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gerrit-public.fairphone.software / toolchain / llvm-project / f03fa189ca73a664fb10cf1bc8447d8453edf810 / . / 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>
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame^]244 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]245 </ol>
246 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]247 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]248 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]249 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]250 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
251 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
252 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]253 </ol>
254 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]255 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
256 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]257 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
258 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
259 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
260 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
261 <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]262 <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]263 </ol>
264 </li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]265 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
266 <ol>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]267 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
268 <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]269 </ol>
270 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]271 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]272 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]273 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]274 <ol>
275 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]276 </ol>
277 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]278 <li><a href="#int_atomics">Atomic intrinsics</a>
279 <ol>
280 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
281 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
282 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
283 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
284 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
285 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
286 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
287 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
288 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
289 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
290 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
291 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
292 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
293 </ol>
294 </li>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]295 <li><a href="#int_memorymarkers">Memory Use Markers</a>
296 <ol>
297 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
298 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
299 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
300 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
301 </ol>
302 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]303 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]304 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]305 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]306 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]307 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]308 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]309 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]310 '<tt>llvm.trap</tt>' Intrinsic</a></li>
311 <li><a href="#int_stackprotector">
312 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]313 <li><a href="#int_objectsize">
314 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]315 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]316 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]317 </ol>
318 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]319</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]320
321<div class="doc_author">
322 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
323 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]324</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]325
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]326<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]327<h2><a name="abstract">Abstract</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]328<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]329
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]330<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]331
332<p>This document is a reference manual for the LLVM assembly language. LLVM is
333 a Static Single Assignment (SSA) based representation that provides type
334 safety, low-level operations, flexibility, and the capability of representing
335 'all' high-level languages cleanly. It is the common code representation
336 used throughout all phases of the LLVM compilation strategy.</p>
337
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]338</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]339
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]340<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]341<h2><a name="introduction">Introduction</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]342<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]343
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]344<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]345
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]346<p>The LLVM code representation is designed to be used in three different forms:
347 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
348 for fast loading by a Just-In-Time compiler), and as a human readable
349 assembly language representation. This allows LLVM to provide a powerful
350 intermediate representation for efficient compiler transformations and
351 analysis, while providing a natural means to debug and visualize the
352 transformations. The three different forms of LLVM are all equivalent. This
353 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]354
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]355<p>The LLVM representation aims to be light-weight and low-level while being
356 expressive, typed, and extensible at the same time. It aims to be a
357 "universal IR" of sorts, by being at a low enough level that high-level ideas
358 may be cleanly mapped to it (similar to how microprocessors are "universal
359 IR's", allowing many source languages to be mapped to them). By providing
360 type information, LLVM can be used as the target of optimizations: for
361 example, through pointer analysis, it can be proven that a C automatic
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]362 variable is never accessed outside of the current function, allowing it to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]363 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]364
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]365<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]366<h4>
367 <a name="wellformed">Well-Formedness</a>
368</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]369
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]370<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]371
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]372<p>It is important to note that this document describes 'well formed' LLVM
373 assembly language. There is a difference between what the parser accepts and
374 what is considered 'well formed'. For example, the following instruction is
375 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]376
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]377<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]378%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]379</pre>
380
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]381<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
382 LLVM infrastructure provides a verification pass that may be used to verify
383 that an LLVM module is well formed. This pass is automatically run by the
384 parser after parsing input assembly and by the optimizer before it outputs
385 bitcode. The violations pointed out by the verifier pass indicate bugs in
386 transformation passes or input to the parser.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]387
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]388</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]389
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]390</div>
391
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]392<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]393
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]394<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]395<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]396<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]397
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]398<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]399
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]400<p>LLVM identifiers come in two basic types: global and local. Global
401 identifiers (functions, global variables) begin with the <tt>'@'</tt>
402 character. Local identifiers (register names, types) begin with
403 the <tt>'%'</tt> character. Additionally, there are three different formats
404 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]405
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]406<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]407 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]408 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
409 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
410 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
411 other characters in their names can be surrounded with quotes. Special
412 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
413 ASCII code for the character in hexadecimal. In this way, any character
414 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]415
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]416 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]417 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]418
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]419 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]420 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]421</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]422
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]423<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]424 don't need to worry about name clashes with reserved words, and the set of
425 reserved words may be expanded in the future without penalty. Additionally,
426 unnamed identifiers allow a compiler to quickly come up with a temporary
427 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]428
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]429<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]430 languages. There are keywords for different opcodes
431 ('<tt><a href="#i_add">add</a></tt>',
432 '<tt><a href="#i_bitcast">bitcast</a></tt>',
433 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
434 ('<tt><a href="#t_void">void</a></tt>',
435 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
436 reserved words cannot conflict with variable names, because none of them
437 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]438
439<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]440 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]441
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]442<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]443
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]444<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]445%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]446</pre>
447
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]448<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]449
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]450<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]451%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]452</pre>
453
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]454<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]455
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]456<pre class="doc_code">
Gabor Greifbd0328f2009-10-28 13:05:07 +0000[diff] [blame]457%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
458%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]459%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]460</pre>
461
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]462<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
463 lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]464
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]465<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]466 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]467 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]468
469 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]470 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]471
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]472 <li>Unnamed temporaries are numbered sequentially</li>
473</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]474
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]475<p>It also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]476 demonstrating instructions, we will follow an instruction with a comment that
477 defines the type and name of value produced. Comments are shown in italic
478 text.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]479
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]480</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]481
482<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]483<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]484<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]485<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]486<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]487<h3>
488 <a name="modulestructure">Module Structure</a>
489</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]490
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]491<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]492
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]493<p>LLVM programs are composed of "Module"s, each of which is a translation unit
494 of the input programs. Each module consists of functions, global variables,
495 and symbol table entries. Modules may be combined together with the LLVM
496 linker, which merges function (and global variable) definitions, resolves
497 forward declarations, and merges symbol table entries. Here is an example of
498 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]499
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]500<pre class="doc_code">
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]501<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckyfea7ddc2011-01-29 01:09:53 +0000[diff] [blame]502<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]503
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]504<i>; External declaration of the puts function</i>&nbsp;
505<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]506
507<i>; Definition of main function</i>
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]508define i32 @main() { <i>; i32()* </i>&nbsp;
509 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
510 %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]511
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]512 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
513 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
514 <a href="#i_ret">ret</a> i32 0&nbsp;
515}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]516
517<i>; Named metadata</i>
518!1 = metadata !{i32 41}
519!foo = !{!1, null}
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]520</pre>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]521
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]522<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]523 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]524 a <a href="#functionstructure">function definition</a> for
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]525 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
526 "<tt>foo"</tt>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]527
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]528<p>In general, a module is made up of a list of global values, where both
529 functions and global variables are global values. Global values are
530 represented by a pointer to a memory location (in this case, a pointer to an
531 array of char, and a pointer to a function), and have one of the
532 following <a href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]533
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]534</div>
535
536<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]537<h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]538 <a name="linkage">Linkage Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]539</h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]540
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]541<div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]542
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]543<p>All Global Variables and Functions have one of the following types of
544 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]545
546<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]547 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]548 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
549 by objects in the current module. In particular, linking code into a
550 module with an private global value may cause the private to be renamed as
551 necessary to avoid collisions. Because the symbol is private to the
552 module, all references can be updated. This doesn't show up in any symbol
553 table in the object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]554
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]555 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]556 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
557 assembler and evaluated by the linker. Unlike normal strong symbols, they
558 are removed by the linker from the final linked image (executable or
559 dynamic library).</dd>
560
561 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
562 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
563 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
564 linker. The symbols are removed by the linker from the final linked image
565 (executable or dynamic library).</dd>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]566
Bill Wendling578ee402010-08-20 22:05:50 +0000[diff] [blame]567 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
568 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
569 of the object is not taken. For instance, functions that had an inline
570 definition, but the compiler decided not to inline it. Note,
571 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
572 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
573 visibility. The symbols are removed by the linker from the final linked
574 image (executable or dynamic library).</dd>
575
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]576 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling36321712010-06-29 22:34:52 +0000[diff] [blame]577 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]578 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
579 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]580
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]581 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]582 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]583 into the object file corresponding to the LLVM module. They exist to
584 allow inlining and other optimizations to take place given knowledge of
585 the definition of the global, which is known to be somewhere outside the
586 module. Globals with <tt>available_externally</tt> linkage are allowed to
587 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
588 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]589
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]590 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]591 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner0de4caa2010-01-09 19:15:14 +0000[diff] [blame]592 the same name when linkage occurs. This can be used to implement
593 some forms of inline functions, templates, or other code which must be
594 generated in each translation unit that uses it, but where the body may
595 be overridden with a more definitive definition later. Unreferenced
596 <tt>linkonce</tt> globals are allowed to be discarded. Note that
597 <tt>linkonce</tt> linkage does not actually allow the optimizer to
598 inline the body of this function into callers because it doesn't know if
599 this definition of the function is the definitive definition within the
600 program or whether it will be overridden by a stronger definition.
601 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
602 linkage.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]603
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]604 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]605 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
606 <tt>linkonce</tt> linkage, except that unreferenced globals with
607 <tt>weak</tt> linkage may not be discarded. This is used for globals that
608 are declared "weak" in C source code.</dd>
609
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]610 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]611 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
612 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
613 global scope.
614 Symbols with "<tt>common</tt>" linkage are merged in the same way as
615 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]616 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]617 must have a zero initializer, and may not be marked '<a
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]618 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
619 have common linkage.</dd>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]620
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]621
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]622 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]623 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]624 pointer to array type. When two global variables with appending linkage
625 are linked together, the two global arrays are appended together. This is
626 the LLVM, typesafe, equivalent of having the system linker append together
627 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]628
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]629 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]630 <dd>The semantics of this linkage follow the ELF object file model: the symbol
631 is weak until linked, if not linked, the symbol becomes null instead of
632 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]633
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]634 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
635 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]636 <dd>Some languages allow differing globals to be merged, such as two functions
637 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]638 that only equivalent globals are ever merged (the "one definition rule"
639 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]640 and <tt>weak_odr</tt> linkage types to indicate that the global will only
641 be merged with equivalent globals. These linkage types are otherwise the
642 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]643
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]644 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]645 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]646 visible, meaning that it participates in linkage and can be used to
647 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]648</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]649
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]650<p>The next two types of linkage are targeted for Microsoft Windows platform
651 only. They are designed to support importing (exporting) symbols from (to)
652 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]653
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]654<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]655 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]656 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]657 or variable via a global pointer to a pointer that is set up by the DLL
658 exporting the symbol. On Microsoft Windows targets, the pointer name is
659 formed by combining <code>__imp_</code> and the function or variable
660 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]661
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]662 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]663 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]664 pointer to a pointer in a DLL, so that it can be referenced with the
665 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
666 name is formed by combining <code>__imp_</code> and the function or
667 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]668</dl>
669
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]670<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
671 another module defined a "<tt>.LC0</tt>" variable and was linked with this
672 one, one of the two would be renamed, preventing a collision. Since
673 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
674 declarations), they are accessible outside of the current module.</p>
675
676<p>It is illegal for a function <i>declaration</i> to have any linkage type
677 other than "externally visible", <tt>dllimport</tt>
678 or <tt>extern_weak</tt>.</p>
679
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]680<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]681 or <tt>weak_odr</tt> linkages.</p>
682
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]683</div>
684
685<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]686<h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]687 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]688</h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]689
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]690<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]691
692<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]693 and <a href="#i_invoke">invokes</a> can all have an optional calling
694 convention specified for the call. The calling convention of any pair of
695 dynamic caller/callee must match, or the behavior of the program is
696 undefined. The following calling conventions are supported by LLVM, and more
697 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]698
699<dl>
700 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]701 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]702 specified) matches the target C calling conventions. This calling
703 convention supports varargs function calls and tolerates some mismatch in
704 the declared prototype and implemented declaration of the function (as
705 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]706
707 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]708 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]709 (e.g. by passing things in registers). This calling convention allows the
710 target to use whatever tricks it wants to produce fast code for the
711 target, without having to conform to an externally specified ABI
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]712 (Application Binary Interface).
713 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]714 when this or the GHC convention is used.</a> This calling convention
715 does not support varargs and requires the prototype of all callees to
716 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]717
718 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]719 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]720 as possible under the assumption that the call is not commonly executed.
721 As such, these calls often preserve all registers so that the call does
722 not break any live ranges in the caller side. This calling convention
723 does not support varargs and requires the prototype of all callees to
724 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]725
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]726 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
727 <dd>This calling convention has been implemented specifically for use by the
728 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
729 It passes everything in registers, going to extremes to achieve this by
730 disabling callee save registers. This calling convention should not be
731 used lightly but only for specific situations such as an alternative to
732 the <em>register pinning</em> performance technique often used when
733 implementing functional programming languages.At the moment only X86
734 supports this convention and it has the following limitations:
735 <ul>
736 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
737 floating point types are supported.</li>
738 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
739 6 floating point parameters.</li>
740 </ul>
741 This calling convention supports
742 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
743 requires both the caller and callee are using it.
