class="layout">
1742 <td class="left"><tt>[41 x i32]</tt></td>
1743 <td class="left">Array of 41 32-bit integer values.</td>
1744 </tr>
1745 <tr class="layout">
1746 <td class="left"><tt>[4 x i8]</tt></td>
1747 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1748 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1749</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1750<p>Here are some examples of multidimensional arrays:</p>
1751<table class="layout">
1752 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1753 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1754 <td class="left">3x4 array of 32-bit integer values.</td>
1755 </tr>
1756 <tr class="layout">
1757 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1758 <td class="left">12x10 array of single precision floating point values.</td>
1759 </tr>
1760 <tr class="layout">
1761 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1762 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1763 </tr>
1764</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1765
Dan Gohmanc74bc282009-11-09 19:01:53 +0000[diff] [blame]1766<p>There is no restriction on indexing beyond the end of the array implied by
1767 a static type (though there are restrictions on indexing beyond the bounds
1768 of an allocated object in some cases). This means that single-dimension
1769 'variable sized array' addressing can be implemented in LLVM with a zero
1770 length array type. An implementation of 'pascal style arrays' in LLVM could
1771 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1772
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1773</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1774
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1775<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1776<h4>
1777 <a name="t_function">Function Type</a>
1778</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1779
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1780<div>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1781
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1782<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1783<p>The function type can be thought of as a function signature. It consists of
1784 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]1785 function type is a first class type or a void type.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1786
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1787<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1788<pre>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1789 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1790</pre>
1791
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1792<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]1793 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1794 which indicates that the function takes a variable number of arguments.
1795 Variable argument functions can access their arguments with
1796 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1797 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1798 <a href="#t_label">label</a>.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1799
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1800<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1801<table class="layout">
1802 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1803 <td class="left"><tt>i32 (i32)</tt></td>
1804 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1805 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1806 </tr><tr class="layout">
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1807 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1808 </tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1809 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1810 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1811 returning <tt>float</tt>.
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1812 </td>
1813 </tr><tr class="layout">
1814 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1815 <td class="left">A vararg function that takes at least one
1816 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1817 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1818 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1819 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1820 </tr><tr class="layout">
1821 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1822 <td class="left">A function taking an <tt>i32</tt>, returning a
1823 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1824 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1825 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1826</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1827
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1828</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1829
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1830<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1831<h4>
1832 <a name="t_struct">Structure Type</a>
1833</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1834
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1835<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1836
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1837<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1838<p>The structure type is used to represent a collection of data members together
1839 in memory. The packing of the field types is defined to match the ABI of the
1840 underlying processor. The elements of a structure may be any type that has a
1841 size.</p>
1842
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]1843<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1844 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1845 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1846 Structures in registers are accessed using the
1847 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1848 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1849<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1850<pre>
1851 { &lt;type list&gt; }
1852</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1853
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1854<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1855<table class="layout">
1856 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1857 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1858 <td class="left">A triple of three <tt>i32</tt> values</td>
1859 </tr><tr class="layout">
1860 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1861 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1862 second element is a <a href="#t_pointer">pointer</a> to a
1863 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1864 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1865 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1866</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1867
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1868</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1869
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1870<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1871<h4>
1872 <a name="t_pstruct">Packed Structure Type</a>
1873</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1874
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1875<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1876
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1877<h5>Overview:</h5>
1878<p>The packed structure type is used to represent a collection of data members
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1879 together in memory. There is no padding between fields. Further, the
1880 alignment of a packed structure is 1 byte. The elements of a packed
1881 structure may be any type that has a size.</p>
1882
1883<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1884 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1885 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1886
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1887<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1888<pre>
1889 &lt; { &lt;type list&gt; } &gt;
1890</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1891
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1892<h5>Examples:</h5>
1893<table class="layout">
1894 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1895 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1896 <td class="left">A triple of three <tt>i32</tt> values</td>
1897 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1898 <td class="left">
1899<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1900 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1901 second element is a <a href="#t_pointer">pointer</a> to a
1902 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1903 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1904 </tr>
1905</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1906
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1907</div>
1908
1909<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1910<h4>
1911 <a name="t_pointer">Pointer Type</a>
1912</h4>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1913
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1914<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1915
1916<h5>Overview:</h5>
Dan Gohman88481112010-02-25 16:50:07 +0000[diff] [blame]1917<p>The pointer type is used to specify memory locations.
1918 Pointers are commonly used to reference objects in memory.</p>
1919
1920<p>Pointer types may have an optional address space attribute defining the
1921 numbered address space where the pointed-to object resides. The default
1922 address space is number zero. The semantics of non-zero address
1923 spaces are target-specific.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1924
1925<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1926 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1927
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1928<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1929<pre>
1930 &lt;type&gt; *
1931</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1932
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1933<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1934<table class="layout">
1935 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]1936 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1937 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1938 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1939 </tr>
1940 <tr class="layout">
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]1941 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1942 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1943 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1944 <tt>i32</tt>.</td>
1945 </tr>
1946 <tr class="layout">
1947 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1948 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1949 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1950 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1951</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1952
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1953</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1954
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1955<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1956<h4>
1957 <a name="t_vector">Vector Type</a>
1958</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1959
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1960<div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1961
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1962<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1963<p>A vector type is a simple derived type that represents a vector of elements.
1964 Vector types are used when multiple primitive data are operated in parallel
1965 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sands31c0e0e2009-11-27 13:38:03 +0000[diff] [blame]1966 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1967 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1968
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1969<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1970<pre>
1971 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1972</pre>
1973
Chris Lattnerf11031a2010-10-10 18:20:35 +0000[diff] [blame]1974<p>The number of elements is a constant integer value larger than 0; elementtype
1975 may be any integer or floating point type. Vectors of size zero are not
1976 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1977
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1978<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1979<table class="layout">
1980 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1981 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1982 <td class="left">Vector of 4 32-bit integer values.</td>
1983 </tr>
1984 <tr class="layout">
1985 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1986 <td class="left">Vector of 8 32-bit floating-point values.</td>
1987 </tr>
1988 <tr class="layout">
1989 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1990 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1991 </tr>
1992</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1993
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1994</div>
1995
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1996<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1997<h4>
1998 <a name="t_opaque">Opaque Type</a>
1999</h4>
2000
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2001<div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2002
2003<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2004<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2005 corresponds (for example) to the C notion of a forward declared structure
2006 type. In LLVM, opaque types can eventually be resolved to any type (not just
2007 a structure type).</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2008
2009<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2010<pre>
2011 opaque
2012</pre>
2013
2014<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2015<table class="layout">
2016 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2017 <td class="left"><tt>opaque</tt></td>
2018 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2019 </tr>
2020</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2021
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2022</div>
2023
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2024</div>
2025
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2026<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2027<h3>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2028 <a name="t_uprefs">Type Up-references</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2029</h3>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2030
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2031<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2032
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2033<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2034<p>An "up reference" allows you to refer to a lexically enclosing type without
2035 requiring it to have a name. For instance, a structure declaration may
2036 contain a pointer to any of the types it is lexically a member of. Example
2037 of up references (with their equivalent as named type declarations)
2038 include:</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2039
2040<pre>
Chris Lattnerbf1d5452009-02-09 10:00:56 +0000[diff] [blame]2041 { \2 * } %x = type { %x* }
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2042 { \2 }* %y = type { %y }*
2043 \1* %z = type %z*
2044</pre>
2045
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2046<p>An up reference is needed by the asmprinter for printing out cyclic types
2047 when there is no declared name for a type in the cycle. Because the
2048 asmprinter does not want to print out an infinite type string, it needs a
2049 syntax to handle recursive types that have no names (all names are optional
2050 in llvm IR).</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2051
2052<h5>Syntax:</h5>
2053<pre>
2054 \&lt;level&gt;
2055</pre>
2056
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2057<p>The level is the count of the lexical type that is being referred to.</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2058
2059<h5>Examples:</h5>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2060<table class="layout">
2061 <tr class="layout">
2062 <td class="left"><tt>\1*</tt></td>
2063 <td class="left">Self-referential pointer.</td>
2064 </tr>
2065 <tr class="layout">
2066 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
2067 <td class="left">Recursive structure where the upref refers to the out-most
2068 structure.</td>
2069 </tr>
2070</table>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2071
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2072</div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2073
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2074</div>
2075
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2076<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2077<h2><a name="constants">Constants</a></h2>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2078<!-- *********************************************************************** -->
2079
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2080<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2081
2082<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2083 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2084
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2085<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2086<h3>
2087 <a name="simpleconstants">Simple Constants</a>
2088</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2089
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2090<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2091
2092<dl>
2093 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2094 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]2095 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2096
2097 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2098 <dd>Standard integers (such as '4') are constants of
2099 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2100 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2101
2102 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2103 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2104 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2105 notation (see below). The assembler requires the exact decimal value of a
2106 floating-point constant. For example, the assembler accepts 1.25 but
2107 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2108 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2109
2110 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2111 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2112 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2113</dl>
2114
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2115<p>The one non-intuitive notation for constants is the hexadecimal form of
2116 floating point constants. For example, the form '<tt>double
2117 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2118 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2119 constants are required (and the only time that they are generated by the
2120 disassembler) is when a floating point constant must be emitted but it cannot
2121 be represented as a decimal floating point number in a reasonable number of
2122 digits. For example, NaN's, infinities, and other special values are
2123 represented in their IEEE hexadecimal format so that assembly and disassembly
2124 do not cause any bits to change in the constants.</p>
2125
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]2126<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2127 represented using the 16-digit form shown above (which matches the IEEE754
2128 representation for double); float values must, however, be exactly
2129 representable as IEE754 single precision. Hexadecimal format is always used
2130 for long double, and there are three forms of long double. The 80-bit format
2131 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2132 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2133 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2134 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2135 currently supported target uses this format. Long doubles will only work if
2136 they match the long double format on your target. All hexadecimal formats
2137 are big-endian (sign bit at the left).</p>
2138
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]2139<p>There are no constants of type x86mmx.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2140</div>
2141
2142<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2143<h3>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2144<a name="aggregateconstants"></a> <!-- old anchor -->
2145<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2146</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2147
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2148<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2149
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2150<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2151 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2152
2153<dl>
2154 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2155 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2156 type definitions (a comma separated list of elements, surrounded by braces
2157 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2158 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2159 Structure constants must have <a href="#t_struct">structure type</a>, and
2160 the number and types of elements must match those specified by the
2161 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2162
2163 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2164 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2165 definitions (a comma separated list of elements, surrounded by square
2166 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2167 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2168 the number and types of elements must match those specified by the
2169 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2170
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2171 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2172 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2173 definitions (a comma separated list of elements, surrounded by
2174 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2175 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2176 have <a href="#t_vector">vector type</a>, and the number and types of
2177 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2178
2179 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2180 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2181 value to zero of <em>any</em> type, including scalar and
2182 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2183 This is often used to avoid having to print large zero initializers
2184 (e.g. for large arrays) and is always exactly equivalent to using explicit
2185 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2186
2187 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]2188 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2189 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2190 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2191 be interpreted as part of the instruction stream, metadata is a place to
2192 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2193</dl>
2194
2195</div>
2196
2197<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2198<h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2199 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2200</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2201
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2202<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2203
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2204<p>The addresses of <a href="#globalvars">global variables</a>
2205 and <a href="#functionstructure">functions</a> are always implicitly valid
2206 (link-time) constants. These constants are explicitly referenced when
2207 the <a href="#identifiers">identifier for the global</a> is used and always
2208 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2209 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2210
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2211<pre class="doc_code">
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]2212@X = global i32 17
2213@Y = global i32 42
2214@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2215</pre>
2216
2217</div>
2218
2219<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2220<h3>
2221 <a name="undefvalues">Undefined Values</a>
2222</h3>
2223
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2224<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2225
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2226<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]2227 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2228 Undefined values may be of any type (other than '<tt>label</tt>'
2229 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2230
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2231<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2232 program is well defined no matter what value is used. This gives the
2233 compiler more freedom to optimize. Here are some examples of (potentially
2234 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2235
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2236
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2237<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2238 %A = add %X, undef
2239 %B = sub %X, undef
2240 %C = xor %X, undef
2241Safe:
2242 %A = undef
2243 %B = undef
2244 %C = undef
2245</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2246
2247<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]2248 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]2249
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2250<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2251 %A = or %X, undef
2252 %B = and %X, undef
2253Safe:
2254 %A = -1
2255 %B = 0
2256Unsafe:
2257 %A = undef
2258 %B = undef
2259</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2260
2261<p>These logical operations have bits that are not always affected by the input.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2262 For example, if <tt>%X</tt> has a zero bit, then the output of the
2263 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2264 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2265 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2266 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2267 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2268 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2269 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2270
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2271<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2272 %A = select undef, %X, %Y
2273 %B = select undef, 42, %Y
2274 %C = select %X, %Y, undef
2275Safe:
2276 %A = %X (or %Y)
2277 %B = 42 (or %Y)
2278 %C = %Y
2279Unsafe:
2280 %A = undef
2281 %B = undef
2282 %C = undef
2283</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2284
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2285<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2286 branch) conditions can go <em>either way</em>, but they have to come from one
2287 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2288 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2289 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2290 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2291 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2292 eliminated.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2293
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2294<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2295 %A = xor undef, undef
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2296
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2297 %B = undef
2298 %C = xor %B, %B
2299
2300 %D = undef
2301 %E = icmp lt %D, 4
2302 %F = icmp gte %D, 4
2303
2304Safe:
2305 %A = undef
2306 %B = undef
2307 %C = undef
2308 %D = undef
2309 %E = undef
2310 %F = undef
2311</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2312
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2313<p>This example points out that two '<tt>undef</tt>' operands are not
2314 necessarily the same. This can be surprising to people (and also matches C
2315 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2316 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2317 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2318 its value over its "live range". This is true because the variable doesn't
2319 actually <em>have a live range</em>. Instead, the value is logically read
2320 from arbitrary registers that happen to be around when needed, so the value
2321 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2322 need to have the same semantics or the core LLVM "replace all uses with"
2323 concept would not hold.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2324
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2325<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2326 %A = fdiv undef, %X
2327 %B = fdiv %X, undef
2328Safe:
2329 %A = undef
2330b: unreachable
2331</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2332
2333<p>These examples show the crucial difference between an <em>undefined
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2334 value</em> and <em>undefined behavior</em>. An undefined value (like
2335 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2336 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2337 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2338 defined on SNaN's. However, in the second example, we can make a more
2339 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2340 arbitrary value, we are allowed to assume that it could be zero. Since a
2341 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2342 the operation does not execute at all. This allows us to delete the divide and
2343 all code after it. Because the undefined operation "can't happen", the
2344 optimizer can assume that it occurs in dead code.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2345
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2346<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2347a: store undef -> %X
2348b: store %X -> undef
2349Safe:
2350a: &lt;deleted&gt;
2351b: unreachable
2352</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2353
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2354<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2355 undefined value can be assumed to not have any effect; we can assume that the
2356 value is overwritten with bits that happen to match what was already there.