744 </dd>
745
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]746 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]747 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]748 target-specific calling conventions to be used. Target specific calling
749 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]750</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]751
752<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]753 support Pascal conventions or any other well-known target-independent
754 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]755
756</div>
757
758<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]759<h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]760 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]761</h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]762
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]763<div>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]764
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]765<p>All Global Variables and Functions have one of the following visibility
766 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]767
768<dl>
769 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]770 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]771 that the declaration is visible to other modules and, in shared libraries,
772 means that the declared entity may be overridden. On Darwin, default
773 visibility means that the declaration is visible to other modules. Default
774 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]775
776 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]777 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]778 object if they are in the same shared object. Usually, hidden visibility
779 indicates that the symbol will not be placed into the dynamic symbol
780 table, so no other module (executable or shared library) can reference it
781 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]782
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]783 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]784 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]785 the dynamic symbol table, but that references within the defining module
786 will bind to the local symbol. That is, the symbol cannot be overridden by
787 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]788</dl>
789
790</div>
791
792<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]793<h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]794 <a name="namedtypes">Named Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]795</h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]796
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]797<div>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]798
799<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]800 it easier to read the IR and make the IR more condensed (particularly when
801 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]802
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]803<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]804%mytype = type { %mytype*, i32 }
805</pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]806
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]807<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattner249b9762010-08-17 23:26:04 +0000[diff] [blame]808 "<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]809 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]810
811<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]812 and that you can therefore specify multiple names for the same type. This
813 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
814 uses structural typing, the name is not part of the type. When printing out
815 LLVM IR, the printer will pick <em>one name</em> to render all types of a
816 particular shape. This means that if you have code where two different
817 source types end up having the same LLVM type, that the dumper will sometimes
818 print the "wrong" or unexpected type. This is an important design point and
819 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]820
821</div>
822
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]823<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]824<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]825 <a name="globalvars">Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]826</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]827
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]828<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]829
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]830<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]831 instead of run-time. Global variables may optionally be initialized, may
832 have an explicit section to be placed in, and may have an optional explicit
833 alignment specified. A variable may be defined as "thread_local", which
834 means that it will not be shared by threads (each thread will have a
835 separated copy of the variable). A variable may be defined as a global
836 "constant," which indicates that the contents of the variable
837 will <b>never</b> be modified (enabling better optimization, allowing the
838 global data to be placed in the read-only section of an executable, etc).
839 Note that variables that need runtime initialization cannot be marked
840 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]841
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]842<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
843 constant, even if the final definition of the global is not. This capability
844 can be used to enable slightly better optimization of the program, but
845 requires the language definition to guarantee that optimizations based on the
846 'constantness' are valid for the translation units that do not include the
847 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]848
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]849<p>As SSA values, global variables define pointer values that are in scope
850 (i.e. they dominate) all basic blocks in the program. Global variables
851 always define a pointer to their "content" type because they describe a
852 region of memory, and all memory objects in LLVM are accessed through
853 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]854
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]855<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
856 that the address is not significant, only the content. Constants marked
Rafael Espindolaf1ed7812011-01-15 08:20:57 +0000[diff] [blame]857 like this can be merged with other constants if they have the same
858 initializer. Note that a constant with significant address <em>can</em>
859 be merged with a <tt>unnamed_addr</tt> constant, the result being a
860 constant whose address is significant.</p>
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]861
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]862<p>A global variable may be declared to reside in a target-specific numbered
863 address space. For targets that support them, address spaces may affect how
864 optimizations are performed and/or what target instructions are used to
865 access the variable. The default address space is zero. The address space
866 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]867
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]868<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]869 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]870
Chris Lattner78e00bc2010-04-28 00:13:42 +0000[diff] [blame]871<p>An explicit alignment may be specified for a global, which must be a power
872 of 2. If not present, or if the alignment is set to zero, the alignment of
873 the global is set by the target to whatever it feels convenient. If an
874 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner4bd85e42010-04-28 00:31:12 +0000[diff] [blame]875 alignment. Targets and optimizers are not allowed to over-align the global
876 if the global has an assigned section. In this case, the extra alignment
877 could be observable: for example, code could assume that the globals are
878 densely packed in their section and try to iterate over them as an array,
879 alignment padding would break this iteration.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]880
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]881<p>For example, the following defines a global in a numbered address space with
882 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]883
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]884<pre class="doc_code">
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]885@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]886</pre>
887
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]888</div>
889
890
891<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]892<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]893 <a name="functionstructure">Functions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]894</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]895
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]896<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]897
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]898<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]899 optional <a href="#linkage">linkage type</a>, an optional
900 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]901 <a href="#callingconv">calling convention</a>,
902 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]903 <a href="#paramattrs">parameter attribute</a> for the return type, a function
904 name, a (possibly empty) argument list (each with optional
905 <a href="#paramattrs">parameter attributes</a>), optional
906 <a href="#fnattrs">function attributes</a>, an optional section, an optional
907 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
908 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]909
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]910<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
911 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]912 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]913 <a href="#callingconv">calling convention</a>,
914 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]915 <a href="#paramattrs">parameter attribute</a> for the return type, a function
916 name, a possibly empty list of arguments, an optional alignment, and an
917 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]918
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]919<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]920 (Control Flow Graph) for the function. Each basic block may optionally start
921 with a label (giving the basic block a symbol table entry), contains a list
922 of instructions, and ends with a <a href="#terminators">terminator</a>
923 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]924
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]925<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]926 executed on entrance to the function, and it is not allowed to have
927 predecessor basic blocks (i.e. there can not be any branches to the entry
928 block of a function). Because the block can have no predecessors, it also
929 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]930
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]931<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]932 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]933
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]934<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]935 the alignment is set to zero, the alignment of the function is set by the
936 target to whatever it feels convenient. If an explicit alignment is
937 specified, the function is forced to have at least that much alignment. All
938 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]939
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]940<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
941 be significant and two identical functions can be merged</p>.
942
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]943<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]944<pre class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]945define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]946 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
947 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
948 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
949 [<a href="#gc">gc</a>] { ... }
950</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]951
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]952</div>
953
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]954<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]955<h3>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]956 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]957</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]958
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]959<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]960
961<p>Aliases act as "second name" for the aliasee value (which can be either
962 function, global variable, another alias or bitcast of global value). Aliases
963 may have an optional <a href="#linkage">linkage type</a>, and an
964 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]965
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]966<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]967<pre class="doc_code">
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]968@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]969</pre>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]970
971</div>
972
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]973<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]974<h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]975 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]976</h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]977
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]978<div>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]979
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]980<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]981 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]982 a named metadata.</p>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]983
984<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]985<pre class="doc_code">
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]986; Some unnamed metadata nodes, which are referenced by the named metadata.
987!0 = metadata !{metadata !"zero"}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]988!1 = metadata !{metadata !"one"}
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]989!2 = metadata !{metadata !"two"}
Dan Gohman58cd65f2010-07-13 19:48:13 +0000[diff] [blame]990; A named metadata.
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]991!name = !{!0, !1, !2}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]992</pre>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]993
994</div>
995
996<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]997<h3>
998 <a name="paramattrs">Parameter Attributes</a>
999</h3>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1000
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1001<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1002
1003<p>The return type and each parameter of a function type may have a set of
1004 <i>parameter attributes</i> associated with them. Parameter attributes are
1005 used to communicate additional information about the result or parameters of
1006 a function. Parameter attributes are considered to be part of the function,
1007 not of the function type, so functions with different parameter attributes
1008 can have the same function type.</p>
1009
1010<p>Parameter attributes are simple keywords that follow the type specified. If
1011 multiple parameter attributes are needed, they are space separated. For
1012 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1013
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1014<pre class="doc_code">
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]1015declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]1016declare i32 @atoi(i8 zeroext)
1017declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1018</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1019
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1020<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1021 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1022
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1023<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1024
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1025<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1026 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1027 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichac106272011-03-16 22:20:18 +0000[diff] [blame]1028 should be zero-extended to the extent required by the target's ABI (which
1029 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1030 parameter) or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1031
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1032 <dt><tt><b>signext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1033 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich341c36d2011-03-17 14:21:58 +0000[diff] [blame]1034 should be sign-extended to the extent required by the target's ABI (which
1035 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1036 return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1037
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1038 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1039 <dd>This indicates that this parameter or return value should be treated in a
1040 special target-dependent fashion during while emitting code for a function
1041 call or return (usually, by putting it in a register as opposed to memory,
1042 though some targets use it to distinguish between two different kinds of
1043 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1044
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1045 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1046 <dd><p>This indicates that the pointer parameter should really be passed by
1047 value to the function. The attribute implies that a hidden copy of the
1048 pointee
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1049 is made between the caller and the callee, so the callee is unable to
1050 modify the value in the callee. This attribute is only valid on LLVM
1051 pointer arguments. It is generally used to pass structs and arrays by
1052 value, but is also valid on pointers to scalars. The copy is considered
1053 to belong to the caller not the callee (for example,
1054 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1055 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1056 values.</p>
1057
1058 <p>The byval attribute also supports specifying an alignment with
1059 the align attribute. It indicates the alignment of the stack slot to
1060 form and the known alignment of the pointer specified to the call site. If
1061 the alignment is not specified, then the code generator makes a
1062 target-specific assumption.</p></dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1063
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1064 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1065 <dd>This indicates that the pointer parameter specifies the address of a
1066 structure that is the return value of the function in the source program.
1067 This pointer must be guaranteed by the caller to be valid: loads and
1068 stores to the structure may be assumed by the callee to not to trap. This
1069 may only be applied to the first parameter. This is not a valid attribute
1070 for return values. </dd>
1071
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1072 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1073 <dd>This indicates that pointer values
1074 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmande256292010-07-02 23:46:54 +0000[diff] [blame]1075 value do not alias pointer values which are not <i>based</i> on it,
1076 ignoring certain "irrelevant" dependencies.
1077 For a call to the parent function, dependencies between memory
1078 references from before or after the call and from those during the call
1079 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1080 return value used in that call.
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1081 The caller shares the responsibility with the callee for ensuring that
1082 these requirements are met.
1083 For further details, please see the discussion of the NoAlias response in
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1084 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1085<br>
John McCall72ed8902010-07-06 21:07:14 +0000[diff] [blame]1086 Note that this definition of <tt>noalias</tt> is intentionally
1087 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner5eff9ca2010-07-06 20:51:35 +0000[diff] [blame]1088 arguments, though it is slightly weaker.
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1089<br>
1090 For function return values, C99's <tt>restrict</tt> is not meaningful,
1091 while LLVM's <tt>noalias</tt> is.
1092 </dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1093
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1094 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1095 <dd>This indicates that the callee does not make any copies of the pointer
1096 that outlive the callee itself. This is not a valid attribute for return
1097 values.</dd>
1098
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1099 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1100 <dd>This indicates that the pointer parameter can be excised using the
1101 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1102 attribute for return values.</dd>
1103</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1104
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1105</div>
1106
1107<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1108<h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1109 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1110</h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1111
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1112<div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1113
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1114<p>Each function may specify a garbage collector name, which is simply a
1115 string:</p>
1116
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1117<pre class="doc_code">
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1118define void @f() gc "name" { ... }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1119</pre>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1120
1121<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1122 collector which will cause the compiler to alter its output in order to
1123 support the named garbage collection algorithm.</p>
1124
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1125</div>
1126
1127<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1128<h3>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1129 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1130</h3>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1131
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1132<div>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1133
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1134<p>Function attributes are set to communicate additional information about a
1135 function. Function attributes are considered to be part of the function, not
1136 of the function type, so functions with different parameter attributes can
1137 have the same function type.</p>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1138
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1139<p>Function attributes are simple keywords that follow the type specified. If
1140 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1141
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1142<pre class="doc_code">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1143define void @f() noinline { ... }
1144define void @f() alwaysinline { ... }
1145define void @f() alwaysinline optsize { ... }
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1146define void @f() optsize { ... }
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1147</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1148
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1149<dl>
Charles Davisbe5557e2010-02-12 00:31:15 +0000[diff] [blame]1150 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1151 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1152 the backend should forcibly align the stack pointer. Specify the
1153 desired alignment, which must be a power of two, in parentheses.
1154
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1155 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1156 <dd>This attribute indicates that the inliner should attempt to inline this
1157 function into callers whenever possible, ignoring any active inlining size
1158 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1159
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1160 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis1b2d3722010-10-25 16:29:03 +0000[diff] [blame]1161 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis74205252010-10-25 19:07:39 +0000[diff] [blame]1162 meaning the function can be patched and/or hooked even while it is
1163 loaded into memory. On x86, the function prologue will be preceded
1164 by six bytes of padding and will begin with a two-byte instruction.