2357 However, a store <em>to</em> an undefined location could clobber arbitrary
2358 memory, therefore, it has undefined behavior.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2359
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2360</div>
2361
2362<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2363<h3>
2364 <a name="trapvalues">Trap Values</a>
2365</h3>
2366
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2367<div>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2368
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2369<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2370 instead of representing an unspecified bit pattern, they represent the
2371 fact that an instruction or constant expression which cannot evoke side
2372 effects has nevertheless detected a condition which results in undefined
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2373 behavior.</p>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2374
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2375<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]2376 only exist when produced by operations such as
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2377 <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]2378
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2379<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2380
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2381<ul>
2382<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2383 their operands.</li>
2384
2385<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2386 to their dynamic predecessor basic block.</li>
2387
2388<li>Function arguments depend on the corresponding actual argument values in
2389 the dynamic callers of their functions.</li>
2390
2391<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2392 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2393 control back to them.</li>
2394
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2395<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2396 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2397 or exception-throwing call instructions that dynamically transfer control
2398 back to them.</li>
2399
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2400<li>Non-volatile loads and stores depend on the most recent stores to all of the
2401 referenced memory addresses, following the order in the IR
2402 (including loads and stores implied by intrinsics such as
2403 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2404
Dan Gohman3513ea52010-05-03 14:59:34 +0000[diff] [blame]2405<!-- TODO: In the case of multiple threads, this only applies if the store
2406 "happens-before" the load or store. -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2407
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2408<!-- TODO: floating-point exception state -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2409
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2410<li>An instruction with externally visible side effects depends on the most
2411 recent preceding instruction with externally visible side effects, following
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]2412 the order in the IR. (This includes
2413 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2414
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2415<li>An instruction <i>control-depends</i> on a
2416 <a href="#terminators">terminator instruction</a>
2417 if the terminator instruction has multiple successors and the instruction
2418 is always executed when control transfers to one of the successors, and
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2419 may not be executed when control is transferred to another.</li>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2420
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2421<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2422 instruction if the set of instructions it otherwise depends on would be
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2423 different if the terminator had transferred control to a different
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2424 successor.</li>
2425
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2426<li>Dependence is transitive.</li>
2427
2428</ul>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2429
2430<p>Whenever a trap value is generated, all values which depend on it evaluate
2431 to trap. If they have side effects, the evoke their side effects as if each
2432 operand with a trap value were undef. If they have externally-visible side
2433 effects, the behavior is undefined.</p>
2434
2435<p>Here are some examples:</p>
Dan Gohman48a25882010-04-26 20:54:53 +0000[diff] [blame]2436
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2437<pre class="doc_code">
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2438entry:
2439 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2440 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2441 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2442 store i32 0, i32* %trap_yet_again ; undefined behavior
2443
2444 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2445 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2446
2447 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2448
2449 %narrowaddr = bitcast i32* @g to i16*
2450 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2451 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2452 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2453
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2454 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2455 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2456
2457true:
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2458 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2459 ; it has undefined behavior.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2460 br label %end
2461
2462end:
2463 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2464 ; Both edges into this PHI are
2465 ; control-dependent on %cmp, so this
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2466 ; always results in a trap value.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2467
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2468 volatile store i32 0, i32* @g ; This would depend on the store in %true
2469 ; if %cmp is true, or the store in %entry
2470 ; otherwise, so this is undefined behavior.
2471
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2472 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2473 ; The same branch again, but this time the
2474 ; true block doesn't have side effects.
2475
2476second_true:
2477 ; No side effects!
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2478 ret void
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2479
2480second_end:
2481 volatile store i32 0, i32* @g ; This time, the instruction always depends
2482 ; on the store in %end. Also, it is
2483 ; control-equivalent to %end, so this is
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2484 ; well-defined (again, ignoring earlier
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2485 ; undefined behavior in this example).
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2486</pre>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2487
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2488</div>
2489
2490<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2491<h3>
2492 <a name="blockaddress">Addresses of Basic Blocks</a>
2493</h3>
2494
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2495<div>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2496
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2497<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2498
2499<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner5c5f0ac2009-10-27 21:49:40 +0000[diff] [blame]2500 basic block in the specified function, and always has an i8* type. Taking
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2501 the address of the entry block is illegal.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2502
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2503<p>This value only has defined behavior when used as an operand to the
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2504 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2505 comparisons against null. Pointer equality tests between labels addresses
2506 results in undefined behavior &mdash; though, again, comparison against null
2507 is ok, and no label is equal to the null pointer. This may be passed around
2508 as an opaque pointer sized value as long as the bits are not inspected. This
2509 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2510 long as the original value is reconstituted before the <tt>indirectbr</tt>
2511 instruction.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2512
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2513<p>Finally, some targets may provide defined semantics when using the value as
2514 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2515
2516</div>
2517
2518
2519<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2520<h3>
2521 <a name="constantexprs">Constant Expressions</a>
2522</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2523
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2524<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2525
2526<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2527 to be used as constants. Constant expressions may be of
2528 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2529 operation that does not have side effects (e.g. load and call are not
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2530 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2531
2532<dl>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2533 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2534 <dd>Truncate a constant to another type. The bit size of CST must be larger
2535 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2536
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2537 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2538 <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]2539 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2540
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2541 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2542 <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]2543 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2544
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2545 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2546 <dd>Truncate a floating point constant to another floating point type. The
2547 size of CST must be larger than the size of TYPE. Both types must be
2548 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2549
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2550 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2551 <dd>Floating point extend a constant to another type. The size of CST must be
2552 smaller or equal to the size of TYPE. Both types must be floating
2553 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2554
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2555 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2556 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2557 constant. TYPE must be a scalar or vector integer type. CST must be of
2558 scalar or vector floating point type. Both CST and TYPE must be scalars,
2559 or vectors of the same number of elements. If the value won't fit in the
2560 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2561
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2562 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2563 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2564 constant. TYPE must be a scalar or vector integer type. CST must be of
2565 scalar or vector floating point type. Both CST and TYPE must be scalars,
2566 or vectors of the same number of elements. If the value won't fit in the
2567 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2568
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2569 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2570 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2571 constant. TYPE must be a scalar or vector floating point type. CST must be
2572 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2573 vectors of the same number of elements. If the value won't fit in the
2574 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2575
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2576 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2577 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2578 constant. TYPE must be a scalar or vector floating point type. CST must be
2579 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2580 vectors of the same number of elements. If the value won't fit in the
2581 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2582
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2583 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2584 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2585 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2586 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2587 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2588
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2589 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2590 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2591 type. CST must be of integer type. The CST value is zero extended,
2592 truncated, or unchanged to make it fit in a pointer size. This one is
2593 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2594
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2595 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2596 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2597 are the same as those for the <a href="#i_bitcast">bitcast
2598 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2599
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2600 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2601 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2602 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2603 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2604 instruction, the index list may have zero or more indexes, which are
2605 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2606
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2607 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2608 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2609
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2610 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2611 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2612
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2613 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2614 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2615
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2616 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2617 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2618 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2619
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2620 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2621 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2622 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2623
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2624 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2625 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2626 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2627
Nick Lewycky9ab9a7f2010-05-29 06:44:15 +0000[diff] [blame]2628 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2629 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2630 constants. The index list is interpreted in a similar manner as indices in
2631 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2632 index value must be specified.</dd>
2633
2634 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2635 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2636 constants. The index list is interpreted in a similar manner as indices in
2637 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2638 index value must be specified.</dd>
2639
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2640 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2641 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2642 be any of the <a href="#binaryops">binary</a>
2643 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2644 on operands are the same as those for the corresponding instruction
2645 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2646</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2647
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2648</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2649
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2650</div>
2651
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2652<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2653<h2><a name="othervalues">Other Values</a></h2>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2654<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2655<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2656<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2657<h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2658<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2659</h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2660
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2661<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2662
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2663<p>LLVM supports inline assembler expressions (as opposed
2664 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2665 a special value. This value represents the inline assembler as a string
2666 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2667 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2668 expression has side effects, and a flag indicating whether the function
2669 containing the asm needs to align its stack conservatively. An example
2670 inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2671
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2672<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2673i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2674</pre>
2675
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2676<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2677 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2678 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2679
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2680<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2681%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]2682</pre>
2683
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2684<p>Inline asms with side effects not visible in the constraint list must be
2685 marked as having side effects. This is done through the use of the
2686 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2687
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2688<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2689call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2690</pre>
2691
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2692<p>In some cases inline asms will contain code that will not work unless the
2693 stack is aligned in some way, such as calls or SSE instructions on x86,
2694 yet will not contain code that does that alignment within the asm.
2695 The compiler should make conservative assumptions about what the asm might
2696 contain and should generate its usual stack alignment code in the prologue
2697 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2698
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2699<pre class="doc_code">
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2700call void asm alignstack "eieio", ""()
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2701</pre>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2702
2703<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2704 first.</p>
2705
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2706<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2707 documented here. Constraints on what can be done (e.g. duplication, moving,
2708 etc need to be documented). This is probably best done by reference to
2709 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2710
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2711<h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2712<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2713</h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2714
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2715<div>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2716
2717<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattner79ffdc72010-11-17 08:20:42 +0000[diff] [blame]2718 attached to it that contains a list of constant integers. If present, the
2719 code generator will use the integer as the location cookie value when report
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2720 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]2721 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2722 source code that produced it. For example:</p>
2723
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2724<pre class="doc_code">
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2725call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2726...
2727!42 = !{ i32 1234567 }
2728</pre>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2729
2730<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]2731 IR. If the MDNode contains multiple constants, the code generator will use
2732 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]2733
2734</div>
2735
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2736</div>
2737
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2738<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2739<h3>
2740 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2741</h3>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2742
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2743<div>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2744
2745<p>LLVM IR allows metadata to be attached to instructions in the program that
2746 can convey extra information about the code to the optimizers and code
2747 generator. One example application of metadata is source-level debug
2748 information. There are two metadata primitives: strings and nodes. All
2749 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2750 preceding exclamation point ('<tt>!</tt>').</p>
2751
2752<p>A metadata string is a string surrounded by double quotes. It can contain
2753 any character by escaping non-printable characters with "\xx" where "xx" is
2754 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2755
2756<p>Metadata nodes are represented with notation similar to structure constants
2757 (a comma separated list of elements, surrounded by braces and preceded by an
2758 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2759 10}</tt>". Metadata nodes can have any values as their operand.</p>
2760
2761<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2762 metadata nodes, which can be looked up in the module symbol table. For
2763 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2764
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2765<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2766 function is using two metadata arguments.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2767
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2768<div class="doc_code">
2769<pre>
2770call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2771</pre>
2772</div>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2773
2774<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2775 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2776
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2777<div class="doc_code">
2778<pre>
2779%indvar.next = add i64 %indvar, 1, !dbg !21
2780</pre>
2781</div>
2782
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2783</div>
2784
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2785</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2786
2787<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2788<h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2789 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2790</h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2791<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2792<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2793<p>LLVM has a number of "magic" global variables that contain data that affect
2794code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2795of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2796section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2797by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2798
2799<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2800<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2801<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2802</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2803
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2804<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2805
2806<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2807href="#linkage_appending">appending linkage</a>. This array contains a list of
2808pointers to global variables and functions which may optionally have a pointer
2809cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2810
2811<pre>
2812 @X = global i8 4
2813 @Y = global i32 123
2814
2815 @llvm.used = appending global [2 x i8*] [
2816 i8* @X,
2817 i8* bitcast (i32* @Y to i8*)
2818 ], section "llvm.metadata"
2819</pre>
2820
2821<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2822compiler, assembler, and linker are required to treat the symbol as if there is
2823a reference to the global that it cannot see. For example, if a variable has
2824internal linkage and no references other than that from the <tt>@llvm.used</tt>
2825list, it cannot be deleted. This is commonly used to represent references from
2826inline asms and other things the compiler cannot "see", and corresponds to
2827"attribute((used))" in GNU C.</p>
2828
2829<p>On some targets, the code generator must emit a directive to the assembler or
2830object file to prevent the assembler and linker from molesting the symbol.</p>
2831
2832</div>
2833
2834<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2835<h3>
2836 <a name="intg_compiler_used">
2837 The '<tt>llvm.compiler.used</tt>' Global Variable
2838 </a>
2839</h3>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2840
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2841<div>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2842
2843<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2844<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2845touching the symbol. On targets that support it, this allows an intelligent
2846linker to optimize references to the symbol without being impeded as it would be
2847by <tt>@llvm.used</tt>.</p>
2848
2849<p>This is a rare construct that should only be used in rare circumstances, and
2850should not be exposed to source languages.</p>
2851
2852</div>
2853
2854<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2855<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2856<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2857</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2858
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2859<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2860<pre>
2861%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2862@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2863</pre>
2864<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.
2865</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2866
2867</div>
2868
2869<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2870<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2871<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2872</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2873
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2874<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2875<pre>
2876%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2877@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2878</pre>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2879
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2880<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.
2881</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2882
2883</div>
2884
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2885</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2886
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2887<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2888<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2889<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2890
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2891<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2892
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2893<p>The LLVM instruction set consists of several different classifications of
2894 instructions: <a href="#terminators">terminator
2895 instructions</a>, <a href="#binaryops">binary instructions</a>,
2896 <a href="#bitwiseops">bitwise binary instructions</a>,
2897 <a href="#memoryops">memory instructions</a>, and
2898 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2899
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2900<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2901<h3>
2902 <a name="terminators">Terminator Instructions</a>
2903</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2904
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2905<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2906
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2907<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2908 in a program ends with a "Terminator" instruction, which indicates which
2909 block should be executed after the current block is finished. These
2910 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2911 control flow, not values (the one exception being the
2912 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2913
Duncan Sands626b0242010-04-15 20:35:54 +0000[diff] [blame]2914<p>There are seven different terminator instructions: the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2915 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2916 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2917 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling33fef7e2009-11-02 00:25:26 +0000[diff] [blame]2918 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2919 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2920 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2921 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2922
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2923<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2924<h4>
2925 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
2926</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2927
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2928<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2929
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2930<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2931<pre>
2932 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]2933 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2934</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2935
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2936<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2937<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2938 a value) from a function back to the caller.</p>
2939
2940<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2941 value and then causes control flow, and one that just causes control flow to
2942 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2943
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2944<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2945<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2946 return value. The type of the return value must be a
2947 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2948
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2949<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2950 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2951 value or a return value with a type that does not match its type, or if it
2952 has a void return type and contains a '<tt>ret</tt>' instruction with a
2953 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2954
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2955<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2956<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2957 the calling function's context. If the caller is a
2958 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2959 instruction after the call. If the caller was an
2960 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2961 the beginning of the "normal" destination block. If the instruction returns
2962 a value, that value shall set the call or invoke instruction's return
2963 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2964
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2965<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2966<pre>
2967 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2968 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]2969 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]2970</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2971
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2972</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2973<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2974<h4>
2975 <a name="i_br">'<tt>br</tt>' Instruction</a>
2976</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2977
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2978<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2979
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2980<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2981<pre>
2982 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]2983</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2984
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2985<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2986<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2987 different basic block in the current function. There are two forms of this
2988 instruction, corresponding to a conditional branch and an unconditional
2989 branch.</p>
2990
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2991<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2992<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2993 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2994 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2995 target.</p>
2996
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2997<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2998<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2999 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3000 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3001 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3002
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3003<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]3004<pre>
3005Test:
3006 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3007 br i1 %cond, label %IfEqual, label %IfUnequal
3008IfEqual:
3009 <a href="#i_ret">ret</a> i32 1
3010IfUnequal:
3011 <a href="#i_ret">ret</a> i32 0
3012</pre>
3013
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3014</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3015
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3016<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3017<h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3018 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3019</h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3020
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3021<div>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3022
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3023<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3024<pre>
3025 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3026</pre>
3027
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3028<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3029<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]3030 several different places. It is a generalization of the '<tt>br</tt>'
3031 instruction, allowing a branch to occur to one of many possible
3032 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3033
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3034<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3035<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3036 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3037 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3038 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3039
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3040<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3041<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3042 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3043 is searched for the given value. If the value is found, control flow is
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]3044 transferred to the corresponding destination; otherwise, control flow is
3045 transferred to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3046
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3047<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3048<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3049 <tt>switch</tt> instruction, this instruction may be code generated in
3050 different ways. For example, it could be generated as a series of chained
3051 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3052
3053<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3054<pre>
3055 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3056 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3057 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3058
3059 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3060 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3061
3062 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3063 switch i32 %val, label %otherwise [ i32 0, label %onzero
3064 i32 1, label %onone
3065 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3066</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3067
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3068</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3069
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3070
3071<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3072<h4>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3073 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3074</h4>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3075
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3076<div>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3077
3078<h5>Syntax:</h5>
3079<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3080 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]3081</pre>
3082
3083<h5>Overview:</h5>
3084
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3085<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3086 within the current function, whose address is specified by
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]3087 "<tt>address</tt>". Address must be derived from a <a
3088 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3089
3090<h5>Arguments:</h5>
3091
3092<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3093 rest of the arguments indicate the full set of possible destinations that the
3094 address may point to. Blocks are allowed to occur multiple times in the
3095 destination list, though this isn't particularly useful.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3096
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3097<p>This destination list is required so that dataflow analysis has an accurate
3098 understanding of the CFG.</p>
3099
3100<h5>Semantics:</h5>
3101
3102<p>Control transfers to the block specified in the address argument. All
3103 possible destination blocks must be listed in the label list, otherwise this
3104 instruction has undefined behavior. This implies that jumps to labels
3105 defined in other functions have undefined behavior as well.</p>
3106
3107<h5>Implementation:</h5>
3108
3109<p>This is typically implemented with a jump through a register.</p>
3110
3111<h5>Example:</h5>
3112<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3113 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3114</pre>
3115
3116</div>
3117
3118
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3119<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3120<h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3121 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3122</h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3123
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3124<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3125
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3126<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3127<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3128 &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]3129 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3130</pre>
3131
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3132<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3133<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3134 function, with the possibility of control flow transfer to either the
3135 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3136 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3137 control flow will return to the "normal" label. If the callee (or any
3138 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3139 instruction, control is interrupted and continued at the dynamically nearest
3140 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3141
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3142<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3143<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3144
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3145<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3146 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3147 convention</a> the call should use. If none is specified, the call
3148 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3149
3150 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3151 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3152 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3153
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3154 <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]3155 function value being invoked. In most cases, this is a direct function
3156 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3157 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3158
3159 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3160 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3161
3162 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]3163 signature argument types and parameter attributes. All arguments must be
3164 of <a href="#t_firstclass">first class</a> type. If the function
3165 signature indicates the function accepts a variable number of arguments,
3166 the extra arguments can be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3167
3168 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3169 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3170
3171 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3172 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3173
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3174 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3175 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3176 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3177</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3178
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3179<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3180<p>This instruction is designed to operate as a standard
3181 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3182 primary difference is that it establishes an association with a label, which
3183 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3184
3185<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3186 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3187 exception. Additionally, this is important for implementation of
3188 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3189
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3190<p>For the purposes of the SSA form, the definition of the value returned by the
3191 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3192 block to the "normal" label. If the callee unwinds then no return value is
3193 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]3194
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3195<p>Note that the code generator does not yet completely support unwind, and
3196that the invoke/unwind semantics are likely to change in future versions.</p>
3197
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3198<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3199<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3200 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3201 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3202 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3203 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3204</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3205
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3206</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3207
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3208<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3209
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3210<h4>
3211 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3212</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3213
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3214<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3215
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3216<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3217<pre>
3218 unwind
3219</pre>
3220
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3221<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3222<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3223 at the first callee in the dynamic call stack which used
3224 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3225 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3226
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3227<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3228<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3229 immediately halt. The dynamic call stack is then searched for the
3230 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3231 Once found, execution continues at the "exceptional" destination block
3232 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3233 instruction in the dynamic call chain, undefined behavior results.</p>
3234
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3235<p>Note that the code generator does not yet completely support unwind, and
3236that the invoke/unwind semantics are likely to change in future versions.</p>
3237
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3238</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3239
3240<!-- _______________________________________________________________________ -->
3241
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3242<h4>
3243 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3244</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3245
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3246<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3247
3248<h5>Syntax:</h5>
3249<pre>
3250 unreachable
3251</pre>
3252
3253<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3254<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3255 instruction is used to inform the optimizer that a particular portion of the
3256 code is not reachable. This can be used to indicate that the code after a
3257 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3258
3259<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3260<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3261
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3262</div>
3263
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3264</div>
3265
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3266<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3267<h3>
3268 <a name="binaryops">Binary Operations</a>
3269</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3270
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3271<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3272
3273<p>Binary operators are used to do most of the computation in a program. They
3274 require two operands of the same type, execute an operation on them, and
3275 produce a single value. The operands might represent multiple data, as is
3276 the case with the <a href="#t_vector">vector</a> data type. The result value
3277 has the same type as its operands.</p>
3278
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3279<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3280
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3281<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3282<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3283 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3284</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3285
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3286<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3287
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3288<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3289<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3290 &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]3291 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3292 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3293 &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]3294</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3295
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3296<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3297<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3298
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3299<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3300<p>The two arguments to the '<tt>add</tt>' instruction must
3301 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3302 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3303
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3304<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3305<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3306
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3307<p>If the sum has unsigned overflow, the result returned is the mathematical
3308 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]3309
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3310<p>Because LLVM integers use a two's complement representation, this instruction
3311 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3312
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3313<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3314 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3315 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3316 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3317 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3318
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3319<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3320<pre>
3321 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3322</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3323
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3324</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3325
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3326<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3327<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3328 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3329</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3330
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3331<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3332
3333<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3334<pre>
3335 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3336</pre>
3337
3338<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3339<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3340
3341<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3342<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3343 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3344 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3345
3346<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3347<p>The value produced is the floating point sum of the two operands.</p>
3348
3349<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3350<pre>
3351 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3352</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3353
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3354</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3355
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3356<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3357<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3358 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3359</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3360
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3361<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3362
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3363<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3364<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3365 &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]3366 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3367 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3368 &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]3369</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3370
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3371<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3372<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3373 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3374
3375<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3376 '<tt>neg</tt>' instruction present in most other intermediate
3377 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3378
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3379<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3380<p>The two arguments to the '<tt>sub</tt>' instruction must
3381 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3382 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3383
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3384<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3385<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3386
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3387<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3388 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3389 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3390
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3391<p>Because LLVM integers use a two's complement representation, this instruction
3392 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3393
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3394<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3395 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3396 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3397 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3398 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3399
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3400<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3401<pre>
3402 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3403 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3404</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3405
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3406</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3407
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3408<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3409<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3410 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3411</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3412
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3413<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3414
3415<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3416<pre>
3417 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3418</pre>
3419
3420<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3421<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3422 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3423
3424<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3425 '<tt>fneg</tt>' instruction present in most other intermediate
3426 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3427
3428<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]3429<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3430 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3431 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3432
3433<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3434<p>The value produced is the floating point difference of the two operands.</p>
3435
3436<h5>Example:</h5>
3437<pre>
3438 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3439 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3440</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3441
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3442</div>
3443
3444<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3445<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3446 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3447</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3448
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3449<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3450
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3451<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3452<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3453 &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]3454 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3455 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3456 &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]3457</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3458
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3459<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3460<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3461
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3462<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3463<p>The two arguments to the '<tt>mul</tt>' instruction must
3464 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3465 integer values. Both arguments must have identical types.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3466
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3467<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3468<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3469
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3470<p>If the result of the multiplication has unsigned overflow, the result
3471 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3472 width of the result.</p>
3473
3474<p>Because LLVM integers use a two's complement representation, and the result
3475 is the same width as the operands, this instruction returns the correct
3476 result for both signed and unsigned integers. If a full product
3477 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3478 be sign-extended or zero-extended as appropriate to the width of the full
3479 product.</p>
3480
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3481<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3482 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3483 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3484 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3485 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3486
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3487<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3488<pre>
3489 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3490</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3491
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3492</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3493
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3494<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3495<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3496 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3497</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3498
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3499<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3500
3501<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3502<pre>
3503 &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]3504</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3505
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3506<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3507<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3508
3509<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3510<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3511 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3512 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3513
3514<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3515<p>The value produced is the floating point product of the two operands.</p>
3516
3517<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3518<pre>
3519 &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]3520</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3521
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3522</div>
3523
3524<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3525<h4>
3526 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3527</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3528
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3529<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3530
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3531<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3532<pre>
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3533 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3534 &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]3535</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3536
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3537<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3538<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3539
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3540<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3541<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3542 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3543 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3544
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3545<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3546<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3547
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3548<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3549 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3550
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3551<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3552
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3553<p>If the <tt>exact</tt> keyword is present, the result value of the
3554 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3555 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3556
3557
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3558<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3559<pre>
3560 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3561</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3562
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3563</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3564
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3565<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3566<h4>
3567 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3568</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3569
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3570<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3571
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3572<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3573<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3574 &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]3575 &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]3576</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3577
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3578<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3579<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3580
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3581<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3582<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3583 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3584 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3585
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3586<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3587<p>The value produced is the signed integer quotient of the two operands rounded
3588 towards zero.</p>
3589
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3590<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3591 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3592
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3593<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3594 undefined behavior; this is a rare case, but can occur, for example, by doing
3595 a 32-bit division of -2147483648 by -1.</p>
3596
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]3597<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]3598 <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]3599 be rounded.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3600
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3601<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3602<pre>
3603 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3604</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3605
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3606</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3607
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3608<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3609<h4>
3610 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3611</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3612
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3613<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3614
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3615<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3616<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3617 &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]3618</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3619
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3620<h5>Overview:</h5>
3621<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3622
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3623<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3624<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3625 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3626 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3627
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3628<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3629<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3630
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3631<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3632<pre>
3633 &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]3634</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3635
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3636</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3637
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3638<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3639<h4>
3640 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3641</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3642
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3643<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3644
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3645<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3646<pre>
3647 &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]3648</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3649
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3650<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3651<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3652 division of its two arguments.</p>
3653
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3654<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3655<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3656 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3657 values. Both arguments must have identical types.</p>
3658
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3659<h5>Semantics:</h5>
3660<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3661 This instruction always performs an unsigned division to get the
3662 remainder.</p>
3663
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3664<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3665 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3666
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3667<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3668
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3669<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3670<pre>
3671 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3672</pre>
3673
3674</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3675
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3676<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3677<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3678 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3679</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3680
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3681<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3682
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3683<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3684<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3685 &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]3686</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3687
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3688<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3689<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3690 division of its two operands. This instruction can also take
3691 <a href="#t_vector">vector</a> versions of the values in which case the
3692 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3693
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3694<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3695<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3696 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3697 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3698
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3699<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3700<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sands2769c6e2011-03-07 09:12:24 +0000[diff] [blame]3701 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3702 <i>modulo</i> operator (where the result is either zero or has the same sign
3703 as the divisor, <tt>op2</tt>) of a value.
3704 For more information about the difference,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3705 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3706 Math Forum</a>. For a table of how this is implemented in various languages,
3707 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3708 Wikipedia: modulo operation</a>.</p>
3709
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3710<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3711 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3712
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3713<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3714 Overflow also leads to undefined behavior; this is a rare case, but can
3715 occur, for example, by taking the remainder of a 32-bit division of
3716 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3717 lets srem be implemented using instructions that return both the result of
3718 the division and the remainder.)</p>
3719
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3720<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3721<pre>
3722 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3723</pre>
3724
3725</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3726
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3727<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3728<h4>
3729 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3730</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3731
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3732<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3733
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3734<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3735<pre>
3736 &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]3737</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3738
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3739<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3740<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3741 its two operands.</p>
3742
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3743<h5>Arguments:</h5>
3744<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3745 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3746 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3747
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3748<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3749<p>This instruction returns the <i>remainder</i> of a division. The remainder
3750 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3751
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3752<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3753<pre>
3754 &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]3755</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3756
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3757</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3758
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3759</div>
3760
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3761<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3762<h3>
3763 <a name="bitwiseops">Bitwise Binary Operations</a>
3764</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3765
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3766<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3767
3768<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3769 program. They are generally very efficient instructions and can commonly be
3770 strength reduced from other instructions. They require two operands of the
3771 same type, execute an operation on them, and produce a single value. The
3772 resulting value is the same type as its operands.</p>
3773
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3774<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3775<h4>
3776 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3777</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3778
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3779<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3780
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3781<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3782<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3783 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3784 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3785 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3786 &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]3787</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3788
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3789<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3790<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3791 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3792
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3793<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3794<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3795 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3796 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3797
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3798<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3799<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3800 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3801 is (statically or dynamically) negative or equal to or larger than the number
3802 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3803 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3804 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3805
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3806<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3807 <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]3808 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3809 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3810 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3811 they would if the shift were expressed as a mul instruction with the same
3812 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3813
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3814<h5>Example:</h5>
3815<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3816 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3817 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3818 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3819 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3820 &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]3821</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3822
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3823</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3824
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3825<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3826<h4>
3827 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3828</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3829
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3830<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3831
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3832<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3833<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3834 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3835 &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]3836</pre>
3837
3838<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3839<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3840 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3841
3842<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3843<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3844 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3845 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3846
3847<h5>Semantics:</h5>
3848<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3849 significant bits of the result will be filled with zero bits after the shift.
3850 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3851 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3852 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3853 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3854
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3855<p>If the <tt>exact</tt> keyword is present, the result value of the
3856 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3857 shifted out are non-zero.</p>
3858
3859
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3860<h5>Example:</h5>
3861<pre>
3862 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3863 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3864 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3865 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3866 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3867 &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]3868</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3869
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3870</div>
3871
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3872<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3873<h4>
3874 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
3875</h4>
3876
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3877<div>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3878
3879<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3880<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3881 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3882 &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]3883</pre>
3884
3885<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3886<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3887 operand shifted to the right a specified number of bits with sign
3888 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3889
3890<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3891<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3892 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3893 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3894
3895<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3896<p>This instruction always performs an arithmetic shift right operation, The
3897 most significant bits of the result will be filled with the sign bit
3898 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3899 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3900 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3901 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3902
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3903<p>If the <tt>exact</tt> keyword is present, the result value of the
3904 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3905 shifted out are non-zero.</p>
3906
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3907<h5>Example:</h5>
3908<pre>
3909 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3910 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3911 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3912 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3913 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3914 &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]3915</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3916
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3917</div>
3918
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3919<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3920<h4>
3921 <a name="i_and">'<tt>and</tt>' Instruction</a>
3922</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3923
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3924<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3925
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3926<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3927<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3928 &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]3929</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3930
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3931<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3932<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3933 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3934
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3935<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3936<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3937 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3938 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3939
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3940<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3941<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3942
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3943<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3944 <tbody>
3945 <tr>
3946 <td>In0</td>
3947 <td>In1</td>
3948 <td>Out</td>
3949 </tr>
3950 <tr>
3951 <td>0</td>
3952 <td>0</td>
3953 <td>0</td>
3954 </tr>
3955 <tr>
3956 <td>0</td>
3957 <td>1</td>
3958 <td>0</td>
3959 </tr>
3960 <tr>
3961 <td>1</td>
3962 <td>0</td>
3963 <td>0</td>
3964 </tr>
3965 <tr>
3966 <td>1</td>
3967 <td>1</td>
3968 <td>1</td>
3969 </tr>
3970 </tbody>
3971</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3972
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3973<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3974<pre>
3975 &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]3976 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3977 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3978</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3979</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3980<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3981<h4>
3982 <a name="i_or">'<tt>or</tt>' Instruction</a>
3983</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3984
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3985<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3986
3987<h5>Syntax:</h5>
3988<pre>
3989 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3990</pre>
3991
3992<h5>Overview:</h5>
3993<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3994 two operands.</p>
3995
3996<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3997<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3998 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3999 values. Both arguments must have identical types.</p>
4000
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4001<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4002<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4003
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4004<table border="1" cellspacing="0" cellpadding="4">
4005 <tbody>
4006 <tr>
4007 <td>In0</td>
4008 <td>In1</td>
4009 <td>Out</td>
4010 </tr>
4011 <tr>
4012 <td>0</td>
4013 <td>0</td>
4014 <td>0</td>
4015 </tr>
4016 <tr>
4017 <td>0</td>
4018 <td>1</td>
4019 <td>1</td>
4020 </tr>
4021 <tr>
4022 <td>1</td>
4023 <td>0</td>
4024 <td>1</td>
4025 </tr>
4026 <tr>
4027 <td>1</td>
4028 <td>1</td>
4029 <td>1</td>
4030 </tr>
4031 </tbody>
4032</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4033
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4034<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4035<pre>
4036 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4037 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4038 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4039</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4040
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4041</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4042
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4043<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4044<h4>
4045 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4046</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4047
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4048<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4049
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4050<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4051<pre>
4052 &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]4053</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4054
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4055<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4056<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4057 its two operands. The <tt>xor</tt> is used to implement the "one's
4058 complement" operation, which is the "~" operator in C.</p>
4059
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4060<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4061<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4062 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4063 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4064
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4065<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4066<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4067
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4068<table border="1" cellspacing="0" cellpadding="4">
4069 <tbody>
4070 <tr>
4071 <td>In0</td>
4072 <td>In1</td>
4073 <td>Out</td>
4074 </tr>
4075 <tr>
4076 <td>0</td>
4077 <td>0</td>
4078 <td>0</td>
4079 </tr>
4080 <tr>
4081 <td>0</td>
4082 <td>1</td>
4083 <td>1</td>
4084 </tr>
4085 <tr>
4086 <td>1</td>
4087 <td>0</td>
4088 <td>1</td>
4089 </tr>
4090 <tr>
4091 <td>1</td>
4092 <td>1</td>
4093 <td>0</td>
4094 </tr>
4095 </tbody>
4096</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4097
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4098<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4099<pre>
4100 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4101 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4102 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4103 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4104</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4105
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4106</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4107
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4108</div>
4109
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4110<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4111<h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4112 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4113</h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4114
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4115<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4116
4117<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4118 target-independent manner. These instructions cover the element-access and
4119 vector-specific operations needed to process vectors effectively. While LLVM
4120 does directly support these vector operations, many sophisticated algorithms
4121 will want to use target-specific intrinsics to take full advantage of a
4122 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4123
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4124<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4125<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4126 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4127</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4128
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4129<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4130
4131<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4132<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4133 &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]4134</pre>
4135
4136<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4137<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4138 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4139
4140
4141<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4142<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4143 of <a href="#t_vector">vector</a> type. The second operand is an index
4144 indicating the position from which to extract the element. The index may be
4145 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4146
4147<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4148<p>The result is a scalar of the same type as the element type of
4149 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4150 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4151 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4152
4153<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4154<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4155 &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]4156</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4157
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4158</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4159
4160<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4161<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4162 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4163</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4164
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4165<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4166
4167<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4168<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]4169 &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]4170</pre>
4171
4172<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4173<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4174 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4175
4176<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4177<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4178 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4179 whose type must equal the element type of the first operand. The third
4180 operand is an index indicating the position at which to insert the value.