1165 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1166 higher were compiled in this fashion.</dd>
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1167
Dan Gohman8bd11f12011-06-16 16:03:13 +0000[diff] [blame]1168 <dt><tt><b>nonlazybind</b></tt></dt>
1169 <dd>This attribute suppresses lazy symbol binding for the function. This
1170 may make calls to the function faster, at the cost of extra program
1171 startup time if the function is not called during program startup.</dd>
1172
Jakob Stoklund Olesen74bb06c2010-02-06 01:16:28 +0000[diff] [blame]1173 <dt><tt><b>inlinehint</b></tt></dt>
1174 <dd>This attribute indicates that the source code contained a hint that inlining
1175 this function is desirable (such as the "inline" keyword in C/C++). It
1176 is just a hint; it imposes no requirements on the inliner.</dd>
1177
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1178 <dt><tt><b>naked</b></tt></dt>
1179 <dd>This attribute disables prologue / epilogue emission for the function.
1180 This can have very system-specific consequences.</dd>
1181
1182 <dt><tt><b>noimplicitfloat</b></tt></dt>
1183 <dd>This attributes disables implicit floating point instructions.</dd>
1184
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1185 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1186 <dd>This attribute indicates that the inliner should never inline this
1187 function in any situation. This attribute may not be used together with
1188 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1189
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1190 <dt><tt><b>noredzone</b></tt></dt>
1191 <dd>This attribute indicates that the code generator should not use a red
1192 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1193
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1194 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1195 <dd>This function attribute indicates that the function never returns
1196 normally. This produces undefined behavior at runtime if the function
1197 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1198
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1199 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1200 <dd>This function attribute indicates that the function never returns with an
1201 unwind or exceptional control flow. If the function does unwind, its
1202 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1203
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1204 <dt><tt><b>optsize</b></tt></dt>
1205 <dd>This attribute suggests that optimization passes and code generator passes
1206 make choices that keep the code size of this function low, and otherwise
1207 do optimizations specifically to reduce code size.</dd>
1208
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1209 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1210 <dd>This attribute indicates that the function computes its result (or decides
1211 to unwind an exception) based strictly on its arguments, without
1212 dereferencing any pointer arguments or otherwise accessing any mutable
1213 state (e.g. memory, control registers, etc) visible to caller functions.
1214 It does not write through any pointer arguments
1215 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1216 changes any state visible to callers. This means that it cannot unwind
1217 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1218 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1219
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1220 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1221 <dd>This attribute indicates that the function does not write through any
1222 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1223 arguments) or otherwise modify any state (e.g. memory, control registers,
1224 etc) visible to caller functions. It may dereference pointer arguments
1225 and read state that may be set in the caller. A readonly function always
1226 returns the same value (or unwinds an exception identically) when called
1227 with the same set of arguments and global state. It cannot unwind an
1228 exception by calling the <tt>C++</tt> exception throwing methods, but may
1229 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1230
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1231 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1232 <dd>This attribute indicates that the function should emit a stack smashing
1233 protector. It is in the form of a "canary"&mdash;a random value placed on
1234 the stack before the local variables that's checked upon return from the
1235 function to see if it has been overwritten. A heuristic is used to
1236 determine if a function needs stack protectors or not.<br>
1237<br>
1238 If a function that has an <tt>ssp</tt> attribute is inlined into a
1239 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1240 function will have an <tt>ssp</tt> attribute.</dd>
1241
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1242 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1243 <dd>This attribute indicates that the function should <em>always</em> emit a
1244 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1245 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1246<br>
1247 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1248 function that doesn't have an <tt>sspreq</tt> attribute or which has
1249 an <tt>ssp</tt> attribute, then the resulting function will have
1250 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1251</dl>
1252
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1253</div>
1254
1255<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1256<h3>
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1257 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1258</h3>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1259
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1260<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1261
1262<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1263 the GCC "file scope inline asm" blocks. These blocks are internally
1264 concatenated by LLVM and treated as a single unit, but may be separated in
1265 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1266
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1267<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1268module asm "inline asm code goes here"
1269module asm "more can go here"
1270</pre>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1271
1272<p>The strings can contain any character by escaping non-printable characters.
1273 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]1274 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1275
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1276<p>The inline asm code is simply printed to the machine code .s file when
1277 assembly code is generated.</p>
1278
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1279</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1280
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1281<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1282<h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1283 <a name="datalayout">Data Layout</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1284</h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1285
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1286<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1287
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1288<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1289 data is to be laid out in memory. The syntax for the data layout is
1290 simply:</p>
1291
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1292<pre class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1293target datalayout = "<i>layout specification</i>"
1294</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1295
1296<p>The <i>layout specification</i> consists of a list of specifications
1297 separated by the minus sign character ('-'). Each specification starts with
1298 a letter and may include other information after the letter to define some
1299 aspect of the data layout. The specifications accepted are as follows:</p>
1300
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1301<dl>
1302 <dt><tt>E</tt></dt>
1303 <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]1304 bits with the most significance have the lowest address location.</dd>
1305
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1306 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1307 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1308 the bits with the least significance have the lowest address
1309 location.</dd>
1310
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1311 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1312 <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]1313 <i>preferred</i> alignments. All sizes are in bits. Specifying
1314 the <i>pref</i> alignment is optional. If omitted, the
1315 preceding <tt>:</tt> should be omitted too.</dd>
1316
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1317 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1318 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1319 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1320
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1321 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1322 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1323 <i>size</i>.</dd>
1324
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1325 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1326 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesence522852010-05-28 18:54:47 +0000[diff] [blame]1327 <i>size</i>. Only values of <i>size</i> that are supported by the target
1328 will work. 32 (float) and 64 (double) are supported on all targets;
1329 80 or 128 (different flavors of long double) are also supported on some
1330 targets.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1331
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1332 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1333 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1334 <i>size</i>.</dd>
1335
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1336 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1337 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1338 <i>size</i>.</dd>
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1339
1340 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1341 <dd>This specifies a set of native integer widths for the target CPU
1342 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1343 "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]1344 this set are considered to support most general arithmetic
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1345 operations efficiently.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1346</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1347
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1348<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]1349 default set of specifications which are then (possibly) overridden by the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1350 specifications in the <tt>datalayout</tt> keyword. The default specifications
1351 are given in this list:</p>
1352
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1353<ul>
1354 <li><tt>E</tt> - big endian</li>
Dan Gohman8ad777d2010-02-23 02:44:03 +0000[diff] [blame]1355 <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]1356 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1357 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1358 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1359 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1360 <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]1361 alignment of 64-bits</li>
1362 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1363 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1364 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1365 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1366 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1367 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1368</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1369
1370<p>When LLVM is determining the alignment for a given type, it uses the
1371 following rules:</p>
1372
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1373<ol>
1374 <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]1375 specification is used.</li>
1376
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1377 <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]1378 smallest integer type that is larger than the bitwidth of the sought type
1379 is used. If none of the specifications are larger than the bitwidth then
1380 the the largest integer type is used. For example, given the default
1381 specifications above, the i7 type will use the alignment of i8 (next
1382 largest) while both i65 and i256 will use the alignment of i64 (largest
1383 specified).</li>
1384
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1385 <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]1386 largest vector type that is smaller than the sought vector type will be
1387 used as a fall back. This happens because &lt;128 x double&gt; can be
1388 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1389</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1390
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1391</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1392
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1393<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1394<h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1395 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1396</h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1397
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1398<div>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1399
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1400<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1401with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1402is undefined. Pointer values are associated with address ranges
1403according to the following rules:</p>
1404
1405<ul>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1406 <li>A pointer value is associated with the addresses associated with
1407 any value it is <i>based</i> on.
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1408 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1409 range of the variable's storage.</li>
1410 <li>The result value of an allocation instruction is associated with
1411 the address range of the allocated storage.</li>
1412 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1413 no address.</li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1414 <li>An integer constant other than zero or a pointer value returned
1415 from a function not defined within LLVM may be associated with address
1416 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1417 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1418 allocated by mechanisms provided by LLVM.</li>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1419</ul>
1420
1421<p>A pointer value is <i>based</i> on another pointer value according
1422 to the following rules:</p>
1423
1424<ul>
1425 <li>A pointer value formed from a
1426 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1427 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1428 <li>The result value of a
1429 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1430 of the <tt>bitcast</tt>.</li>
1431 <li>A pointer value formed by an
1432 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1433 pointer values that contribute (directly or indirectly) to the
1434 computation of the pointer's value.</li>
1435 <li>The "<i>based</i> on" relationship is transitive.</li>
1436</ul>
1437
1438<p>Note that this definition of <i>"based"</i> is intentionally
1439 similar to the definition of <i>"based"</i> in C99, though it is
1440 slightly weaker.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1441
1442<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1443<tt><a href="#i_load">load</a></tt> merely indicates the size and
1444alignment of the memory from which to load, as well as the
Dan Gohman4eb47192010-06-17 19:23:50 +0000[diff] [blame]1445interpretation of the value. The first operand type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1446<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1447and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1448
1449<p>Consequently, type-based alias analysis, aka TBAA, aka
1450<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1451LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1452additional information which specialized optimization passes may use
1453to implement type-based alias analysis.</p>
1454
1455</div>
1456
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1457<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1458<h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1459 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1460</h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1461
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1462<div>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1463
1464<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1465href="#i_store"><tt>store</tt></a>s, and <a
1466href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1467The optimizers must not change the number of volatile operations or change their
1468order of execution relative to other volatile operations. The optimizers
1469<i>may</i> change the order of volatile operations relative to non-volatile
1470operations. This is not Java's "volatile" and has no cross-thread
1471synchronization behavior.</p>
1472
1473</div>
1474
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1475</div>
1476
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1477<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1478<h2><a name="typesystem">Type System</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1479<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1480
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1481<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1482
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1483<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1484 intermediate representation. Being typed enables a number of optimizations
1485 to be performed on the intermediate representation directly, without having
1486 to do extra analyses on the side before the transformation. A strong type
1487 system makes it easier to read the generated code and enables novel analyses
1488 and transformations that are not feasible to perform on normal three address
1489 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1490
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1491<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1492<h3>
1493 <a name="t_classifications">Type Classifications</a>
1494</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1495
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1496<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1497
1498<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1499
1500<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1501 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1502 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1503 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1504 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1505 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1506 </tr>
1507 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1508 <td><a href="#t_floating">floating point</a></td>
1509 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1510 </tr>
1511 <tr>
1512 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1513 <td><a href="#t_integer">integer</a>,
1514 <a href="#t_floating">floating point</a>,
1515 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1516 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1517 <a href="#t_struct">structure</a>,
1518 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1519 <a href="#t_label">label</a>,
1520 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1521 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1522 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1523 <tr>
1524 <td><a href="#t_primitive">primitive</a></td>
1525 <td><a href="#t_label">label</a>,
1526 <a href="#t_void">void</a>,
Tobias Grosser4c8c95b2010-12-28 20:29:31 +0000[diff] [blame]1527 <a href="#t_integer">integer</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1528 <a href="#t_floating">floating point</a>,
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1529 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1530 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1531 </tr>
1532 <tr>
1533 <td><a href="#t_derived">derived</a></td>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1534 <td><a href="#t_array">array</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1535 <a href="#t_function">function</a>,
1536 <a href="#t_pointer">pointer</a>,
1537 <a href="#t_struct">structure</a>,
1538 <a href="#t_pstruct">packed structure</a>,
1539 <a href="#t_vector">vector</a>,
1540 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1541 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1542 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1543 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1544</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1545
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1546<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1547 important. Values of these types are the only ones which can be produced by
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1548 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1549
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1550</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1551
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1552<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1553<h3>
1554 <a name="t_primitive">Primitive Types</a>
1555</h3>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1556
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1557<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1558
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1559<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1560 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1561
1562<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1563<h4>
1564 <a name="t_integer">Integer Type</a>
1565</h4>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1566
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1567<div>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1568
1569<h5>Overview:</h5>
1570<p>The integer type is a very simple type that simply specifies an arbitrary
1571 bit width for the integer type desired. Any bit width from 1 bit to
1572 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1573
1574<h5>Syntax:</h5>
1575<pre>
1576 iN
1577</pre>
1578
1579<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1580 value.</p>
1581
1582<h5>Examples:</h5>
1583<table class="layout">
1584 <tr class="layout">
1585 <td class="left"><tt>i1</tt></td>
1586 <td class="left">a single-bit integer.</td>
1587 </tr>
1588 <tr class="layout">
1589 <td class="left"><tt>i32</tt></td>
1590 <td class="left">a 32-bit integer.</td>
1591 </tr>
1592 <tr class="layout">
1593 <td class="left"><tt>i1942652</tt></td>
1594 <td class="left">a really big integer of over 1 million bits.</td>
1595 </tr>
1596</table>
1597
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1598</div>
1599
1600<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1601<h4>
1602 <a name="t_floating">Floating Point Types</a>
1603</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1604
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1605<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1606
1607<table>
1608 <tbody>
1609 <tr><th>Type</th><th>Description</th></tr>
1610 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1611 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1612 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1613 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1614 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1615 </tbody>
1616</table>
1617
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1618</div>
1619
1620<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1621<h4>
1622 <a name="t_x86mmx">X86mmx Type</a>
1623</h4>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1624
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1625<div>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1626
1627<h5>Overview:</h5>
1628<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>
1629
1630<h5>Syntax:</h5>
1631<pre>
Dale Johannesenb1f0ff12010-10-01 01:07:02 +0000[diff] [blame]1632 x86mmx
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1633</pre>
1634
1635</div>
1636
1637<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1638<h4>
1639 <a name="t_void">Void Type</a>
1640</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1641
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1642<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1643
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1644<h5>Overview:</h5>
1645<p>The void type does not represent any value and has no size.</p>
1646
1647<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1648<pre>
1649 void
1650</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1651
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1652</div>
1653
1654<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1655<h4>
1656 <a name="t_label">Label Type</a>
1657</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1658
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1659<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1660
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1661<h5>Overview:</h5>
1662<p>The label type represents code labels.</p>
1663
1664<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1665<pre>
1666 label
1667</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1668
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1669</div>
1670
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1671<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1672<h4>
1673 <a name="t_metadata">Metadata Type</a>
1674</h4>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1675
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1676<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1677
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1678<h5>Overview:</h5>
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1679<p>The metadata type represents embedded metadata. No derived types may be
1680 created from metadata except for <a href="#t_function">function</a>
1681 arguments.