4181 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4182
4183<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4184<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4185 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4186 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4187 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4188
4189<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4190<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4191 &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]4192</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4193
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4194</div>
4195
4196<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4197<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4198 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4199</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4200
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4201<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4202
4203<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4204<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4205 &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]4206</pre>
4207
4208<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4209<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4210 from two input vectors, returning a vector with the same element type as the
4211 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4212
4213<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4214<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4215 with types that match each other. The third argument is a shuffle mask whose
4216 element type is always 'i32'. The result of the instruction is a vector
4217 whose length is the same as the shuffle mask and whose element type is the
4218 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4219
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4220<p>The shuffle mask operand is required to be a constant vector with either
4221 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4222
4223<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4224<p>The elements of the two input vectors are numbered from left to right across
4225 both of the vectors. The shuffle mask operand specifies, for each element of
4226 the result vector, which element of the two input vectors the result element
4227 gets. The element selector may be undef (meaning "don't care") and the
4228 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4229
4230<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4231<pre>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4232 &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]4233 &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]4234 &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]4235 &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]4236 &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]4237 &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]4238 &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]4239 &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]4240</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4241
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4242</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]4243
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4244</div>
4245
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4246<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4247<h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4248 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4249</h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4250
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4251<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4252
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4253<p>LLVM supports several instructions for working with
4254 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4255
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4256<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4257<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4258 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4259</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4260
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4261<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4262
4263<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4264<pre>
4265 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4266</pre>
4267
4268<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4269<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4270 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4271
4272<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4273<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4274 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4275 <a href="#t_array">array</a> type. The operands are constant indices to
4276 specify which value to extract in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4277 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel7cf63ac2010-12-05 20:54:38 +0000[diff] [blame]4278 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4279 <ul>
4280 <li>Since the value being indexed is not a pointer, the first index is
4281 omitted and assumed to be zero.</li>
4282 <li>At least one index must be specified.</li>
4283 <li>Not only struct indices but also array indices must be in
4284 bounds.</li>
4285 </ul>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4286
4287<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4288<p>The result is the value at the position in the aggregate specified by the
4289 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4290
4291<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4292<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4293 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4294</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4295
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4296</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4297
4298<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4299<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4300 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4301</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4302
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4303<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4304
4305<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4306<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4307 &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]4308</pre>
4309
4310<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4311<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4312 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4313
4314<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4315<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4316 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4317 <a href="#t_array">array</a> type. The second operand is a first-class
4318 value to insert. The following operands are constant indices indicating
4319 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]4320 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4321 value to insert must have the same type as the value identified by the
4322 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4323
4324<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4325<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4326 that of <tt>val</tt> except that the value at the position specified by the
4327 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4328
4329<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4330<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4331 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4332 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4333 %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]4334</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4335
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4336</div>
4337
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4338</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4339
4340<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4341<h3>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4342 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4343</h3>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4344
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4345<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4346
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4347<p>A key design point of an SSA-based representation is how it represents
4348 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]4349 very simple. This section describes how to read, write, and allocate
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4350 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4351
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4352<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4353<h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4354 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4355</h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4356
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4357<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4358
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4359<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4360<pre>
Dan Gohman2140a742010-05-28 01:14:11 +0000[diff] [blame]4361 &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]4362</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4363
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4364<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4365<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4366 currently executing function, to be automatically released when this function
4367 returns to its caller. The object is always allocated in the generic address
4368 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4369
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4370<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4371<p>The '<tt>alloca</tt>' instruction
4372 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4373 runtime stack, returning a pointer of the appropriate type to the program.
4374 If "NumElements" is specified, it is the number of elements allocated,
4375 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4376 specified, the value result of the allocation is guaranteed to be aligned to
4377 at least that boundary. If not specified, or if zero, the target can choose
4378 to align the allocation on any convenient boundary compatible with the
4379 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4380
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4381<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4382
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4383<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]4384<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4385 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4386 memory is automatically released when the function returns. The
4387 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4388 variables that must have an address available. When the function returns
4389 (either with the <tt><a href="#i_ret">ret</a></tt>
4390 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4391 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4392
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4393<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4394<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]4395 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4396 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4397 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4398 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4399</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4400
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4401</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4402
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4403<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4404<h4>
4405 <a name="i_load">'<tt>load</tt>' Instruction</a>
4406</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4407
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4408<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4409
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4410<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4411<pre>
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4412 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4413 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4414 !&lt;index&gt; = !{ i32 1 }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4415</pre>
4416
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4417<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4418<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4419
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4420<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4421<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4422 from which to load. The pointer must point to
4423 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4424 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4425 number or order of execution of this <tt>load</tt> with other <a
4426 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4427
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4428<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4429 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]4430 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4431 alignment for the target. It is the responsibility of the code emitter to
4432 ensure that the alignment information is correct. Overestimating the
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4433 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4434 produce less efficient code. An alignment of 1 is always safe.</p>
4435
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4436<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4437 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4438 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4439 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4440 and code generator that this load is not expected to be reused in the cache.
4441 The code generator may select special instructions to save cache bandwidth,
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4442 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4443
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4444<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4445<p>The location of memory pointed to is loaded. If the value being loaded is of
4446 scalar type then the number of bytes read does not exceed the minimum number
4447 of bytes needed to hold all bits of the type. For example, loading an
4448 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4449 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4450 is undefined if the value was not originally written using a store of the
4451 same type.</p>
4452
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4453<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4454<pre>
4455 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4456 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4457 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4458</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4459
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4460</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4461
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4462<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4463<h4>
4464 <a name="i_store">'<tt>store</tt>' Instruction</a>
4465</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4466
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4467<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4468
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4469<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4470<pre>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4471 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>
4472 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]4473</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4474
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4475<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4476<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4477
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4478<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4479<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4480 and an address at which to store it. The type of the
4481 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4482 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4483 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4484 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4485 order of execution of this <tt>store</tt> with other <a
4486 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4487
4488<p>The optional constant "align" argument specifies the alignment of the
4489 operation (that is, the alignment of the memory address). A value of 0 or an
4490 omitted "align" argument means that the operation has the preferential
4491 alignment for the target. It is the responsibility of the code emitter to
4492 ensure that the alignment information is correct. Overestimating the
4493 alignment results in an undefined behavior. Underestimating the alignment may
4494 produce less efficient code. An alignment of 1 is always safe.</p>
4495
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4496<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4497 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4498 value 1. The existence of the !nontemporal metatadata on the
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4499 instruction tells the optimizer and code generator that this load is
4500 not expected to be reused in the cache. The code generator may
4501 select special instructions to save cache bandwidth, such as the
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4502 MOVNT instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4503
4504
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4505<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4506<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4507 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4508 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4509 does not exceed the minimum number of bytes needed to hold all bits of the
4510 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4511 writing a value of a type like <tt>i20</tt> with a size that is not an
4512 integral number of bytes, it is unspecified what happens to the extra bits
4513 that do not belong to the type, but they will typically be overwritten.</p>
4514
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4515<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4516<pre>
4517 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]4518 store i32 3, i32* %ptr <i>; yields {void}</i>
4519 %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]4520</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4521
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4522</div>
4523
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4524<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4525<h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4526 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4527</h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4528
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4529<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4530
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4531<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4532<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4533 &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]4534 &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]4535</pre>
4536
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4537<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4538<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4539 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4540 It performs address calculation only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4541
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4542<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4543<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4544 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4545 elements of the aggregate object are indexed. The interpretation of each
4546 index is dependent on the type being indexed into. The first index always
4547 indexes the pointer value given as the first argument, the second index
4548 indexes a value of the type pointed to (not necessarily the value directly
4549 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4550 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4551 vectors, and structs. Note that subsequent types being indexed into
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4552 can never be pointers, since that would require loading the pointer before
4553 continuing calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4554
4555<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]4556 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4557 integer <b>constants</b> are allowed. When indexing into an array, pointer
4558 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]4559 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4560
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4561<p>For example, let's consider a C code fragment and how it gets compiled to
4562 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4563
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4564<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4565struct RT {
4566 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4567 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4568 char C;
4569};
4570struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4571 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4572 double Y;
4573 struct RT Z;
4574};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4575
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4576int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4577 return &amp;s[1].Z.B[5][13];
4578}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4579</pre>
4580
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4581<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4582
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4583<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]4584%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4585%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4586
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4587define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4588entry:
4589 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4590 ret i32* %reg
4591}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4592</pre>
4593
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4594<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4595<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]4596 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4597 }</tt>' type, a structure. The second index indexes into the third element
4598 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4599 i8 }</tt>' type, another structure. The third index indexes into the second
4600 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4601 array. The two dimensions of the array are subscripted into, yielding an
4602 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4603 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4604
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4605<p>Note that it is perfectly legal to index partially through a structure,
4606 returning a pointer to an inner element. Because of this, the LLVM code for
4607 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4608
4609<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4610 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4611 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4612 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4613 %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]4614 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4615 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4616 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4617 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4618</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]4619
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4620<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]4621 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4622 base pointer is not an <i>in bounds</i> address of an allocated object,
4623 or if any of the addresses that would be formed by successive addition of
4624 the offsets implied by the indices to the base address with infinitely
4625 precise arithmetic are not an <i>in bounds</i> address of that allocated
4626 object. The <i>in bounds</i> addresses for an allocated object are all
4627 the addresses that point into the object, plus the address one byte past
4628 the end.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4629
4630<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4631 the base address with silently-wrapping two's complement arithmetic, and
4632 the result value of the <tt>getelementptr</tt> may be outside the object
4633 pointed to by the base pointer. The result value may not necessarily be
4634 used to access memory though, even if it happens to point into allocated
4635 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4636 section for more information.</p>
4637
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4638<p>The getelementptr instruction is often confusing. For some more insight into
4639 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4640
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4641<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4642<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4643 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4644 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4645 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4646 %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]4647 <i>; yields i8*:eptr</i>
4648 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]4649 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]4650 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4651</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4652
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4653</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4654
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4655</div>
4656
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4657<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4658<h3>
4659 <a name="convertops">Conversion Operations</a>
4660</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4661
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4662<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4663
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4664<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4665 which all take a single operand and a type. They perform various bit
4666 conversions on the operand.</p>
4667
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4668<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4669<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4670 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4671</h4>
4672
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4673<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4674
4675<h5>Syntax:</h5>
4676<pre>
4677 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4678</pre>
4679
4680<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4681<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4682 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4683
4684<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4685<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
4686 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4687 of the same number of integers.
4688 The bit size of the <tt>value</tt> must be larger than
4689 the bit size of the destination type, <tt>ty2</tt>.
4690 Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4691
4692<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4693<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4694 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4695 source size must be larger than the destination size, <tt>trunc</tt> cannot
4696 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4697
4698<h5>Example:</h5>
4699<pre>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4700 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
4701 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4702 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
4703 %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]4704</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4705
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4706</div>
4707
4708<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4709<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4710 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4711</h4>
4712
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4713<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4714
4715<h5>Syntax:</h5>
4716<pre>
4717 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4718</pre>
4719
4720<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4721<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4722 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4723
4724
4725<h5>Arguments:</h5>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]4726<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
4727 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4728 of the same number of integers.
4729 The bit size of the <tt>value</tt> must be smaller than
4730 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4731 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4732
4733<h5>Semantics:</h5>
4734<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]4735 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4736
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]4737<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]4738
4739<h5>Example:</h5>
4740<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4741 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4742 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]4743 %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]4744</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4745
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4746</div>
4747
4748<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4749<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4750 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4751</h4>
4752
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4753<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4754
4755<h5>Syntax:</h5>
4756<pre>
4757 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4758</pre>
4759
4760<h5>Overview:</h5>
4761<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4762
4763<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4764<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
4765 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4766 of the same number of integers.
4767 The bit size of the <tt>value</tt> must be smaller than
4768 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4769 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4770
4771<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4772<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4773 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4774 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4775
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4776<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]4777
4778<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4779<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4780 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4781 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4782 %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]4783</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4784
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4785</div>
4786
4787<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4788<h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4789 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4790</h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4791
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4792<div>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4793
4794<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4795<pre>
4796 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4797</pre>
4798
4799<h5>Overview:</h5>
4800<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4801 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4802
4803<h5>Arguments:</h5>
4804<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4805 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4806 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]4807 <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]4808 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4809
4810<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4811<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4812 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4813 <a href="#t_floating">floating point</a> type. If the value cannot fit
4814 within the destination type, <tt>ty2</tt>, then the results are
4815 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4816
4817<h5>Example:</h5>
4818<pre>
4819 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4820 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4821</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4822
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4823</div>
4824
4825<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4826<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4827 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4828</h4>
4829
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4830<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4831
4832<h5>Syntax:</h5>
4833<pre>
4834 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4835</pre>
4836
4837<h5>Overview:</h5>
4838<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]4839 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4840
4841<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4842<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4843 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4844 a <a href="#t_floating">floating point</a> type to cast it to. The source
4845 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4846
4847<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4848<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4849 <a href="#t_floating">floating point</a> type to a larger
4850 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4851 used to make a <i>no-op cast</i> because it always changes bits. Use
4852 <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]4853
4854<h5>Example:</h5>
4855<pre>
Nick Lewycky9feca672011-03-31 18:20:19 +0000[diff] [blame]4856 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
4857 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4858</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4859
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4860</div>
4861
4862<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4863<h4>
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]4864 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4865</h4>
4866
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4867<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4868
4869<h5>Syntax:</h5>
4870<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4871 &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]4872</pre>
4873
4874<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4875<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4876 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4877
4878<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4879<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4880 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4881 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4882 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4883 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4884
4885<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4886<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4887 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4888 towards zero) unsigned integer value. If the value cannot fit
4889 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4890
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4891<h5>Example:</h5>
4892<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4893 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4894 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4895 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4896</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4897
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4898</div>
4899
4900<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4901<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4902 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4903</h4>
4904
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4905<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4906
4907<h5>Syntax:</h5>
4908<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4909 &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]4910</pre>
4911
4912<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4913<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4914 <a href="#t_floating">floating point</a> <tt>value</tt> to
4915 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4916
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4917<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4918<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4919 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4920 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4921 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4922 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4923
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4924<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4925<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4926 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4927 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4928 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4929
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4930<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4931<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4932 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4933 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4934 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4935</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4936
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4937</div>
4938
4939<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4940<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4941 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4942</h4>
4943
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4944<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4945
4946<h5>Syntax:</h5>
4947<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4948 &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]4949</pre>
4950
4951<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4952<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4953 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4954
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4955<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4956<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]4957 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4958 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4959 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4960 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4961
4962<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4963<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4964 integer quantity and converts it to the corresponding floating point
4965 value. If the value cannot fit in the floating point value, the results are
4966 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4967
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4968<h5>Example:</h5>
4969<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4970 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4971 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4972</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4973
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4974</div>
4975
4976<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4977<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4978 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4979</h4>
4980
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4981<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4982
4983<h5>Syntax:</h5>
4984<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4985 &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]4986</pre>
4987
4988<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4989<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4990 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4991
4992<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4993<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]4994 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4995 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4996 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4997 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4998
4999<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5000<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5001 quantity and converts it to the corresponding floating point value. If the
5002 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5003
5004<h5>Example:</h5>
5005<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5006 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5007 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5008</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5009
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5010</div>
5011
5012<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5013<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5014 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5015</h4>
5016
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5017<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5018
5019<h5>Syntax:</h5>
5020<pre>
5021 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5022</pre>
5023
5024<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5025<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5026 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5027
5028<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5029<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5030 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5031 <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]5032
5033<h5>Semantics:</h5>
5034<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5035 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5036 truncating or zero extending that value to the size of the integer type. If
5037 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5038 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5039 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5040 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5041
5042<h5>Example:</h5>
5043<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5044 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5045 %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]5046</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5047
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5048</div>
5049
5050<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5051<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5052 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5053</h4>
5054
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5055<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5056
5057<h5>Syntax:</h5>
5058<pre>
5059 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5060</pre>
5061
5062<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5063<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5064 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5065
5066<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]5067<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5068 value to cast, and a type to cast it to, which must be a
5069 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5070
5071<h5>Semantics:</h5>
5072<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5073 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5074 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5075 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5076 than the size of a pointer then a zero extension is done. If they are the
5077 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5078
5079<h5>Example:</h5>
5080<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5081 %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]5082 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5083 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5084</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5085
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5086</div>
5087
5088<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5089<h4>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5090 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5091</h4>
5092
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5093<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5094
5095<h5>Syntax:</h5>
5096<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5097 &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]5098</pre>
5099
5100<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5101<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5102 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5103
5104<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5105<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5106 non-aggregate first class value, and a type to cast it to, which must also be
5107 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5108 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5109 identical. If the source type is a pointer, the destination type must also be
5110 a pointer. This instruction supports bitwise conversion of vectors to
5111 integers and to vectors of other types (as long as they have the same
5112 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5113
5114<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5115<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5116 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5117 this conversion. The conversion is done as if the <tt>value</tt> had been
5118 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5119 be converted to other pointer types with this instruction. To convert
5120 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5121 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5122
5123<h5>Example:</h5>
5124<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5125 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5126 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5127 %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]5128</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5129
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5130</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5131
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5132</div>
5133
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5134<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5135<h3>
5136 <a name="otherops">Other Operations</a>
5137</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5138
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5139<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5140
5141<p>The instructions in this category are the "miscellaneous" instructions, which
5142 defy better classification.</p>
5143
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5144<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5145<h4>
5146 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5147</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5148
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5149<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5150
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5151<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5152<pre>
5153 &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]5154</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5155
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5156<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5157<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5158 boolean values based on comparison of its two integer, integer vector, or
5159 pointer operands.</p>
5160
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5161<h5>Arguments:</h5>
5162<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5163 the condition code indicating the kind of comparison to perform. It is not a
5164 value, just a keyword. The possible condition code are:</p>
5165
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5166<ol>
5167 <li><tt>eq</tt>: equal</li>
5168 <li><tt>ne</tt>: not equal </li>
5169 <li><tt>ugt</tt>: unsigned greater than</li>
5170 <li><tt>uge</tt>: unsigned greater or equal</li>
5171 <li><tt>ult</tt>: unsigned less than</li>
5172 <li><tt>ule</tt>: unsigned less or equal</li>
5173 <li><tt>sgt</tt>: signed greater than</li>
5174 <li><tt>sge</tt>: signed greater or equal</li>
5175 <li><tt>slt</tt>: signed less than</li>
5176 <li><tt>sle</tt>: signed less or equal</li>
5177</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5178
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]5179<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5180 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5181 typed. They must also be identical types.</p>
5182
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5183<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5184<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5185 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5186 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]5187 result, as follows:</p>
5188
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5189<ol>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5190 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5191 <tt>false</tt> otherwise. No sign interpretation is necessary or
5192 performed.</li>
5193
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5194 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5195 <tt>false</tt> otherwise. No sign interpretation is necessary or
5196 performed.</li>
5197
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5198 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5199 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5200
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5201 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5202 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5203 to <tt>op2</tt>.</li>
5204
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5205 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5206 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5207
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5208 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5209 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5210
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5211 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5212 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5213
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5214 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5215 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5216 to <tt>op2</tt>.</li>
5217
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5218 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5219 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5220
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5221 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5222 <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]5223</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5224
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5225<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5226 values are compared as if they were integers.</p>
5227
5228<p>If the operands are integer vectors, then they are compared element by
5229 element. The result is an <tt>i1</tt> vector with the same number of elements
5230 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5231
5232<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5233<pre>
5234 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5235 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5236 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5237 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5238 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5239 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5240</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5241
5242<p>Note that the code generator does not yet support vector types with
5243 the <tt>icmp</tt> instruction.</p>
5244
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5245</div>
5246
5247<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5248<h4>
5249 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5250</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5251
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5252<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5253
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5254<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5255<pre>
5256 &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]5257</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5258
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5259<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5260<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5261 values based on comparison of its operands.</p>
5262
5263<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]5264(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5265
5266<p>If the operands are floating point vectors, then the result type is a vector
5267 of boolean with the same number of elements as the operands being
5268 compared.</p>
5269
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5270<h5>Arguments:</h5>
5271<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5272 the condition code indicating the kind of comparison to perform. It is not a
5273 value, just a keyword. The possible condition code are:</p>
5274
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5275<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5276 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5277 <li><tt>oeq</tt>: ordered and equal</li>
5278 <li><tt>ogt</tt>: ordered and greater than </li>
5279 <li><tt>oge</tt>: ordered and greater than or equal</li>
5280 <li><tt>olt</tt>: ordered and less than </li>
5281 <li><tt>ole</tt>: ordered and less than or equal</li>
5282 <li><tt>one</tt>: ordered and not equal</li>
5283 <li><tt>ord</tt>: ordered (no nans)</li>
5284 <li><tt>ueq</tt>: unordered or equal</li>
5285 <li><tt>ugt</tt>: unordered or greater than </li>
5286 <li><tt>uge</tt>: unordered or greater than or equal</li>
5287 <li><tt>ult</tt>: unordered or less than </li>
5288 <li><tt>ule</tt>: unordered or less than or equal</li>
5289 <li><tt>une</tt>: unordered or not equal</li>
5290 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5291 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5292</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5293
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5294<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5295 <i>unordered</i> means that either operand may be a QNAN.</p>
5296
5297<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5298 a <a href="#t_floating">floating point</a> type or
5299 a <a href="#t_vector">vector</a> of floating point type. They must have
5300 identical types.</p>
5301
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5302<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]5303<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5304 according to the condition code given as <tt>cond</tt>. If the operands are
5305 vectors, then the vectors are compared element by element. Each comparison
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5306 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5307 follows:</p>
5308
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5309<ol>
5310 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5311
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5312 <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]5313 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5314
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5315 <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]5316 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5317
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5318 <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]5319 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5320
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5321 <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]5322 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5323
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5324 <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]5325 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5326
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5327 <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]5328 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5329
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5330 <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]5331
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5332 <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]5333 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5334
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5335 <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]5336 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5337
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5338 <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]5339 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5340
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5341 <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]5342 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5343
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5344 <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]5345 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5346
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5347 <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]5348 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5349
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5350 <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]5351
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5352 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5353</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5354
5355<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5356<pre>
5357 &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]5358 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5359 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5360 &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]5361</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5362
5363<p>Note that the code generator does not yet support vector types with
5364 the <tt>fcmp</tt> instruction.</p>
5365
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5366</div>
5367
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5368<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5369<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5370 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5371</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5372
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5373<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5374
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5375<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5376<pre>
5377 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5378</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5379
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5380<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5381<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5382 SSA graph representing the function.</p>
5383
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5384<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5385<p>The type of the incoming values is specified with the first type field. After
5386 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5387 one pair for each predecessor basic block of the current block. Only values
5388 of <a href="#t_firstclass">first class</a> type may be used as the value
5389 arguments to the PHI node. Only labels may be used as the label
5390 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5391
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5392<p>There must be no non-phi instructions between the start of a basic block and
5393 the PHI instructions: i.e. PHI instructions must be first in a basic
5394 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5395
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5396<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5397 occur on the edge from the corresponding predecessor block to the current
5398 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5399 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]5400
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5401<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5402<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5403 specified by the pair corresponding to the predecessor basic block that
5404 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5405
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5406<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5407<pre>
5408Loop: ; Infinite loop that counts from 0 on up...
5409 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5410 %nextindvar = add i32 %indvar, 1
5411 br label %Loop
5412</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5413
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5414</div>
5415
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5416<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5417<h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5418 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5419</h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5420
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5421<div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5422
5423<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5424<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]5425 &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>
5426
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5427 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5428</pre>
5429
5430<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5431<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5432 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5433
5434
5435<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5436<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5437 values indicating the condition, and two values of the
5438 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5439 vectors and the condition is a scalar, then entire vectors are selected, not
5440 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5441
5442<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5443<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5444 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5445
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5446<p>If the condition is a vector of i1, then the value arguments must be vectors
5447 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5448
5449<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5450<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5451 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5452</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5453
5454<p>Note that the code generator does not yet support conditions
5455 with vector type.</p>
5456
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5457</div>
5458
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]5459<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5460<h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5461 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5462</h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5463
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5464<div>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5465
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5466<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5467<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]5468 &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]5469</pre>
5470
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5471<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5472<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5473
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5474<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5475<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5476
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5477<ol>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5478 <li>The optional "tail" marker indicates that the callee function does not
5479 access any allocas or varargs in the caller. Note that calls may be
5480 marked "tail" even if they do not occur before
5481 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5482 present, the function call is eligible for tail call optimization,
5483 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Cheng59676492010-03-08 21:05:02 +0000[diff] [blame]5484 optimized into a jump</a>. The code generator may optimize calls marked
5485 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5486 sibling call optimization</a> when the caller and callee have
5487 matching signatures, or 2) forced tail call optimization when the
5488 following extra requirements are met:
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5489 <ul>
5490 <li>Caller and callee both have the calling
5491 convention <tt>fastcc</tt>.</li>
5492 <li>The call is in tail position (ret immediately follows call and ret
5493 uses value of call or is void).</li>
5494 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohman6232f732010-03-02 01:08:11 +0000[diff] [blame]5495 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5496 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5497 constraints are met.</a></li>
5498 </ul>
5499 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5500
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5501 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5502 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5503 defaults to using C calling conventions. The calling convention of the
5504 call must match the calling convention of the target function, or else the
5505 behavior is undefined.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5506
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5507 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5508 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5509 '<tt>inreg</tt>' attributes are valid here.</li>
5510
5511 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5512 type of the return value. Functions that return no value are marked
5513 <tt><a href="#t_void">void</a></tt>.</li>
5514
5515 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5516 being invoked. The argument types must match the types implied by this
5517 signature. This type can be omitted if the function is not varargs and if
5518 the function type does not return a pointer to a function.</li>
5519
5520 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5521 be invoked. In most cases, this is a direct function invocation, but
5522 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5523 to function value.</li>
5524
5525 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]5526 signature argument types and parameter attributes. All arguments must be
5527 of <a href="#t_firstclass">first class</a> type. If the function
5528 signature indicates the function accepts a variable number of arguments,
5529 the extra arguments can be specified.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5530
5531 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5532 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5533 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5534</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5535
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5536<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5537<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5538 a specified function, with its incoming arguments bound to the specified
5539 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5540 function, control flow continues with the instruction after the function
5541 call, and the return value of the function is bound to the result
5542 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5543
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5544<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5545<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]5546 %retval = call i32 @test(i32 %argc)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5547 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]5548 %X = tail call i32 @foo() <i>; yields i32</i>
5549 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5550 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]5551
5552 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5553 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]5554 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5555 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]5556 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]5557 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5558</pre>
5559
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5560<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen722212d2009-09-25 17:04:42 +0000[diff] [blame]5561standard C99 library as being the C99 library functions, and may perform
5562optimizations or generate code for them under that assumption. This is
5563something we'd like to change in the future to provide better support for
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5564freestanding environments and non-C-based languages.</p>
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5565
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5566</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5567
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5568<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5569<h4>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]5570 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5571</h4>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5572
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5573<div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5574
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5575<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5576<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5577 &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]5578</pre>
5579
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5580<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5581<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5582 the "variable argument" area of a function call. It is used to implement the
5583 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5584
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5585<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5586<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5587 argument. It returns a value of the specified argument type and increments
5588 the <tt>va_list</tt> to point to the next argument. The actual type
5589 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5590
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5591<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5592<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5593 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5594 to the next argument. For more information, see the variable argument
5595 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5596
5597<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]5598 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5599 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5600
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5601<p><tt>va_arg</tt> is an LLVM instruction instead of
5602 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5603 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5604
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5605<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5606<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5607
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5608<p>Note that the code generator does not yet fully support va_arg on many
5609 targets. Also, it does not currently support va_arg with aggregate types on
5610 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]5611
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5612</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5613
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5614</div>
5615
5616</div>
5617
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5618<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5619<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]5620<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5621
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5622<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5623
5624<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5625 well known names and semantics and are required to follow certain
5626 restrictions. Overall, these intrinsics represent an extension mechanism for
5627 the LLVM language that does not require changing all of the transformations
5628 in LLVM when adding to the language (or the bitcode reader/writer, the
5629 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5630
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5631<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5632 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5633 begin with this prefix. Intrinsic functions must always be external
5634 functions: you cannot define the body of intrinsic functions. Intrinsic
5635 functions may only be used in call or invoke instructions: it is illegal to
5636 take the address of an intrinsic function. Additionally, because intrinsic
5637 functions are part of the LLVM language, it is required if any are added that
5638 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5639
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5640<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5641 family of functions that perform the same operation but on different data
5642 types. Because LLVM can represent over 8 million different integer types,
5643 overloading is used commonly to allow an intrinsic function to operate on any
5644 integer type. One or more of the argument types or the result type can be
5645 overloaded to accept any integer type. Argument types may also be defined as
5646 exactly matching a previous argument's type or the result type. This allows
5647 an intrinsic function which accepts multiple arguments, but needs all of them
5648 to be of the same type, to only be overloaded with respect to a single
5649 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5650
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5651<p>Overloaded intrinsics will have the names of its overloaded argument types
5652 encoded into its function name, each preceded by a period. Only those types
5653 which are overloaded result in a name suffix. Arguments whose type is matched
5654 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5655 can take an integer of any width and returns an integer of exactly the same
5656 integer width. This leads to a family of functions such as
5657 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5658 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5659 suffix is required. Because the argument's type is matched against the return
5660 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5661
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5662<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5663 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5664
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5665<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5666<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5667 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5668</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5669