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1682
1683<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1684<pre>
1685 metadata
1686</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1687
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1688</div>
1689
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1690</div>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1691
1692<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1693<h3>
1694 <a name="t_derived">Derived Types</a>
1695</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1696
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1697<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1698
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1699<p>The real power in LLVM comes from the derived types in the system. This is
1700 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1701 useful types. Each of these types contain one or more element types which
1702 may be a primitive type, or another derived type. For example, it is
1703 possible to have a two dimensional array, using an array as the element type
1704 of another array.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1705
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1706
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1707<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1708<h4>
1709 <a name="t_aggregate">Aggregate Types</a>
1710</h4>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1711
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1712<div>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1713
1714<p>Aggregate Types are a subset of derived types that can contain multiple
1715 member types. <a href="#t_array">Arrays</a>,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]1716 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1717 aggregate types.</p>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1718
1719</div>
1720
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1721<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1722<h4>
1723 <a name="t_array">Array Type</a>
1724</h4>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1725
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1726<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1727
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1728<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1729<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1730 sequentially in memory. The array type requires a size (number of elements)
1731 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1732
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1733<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1734<pre>
1735 [&lt;# elements&gt; x &lt;elementtype&gt;]
1736</pre>
1737
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1738<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1739 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1740
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1741<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1742<table class="layout">
1743 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1744 <td class="left"><tt>[40 x i32]</tt></td>
1745 <td class="left">Array of 40 32-bit integer values.</td>
1746 </tr>
1747 <tr class="layout">
1748 <td class="left"><tt>[41 x i32]</tt></td>
1749 <td class="left">Array of 41 32-bit integer values.</td>
1750 </tr>
1751 <tr class="layout">
1752 <td class="left"><tt>[4 x i8]</tt></td>
1753 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1754 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1755</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1756<p>Here are some examples of multidimensional arrays:</p>
1757<table class="layout">
1758 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1759 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1760 <td class="left">3x4 array of 32-bit integer values.</td>
1761 </tr>
1762 <tr class="layout">
1763 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1764 <td class="left">12x10 array of single precision floating point values.</td>
1765 </tr>
1766 <tr class="layout">
1767 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1768 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1769 </tr>
1770</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1771
Dan Gohmanc74bc282009-11-09 19:01:53 +0000[diff] [blame]1772<p>There is no restriction on indexing beyond the end of the array implied by
1773 a static type (though there are restrictions on indexing beyond the bounds
1774 of an allocated object in some cases). This means that single-dimension
1775 'variable sized array' addressing can be implemented in LLVM with a zero
1776 length array type. An implementation of 'pascal style arrays' in LLVM could
1777 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1778
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1779</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1780
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1781<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1782<h4>
1783 <a name="t_function">Function Type</a>
1784</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1785
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1786<div>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1787
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1788<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1789<p>The function type can be thought of as a function signature. It consists of
1790 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]1791 function type is a first class type or a void type.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1792
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1793<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1794<pre>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1795 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1796</pre>
1797
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1798<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]1799 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1800 which indicates that the function takes a variable number of arguments.
1801 Variable argument functions can access their arguments with
1802 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1803 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1804 <a href="#t_label">label</a>.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1805
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1806<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1807<table class="layout">
1808 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1809 <td class="left"><tt>i32 (i32)</tt></td>
1810 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1811 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1812 </tr><tr class="layout">
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1813 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1814 </tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1815 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1816 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1817 returning <tt>float</tt>.
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1818 </td>
1819 </tr><tr class="layout">
1820 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1821 <td class="left">A vararg function that takes at least one
1822 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1823 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1824 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1825 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1826 </tr><tr class="layout">
1827 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1828 <td class="left">A function taking an <tt>i32</tt>, returning a
1829 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1830 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1831 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1832</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1833
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1834</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1835
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1836<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1837<h4>
1838 <a name="t_struct">Structure Type</a>
1839</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1840
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1841<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1842
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1843<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1844<p>The structure type is used to represent a collection of data members together
1845 in memory. The packing of the field types is defined to match the ABI of the
1846 underlying processor. The elements of a structure may be any type that has a
1847 size.</p>
1848
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]1849<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1850 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1851 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1852 Structures in registers are accessed using the
1853 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1854 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1855<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1856<pre>
1857 { &lt;type list&gt; }
1858</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1859
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1860<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1861<table class="layout">
1862 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1863 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1864 <td class="left">A triple of three <tt>i32</tt> values</td>
1865 </tr><tr class="layout">
1866 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1867 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1868 second element is a <a href="#t_pointer">pointer</a> to a
1869 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1870 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1871 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1872</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1873
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1874</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1875
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1876<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1877<h4>
1878 <a name="t_pstruct">Packed Structure Type</a>
1879</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1880
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1881<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1882
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1883<h5>Overview:</h5>
1884<p>The packed structure type is used to represent a collection of data members
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1885 together in memory. There is no padding between fields. Further, the
1886 alignment of a packed structure is 1 byte. The elements of a packed
1887 structure may be any type that has a size.</p>
1888
1889<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1890 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1891 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1892
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1893<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1894<pre>
1895 &lt; { &lt;type list&gt; } &gt;
1896</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1897
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1898<h5>Examples:</h5>
1899<table class="layout">
1900 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1901 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1902 <td class="left">A triple of three <tt>i32</tt> values</td>
1903 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1904 <td class="left">
1905<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1906 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1907 second element is a <a href="#t_pointer">pointer</a> to a
1908 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1909 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1910 </tr>
1911</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1912
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1913</div>
1914
1915<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1916<h4>
1917 <a name="t_pointer">Pointer Type</a>
1918</h4>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1919
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1920<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1921
1922<h5>Overview:</h5>
Dan Gohman88481112010-02-25 16:50:07 +0000[diff] [blame]1923<p>The pointer type is used to specify memory locations.
1924 Pointers are commonly used to reference objects in memory.</p>
1925
1926<p>Pointer types may have an optional address space attribute defining the
1927 numbered address space where the pointed-to object resides. The default
1928 address space is number zero. The semantics of non-zero address
1929 spaces are target-specific.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1930
1931<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1932 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1933
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1934<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1935<pre>
1936 &lt;type&gt; *
1937</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1938
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1939<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1940<table class="layout">
1941 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]1942 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1943 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1944 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1945 </tr>
1946 <tr class="layout">
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]1947 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1948 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1949 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1950 <tt>i32</tt>.</td>
1951 </tr>
1952 <tr class="layout">
1953 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1954 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1955 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1956 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1957</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1958
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1959</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1960
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1961<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1962<h4>
1963 <a name="t_vector">Vector Type</a>
1964</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1965
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1966<div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1967
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1968<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1969<p>A vector type is a simple derived type that represents a vector of elements.
1970 Vector types are used when multiple primitive data are operated in parallel
1971 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sands31c0e0e2009-11-27 13:38:03 +0000[diff] [blame]1972 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1973 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1974
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1975<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1976<pre>
1977 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1978</pre>
1979
Chris Lattnerf11031a2010-10-10 18:20:35 +0000[diff] [blame]1980<p>The number of elements is a constant integer value larger than 0; elementtype
1981 may be any integer or floating point type. Vectors of size zero are not
1982 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1983
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1984<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1985<table class="layout">
1986 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1987 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1988 <td class="left">Vector of 4 32-bit integer values.</td>
1989 </tr>
1990 <tr class="layout">
1991 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1992 <td class="left">Vector of 8 32-bit floating-point values.</td>
1993 </tr>
1994 <tr class="layout">
1995 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1996 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1997 </tr>
1998</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1999
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2000</div>
2001
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2002<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2003<h4>
2004 <a name="t_opaque">Opaque Type</a>
2005</h4>
2006
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2007<div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2008
2009<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2010<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2011 corresponds (for example) to the C notion of a forward declared structure
2012 type. In LLVM, opaque types can eventually be resolved to any type (not just
2013 a structure type).</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2014
2015<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2016<pre>
2017 opaque
2018</pre>
2019
2020<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2021<table class="layout">
2022 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]2023 <td class="left"><tt>opaque</tt></td>
2024 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2025 </tr>
2026</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2027
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2028</div>
2029
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2030</div>
2031
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2032<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2033<h3>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2034 <a name="t_uprefs">Type Up-references</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2035</h3>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2036
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2037<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2038
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2039<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2040<p>An "up reference" allows you to refer to a lexically enclosing type without
2041 requiring it to have a name. For instance, a structure declaration may
2042 contain a pointer to any of the types it is lexically a member of. Example
2043 of up references (with their equivalent as named type declarations)
2044 include:</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2045
2046<pre>
Chris Lattnerbf1d5452009-02-09 10:00:56 +0000[diff] [blame]2047 { \2 * } %x = type { %x* }
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2048 { \2 }* %y = type { %y }*
2049 \1* %z = type %z*
2050</pre>
2051
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2052<p>An up reference is needed by the asmprinter for printing out cyclic types
2053 when there is no declared name for a type in the cycle. Because the
2054 asmprinter does not want to print out an infinite type string, it needs a
2055 syntax to handle recursive types that have no names (all names are optional
2056 in llvm IR).</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2057
2058<h5>Syntax:</h5>
2059<pre>
2060 \&lt;level&gt;
2061</pre>
2062
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2063<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]2064
2065<h5>Examples:</h5>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2066<table class="layout">
2067 <tr class="layout">
2068 <td class="left"><tt>\1*</tt></td>
2069 <td class="left">Self-referential pointer.</td>
2070 </tr>
2071 <tr class="layout">
2072 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
2073 <td class="left">Recursive structure where the upref refers to the out-most
2074 structure.</td>
2075 </tr>
2076</table>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]2077
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2078</div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]2079
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2080</div>
2081
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2082<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2083<h2><a name="constants">Constants</a></h2>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2084<!-- *********************************************************************** -->
2085
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2086<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2087
2088<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2089 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2090
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2091<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2092<h3>
2093 <a name="simpleconstants">Simple Constants</a>
2094</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2095
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2096<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2097
2098<dl>
2099 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2100 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]2101 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2102
2103 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2104 <dd>Standard integers (such as '4') are constants of
2105 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2106 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2107
2108 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2109 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2110 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2111 notation (see below). The assembler requires the exact decimal value of a
2112 floating-point constant. For example, the assembler accepts 1.25 but
2113 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2114 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2115
2116 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2117 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2118 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2119</dl>
2120
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2121<p>The one non-intuitive notation for constants is the hexadecimal form of
2122 floating point constants. For example, the form '<tt>double
2123 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2124 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2125 constants are required (and the only time that they are generated by the
2126 disassembler) is when a floating point constant must be emitted but it cannot
2127 be represented as a decimal floating point number in a reasonable number of
2128 digits. For example, NaN's, infinities, and other special values are
2129 represented in their IEEE hexadecimal format so that assembly and disassembly
2130 do not cause any bits to change in the constants.</p>
2131
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]2132<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2133 represented using the 16-digit form shown above (which matches the IEEE754
2134 representation for double); float values must, however, be exactly
2135 representable as IEE754 single precision. Hexadecimal format is always used
2136 for long double, and there are three forms of long double. The 80-bit format
2137 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2138 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2139 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2140 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2141 currently supported target uses this format. Long doubles will only work if
2142 they match the long double format on your target. All hexadecimal formats
2143 are big-endian (sign bit at the left).</p>
2144
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]2145<p>There are no constants of type x86mmx.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2146</div>
2147
2148<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2149<h3>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2150<a name="aggregateconstants"></a> <!-- old anchor -->
2151<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2152</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2153
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2154<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2155
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2156<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2157 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2158
2159<dl>
2160 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2161 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2162 type definitions (a comma separated list of elements, surrounded by braces
2163 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2164 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2165 Structure constants must have <a href="#t_struct">structure type</a>, and
2166 the number and types of elements must match those specified by the
2167 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2168
2169 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2170 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2171 definitions (a comma separated list of elements, surrounded by square
2172 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2173 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2174 the number and types of elements must match those specified by the
2175 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2176
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2177 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2178 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2179 definitions (a comma separated list of elements, surrounded by
2180 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2181 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2182 have <a href="#t_vector">vector type</a>, and the number and types of
2183 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2184
2185 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2186 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2187 value to zero of <em>any</em> type, including scalar and
2188 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2189 This is often used to avoid having to print large zero initializers
2190 (e.g. for large arrays) and is always exactly equivalent to using explicit
2191 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2192
2193 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]2194 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2195 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2196 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2197 be interpreted as part of the instruction stream, metadata is a place to
2198 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2199</dl>
2200
2201</div>
2202
2203<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2204<h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2205 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2206</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2207
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2208<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2209
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2210<p>The addresses of <a href="#globalvars">global variables</a>
2211 and <a href="#functionstructure">functions</a> are always implicitly valid
2212 (link-time) constants. These constants are explicitly referenced when
2213 the <a href="#identifiers">identifier for the global</a> is used and always
2214 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2215 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2216
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2217<pre class="doc_code">
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]2218@X = global i32 17
2219@Y = global i32 42
2220@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2221</pre>
2222
2223</div>
2224
2225<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2226<h3>
2227 <a name="undefvalues">Undefined Values</a>
2228</h3>
2229
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2230<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2231
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2232<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]2233 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2234 Undefined values may be of any type (other than '<tt>label</tt>'
2235 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2236
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2237<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2238 program is well defined no matter what value is used. This gives the
2239 compiler more freedom to optimize. Here are some examples of (potentially
2240 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2241
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2242
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2243<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2244 %A = add %X, undef
2245 %B = sub %X, undef
2246 %C = xor %X, undef
2247Safe:
2248 %A = undef
2249 %B = undef
2250 %C = undef
2251</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2252
2253<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]2254 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]2255
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2256<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2257 %A = or %X, undef
2258 %B = and %X, undef
2259Safe:
2260 %A = -1
2261 %B = 0
2262Unsafe:
2263 %A = undef
2264 %B = undef
2265</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2266
2267<p>These logical operations have bits that are not always affected by the input.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2268 For example, if <tt>%X</tt> has a zero bit, then the output of the
2269 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2270 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2271 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2272 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2273 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2274 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2275 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2276
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2277<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2278 %A = select undef, %X, %Y
2279 %B = select undef, 42, %Y
2280 %C = select %X, %Y, undef
2281Safe:
2282 %A = %X (or %Y)
2283 %B = 42 (or %Y)
2284 %C = %Y
2285Unsafe:
2286 %A = undef
2287 %B = undef
2288 %C = undef
2289</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2290
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2291<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2292 branch) conditions can go <em>either way</em>, but they have to come from one
2293 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2294 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2295 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2296 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2297 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2298 eliminated.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2299
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2300<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2301 %A = xor undef, undef
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2302
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2303 %B = undef
2304 %C = xor %B, %B
2305
2306 %D = undef
2307 %E = icmp lt %D, 4
2308 %F = icmp gte %D, 4
2309
2310Safe:
2311 %A = undef
2312 %B = undef
2313 %C = undef
2314 %D = undef
2315 %E = undef
2316 %F = undef
2317</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2318
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2319<p>This example points out that two '<tt>undef</tt>' operands are not
2320 necessarily the same. This can be surprising to people (and also matches C
2321 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2322 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2323 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2324 its value over its "live range". This is true because the variable doesn't
2325 actually <em>have a live range</em>. Instead, the value is logically read
2326 from arbitrary registers that happen to be around when needed, so the value
2327 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2328 need to have the same semantics or the core LLVM "replace all uses with"
2329 concept would not hold.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2330
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2331<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2332 %A = fdiv undef, %X
2333 %B = fdiv %X, undef
2334Safe:
2335 %A = undef
2336b: unreachable
2337</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2338
2339<p>These examples show the crucial difference between an <em>undefined
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2340 value</em> and <em>undefined behavior</em>. An undefined value (like
2341 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2342 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2343 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2344 defined on SNaN's. However, in the second example, we can make a more
2345 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2346 arbitrary value, we are allowed to assume that it could be zero. Since a
2347 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2348 the operation does not execute at all. This allows us to delete the divide and
2349 all code after it. Because the undefined operation "can't happen", the
2350 optimizer can assume that it occurs in dead code.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2351
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2352<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2353a: store undef -> %X
2354b: store %X -> undef
2355Safe:
2356a: &lt;deleted&gt;
2357b: unreachable
2358</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2359
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2360<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2361 undefined value can be assumed to not have any effect; we can assume that the
2362 value is overwritten with bits that happen to match what was already there.
2363 However, a store <em>to</em> an undefined location could clobber arbitrary
2364 memory, therefore, it has undefined behavior.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2365
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2366</div>
2367
2368<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2369<h3>
2370 <a name="trapvalues">Trap Values</a>
2371</h3>
2372
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2373<div>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2374
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2375<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2376 instead of representing an unspecified bit pattern, they represent the
2377 fact that an instruction or constant expression which cannot evoke side
2378 effects has nevertheless detected a condition which results in undefined
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2379 behavior.</p>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2380
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2381<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]2382 only exist when produced by operations such as
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2383 <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]2384
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2385<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2386
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2387<ul>
2388<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2389 their operands.</li>
2390
2391<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2392 to their dynamic predecessor basic block.</li>
2393
2394<li>Function arguments depend on the corresponding actual argument values in
2395 the dynamic callers of their functions.</li>
2396
2397<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2398 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2399 control back to them.</li>
2400
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2401<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2402 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2403 or exception-throwing call instructions that dynamically transfer control
2404 back to them.</li>
2405
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2406<li>Non-volatile loads and stores depend on the most recent stores to all of the
2407 referenced memory addresses, following the order in the IR
2408 (including loads and stores implied by intrinsics such as
2409 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2410
Dan Gohman3513ea52010-05-03 14:59:34 +0000[diff] [blame]2411<!-- TODO: In the case of multiple threads, this only applies if the store
2412 "happens-before" the load or store. -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2413
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2414<!-- TODO: floating-point exception state -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2415
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2416<li>An instruction with externally visible side effects depends on the most
2417 recent preceding instruction with externally visible side effects, following
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]2418 the order in the IR. (This includes
2419 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2420
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2421<li>An instruction <i>control-depends</i> on a
2422 <a href="#terminators">terminator instruction</a>
2423 if the terminator instruction has multiple successors and the instruction
2424 is always executed when control transfers to one of the successors, and
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2425 may not be executed when control is transferred to another.</li>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2426
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2427<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2428 instruction if the set of instructions it otherwise depends on would be
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2429 different if the terminator had transferred control to a different
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2430 successor.</li>
2431
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2432<li>Dependence is transitive.</li>
2433
2434</ul>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2435
2436<p>Whenever a trap value is generated, all values which depend on it evaluate
2437 to trap. If they have side effects, the evoke their side effects as if each
2438 operand with a trap value were undef. If they have externally-visible side
2439 effects, the behavior is undefined.</p>
2440
2441<p>Here are some examples:</p>
Dan Gohman48a25882010-04-26 20:54:53 +0000[diff] [blame]2442
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2443<pre class="doc_code">
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2444entry:
2445 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2446 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2447 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2448 store i32 0, i32* %trap_yet_again ; undefined behavior
2449
2450 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2451 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2452
2453 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2454
2455 %narrowaddr = bitcast i32* @g to i16*
2456 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2457 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2458 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2459
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2460 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2461 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2462
2463true:
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2464 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2465 ; it has undefined behavior.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2466 br label %end
2467
2468end:
2469 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2470 ; Both edges into this PHI are
2471 ; control-dependent on %cmp, so this
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2472 ; always results in a trap value.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2473
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2474 volatile store i32 0, i32* @g ; This would depend on the store in %true
2475 ; if %cmp is true, or the store in %entry
2476 ; otherwise, so this is undefined behavior.
2477
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2478 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2479 ; The same branch again, but this time the
2480 ; true block doesn't have side effects.
2481
2482second_true:
2483 ; No side effects!
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2484 ret void
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2485
2486second_end:
2487 volatile store i32 0, i32* @g ; This time, the instruction always depends
2488 ; on the store in %end. Also, it is
2489 ; control-equivalent to %end, so this is
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2490 ; well-defined (again, ignoring earlier
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2491 ; undefined behavior in this example).
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2492</pre>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2493
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2494</div>
2495
2496<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2497<h3>
2498 <a name="blockaddress">Addresses of Basic Blocks</a>
2499</h3>
2500
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2501<div>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2502
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2503<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2504
2505<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner5c5f0ac2009-10-27 21:49:40 +0000[diff] [blame]2506 basic block in the specified function, and always has an i8* type. Taking
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2507 the address of the entry block is illegal.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2508
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2509<p>This value only has defined behavior when used as an operand to the
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2510 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2511 comparisons against null. Pointer equality tests between labels addresses
2512 results in undefined behavior &mdash; though, again, comparison against null
2513 is ok, and no label is equal to the null pointer. This may be passed around
2514 as an opaque pointer sized value as long as the bits are not inspected. This
2515 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2516 long as the original value is reconstituted before the <tt>indirectbr</tt>
2517 instruction.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2518
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2519<p>Finally, some targets may provide defined semantics when using the value as
2520 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2521
2522</div>
2523
2524
2525<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2526<h3>
2527 <a name="constantexprs">Constant Expressions</a>
2528</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2529
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2530<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2531
2532<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2533 to be used as constants. Constant expressions may be of
2534 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2535 operation that does not have side effects (e.g. load and call are not
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2536 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2537
2538<dl>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2539 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2540 <dd>Truncate a constant to another type. The bit size of CST must be larger
2541 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2542
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2543 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2544 <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]2545 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2546
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2547 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2548 <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]2549 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2550
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2551 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2552 <dd>Truncate a floating point constant to another floating point type. The
2553 size of CST must be larger than the size of TYPE. Both types must be
2554 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2555
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2556 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2557 <dd>Floating point extend a constant to another type. The size of CST must be
2558 smaller or equal to the size of TYPE. Both types must be floating
2559 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2560
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2561 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2562 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2563 constant. TYPE must be a scalar or vector integer type. CST must be of
2564 scalar or vector floating point type. Both CST and TYPE must be scalars,
2565 or vectors of the same number of elements. If the value won't fit in the
2566 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2567
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2568 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2569 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2570 constant. TYPE must be a scalar or vector integer type. CST must be of
2571 scalar or vector floating point type. Both CST and TYPE must be scalars,
2572 or vectors of the same number of elements. If the value won't fit in the
2573 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2574
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2575 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2576 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2577 constant. TYPE must be a scalar or vector floating point type. CST must be
2578 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2579 vectors of the same number of elements. If the value won't fit in the
2580 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2581
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2582 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2583 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2584 constant. TYPE must be a scalar or vector floating point type. CST must be
2585 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2586 vectors of the same number of elements. If the value won't fit in the
2587 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2588
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2589 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2590 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2591 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2592 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2593 make it fit in <tt>TYPE</tt>.</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>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2596 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2597 type. CST must be of integer type. The CST value is zero extended,
2598 truncated, or unchanged to make it fit in a pointer size. This one is
2599 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2600
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2601 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2602 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2603 are the same as those for the <a href="#i_bitcast">bitcast
2604 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2605
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2606 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2607 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2608 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2609 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2610 instruction, the index list may have zero or more indexes, which are
2611 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2612
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2613 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2614 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2615
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2616 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2617 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2618
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2619 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2620 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2621
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2622 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2623 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2624 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2625
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2626 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2627 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2628 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2629
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2630 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2631 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2632 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2633
Nick Lewycky9ab9a7f2010-05-29 06:44:15 +0000[diff] [blame]2634 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2635 <dd>Perform the <a href="#i_extractvalue">extractvalue 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
2640 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2641 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2642 constants. The index list is interpreted in a similar manner as indices in
2643 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2644 index value must be specified.</dd>
2645
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2646 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2647 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2648 be any of the <a href="#binaryops">binary</a>
2649 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2650 on operands are the same as those for the corresponding instruction
2651 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2652</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2653
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2654</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2655
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2656</div>
2657
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2658<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2659<h2><a name="othervalues">Other Values</a></h2>
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<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2663<h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2664<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2665</h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2666
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2667<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2668
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2669<p>LLVM supports inline assembler expressions (as opposed
2670 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2671 a special value. This value represents the inline assembler as a string
2672 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2673 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2674 expression has side effects, and a flag indicating whether the function
2675 containing the asm needs to align its stack conservatively. An example
2676 inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2677
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2678<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2679i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2680</pre>
2681
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2682<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2683 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2684 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2685
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2686<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2687%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]2688</pre>
2689
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2690<p>Inline asms with side effects not visible in the constraint list must be
2691 marked as having side effects. This is done through the use of the
2692 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2693
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2694<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2695call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2696</pre>
2697
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2698<p>In some cases inline asms will contain code that will not work unless the
2699 stack is aligned in some way, such as calls or SSE instructions on x86,
2700 yet will not contain code that does that alignment within the asm.