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5670<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5671
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5672<p>Variable argument support is defined in LLVM with
5673 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5674 intrinsic functions. These functions are related to the similarly named
5675 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5676
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5677<p>All of these functions operate on arguments that use a target-specific value
5678 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5679 not define what this type is, so all transformations should be prepared to
5680 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5681
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]5682<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]5683 instruction and the variable argument handling intrinsic functions are
5684 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5685
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]5686<pre class="doc_code">
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5687define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5688 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5689 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5690 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5691 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5692
5693 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5694 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5695
5696 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5697 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5698 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5699 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5700 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5701
5702 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5703 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5704 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5705}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5706
5707declare void @llvm.va_start(i8*)
5708declare void @llvm.va_copy(i8*, i8*)
5709declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5710</pre>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5711
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5712<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5713<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5714 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5715</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5716
5717
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5718<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5719
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5720<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5721<pre>
5722 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5723</pre>
5724
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5725<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5726<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5727 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]5728
5729<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5730<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]5731
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5732<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5733<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]5734 macro available in C. In a target-dependent way, it initializes
5735 the <tt>va_list</tt> element to which the argument points, so that the next
5736 call to <tt>va_arg</tt> will produce the first variable argument passed to
5737 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5738 need to know the last argument of the function as the compiler can figure
5739 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5740
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5741</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5742
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5743<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5744<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5745 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5746</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5747
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5748<div>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5749
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5750<h5>Syntax:</h5>
5751<pre>
5752 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5753</pre>
5754
5755<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5756<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5757 which has been initialized previously
5758 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5759 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5760
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5761<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5762<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]5763
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5764<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5765<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]5766 macro available in C. In a target-dependent way, it destroys
5767 the <tt>va_list</tt> element to which the argument points. Calls
5768 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5769 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5770 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5771
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5772</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5773
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5774<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5775<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5776 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5777</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5778
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5779<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5780
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5781<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5782<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5783 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5784</pre>
5785
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5786<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5787<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5788 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5789
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5790<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5791<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]5792 The second argument is a pointer to a <tt>va_list</tt> element to copy
5793 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5794
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5795<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5796<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]5797 macro available in C. In a target-dependent way, it copies the
5798 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5799 element. This intrinsic is necessary because
5800 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5801 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5802
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5803</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5804
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5805</div>
5806
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5807<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5808<h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5809 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5810</h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5811
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5812<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5813
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5814<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5815Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5816intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5817roots on the stack</a>, as well as garbage collector implementations that
5818require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5819barriers. Front-ends for type-safe garbage collected languages should generate
5820these intrinsics to make use of the LLVM garbage collectors. For more details,
5821see <a href="GarbageCollection.html">Accurate Garbage Collection with
5822LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5823
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5824<p>The garbage collection intrinsics only operate on objects in the generic
5825 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5826
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5827<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5828<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5829 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5830</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5831
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5832<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5833
5834<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5835<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5836 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5837</pre>
5838
5839<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]5840<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]5841 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5842
5843<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5844<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5845 root pointer. The second pointer (which must be either a constant or a
5846 global value address) contains the meta-data to be associated with the
5847 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5848
5849<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]5850<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]5851 location. At compile-time, the code generator generates information to allow
5852 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5853 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5854 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5855
5856</div>
5857
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5858<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5859<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5860 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5861</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5862
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5863<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5864
5865<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5866<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5867 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5868</pre>
5869
5870<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5871<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5872 locations, allowing garbage collector implementations that require read
5873 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5874
5875<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5876<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]5877 allocated from the garbage collector. The first object is a pointer to the
5878 start of the referenced object, if needed by the language runtime (otherwise
5879 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5880
5881<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5882<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5883 instruction, but may be replaced with substantially more complex code by the
5884 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5885 may only be used in a function which <a href="#gc">specifies a GC
5886 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5887
5888</div>
5889
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5890<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5891<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5892 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5893</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5894
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5895<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5896
5897<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5898<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5899 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5900</pre>
5901
5902<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5903<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5904 locations, allowing garbage collector implementations that require write
5905 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5906
5907<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5908<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]5909 object to store it to, and the third is the address of the field of Obj to
5910 store to. If the runtime does not require a pointer to the object, Obj may
5911 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5912
5913<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5914<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5915 instruction, but may be replaced with substantially more complex code by the
5916 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5917 may only be used in a function which <a href="#gc">specifies a GC
5918 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5919
5920</div>
5921
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5922</div>
5923
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5924<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5925<h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5926 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5927</h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5928
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5929<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5930
5931<p>These intrinsics are provided by LLVM to expose special features that may
5932 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5933
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5934<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5935<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5936 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5937</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5938
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5939<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5940
5941<h5>Syntax:</h5>
5942<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5943 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5944</pre>
5945
5946<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5947<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5948 target-specific value indicating the return address of the current function
5949 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5950
5951<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5952<p>The argument to this intrinsic indicates which function to return the address
5953 for. Zero indicates the calling function, one indicates its caller, etc.
5954 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5955
5956<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5957<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5958 indicating the return address of the specified call frame, or zero if it
5959 cannot be identified. The value returned by this intrinsic is likely to be
5960 incorrect or 0 for arguments other than zero, so it should only be used for
5961 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5962
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5963<p>Note that calling this intrinsic does not prevent function inlining or other
5964 aggressive transformations, so the value returned may not be that of the
5965 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5966
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5967</div>
5968
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5969<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5970<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5971 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5972</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5973
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5974<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5975
5976<h5>Syntax:</h5>
5977<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5978 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5979</pre>
5980
5981<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5982<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5983 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5984
5985<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5986<p>The argument to this intrinsic indicates which function to return the frame
5987 pointer for. Zero indicates the calling function, one indicates its caller,
5988 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5989
5990<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5991<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5992 indicating the frame address of the specified call frame, or zero if it
5993 cannot be identified. The value returned by this intrinsic is likely to be
5994 incorrect or 0 for arguments other than zero, so it should only be used for
5995 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5996
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5997<p>Note that calling this intrinsic does not prevent function inlining or other
5998 aggressive transformations, so the value returned may not be that of the
5999 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6000
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6001</div>
6002
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6003<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6004<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6005 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6006</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6007
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6008<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6009
6010<h5>Syntax:</h5>
6011<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6012 declare i8* @llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6013</pre>
6014
6015<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6016<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6017 of the function stack, for use
6018 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6019 useful for implementing language features like scoped automatic variable
6020 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6021
6022<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6023<p>This intrinsic returns a opaque pointer value that can be passed
6024 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6025 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6026 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6027 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6028 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6029 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6030
6031</div>
6032
6033<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6034<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6035 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6036</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6037
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6038<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6039
6040<h5>Syntax:</h5>
6041<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6042 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6043</pre>
6044
6045<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6046<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6047 the function stack to the state it was in when the
6048 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6049 executed. This is useful for implementing language features like scoped
6050 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6051
6052<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6053<p>See the description
6054 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6055
6056</div>
6057
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6058<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6059<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6060 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6061</h4>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6062
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6063<div>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6064
6065<h5>Syntax:</h5>
6066<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6067 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6068</pre>
6069
6070<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6071<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6072 insert a prefetch instruction if supported; otherwise, it is a noop.
6073 Prefetches have no effect on the behavior of the program but can change its
6074 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6075
6076<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6077<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6078 specifier determining if the fetch should be for a read (0) or write (1),
6079 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
6080 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
6081 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6082
6083<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6084<p>This intrinsic does not modify the behavior of the program. In particular,
6085 prefetches cannot trap and do not produce a value. On targets that support
6086 this intrinsic, the prefetch can provide hints to the processor cache for
6087 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6088
6089</div>
6090
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6091<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6092<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6093 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6094</h4>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6095
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6096<div>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6097
6098<h5>Syntax:</h5>
6099<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6100 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6101</pre>
6102
6103<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6104<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6105 Counter (PC) in a region of code to simulators and other tools. The method
6106 is target specific, but it is expected that the marker will use exported
6107 symbols to transmit the PC of the marker. The marker makes no guarantees
6108 that it will remain with any specific instruction after optimizations. It is
6109 possible that the presence of a marker will inhibit optimizations. The
6110 intended use is to be inserted after optimizations to allow correlations of
6111 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6112
6113<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6114<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6115
6116<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6117<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6118 not support this intrinsic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6119
6120</div>
6121
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6122<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6123<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6124 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6125</h4>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6126
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6127<div>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6128
6129<h5>Syntax:</h5>
6130<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]6131 declare i64 @llvm.readcyclecounter()
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6132</pre>
6133
6134<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6135<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6136 counter register (or similar low latency, high accuracy clocks) on those
6137 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6138 should map to RPCC. As the backing counters overflow quickly (on the order
6139 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6140
6141<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6142<p>When directly supported, reading the cycle counter should not modify any
6143 memory. Implementations are allowed to either return a application specific
6144 value or a system wide value. On backends without support, this is lowered
6145 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6146
6147</div>
6148
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6149</div>
6150
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6151<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6152<h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6153 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6154</h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6155
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6156<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6157
6158<p>LLVM provides intrinsics for a few important standard C library functions.
6159 These intrinsics allow source-language front-ends to pass information about
6160 the alignment of the pointer arguments to the code generator, providing
6161 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6162
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6163<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6164<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6165 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6166</h4>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6167
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6168<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6169
6170<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6171<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]6172 integer bit width and for different address spaces. Not all targets support
6173 all bit widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6174
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6175<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6176 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]6177 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6178 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]6179 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6180</pre>
6181
6182<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6183<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6184 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6185
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6186<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6187 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6188 and the pointers can be in specified address spaces.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6189
6190<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6191
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6192<p>The first argument is a pointer to the destination, the second is a pointer
6193 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6194 number of bytes to copy, the fourth argument is the alignment of the
6195 source and destination locations, and the fifth is a boolean indicating a
6196 volatile access.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6197
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6198<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]6199 then the caller guarantees that both the source and destination pointers are
6200 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6201
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6202<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6203 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6204 The detailed access behavior is not very cleanly specified and it is unwise
6205 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6206
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6207<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6208
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6209<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6210 source location to the destination location, which are not allowed to
6211 overlap. It copies "len" bytes of memory over. If the argument is known to
6212 be aligned to some boundary, this can be specified as the fourth argument,
6213 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6214
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6215</div>
6216
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6217<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6218<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6219 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6220</h4>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6221
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6222<div>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6223
6224<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6225<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]6226 width and for different address space. Not all targets support all bit
6227 widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6228
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6229<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6230 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]6231 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6232 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]6233 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6234</pre>
6235
6236<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6237<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6238 source location to the destination location. It is similar to the
6239 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6240 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6241
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6242<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6243 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6244 and the pointers can be in specified address spaces.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6245
6246<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6247
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6248<p>The first argument is a pointer to the destination, the second is a pointer
6249 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6250 number of bytes to copy, the fourth argument is the alignment of the
6251 source and destination locations, and the fifth is a boolean indicating a
6252 volatile access.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6253
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6254<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]6255 then the caller guarantees that the source and destination pointers are
6256 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6257
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6258<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6259 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6260 The detailed access behavior is not very cleanly specified and it is unwise
6261 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6262
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6263<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6264
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6265<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6266 source location to the destination location, which may overlap. It copies
6267 "len" bytes of memory over. If the argument is known to be aligned to some
6268 boundary, this can be specified as the fourth argument, otherwise it should
6269 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6270
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6271</div>
6272
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6273<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6274<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6275 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6276</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6277
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6278<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6279
6280<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6281<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]6282 width and for different address spaces. However, not all targets support all
6283 bit widths.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6284
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6285<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6286 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6287 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6288 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6289 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6290</pre>
6291
6292<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6293<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6294 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6295
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6296<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6297 intrinsic does not return a value and takes extra alignment/volatile
6298 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6299
6300<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6301<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]6302 byte value with which to fill it, the third argument is an integer argument
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6303 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6304 alignment of the destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6305
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6306<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]6307 then the caller guarantees that the destination pointer is aligned to that
6308 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6309
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6310<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6311 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6312 The detailed access behavior is not very cleanly specified and it is unwise
6313 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6314
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6315<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6316<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6317 at the destination location. If the argument is known to be aligned to some
6318 boundary, this can be specified as the fourth argument, otherwise it should
6319 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6320
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6321</div>
6322
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6323<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6324<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6325 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6326</h4>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6327
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6328<div>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6329
6330<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6331<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6332 floating point or vector of floating point type. Not all targets support all
6333 types however.</p>
6334
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6335<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6336 declare float @llvm.sqrt.f32(float %Val)
6337 declare double @llvm.sqrt.f64(double %Val)
6338 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6339 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6340 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6341</pre>
6342
6343<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6344<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6345 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6346 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6347 behavior for negative numbers other than -0.0 (which allows for better
6348 optimization, because there is no need to worry about errno being
6349 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]6350
6351<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6352<p>The argument and return value are floating point numbers of the same
6353 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6354
6355<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6356<p>This function returns the sqrt of the specified operand if it is a
6357 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6358
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6359</div>
6360
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6361<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6362<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6363 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6364</h4>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6365
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6366<div>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6367
6368<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6369<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6370 floating point or vector of floating point type. Not all targets support all
6371 types however.</p>
6372
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6373<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6374 declare float @llvm.powi.f32(float %Val, i32 %power)
6375 declare double @llvm.powi.f64(double %Val, i32 %power)
6376 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6377 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6378 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6379</pre>
6380
6381<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6382<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6383 specified (positive or negative) power. The order of evaluation of
6384 multiplications is not defined. When a vector of floating point type is
6385 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6386
6387<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6388<p>The second argument is an integer power, and the first is a value to raise to
6389 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6390
6391<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6392<p>This function returns the first value raised to the second power with an
6393 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6394
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6395</div>
6396
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6397<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6398<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6399 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6400</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6401
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6402<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6403
6404<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6405<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6406 floating point or vector of floating point type. Not all targets support all
6407 types however.</p>
6408
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6409<pre>
6410 declare float @llvm.sin.f32(float %Val)
6411 declare double @llvm.sin.f64(double %Val)
6412 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6413 declare fp128 @llvm.sin.f128(fp128 %Val)
6414 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6415</pre>
6416
6417<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6418<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6419
6420<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6421<p>The argument and return value are floating point numbers of the same
6422 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6423
6424<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6425<p>This function returns the sine of the specified operand, returning the same
6426 values as the libm <tt>sin</tt> functions would, and handles error conditions
6427 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6428
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6429</div>
6430
6431<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6432<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6433 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6434</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6435
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6436<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6437
6438<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6439<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6440 floating point or vector of floating point type. Not all targets support all
6441 types however.</p>
6442
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6443<pre>
6444 declare float @llvm.cos.f32(float %Val)
6445 declare double @llvm.cos.f64(double %Val)
6446 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6447 declare fp128 @llvm.cos.f128(fp128 %Val)
6448 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6449</pre>
6450
6451<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6452<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6453
6454<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6455<p>The argument and return value are floating point numbers of the same
6456 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6457
6458<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6459<p>This function returns the cosine of the specified operand, returning the same
6460 values as the libm <tt>cos</tt> functions would, and handles error conditions
6461 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6462
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6463</div>
6464
6465<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6466<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6467 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6468</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6469
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6470<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6471
6472<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6473<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6474 floating point or vector of floating point type. Not all targets support all
6475 types however.</p>
6476
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6477<pre>
6478 declare float @llvm.pow.f32(float %Val, float %Power)
6479 declare double @llvm.pow.f64(double %Val, double %Power)
6480 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6481 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6482 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6483</pre>
6484
6485<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6486<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6487 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6488
6489<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6490<p>The second argument is a floating point power, and the first is a value to
6491 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6492
6493<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6494<p>This function returns the first value raised to the second power, returning
6495 the same values as the libm <tt>pow</tt> functions would, and handles error
6496 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6497
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6498</div>
6499
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6500</div>
6501
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6502<!-- _______________________________________________________________________ -->
6503<h4>
6504 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6505</h4>
6506
6507<div>
6508
6509<h5>Syntax:</h5>
6510<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6511 floating point or vector of floating point type. Not all targets support all
6512 types however.</p>
6513
6514<pre>
6515 declare float @llvm.exp.f32(float %Val)
6516 declare double @llvm.exp.f64(double %Val)
6517 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6518 declare fp128 @llvm.exp.f128(fp128 %Val)
6519 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6520</pre>
6521
6522<h5>Overview:</h5>
6523<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6524
6525<h5>Arguments:</h5>
6526<p>The argument and return value are floating point numbers of the same
6527 type.</p>
6528
6529<h5>Semantics:</h5>
6530<p>This function returns the same values as the libm <tt>exp</tt> functions
6531 would, and handles error conditions in the same way.</p>
6532
6533</div>
6534
6535<!-- _______________________________________________________________________ -->
6536<h4>
6537 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6538</h4>
6539
6540<div>
6541
6542<h5>Syntax:</h5>
6543<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6544 floating point or vector of floating point type. Not all targets support all
6545 types however.</p>
6546
6547<pre>
6548 declare float @llvm.log.f32(float %Val)
6549 declare double @llvm.log.f64(double %Val)
6550 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
6551 declare fp128 @llvm.log.f128(fp128 %Val)
6552 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
6553</pre>
6554
6555<h5>Overview:</h5>
6556<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
6557
6558<h5>Arguments:</h5>
6559<p>The argument and return value are floating point numbers of the same
6560 type.</p>
6561
6562<h5>Semantics:</h5>
6563<p>This function returns the same values as the libm <tt>log</tt> functions
6564 would, and handles error conditions in the same way.</p>
6565
6566</div>
6567
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6568<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6569<h3>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6570 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6571</h3>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6572
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6573<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6574
6575<p>LLVM provides intrinsics for a few important bit manipulation operations.