2701 The compiler should make conservative assumptions about what the asm might
2702 contain and should generate its usual stack alignment code in the prologue
2703 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2704
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2705<pre class="doc_code">
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2706call void asm alignstack "eieio", ""()
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2707</pre>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2708
2709<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2710 first.</p>
2711
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2712<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2713 documented here. Constraints on what can be done (e.g. duplication, moving,
2714 etc need to be documented). This is probably best done by reference to
2715 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2716
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2717<h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2718<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2719</h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2720
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2721<div>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2722
2723<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattner79ffdc72010-11-17 08:20:42 +0000[diff] [blame]2724 attached to it that contains a list of constant integers. If present, the
2725 code generator will use the integer as the location cookie value when report
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2726 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]2727 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2728 source code that produced it. For example:</p>
2729
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2730<pre class="doc_code">
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2731call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2732...
2733!42 = !{ i32 1234567 }
2734</pre>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2735
2736<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]2737 IR. If the MDNode contains multiple constants, the code generator will use
2738 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]2739
2740</div>
2741
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2742</div>
2743
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2744<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2745<h3>
2746 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2747</h3>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2748
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2749<div>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2750
2751<p>LLVM IR allows metadata to be attached to instructions in the program that
2752 can convey extra information about the code to the optimizers and code
2753 generator. One example application of metadata is source-level debug
2754 information. There are two metadata primitives: strings and nodes. All
2755 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2756 preceding exclamation point ('<tt>!</tt>').</p>
2757
2758<p>A metadata string is a string surrounded by double quotes. It can contain
2759 any character by escaping non-printable characters with "\xx" where "xx" is
2760 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2761
2762<p>Metadata nodes are represented with notation similar to structure constants
2763 (a comma separated list of elements, surrounded by braces and preceded by an
2764 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2765 10}</tt>". Metadata nodes can have any values as their operand.</p>
2766
2767<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2768 metadata nodes, which can be looked up in the module symbol table. For
2769 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2770
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2771<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2772 function is using two metadata arguments.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2773
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2774<div class="doc_code">
2775<pre>
2776call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2777</pre>
2778</div>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2779
2780<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2781 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2782
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2783<div class="doc_code">
2784<pre>
2785%indvar.next = add i64 %indvar, 1, !dbg !21
2786</pre>
2787</div>
2788
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2789</div>
2790
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2791</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2792
2793<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2794<h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2795 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2796</h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2797<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2798<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2799<p>LLVM has a number of "magic" global variables that contain data that affect
2800code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2801of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2802section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2803by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2804
2805<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2806<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2807<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2808</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2809
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2810<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2811
2812<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2813href="#linkage_appending">appending linkage</a>. This array contains a list of
2814pointers to global variables and functions which may optionally have a pointer
2815cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2816
2817<pre>
2818 @X = global i8 4
2819 @Y = global i32 123
2820
2821 @llvm.used = appending global [2 x i8*] [
2822 i8* @X,
2823 i8* bitcast (i32* @Y to i8*)
2824 ], section "llvm.metadata"
2825</pre>
2826
2827<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2828compiler, assembler, and linker are required to treat the symbol as if there is
2829a reference to the global that it cannot see. For example, if a variable has
2830internal linkage and no references other than that from the <tt>@llvm.used</tt>
2831list, it cannot be deleted. This is commonly used to represent references from
2832inline asms and other things the compiler cannot "see", and corresponds to
2833"attribute((used))" in GNU C.</p>
2834
2835<p>On some targets, the code generator must emit a directive to the assembler or
2836object file to prevent the assembler and linker from molesting the symbol.</p>
2837
2838</div>
2839
2840<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2841<h3>
2842 <a name="intg_compiler_used">
2843 The '<tt>llvm.compiler.used</tt>' Global Variable
2844 </a>
2845</h3>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2846
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2847<div>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2848
2849<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2850<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2851touching the symbol. On targets that support it, this allows an intelligent
2852linker to optimize references to the symbol without being impeded as it would be
2853by <tt>@llvm.used</tt>.</p>
2854
2855<p>This is a rare construct that should only be used in rare circumstances, and
2856should not be exposed to source languages.</p>
2857
2858</div>
2859
2860<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2861<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2862<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2863</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2864
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2865<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2866<pre>
2867%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2868@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2869</pre>
2870<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.
2871</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2872
2873</div>
2874
2875<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2876<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2877<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2878</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2879
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2880<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2881<pre>
2882%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2883@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2884</pre>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2885
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2886<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.
2887</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2888
2889</div>
2890
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2891</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2892
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2893<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2894<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2895<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2896
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2897<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2898
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2899<p>The LLVM instruction set consists of several different classifications of
2900 instructions: <a href="#terminators">terminator
2901 instructions</a>, <a href="#binaryops">binary instructions</a>,
2902 <a href="#bitwiseops">bitwise binary instructions</a>,
2903 <a href="#memoryops">memory instructions</a>, and
2904 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2905
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2906<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2907<h3>
2908 <a name="terminators">Terminator Instructions</a>
2909</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2910
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2911<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2912
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2913<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2914 in a program ends with a "Terminator" instruction, which indicates which
2915 block should be executed after the current block is finished. These
2916 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2917 control flow, not values (the one exception being the
2918 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2919
Duncan Sands626b0242010-04-15 20:35:54 +0000[diff] [blame]2920<p>There are seven different terminator instructions: the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2921 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2922 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2923 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling33fef7e2009-11-02 00:25:26 +0000[diff] [blame]2924 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2925 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2926 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2927 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2928
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2929<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2930<h4>
2931 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
2932</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2933
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2934<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2935
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2936<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2937<pre>
2938 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]2939 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2940</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2941
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2942<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2943<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2944 a value) from a function back to the caller.</p>
2945
2946<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2947 value and then causes control flow, and one that just causes control flow to
2948 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2949
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2950<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2951<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2952 return value. The type of the return value must be a
2953 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2954
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2955<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2956 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2957 value or a return value with a type that does not match its type, or if it
2958 has a void return type and contains a '<tt>ret</tt>' instruction with a
2959 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2960
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2961<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2962<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2963 the calling function's context. If the caller is a
2964 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2965 instruction after the call. If the caller was an
2966 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2967 the beginning of the "normal" destination block. If the instruction returns
2968 a value, that value shall set the call or invoke instruction's return
2969 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2970
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2971<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2972<pre>
2973 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2974 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]2975 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]2976</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2977
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2978</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2979<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2980<h4>
2981 <a name="i_br">'<tt>br</tt>' Instruction</a>
2982</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2983
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2984<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2985
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2986<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2987<pre>
2988 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]2989</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2990
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2991<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2992<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2993 different basic block in the current function. There are two forms of this
2994 instruction, corresponding to a conditional branch and an unconditional
2995 branch.</p>
2996
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2997<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2998<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2999 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3000 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3001 target.</p>
3002
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3003<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3004<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3005 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3006 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3007 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3008
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3009<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]3010<pre>
3011Test:
3012 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3013 br i1 %cond, label %IfEqual, label %IfUnequal
3014IfEqual:
3015 <a href="#i_ret">ret</a> i32 1
3016IfUnequal:
3017 <a href="#i_ret">ret</a> i32 0
3018</pre>
3019
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3020</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3021
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3022<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3023<h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3024 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3025</h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3026
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3027<div>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3028
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3029<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3030<pre>
3031 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3032</pre>
3033
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3034<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3035<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]3036 several different places. It is a generalization of the '<tt>br</tt>'
3037 instruction, allowing a branch to occur to one of many possible
3038 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3039
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3040<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3041<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3042 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3043 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3044 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3045
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3046<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3047<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3048 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3049 is searched for the given value. If the value is found, control flow is
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]3050 transferred to the corresponding destination; otherwise, control flow is
3051 transferred to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3052
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3053<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3054<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3055 <tt>switch</tt> instruction, this instruction may be code generated in
3056 different ways. For example, it could be generated as a series of chained
3057 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3058
3059<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3060<pre>
3061 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3062 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3063 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3064
3065 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3066 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]3067
3068 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]3069 switch i32 %val, label %otherwise [ i32 0, label %onzero
3070 i32 1, label %onone
3071 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3072</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3073
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3074</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3075
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3076
3077<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3078<h4>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3079 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3080</h4>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3081
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3082<div>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3083
3084<h5>Syntax:</h5>
3085<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3086 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]3087</pre>
3088
3089<h5>Overview:</h5>
3090
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3091<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3092 within the current function, whose address is specified by
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]3093 "<tt>address</tt>". Address must be derived from a <a
3094 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3095
3096<h5>Arguments:</h5>
3097
3098<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3099 rest of the arguments indicate the full set of possible destinations that the
3100 address may point to. Blocks are allowed to occur multiple times in the
3101 destination list, though this isn't particularly useful.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3102
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3103<p>This destination list is required so that dataflow analysis has an accurate
3104 understanding of the CFG.</p>
3105
3106<h5>Semantics:</h5>
3107
3108<p>Control transfers to the block specified in the address argument. All
3109 possible destination blocks must be listed in the label list, otherwise this
3110 instruction has undefined behavior. This implies that jumps to labels
3111 defined in other functions have undefined behavior as well.</p>
3112
3113<h5>Implementation:</h5>
3114
3115<p>This is typically implemented with a jump through a register.</p>
3116
3117<h5>Example:</h5>
3118<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3119 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3120</pre>
3121
3122</div>
3123
3124
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3125<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3126<h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3127 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3128</h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3129
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3130<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3131
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3132<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3133<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3134 &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]3135 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3136</pre>
3137
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3138<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3139<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3140 function, with the possibility of control flow transfer to either the
3141 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3142 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3143 control flow will return to the "normal" label. If the callee (or any
3144 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3145 instruction, control is interrupted and continued at the dynamically nearest
3146 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3147
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3148<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3149<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3150
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3151<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3152 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3153 convention</a> the call should use. If none is specified, the call
3154 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3155
3156 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3157 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3158 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3159
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3160 <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]3161 function value being invoked. In most cases, this is a direct function
3162 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3163 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3164
3165 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3166 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3167
3168 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]3169 signature argument types and parameter attributes. All arguments must be
3170 of <a href="#t_firstclass">first class</a> type. If the function
3171 signature indicates the function accepts a variable number of arguments,
3172 the extra arguments can be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3173
3174 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3175 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3176
3177 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3178 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3179
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3180 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3181 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3182 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3183</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3184
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3185<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3186<p>This instruction is designed to operate as a standard
3187 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3188 primary difference is that it establishes an association with a label, which
3189 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3190
3191<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3192 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3193 exception. Additionally, this is important for implementation of
3194 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3195
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3196<p>For the purposes of the SSA form, the definition of the value returned by the
3197 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3198 block to the "normal" label. If the callee unwinds then no return value is
3199 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]3200
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3201<p>Note that the code generator does not yet completely support unwind, and
3202that the invoke/unwind semantics are likely to change in future versions.</p>
3203
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3204<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3205<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3206 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3207 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3208 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3209 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3210</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3211
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3212</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3213
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3214<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3215
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3216<h4>
3217 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3218</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3219
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3220<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3221
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3222<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3223<pre>
3224 unwind
3225</pre>
3226
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3227<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3228<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3229 at the first callee in the dynamic call stack which used
3230 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3231 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3232
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3233<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3234<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3235 immediately halt. The dynamic call stack is then searched for the
3236 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3237 Once found, execution continues at the "exceptional" destination block
3238 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3239 instruction in the dynamic call chain, undefined behavior results.</p>
3240
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3241<p>Note that the code generator does not yet completely support unwind, and
3242that the invoke/unwind semantics are likely to change in future versions.</p>
3243
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3244</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3245
3246<!-- _______________________________________________________________________ -->
3247
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3248<h4>
3249 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3250</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3251
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3252<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3253
3254<h5>Syntax:</h5>
3255<pre>
3256 unreachable
3257</pre>
3258
3259<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3260<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3261 instruction is used to inform the optimizer that a particular portion of the
3262 code is not reachable. This can be used to indicate that the code after a
3263 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3264
3265<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3266<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3267
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3268</div>
3269
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3270</div>
3271
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3272<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3273<h3>
3274 <a name="binaryops">Binary Operations</a>
3275</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3276
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3277<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3278
3279<p>Binary operators are used to do most of the computation in a program. They
3280 require two operands of the same type, execute an operation on them, and
3281 produce a single value. The operands might represent multiple data, as is
3282 the case with the <a href="#t_vector">vector</a> data type. The result value
3283 has the same type as its operands.</p>
3284
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3285<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3286
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3287<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3288<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3289 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3290</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3291
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3292<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3293
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3294<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3295<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3296 &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]3297 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3298 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3299 &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]3300</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3301
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3302<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3303<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3304
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3305<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3306<p>The two arguments to the '<tt>add</tt>' instruction must
3307 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3308 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3309
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3310<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3311<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3312
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3313<p>If the sum has unsigned overflow, the result returned is the mathematical
3314 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]3315
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3316<p>Because LLVM integers use a two's complement representation, this instruction
3317 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3318
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3319<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3320 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3321 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3322 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3323 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3324
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3325<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3326<pre>
3327 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3328</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3329
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3330</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3331
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3332<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3333<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3334 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3335</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3336
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3337<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3338
3339<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3340<pre>
3341 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3342</pre>
3343
3344<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3345<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3346
3347<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3348<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3349 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3350 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3351
3352<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3353<p>The value produced is the floating point sum of the two operands.</p>
3354
3355<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3356<pre>
3357 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3358</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3359
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3360</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3361
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3362<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3363<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3364 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3365</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3366
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3367<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3368
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3369<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3370<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3371 &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]3372 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3373 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3374 &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]3375</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3376
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3377<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3378<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3379 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3380
3381<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3382 '<tt>neg</tt>' instruction present in most other intermediate
3383 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3384
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3385<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3386<p>The two arguments to the '<tt>sub</tt>' instruction must
3387 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3388 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3389
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3390<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3391<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3392
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3393<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3394 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3395 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3396
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3397<p>Because LLVM integers use a two's complement representation, this instruction
3398 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3399
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3400<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3401 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3402 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3403 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3404 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3405
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3406<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3407<pre>
3408 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3409 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3410</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3411
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3412</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3413
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3414<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3415<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3416 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3417</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3418
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3419<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3420
3421<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3422<pre>
3423 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3424</pre>
3425
3426<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3427<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3428 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3429
3430<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3431 '<tt>fneg</tt>' instruction present in most other intermediate
3432 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3433
3434<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]3435<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3436 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3437 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3438
3439<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3440<p>The value produced is the floating point difference of the two operands.</p>
3441
3442<h5>Example:</h5>
3443<pre>
3444 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3445 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3446</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3447
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3448</div>
3449
3450<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3451<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3452 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3453</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3454
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3455<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3456
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3457<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3458<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3459 &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]3460 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3461 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3462 &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]3463</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3464
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3465<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3466<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3467
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3468<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3469<p>The two arguments to the '<tt>mul</tt>' instruction must
3470 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3471 integer values. Both arguments must have identical types.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3472
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3473<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3474<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3475
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3476<p>If the result of the multiplication has unsigned overflow, the result
3477 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3478 width of the result.</p>
3479
3480<p>Because LLVM integers use a two's complement representation, and the result
3481 is the same width as the operands, this instruction returns the correct
3482 result for both signed and unsigned integers. If a full product
3483 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3484 be sign-extended or zero-extended as appropriate to the width of the full
3485 product.</p>
3486
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3487<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3488 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3489 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3490 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3491 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3492
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3493<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3494<pre>
3495 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3496</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3497
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3498</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3499
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3500<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3501<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3502 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3503</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3504
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3505<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3506
3507<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3508<pre>
3509 &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]3510</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3511
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3512<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3513<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3514
3515<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3516<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3517 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3518 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3519
3520<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3521<p>The value produced is the floating point product of the two operands.</p>
3522
3523<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3524<pre>
3525 &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]3526</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3527
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3528</div>
3529
3530<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3531<h4>
3532 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3533</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3534
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3535<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3536
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3537<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3538<pre>
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3539 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3540 &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]3541</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3542
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3543<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3544<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3545
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3546<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3547<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3548 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3549 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3550
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3551<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3552<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3553
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3554<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3555 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3556
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3557<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3558
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3559<p>If the <tt>exact</tt> keyword is present, the result value of the
3560 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3561 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3562
3563
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3564<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3565<pre>
3566 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3567</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3568
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3569</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3570
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3571<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3572<h4>
3573 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3574</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3575
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3576<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3577
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3578<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3579<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3580 &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]3581 &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]3582</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3583
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3584<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3585<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3586
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3587<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3588<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3589 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3590 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3591
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3592<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3593<p>The value produced is the signed integer quotient of the two operands rounded
3594 towards zero.</p>
3595
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3596<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3597 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3598
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3599<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3600 undefined behavior; this is a rare case, but can occur, for example, by doing
3601 a 32-bit division of -2147483648 by -1.</p>
3602
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]3603<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]3604 <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]3605 be rounded.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3606
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3607<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3608<pre>
3609 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3610</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3611
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3612</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3613
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3614<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3615<h4>
3616 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3617</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3618
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3619<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3620
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3621<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3622<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3623 &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]3624</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3625
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3626<h5>Overview:</h5>
3627<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3628
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3629<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3630<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3631 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3632 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3633
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3634<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3635<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3636
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3637<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3638<pre>
3639 &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]3640</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3641
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3642</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3643
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3644<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3645<h4>
3646 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3647</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3648
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3649<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3650
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3651<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3652<pre>
3653 &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]3654</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3655
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3656<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3657<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3658 division of its two arguments.</p>
3659
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3660<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3661<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3662 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3663 values. Both arguments must have identical types.</p>
3664
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3665<h5>Semantics:</h5>
3666<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3667 This instruction always performs an unsigned division to get the
3668 remainder.</p>
3669
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3670<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3671 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3672
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3673<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3674
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3675<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3676<pre>
3677 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3678</pre>
3679
3680</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3681
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3682<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3683<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3684 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3685</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3686
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3687<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3688
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3689<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3690<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3691 &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]3692</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3693
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3694<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3695<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3696 division of its two operands. This instruction can also take
3697 <a href="#t_vector">vector</a> versions of the values in which case the
3698 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3699
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3700<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3701<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3702 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3703 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3704
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3705<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3706<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sands2769c6e2011-03-07 09:12:24 +0000[diff] [blame]3707 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3708 <i>modulo</i> operator (where the result is either zero or has the same sign
3709 as the divisor, <tt>op2</tt>) of a value.
3710 For more information about the difference,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3711 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3712 Math Forum</a>. For a table of how this is implemented in various languages,
3713 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3714 Wikipedia: modulo operation</a>.</p>
3715
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3716<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3717 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3718
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3719<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3720 Overflow also leads to undefined behavior; this is a rare case, but can
3721 occur, for example, by taking the remainder of a 32-bit division of
3722 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3723 lets srem be implemented using instructions that return both the result of
3724 the division and the remainder.)</p>
3725
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3726<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3727<pre>
3728 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3729</pre>
3730
3731</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3732
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3733<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3734<h4>
3735 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3736</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3737
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3738<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3739
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3740<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3741<pre>
3742 &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]3743</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3744
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3745<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3746<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3747 its two operands.</p>
3748
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3749<h5>Arguments:</h5>
3750<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3751 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3752 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3753
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3754<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3755<p>This instruction returns the <i>remainder</i> of a division. The remainder
3756 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3757
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3758<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3759<pre>
3760 &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]3761</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3762
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3763</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3764
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3765</div>
3766
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3767<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3768<h3>
3769 <a name="bitwiseops">Bitwise Binary Operations</a>
3770</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3771
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3772<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3773
3774<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3775 program. They are generally very efficient instructions and can commonly be
3776 strength reduced from other instructions. They require two operands of the
3777 same type, execute an operation on them, and produce a single value. The
3778 resulting value is the same type as its operands.</p>
3779
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3780<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3781<h4>
3782 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3783</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3784
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3785<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3786
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3787<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3788<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3789 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3790 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3791 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3792 &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]3793</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3794
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3795<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3796<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3797 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3798
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3799<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3800<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3801 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3802 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3803
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3804<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3805<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3806 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3807 is (statically or dynamically) negative or equal to or larger than the number
3808 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3809 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3810 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3811
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3812<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3813 <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]3814 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3815 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3816 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3817 they would if the shift were expressed as a mul instruction with the same
3818 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3819
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3820<h5>Example:</h5>
3821<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3822 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3823 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3824 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3825 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3826 &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]3827</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3828
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3829</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3830
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3831<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3832<h4>
3833 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3834</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3835
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3836<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3837
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3838<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3839<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3840 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3841 &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]3842</pre>
3843
3844<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3845<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3846 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3847
3848<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3849<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3850 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3851 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3852
3853<h5>Semantics:</h5>
3854<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3855 significant bits of the result will be filled with zero bits after the shift.
3856 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3857 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3858 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3859 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3860
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3861<p>If the <tt>exact</tt> keyword is present, the result value of the
3862 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3863 shifted out are non-zero.</p>
3864
3865
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3866<h5>Example:</h5>
3867<pre>
3868 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3869 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3870 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3871 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3872 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3873 &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]3874</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3875
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3876</div>
3877
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3878<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3879<h4>
3880 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
3881</h4>
3882
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3883<div>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3884
3885<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3886<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3887 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3888 &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]3889</pre>
3890
3891<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3892<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3893 operand shifted to the right a specified number of bits with sign
3894 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3895
3896<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3897<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3898 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3899 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3900
3901<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3902<p>This instruction always performs an arithmetic shift right operation, The
3903 most significant bits of the result will be filled with the sign bit
3904 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3905 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3906 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3907 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3908
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3909<p>If the <tt>exact</tt> keyword is present, the result value of the
3910 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3911 shifted out are non-zero.</p>
3912
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3913<h5>Example:</h5>
3914<pre>
3915 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3916 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3917 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3918 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3919 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3920 &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]3921</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3922
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3923</div>
3924
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3925<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3926<h4>
3927 <a name="i_and">'<tt>and</tt>' Instruction</a>
3928</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3929
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3930<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3931
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3932<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3933<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3934 &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]3935</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3936
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3937<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3938<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3939 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3940
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3941<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3942<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3943 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3944 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3945
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3946<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3947<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3948
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3949<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3950 <tbody>
3951 <tr>
3952 <td>In0</td>
3953 <td>In1</td>
3954 <td>Out</td>
3955 </tr>
3956 <tr>
3957 <td>0</td>
3958 <td>0</td>
3959 <td>0</td>
3960 </tr>
3961 <tr>
3962 <td>0</td>
3963 <td>1</td>
3964 <td>0</td>
3965 </tr>
3966 <tr>
3967 <td>1</td>
3968 <td>0</td>
3969 <td>0</td>
3970 </tr>
3971 <tr>
3972 <td>1</td>
3973 <td>1</td>
3974 <td>1</td>
3975 </tr>
3976 </tbody>
3977</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3978
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3979<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3980<pre>
3981 &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]3982 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3983 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3984</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3985</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3986<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3987<h4>
3988 <a name="i_or">'<tt>or</tt>' Instruction</a>
3989</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3990
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3991<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3992
3993<h5>Syntax:</h5>
3994<pre>
3995 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3996</pre>
3997
3998<h5>Overview:</h5>
3999<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4000 two operands.</p>
4001
4002<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4003<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4004 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4005 values. Both arguments must have identical types.</p>
4006
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4007<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4008<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4009
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4010<table border="1" cellspacing="0" cellpadding="4">
4011 <tbody>
4012 <tr>
4013 <td>In0</td>
4014 <td>In1</td>
4015 <td>Out</td>
4016 </tr>
4017 <tr>
4018 <td>0</td>
4019 <td>0</td>
4020 <td>0</td>
4021 </tr>
4022 <tr>
4023 <td>0</td>
4024 <td>1</td>
4025 <td>1</td>
4026 </tr>
4027 <tr>
4028 <td>1</td>
4029 <td>0</td>
4030 <td>1</td>
4031 </tr>
4032 <tr>
4033 <td>1</td>
4034 <td>1</td>
4035 <td>1</td>
4036 </tr>
4037 </tbody>
4038</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4039
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4040<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4041<pre>
4042 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4043 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4044 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4045</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4046
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4047</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4048
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4049<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4050<h4>
4051 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4052</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4053
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4054<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4055
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4056<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4057<pre>
4058 &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]4059</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4060
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4061<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4062<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4063 its two operands. The <tt>xor</tt> is used to implement the "one's
4064 complement" operation, which is the "~" operator in C.</p>
4065
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4066<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4067<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4068 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4069 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4070
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4071<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4072<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4073
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4074<table border="1" cellspacing="0" cellpadding="4">
4075 <tbody>
4076 <tr>
4077 <td>In0</td>
4078 <td>In1</td>
4079 <td>Out</td>
4080 </tr>
4081 <tr>
4082 <td>0</td>
4083 <td>0</td>
4084 <td>0</td>
4085 </tr>
4086 <tr>
4087 <td>0</td>
4088 <td>1</td>
4089 <td>1</td>
4090 </tr>
4091 <tr>
4092 <td>1</td>
4093 <td>0</td>
4094 <td>1</td>
4095 </tr>
4096 <tr>
4097 <td>1</td>
4098 <td>1</td>
4099 <td>0</td>
4100 </tr>
4101 </tbody>
4102</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4103
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4104<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4105<pre>
4106 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4107 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4108 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4109 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4110</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4111
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4112</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4113
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4114</div>
4115
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4116<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4117<h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4118 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4119</h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4120
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4121<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4122
4123<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4124 target-independent manner. These instructions cover the element-access and
4125 vector-specific operations needed to process vectors effectively. While LLVM
4126 does directly support these vector operations, many sophisticated algorithms
4127 will want to use target-specific intrinsics to take full advantage of a
4128 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4129
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4130<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4131<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4132 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4133</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4134
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4135<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4136
4137<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4138<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4139 &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]4140</pre>
4141
4142<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4143<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4144 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4145
4146
4147<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4148<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4149 of <a href="#t_vector">vector</a> type. The second operand is an index
4150 indicating the position from which to extract the element. The index may be
4151 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4152
4153<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4154<p>The result is a scalar of the same type as the element type of
4155 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4156 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4157 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4158
4159<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4160<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4161 &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]4162</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4163
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4164</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4165
4166<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4167<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4168 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4169</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4170
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4171<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4172
4173<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4174<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]4175 &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]4176</pre>
4177
4178<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4179<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4180 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4181
4182<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4183<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4184 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4185 whose type must equal the element type of the first operand. The third
4186 operand is an index indicating the position at which to insert the value.