6576 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6577
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6578<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6579<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6580 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6581</h4>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6582
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6583<div>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6584
6585<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6586<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6587 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6588
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6589<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6590 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6591 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6592 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6593</pre>
6594
6595<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6596<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6597 values with an even number of bytes (positive multiple of 16 bits). These
6598 are useful for performing operations on data that is not in the target's
6599 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6600
6601<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6602<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6603 and low byte of the input i16 swapped. Similarly,
6604 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6605 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6606 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6607 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6608 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6609 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6610
6611</div>
6612
6613<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6614<h4>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]6615 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6616</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6617
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6618<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6619
6620<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6621<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6622 width. Not all targets support all bit widths however.</p>
6623
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6624<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6625 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6626 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6627 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6628 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6629 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6630</pre>
6631
6632<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6633<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6634 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6635
6636<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6637<p>The only argument is the value to be counted. The argument may be of any
6638 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6639
6640<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6641<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6642
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6643</div>
6644
6645<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6646<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6647 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6648</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6649
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6650<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6651
6652<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6653<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
6654 integer bit width. Not all targets support all bit widths however.</p>
6655
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6656<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6657 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6658 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6659 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6660 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6661 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6662</pre>
6663
6664<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6665<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6666 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6667
6668<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6669<p>The only argument is the value to be counted. The argument may be of any
6670 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6671
6672<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6673<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
6674 zeros in a variable. If the src == 0 then the result is the size in bits of
6675 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6676
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6677</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6678
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6679<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6680<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6681 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6682</h4>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6683
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6684<div>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6685
6686<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6687<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
6688 integer bit width. Not all targets support all bit widths however.</p>
6689
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6690<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6691 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6692 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6693 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6694 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6695 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6696</pre>
6697
6698<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6699<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6700 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6701
6702<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6703<p>The only argument is the value to be counted. The argument may be of any
6704 integer type. The return type must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6705
6706<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6707<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
6708 zeros in a variable. If the src == 0 then the result is the size in bits of
6709 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6710
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6711</div>
6712
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6713</div>
6714
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6715<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6716<h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6717 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6718</h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6719
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6720<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6721
6722<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6723
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6724<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6725<h4>
6726 <a name="int_sadd_overflow">
6727 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
6728 </a>
6729</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6730
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6731<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6732
6733<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6734<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]6735 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6736
6737<pre>
6738 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6739 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6740 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6741</pre>
6742
6743<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6744<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6745 a signed addition of the two arguments, and indicate whether an overflow
6746 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6747
6748<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6749<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]6750 be of integer types of any bit width, but they must have the same bit
6751 width. The second element of the result structure must be of
6752 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6753 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6754
6755<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6756<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6757 a signed addition of the two variables. They return a structure &mdash; the
6758 first element of which is the signed summation, and the second element of
6759 which is a bit specifying if the signed summation resulted in an
6760 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6761
6762<h5>Examples:</h5>
6763<pre>
6764 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6765 %sum = extractvalue {i32, i1} %res, 0
6766 %obit = extractvalue {i32, i1} %res, 1
6767 br i1 %obit, label %overflow, label %normal
6768</pre>
6769
6770</div>
6771
6772<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6773<h4>
6774 <a name="int_uadd_overflow">
6775 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
6776 </a>
6777</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6778
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6779<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6780
6781<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6782<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]6783 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6784
6785<pre>
6786 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6787 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6788 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6789</pre>
6790
6791<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6792<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6793 an unsigned addition of the two arguments, and indicate whether a carry
6794 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6795
6796<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6797<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]6798 be of integer types of any bit width, but they must have the same bit
6799 width. The second element of the result structure must be of
6800 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6801 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6802
6803<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6804<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6805 an unsigned addition of the two arguments. They return a structure &mdash;
6806 the first element of which is the sum, and the second element of which is a
6807 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6808
6809<h5>Examples:</h5>
6810<pre>
6811 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6812 %sum = extractvalue {i32, i1} %res, 0
6813 %obit = extractvalue {i32, i1} %res, 1
6814 br i1 %obit, label %carry, label %normal
6815</pre>
6816
6817</div>
6818
6819<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6820<h4>
6821 <a name="int_ssub_overflow">
6822 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
6823 </a>
6824</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6825
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6826<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6827
6828<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6829<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]6830 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6831
6832<pre>
6833 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6834 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6835 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6836</pre>
6837
6838<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6839<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6840 a signed subtraction of the two arguments, and indicate whether an overflow
6841 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6842
6843<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6844<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]6845 be of integer types of any bit width, but they must have the same bit
6846 width. The second element of the result structure must be of
6847 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6848 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6849
6850<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6851<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6852 a signed subtraction of the two arguments. They return a structure &mdash;
6853 the first element of which is the subtraction, and the second element of
6854 which is a bit specifying if the signed subtraction resulted in an
6855 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6856
6857<h5>Examples:</h5>
6858<pre>
6859 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6860 %sum = extractvalue {i32, i1} %res, 0
6861 %obit = extractvalue {i32, i1} %res, 1
6862 br i1 %obit, label %overflow, label %normal
6863</pre>
6864
6865</div>
6866
6867<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6868<h4>
6869 <a name="int_usub_overflow">
6870 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
6871 </a>
6872</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6873
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6874<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6875
6876<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6877<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]6878 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6879
6880<pre>
6881 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6882 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6883 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6884</pre>
6885
6886<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6887<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6888 an unsigned subtraction of the two arguments, and indicate whether an
6889 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6890
6891<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6892<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]6893 be of integer types of any bit width, but they must have the same bit
6894 width. The second element of the result structure must be of
6895 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6896 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6897
6898<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6899<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6900 an unsigned subtraction of the two arguments. They return a structure &mdash;
6901 the first element of which is the subtraction, and the second element of
6902 which is a bit specifying if the unsigned subtraction resulted in an
6903 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6904
6905<h5>Examples:</h5>
6906<pre>
6907 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6908 %sum = extractvalue {i32, i1} %res, 0
6909 %obit = extractvalue {i32, i1} %res, 1
6910 br i1 %obit, label %overflow, label %normal
6911</pre>
6912
6913</div>
6914
6915<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6916<h4>
6917 <a name="int_smul_overflow">
6918 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
6919 </a>
6920</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6921
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6922<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6923
6924<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6925<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]6926 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6927
6928<pre>
6929 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6930 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6931 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6932</pre>
6933
6934<h5>Overview:</h5>
6935
6936<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6937 a signed multiplication of the two arguments, and indicate whether an
6938 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6939
6940<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6941<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]6942 be of integer types of any bit width, but they must have the same bit
6943 width. The second element of the result structure must be of
6944 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6945 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6946
6947<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6948<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6949 a signed multiplication of the two arguments. They return a structure &mdash;
6950 the first element of which is the multiplication, and the second element of
6951 which is a bit specifying if the signed multiplication resulted in an
6952 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6953
6954<h5>Examples:</h5>
6955<pre>
6956 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6957 %sum = extractvalue {i32, i1} %res, 0
6958 %obit = extractvalue {i32, i1} %res, 1
6959 br i1 %obit, label %overflow, label %normal
6960</pre>
6961
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]6962</div>
6963
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6964<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6965<h4>
6966 <a name="int_umul_overflow">
6967 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
6968 </a>
6969</h4>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6970
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6971<div>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6972
6973<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6974<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]6975 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6976
6977<pre>
6978 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6979 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6980 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6981</pre>
6982
6983<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6984<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6985 a unsigned multiplication of the two arguments, and indicate whether an
6986 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6987
6988<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6989<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]6990 be of integer types of any bit width, but they must have the same bit
6991 width. The second element of the result structure must be of
6992 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6993 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6994
6995<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6996<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6997 an unsigned multiplication of the two arguments. They return a structure
6998 &mdash; the first element of which is the multiplication, and the second
6999 element of which is a bit specifying if the unsigned multiplication resulted
7000 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7001
7002<h5>Examples:</h5>
7003<pre>
7004 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7005 %sum = extractvalue {i32, i1} %res, 0
7006 %obit = extractvalue {i32, i1} %res, 1
7007 br i1 %obit, label %overflow, label %normal
7008</pre>
7009
7010</div>
7011
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7012</div>
7013
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7014<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7015<h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7016 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7017</h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7018
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7019<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7020
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7021<p>Half precision floating point is a storage-only format. This means that it is
7022 a dense encoding (in memory) but does not support computation in the
7023 format.</p>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7024
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7025<p>This means that code must first load the half-precision floating point
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7026 value as an i16, then convert it to float with <a
7027 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7028 Computation can then be performed on the float value (including extending to
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7029 double etc). To store the value back to memory, it is first converted to
7030 float if needed, then converted to i16 with
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7031 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7032 storing as an i16 value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7033
7034<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7035<h4>
7036 <a name="int_convert_to_fp16">
7037 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7038 </a>
7039</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7040
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7041<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7042
7043<h5>Syntax:</h5>
7044<pre>
7045 declare i16 @llvm.convert.to.fp16(f32 %a)
7046</pre>
7047
7048<h5>Overview:</h5>
7049<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7050 a conversion from single precision floating point format to half precision
7051 floating point format.</p>
7052
7053<h5>Arguments:</h5>
7054<p>The intrinsic function contains single argument - the value to be
7055 converted.</p>
7056
7057<h5>Semantics:</h5>
7058<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7059 a conversion from single precision floating point format to half precision
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7060 floating point format. The return value is an <tt>i16</tt> which
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7061 contains the converted number.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7062
7063<h5>Examples:</h5>
7064<pre>
7065 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7066 store i16 %res, i16* @x, align 2
7067</pre>
7068
7069</div>
7070
7071<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7072<h4>
7073 <a name="int_convert_from_fp16">
7074 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7075 </a>
7076</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7077
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7078<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7079
7080<h5>Syntax:</h5>
7081<pre>
7082 declare f32 @llvm.convert.from.fp16(i16 %a)
7083</pre>
7084
7085<h5>Overview:</h5>
7086<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7087 a conversion from half precision floating point format to single precision
7088 floating point format.</p>
7089
7090<h5>Arguments:</h5>
7091<p>The intrinsic function contains single argument - the value to be
7092 converted.</p>
7093
7094<h5>Semantics:</h5>
7095<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7096 conversion from half single precision floating point format to single
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7097 precision floating point format. The input half-float value is represented by
7098 an <tt>i16</tt> value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7099
7100<h5>Examples:</h5>
7101<pre>
7102 %a = load i16* @x, align 2
7103 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7104</pre>
7105
7106</div>
7107
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7108</div>
7109
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7110<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7111<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7112 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7113</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7114
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7115<div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7116
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7117<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7118 prefix), are described in
7119 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7120 Level Debugging</a> document.</p>
7121
7122</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7123
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7124<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7125<h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7126 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7127</h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7128
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7129<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7130
7131<p>The LLVM exception handling intrinsics (which all start with
7132 <tt>llvm.eh.</tt> prefix), are described in
7133 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7134 Handling</a> document.</p>
7135
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7136</div>
7137
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7138<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7139<h3>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7140 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7141</h3>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7142
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7143<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7144
7145<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]7146 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7147 The result is a callable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7148 function pointer lacking the nest parameter - the caller does not need to
7149 provide a value for it. Instead, the value to use is stored in advance in a
7150 "trampoline", a block of memory usually allocated on the stack, which also
7151 contains code to splice the nest value into the argument list. This is used
7152 to implement the GCC nested function address extension.</p>
7153
7154<p>For example, if the function is
7155 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7156 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7157 follows:</p>
7158
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]7159<pre class="doc_code">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7160 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7161 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7162 %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]7163 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7164</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7165
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7166<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7167 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7168
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7169<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7170<h4>
7171 <a name="int_it">
7172 '<tt>llvm.init.trampoline</tt>' Intrinsic
7173 </a>
7174</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7175
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7176<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7177
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7178<h5>Syntax:</h5>
7179<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7180 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]7181</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7182
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7183<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7184<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7185 function pointer suitable for executing it.</p>
7186
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7187<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7188<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7189 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7190 sufficiently aligned block of memory; this memory is written to by the
7191 intrinsic. Note that the size and the alignment are target-specific - LLVM
7192 currently provides no portable way of determining them, so a front-end that
7193 generates this intrinsic needs to have some target-specific knowledge.
7194 The <tt>func</tt> argument must hold a function bitcast to
7195 an <tt>i8*</tt>.</p>
7196
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7197<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7198<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7199 dependent code, turning it into a function. A pointer to this function is
7200 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7201 function pointer type</a> before being called. The new function's signature
7202 is the same as that of <tt>func</tt> with any arguments marked with
7203 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7204 is allowed, and it must be of pointer type. Calling the new function is
7205 equivalent to calling <tt>func</tt> with the same argument list, but
7206 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7207 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7208 by <tt>tramp</tt> is modified, then the effect of any later call to the
7209 returned function pointer is undefined.</p>
7210
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7211</div>
7212
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7213</div>
7214
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7215<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7216<h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7217 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7218</h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7219
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7220<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7221
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7222<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7223 hardware constructs for atomic operations and memory synchronization. This
7224 provides an interface to the hardware, not an interface to the programmer. It
7225 is aimed at a low enough level to allow any programming models or APIs
7226 (Application Programming Interfaces) which need atomic behaviors to map
7227 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7228 hardware provides a "universal IR" for source languages, it also provides a
7229 starting point for developing a "universal" atomic operation and
7230 synchronization IR.</p>
7231
7232<p>These do <em>not</em> form an API such as high-level threading libraries,
7233 software transaction memory systems, atomic primitives, and intrinsic
7234 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7235 application libraries. The hardware interface provided by LLVM should allow
7236 a clean implementation of all of these APIs and parallel programming models.
7237 No one model or paradigm should be selected above others unless the hardware
7238 itself ubiquitously does so.</p>
7239
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7240<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7241<h4>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7242 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7243</h4>
7244
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7245<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7246<h5>Syntax:</h5>
7247<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7248 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]7249</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7250
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7251<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7252<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7253 specific pairs of memory access types.</p>
7254
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7255<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7256<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7257 The first four arguments enables a specific barrier as listed below. The
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]7258 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7259 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7260
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7261<ul>
7262 <li><tt>ll</tt>: load-load barrier</li>
7263 <li><tt>ls</tt>: load-store barrier</li>
7264 <li><tt>sl</tt>: store-load barrier</li>
7265 <li><tt>ss</tt>: store-store barrier</li>
7266 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7267</ul>
7268
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7269<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7270<p>This intrinsic causes the system to enforce some ordering constraints upon
7271 the loads and stores of the program. This barrier does not
7272 indicate <em>when</em> any events will occur, it only enforces
7273 an <em>order</em> in which they occur. For any of the specified pairs of load
7274 and store operations (f.ex. load-load, or store-load), all of the first
7275 operations preceding the barrier will complete before any of the second
7276 operations succeeding the barrier begin. Specifically the semantics for each
7277 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7278
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7279<ul>
7280 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7281 after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7282 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7283 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7284 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7285 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7286 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7287 load after the barrier begins.</li>
7288</ul>
7289
7290<p>These semantics are applied with a logical "and" behavior when more than one
7291 is enabled in a single memory barrier intrinsic.</p>
7292
7293<p>Backends may implement stronger barriers than those requested when they do
7294 not support as fine grained a barrier as requested. Some architectures do
7295 not need all types of barriers and on such architectures, these become
7296 noops.</p>
7297
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7298<h5>Example:</h5>
7299<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7300%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7301%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7302 store i32 4, %ptr
7303
7304%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7305 call void @llvm.memory.barrier(i1 false, i1 true, i1 false, i1 false)
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7306 <i>; guarantee the above finishes</i>
7307 store i32 8, %ptr <i>; before this begins</i>
7308</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7309
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7310</div>
7311
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7312<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7313<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7314 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7315</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7316
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7317<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7318
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7319<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7320<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7321 any integer bit width and for different address spaces. Not all targets
7322 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7323
7324<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7325 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7326 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7327 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7328 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]7329</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7330
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7331<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7332<p>This loads a value in memory and compares it to a given value. If they are
7333 equal, it stores a new value into the memory.</p>
7334
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7335<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7336<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7337 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7338 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7339 this integer type. While any bit width integer may be used, targets may only
7340 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7341
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7342<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7343<p>This entire intrinsic must be executed atomically. It first loads the value
7344 in memory pointed to by <tt>ptr</tt> and compares it with the
7345 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7346 memory. The loaded value is yielded in all cases. This provides the
7347 equivalent of an atomic compare-and-swap operation within the SSA
7348 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7349
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7350<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7351<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7352%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7353%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7354 store i32 4, %ptr
7355
7356%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7357%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7358 <i>; yields {i32}:result1 = 4</i>
7359%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7360%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7361
7362%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7363%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7364 <i>; yields {i32}:result2 = 8</i>
7365%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7366
7367%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7368</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7369
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7370</div>
7371
7372<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7373<h4>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7374 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7375</h4>
7376
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7377<div>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7378<h5>Syntax:</h5>
7379
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7380<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7381 integer bit width. Not all targets support all bit widths however.</p>
7382
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7383<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7384 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7385 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7386 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7387 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]7388</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7389
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7390<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7391<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7392 the value from memory. It then stores the value in <tt>val</tt> in the memory
7393 at <tt>ptr</tt>.</p>
7394
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7395<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7396<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7397 the <tt>val</tt> argument and the result must be integers of the same bit
7398 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7399 integer type. The targets may only lower integer representations they
7400 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7401
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7402<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7403<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7404 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7405 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7406
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7407<h5>Examples:</h5>
7408<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7409%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7410%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7411 store i32 4, %ptr
7412
7413%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7414%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7415 <i>; yields {i32}:result1 = 4</i>
7416%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7417%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7418
7419%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7420%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7421 <i>; yields {i32}:result2 = 8</i>
7422
7423%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7424%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7425</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7426
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7427</div>
7428
7429<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7430<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7431 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7432</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7433
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7434<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7435
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7436<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7437<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7438 any integer bit width. Not all targets support all bit widths however.</p>
7439
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7440<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7441 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7442 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7443 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7444 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]7445</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7446
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7447<h5>Overview:</h5>
7448<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7449 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7450
7451<h5>Arguments:</h5>
7452<p>The intrinsic takes two arguments, the first a pointer to an integer value
7453 and the second an integer value. The result is also an integer value. These
7454 integer types can have any bit width, but they must all have the same bit
7455 width. The targets may only lower integer representations they support.</p>
7456
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7457<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7458<p>This intrinsic does a series of operations atomically. It first loads the
7459 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7460 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]7461
7462<h5>Examples:</h5>
7463<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7464%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7465%ptr = bitcast i8* %mallocP to i32*
7466 store i32 4, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7467%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7468 <i>; yields {i32}:result1 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7469%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7470 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7471%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7472 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7473%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7474</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7475
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7476</div>
7477
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7478<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7479<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7480 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7481</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7482
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7483<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7484
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7485<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7486<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7487 any integer bit width and for different address spaces. Not all targets
7488 support all bit widths however.</p>
7489
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7490<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7491 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7492 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7493 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7494 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]7495</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7496
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7497<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7498<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7499 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7500
7501<h5>Arguments:</h5>
7502<p>The intrinsic takes two arguments, the first a pointer to an integer value
7503 and the second an integer value. The result is also an integer value. These
7504 integer types can have any bit width, but they must all have the same bit
7505 width. The targets may only lower integer representations they support.</p>
7506
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7507<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7508<p>This intrinsic does a series of operations atomically. It first loads the
7509 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7510 result to <tt>ptr</tt>. It yields the original value stored
7511 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7512
7513<h5>Examples:</h5>
7514<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7515%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7516%ptr = bitcast i8* %mallocP to i32*
7517 store i32 8, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7518%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7519 <i>; yields {i32}:result1 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7520%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7521 <i>; yields {i32}:result2 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7522%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7523 <i>; yields {i32}:result3 = 2</i>
7524%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7525</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7526
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7527</div>
7528
7529<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7530<h4>
7531 <a name="int_atomic_load_and">
7532 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7533 </a>
7534 <br>
7535 <a name="int_atomic_load_nand">
7536 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7537 </a>
7538 <br>
7539 <a name="int_atomic_load_or">
7540 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7541 </a>
7542 <br>
7543 <a name="int_atomic_load_xor">
7544 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7545 </a>
7546</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7547
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7548<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7549
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7550<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7551<p>These are overloaded intrinsics. You can
7552 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7553 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7554 bit width and for different address spaces. Not all targets support all bit
7555 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7556
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7557<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7558 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7559 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7560 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7561 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]7562</pre>
7563
7564<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7565 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7566 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7567 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7568 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]7569</pre>
7570
7571<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7572 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7573 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7574 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7575 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]7576</pre>
7577
7578<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7579 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7580 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7581 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7582 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]7583</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7584
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7585<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7586<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7587 the value stored in memory at <tt>ptr</tt>. It yields the original value
7588 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7589
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7590<h5>Arguments:</h5>
7591<p>These intrinsics take two arguments, the first a pointer to an integer value
7592 and the second an integer value. The result is also an integer value. These
7593 integer types can have any bit width, but they must all have the same bit
7594 width. The targets may only lower integer representations they support.</p>
7595
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7596<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7597<p>These intrinsics does a series of operations atomically. They first load the
7598 value stored at <tt>ptr</tt>. They then do the bitwise
7599 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7600 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7601
7602<h5>Examples:</h5>
7603<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7604%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7605%ptr = bitcast i8* %mallocP to i32*
7606 store i32 0x0F0F, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7607%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7608 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7609%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7610 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7611%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7612 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7613%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7614 <i>; yields {i32}:result3 = FF</i>
7615%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7616</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7617
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7618</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7619
7620<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7621<h4>
7622 <a name="int_atomic_load_max">
7623 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
7624 </a>
7625 <br>
7626 <a name="int_atomic_load_min">
7627 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
7628 </a>
7629 <br>
7630 <a name="int_atomic_load_umax">
7631 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
7632 </a>
7633 <br>
7634 <a name="int_atomic_load_umin">
7635 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
7636 </a>
7637</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7638
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7639<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7640
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7641<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7642<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7643 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7644 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7645 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7646
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7647<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7648 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7649 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7650 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7651 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]7652</pre>
7653
7654<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7655 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7656 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7657 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7658 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]7659</pre>
7660
7661<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7662 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7663 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7664 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7665 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]7666</pre>
7667
7668<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7669 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7670 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7671 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7672 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]7673</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7674
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7675<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7676<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7677 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7678 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7679
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7680<h5>Arguments:</h5>
7681<p>These intrinsics take two arguments, the first a pointer to an integer value
7682 and the second an integer value. The result is also an integer value. These
7683 integer types can have any bit width, but they must all have the same bit
7684 width. The targets may only lower integer representations they support.</p>
7685
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7686<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7687<p>These intrinsics does a series of operations atomically. They first load the
7688 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7689 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7690 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7691
7692<h5>Examples:</h5>
7693<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7694%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7695%ptr = bitcast i8* %mallocP to i32*
7696 store i32 7, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7697%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7698 <i>; yields {i32}:result0 = 7</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7699%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7700 <i>; yields {i32}:result1 = -2</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7701%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7702 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7703%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7704 <i>; yields {i32}:result3 = 8</i>
7705%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7706</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7707
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7708</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7709
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7710</div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7711
7712<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7713<h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7714 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7715</h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7716
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7717<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7718
7719<p>This class of intrinsics exists to information about the lifetime of memory
7720 objects and ranges where variables are immutable.</p>
7721
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7722<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7723<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7724 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7725</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7726
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7727<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7728
7729<h5>Syntax:</h5>
7730<pre>
7731 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7732</pre>
7733
7734<h5>Overview:</h5>
7735<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7736 object's lifetime.</p>
7737
7738<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7739<p>The first argument is a constant integer representing the size of the
7740 object, or -1 if it is variable sized. The second argument is a pointer to
7741 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7742
7743<h5>Semantics:</h5>
7744<p>This intrinsic indicates that before this point in the code, the value of the
7745 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]7746 never be used and has an undefined value. A load from the pointer that
7747 precedes this intrinsic can be replaced with
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7748 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7749
7750</div>
7751
7752<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7753<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7754 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7755</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7756
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7757<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7758
7759<h5>Syntax:</h5>
7760<pre>
7761 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7762</pre>
7763
7764<h5>Overview:</h5>
7765<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7766 object's lifetime.</p>
7767
7768<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7769<p>The first argument is a constant integer representing the size of the
7770 object, or -1 if it is variable sized. The second argument is a pointer to
7771 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7772
7773<h5>Semantics:</h5>
7774<p>This intrinsic indicates that after this point in the code, the value of the
7775 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7776 never be used and has an undefined value. Any stores into the memory object
7777 following this intrinsic may be removed as dead.
7778
7779</div>
7780
7781<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7782<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7783 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7784</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7785
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7786<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7787
7788<h5>Syntax:</h5>
7789<pre>
Nick Lewycky2965d3e2010-11-30 04:13:41 +0000[diff] [blame]7790 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7791</pre>
7792
7793<h5>Overview:</h5>
7794<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7795 a memory object will not change.</p>
7796
7797<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7798<p>The first argument is a constant integer representing the size of the
7799 object, or -1 if it is variable sized. The second argument is a pointer to
7800 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7801
7802<h5>Semantics:</h5>
7803<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7804 the return value, the referenced memory location is constant and
7805 unchanging.</p>
7806
7807</div>
7808
7809<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7810<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7811 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7812</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7813
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7814<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7815
7816<h5>Syntax:</h5>
7817<pre>
7818 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7819</pre>
7820
7821<h5>Overview:</h5>
7822<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7823 a memory object are mutable.</p>
7824
7825<h5>Arguments:</h5>
7826<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7827 The second argument is a constant integer representing the size of the
7828 object, or -1 if it is variable sized and the third argument is a pointer
7829 to the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7830
7831<h5>Semantics:</h5>
7832<p>This intrinsic indicates that the memory is mutable again.</p>
7833
7834</div>
7835
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7836</div>
7837
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7838<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7839<h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7840 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7841</h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7842
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7843<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7844
7845<p>This class of intrinsics is designed to be generic and has no specific
7846 purpose.</p>
7847
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7848<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7849<h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7850 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7851</h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7852
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7853<div>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7854
7855<h5>Syntax:</h5>
7856<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7857 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]7858</pre>
7859
7860<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7861<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7862
7863<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7864<p>The first argument is a pointer to a value, the second is a pointer to a
7865 global string, the third is a pointer to a global string which is the source
7866 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7867
7868<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7869<p>This intrinsic allows annotation of local variables with arbitrary strings.
7870 This can be useful for special purpose optimizations that want to look for
7871 these annotations. These have no other defined use, they are ignored by code
7872 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7873
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7874</div>
7875
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7876<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7877<h4>
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]7878 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7879</h4>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7880
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7881<div>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7882
7883<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7884<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7885 any integer bit width.</p>
7886
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7887<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7888 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7889 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7890 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7891 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7892 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]7893</pre>
7894
7895<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7896<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7897
7898<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7899<p>The first argument is an integer value (result of some expression), the
7900 second is a pointer to a global string, the third is a pointer to a global
7901 string which is the source file name, and the last argument is the line
7902 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7903
7904<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7905<p>This intrinsic allows annotations to be put on arbitrary expressions with
7906 arbitrary strings. This can be useful for special purpose optimizations that
7907 want to look for these annotations. These have no other defined use, they
7908 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7909
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7910</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7911
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7912<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7913<h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7914 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7915</h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7916
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7917<div>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7918
7919<h5>Syntax:</h5>
7920<pre>
7921 declare void @llvm.trap()
7922</pre>
7923
7924<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7925<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7926
7927<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7928<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7929
7930<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7931<p>This intrinsics is lowered to the target dependent trap instruction. If the
7932 target does not have a trap instruction, this intrinsic will be lowered to
7933 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7934
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7935</div>
7936
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7937<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7938<h4>
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]7939 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7940</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7941
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7942<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7943
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7944<h5>Syntax:</h5>
7945<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7946 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7947</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7948
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7949<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7950<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
7951 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
7952 ensure that it is placed on the stack before local variables.</p>
7953
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7954<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7955<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
7956 arguments. The first argument is the value loaded from the stack
7957 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
7958 that has enough space to hold the value of the guard.</p>
7959
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7960<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7961<p>This intrinsic causes the prologue/epilogue inserter to force the position of
7962 the <tt>AllocaInst</tt> stack slot to be before local variables on the
7963 stack. This is to ensure that if a local variable on the stack is
7964 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]7965 the guard on the stack is checked against the original guard. If they are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7966 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
7967 function.</p>
7968
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7969</div>
7970
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7971<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7972<h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7973 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7974</h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7975
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7976<div>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7977
7978<h5>Syntax:</h5>
7979<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7980 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
7981 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7982</pre>
7983
7984<h5>Overview:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]7985<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
7986 the optimizers to determine at compile time whether a) an operation (like
7987 memcpy) will overflow a buffer that corresponds to an object, or b) that a
7988 runtime check for overflow isn't necessary. An object in this context means
7989 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7990
7991<h5>Arguments:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]7992<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]7993 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]7994 is a boolean 0 or 1. This argument determines whether you want the
7995 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]7996 1, variables are not allowed.</p>
7997
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7998<h5>Semantics:</h5>
7999<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8000 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8001 depending on the <tt>type</tt> argument, if the size cannot be determined at
8002 compile time.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8003
8004</div>
8005
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8006</div>
8007
8008</div>
8009
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8010<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8011<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8012<address>
8013 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8014 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8015 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8016 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]8017
8018 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumica46f5a2011-04-09 02:13:37 +0000[diff] [blame]8019 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8020 Last modified: $Date$
8021</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]8022
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]8023</body>
8024</html>