4187 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4188
4189<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4190<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4191 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4192 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4193 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4194
4195<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4196<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4197 &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]4198</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4199
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4200</div>
4201
4202<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4203<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4204 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4205</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4206
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4207<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4208
4209<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4210<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4211 &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]4212</pre>
4213
4214<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4215<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4216 from two input vectors, returning a vector with the same element type as the
4217 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4218
4219<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4220<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4221 with types that match each other. The third argument is a shuffle mask whose
4222 element type is always 'i32'. The result of the instruction is a vector
4223 whose length is the same as the shuffle mask and whose element type is the
4224 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4225
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4226<p>The shuffle mask operand is required to be a constant vector with either
4227 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4228
4229<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4230<p>The elements of the two input vectors are numbered from left to right across
4231 both of the vectors. The shuffle mask operand specifies, for each element of
4232 the result vector, which element of the two input vectors the result element
4233 gets. The element selector may be undef (meaning "don't care") and the
4234 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4235
4236<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4237<pre>
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,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4239 &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]4240 &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]4241 &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]4242 &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]4243 &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]4244 &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]4245 &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]4246</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4247
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4248</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]4249
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4250</div>
4251
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4252<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4253<h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4254 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4255</h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4256
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4257<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4258
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4259<p>LLVM supports several instructions for working with
4260 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4261
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4262<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4263<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4264 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4265</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4266
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4267<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4268
4269<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4270<pre>
4271 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4272</pre>
4273
4274<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4275<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4276 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4277
4278<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4279<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4280 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4281 <a href="#t_array">array</a> type. The operands are constant indices to
4282 specify which value to extract in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4283 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel7cf63ac2010-12-05 20:54:38 +0000[diff] [blame]4284 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4285 <ul>
4286 <li>Since the value being indexed is not a pointer, the first index is
4287 omitted and assumed to be zero.</li>
4288 <li>At least one index must be specified.</li>
4289 <li>Not only struct indices but also array indices must be in
4290 bounds.</li>
4291 </ul>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4292
4293<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4294<p>The result is the value at the position in the aggregate specified by the
4295 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4296
4297<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4298<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4299 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4300</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4301
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4302</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4303
4304<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4305<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4306 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4307</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4308
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4309<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4310
4311<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4312<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4313 &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]4314</pre>
4315
4316<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4317<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4318 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4319
4320<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4321<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4322 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4323 <a href="#t_array">array</a> type. The second operand is a first-class
4324 value to insert. The following operands are constant indices indicating
4325 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]4326 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4327 value to insert must have the same type as the value identified by the
4328 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4329
4330<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4331<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4332 that of <tt>val</tt> except that the value at the position specified by the
4333 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4334
4335<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4336<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4337 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4338 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4339 %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]4340</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4341
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4342</div>
4343
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4344</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4345
4346<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4347<h3>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4348 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4349</h3>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4350
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4351<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4352
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4353<p>A key design point of an SSA-based representation is how it represents
4354 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]4355 very simple. This section describes how to read, write, and allocate
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4356 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4357
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4358<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4359<h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4360 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4361</h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4362
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4363<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4364
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4365<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4366<pre>
Dan Gohman2140a742010-05-28 01:14:11 +0000[diff] [blame]4367 &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]4368</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4369
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4370<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4371<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4372 currently executing function, to be automatically released when this function
4373 returns to its caller. The object is always allocated in the generic address
4374 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4375
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4376<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4377<p>The '<tt>alloca</tt>' instruction
4378 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4379 runtime stack, returning a pointer of the appropriate type to the program.
4380 If "NumElements" is specified, it is the number of elements allocated,
4381 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4382 specified, the value result of the allocation is guaranteed to be aligned to
4383 at least that boundary. If not specified, or if zero, the target can choose
4384 to align the allocation on any convenient boundary compatible with the
4385 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4386
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4387<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4388
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4389<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]4390<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4391 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4392 memory is automatically released when the function returns. The
4393 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4394 variables that must have an address available. When the function returns
4395 (either with the <tt><a href="#i_ret">ret</a></tt>
4396 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4397 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4398
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4399<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4400<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]4401 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4402 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4403 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4404 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4405</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4406
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4407</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4408
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4409<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4410<h4>
4411 <a name="i_load">'<tt>load</tt>' Instruction</a>
4412</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4413
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4414<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4415
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4416<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4417<pre>
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4418 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4419 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4420 !&lt;index&gt; = !{ i32 1 }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4421</pre>
4422
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4423<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4424<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4425
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4426<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4427<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4428 from which to load. The pointer must point to
4429 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4430 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4431 number or order of execution of this <tt>load</tt> with other <a
4432 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4433
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4434<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4435 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]4436 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4437 alignment for the target. It is the responsibility of the code emitter to
4438 ensure that the alignment information is correct. Overestimating the
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4439 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4440 produce less efficient code. An alignment of 1 is always safe.</p>
4441
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4442<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4443 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4444 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4445 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4446 and code generator that this load is not expected to be reused in the cache.
4447 The code generator may select special instructions to save cache bandwidth,
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4448 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4449
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4450<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4451<p>The location of memory pointed to is loaded. If the value being loaded is of
4452 scalar type then the number of bytes read does not exceed the minimum number
4453 of bytes needed to hold all bits of the type. For example, loading an
4454 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4455 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4456 is undefined if the value was not originally written using a store of the
4457 same type.</p>
4458
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4459<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4460<pre>
4461 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4462 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4463 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4464</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4465
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4466</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4467
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4468<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4469<h4>
4470 <a name="i_store">'<tt>store</tt>' Instruction</a>
4471</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4472
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4473<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4474
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4475<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4476<pre>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4477 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>
4478 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]4479</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4480
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4481<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4482<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4483
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4484<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4485<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4486 and an address at which to store it. The type of the
4487 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4488 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4489 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4490 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4491 order of execution of this <tt>store</tt> with other <a
4492 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4493
4494<p>The optional constant "align" argument specifies the alignment of the
4495 operation (that is, the alignment of the memory address). A value of 0 or an
4496 omitted "align" argument means that the operation has the preferential
4497 alignment for the target. It is the responsibility of the code emitter to
4498 ensure that the alignment information is correct. Overestimating the
4499 alignment results in an undefined behavior. Underestimating the alignment may
4500 produce less efficient code. An alignment of 1 is always safe.</p>
4501
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4502<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4503 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4504 value 1. The existence of the !nontemporal metatadata on the
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4505 instruction tells the optimizer and code generator that this load is
4506 not expected to be reused in the cache. The code generator may
4507 select special instructions to save cache bandwidth, such as the
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4508 MOVNT instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4509
4510
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4511<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4512<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4513 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4514 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4515 does not exceed the minimum number of bytes needed to hold all bits of the
4516 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4517 writing a value of a type like <tt>i20</tt> with a size that is not an
4518 integral number of bytes, it is unspecified what happens to the extra bits
4519 that do not belong to the type, but they will typically be overwritten.</p>
4520
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4521<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4522<pre>
4523 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]4524 store i32 3, i32* %ptr <i>; yields {void}</i>
4525 %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]4526</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4527
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4528</div>
4529
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4530<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4531<h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4532 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4533</h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4534
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4535<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4536
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4537<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4538<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4539 &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]4540 &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]4541</pre>
4542
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4543<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4544<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4545 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4546 It performs address calculation only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4547
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4548<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4549<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4550 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4551 elements of the aggregate object are indexed. The interpretation of each
4552 index is dependent on the type being indexed into. The first index always
4553 indexes the pointer value given as the first argument, the second index
4554 indexes a value of the type pointed to (not necessarily the value directly
4555 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4556 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4557 vectors, and structs. Note that subsequent types being indexed into
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4558 can never be pointers, since that would require loading the pointer before
4559 continuing calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4560
4561<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]4562 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4563 integer <b>constants</b> are allowed. When indexing into an array, pointer
4564 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]4565 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4566
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4567<p>For example, let's consider a C code fragment and how it gets compiled to
4568 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4569
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4570<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4571struct RT {
4572 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4573 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4574 char C;
4575};
4576struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4577 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4578 double Y;
4579 struct RT Z;
4580};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4581
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4582int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4583 return &amp;s[1].Z.B[5][13];
4584}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4585</pre>
4586
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4587<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4588
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4589<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]4590%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4591%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4592
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4593define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4594entry:
4595 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4596 ret i32* %reg
4597}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4598</pre>
4599
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4600<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4601<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]4602 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4603 }</tt>' type, a structure. The second index indexes into the third element
4604 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4605 i8 }</tt>' type, another structure. The third index indexes into the second
4606 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4607 array. The two dimensions of the array are subscripted into, yielding an
4608 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4609 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4610
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4611<p>Note that it is perfectly legal to index partially through a structure,
4612 returning a pointer to an inner element. Because of this, the LLVM code for
4613 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4614
4615<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4616 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4617 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4618 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4619 %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]4620 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4621 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4622 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4623 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4624</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]4625
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4626<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]4627 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4628 base pointer is not an <i>in bounds</i> address of an allocated object,
4629 or if any of the addresses that would be formed by successive addition of
4630 the offsets implied by the indices to the base address with infinitely
4631 precise arithmetic are not an <i>in bounds</i> address of that allocated
4632 object. The <i>in bounds</i> addresses for an allocated object are all
4633 the addresses that point into the object, plus the address one byte past
4634 the end.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4635
4636<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4637 the base address with silently-wrapping two's complement arithmetic, and
4638 the result value of the <tt>getelementptr</tt> may be outside the object
4639 pointed to by the base pointer. The result value may not necessarily be
4640 used to access memory though, even if it happens to point into allocated
4641 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4642 section for more information.</p>
4643
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4644<p>The getelementptr instruction is often confusing. For some more insight into
4645 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4646
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4647<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4648<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4649 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4650 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4651 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4652 %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]4653 <i>; yields i8*:eptr</i>
4654 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]4655 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]4656 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4657</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4658
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4659</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4660
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4661</div>
4662
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4663<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4664<h3>
4665 <a name="convertops">Conversion Operations</a>
4666</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4667
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4668<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4669
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4670<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4671 which all take a single operand and a type. They perform various bit
4672 conversions on the operand.</p>
4673
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4674<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4675<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4676 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4677</h4>
4678
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4679<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4680
4681<h5>Syntax:</h5>
4682<pre>
4683 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4684</pre>
4685
4686<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4687<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4688 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4689
4690<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4691<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
4692 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4693 of the same number of integers.
4694 The bit size of the <tt>value</tt> must be larger than
4695 the bit size of the destination type, <tt>ty2</tt>.
4696 Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4697
4698<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4699<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4700 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4701 source size must be larger than the destination size, <tt>trunc</tt> cannot
4702 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4703
4704<h5>Example:</h5>
4705<pre>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4706 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
4707 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4708 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
4709 %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]4710</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4711
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4712</div>
4713
4714<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4715<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4716 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4717</h4>
4718
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4719<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4720
4721<h5>Syntax:</h5>
4722<pre>
4723 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4724</pre>
4725
4726<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4727<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4728 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4729
4730
4731<h5>Arguments:</h5>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]4732<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
4733 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4734 of the same number of integers.
4735 The bit size of the <tt>value</tt> must be smaller than
4736 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4737 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4738
4739<h5>Semantics:</h5>
4740<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]4741 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4742
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]4743<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]4744
4745<h5>Example:</h5>
4746<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4747 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4748 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]4749 %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]4750</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4751
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4752</div>
4753
4754<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4755<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4756 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4757</h4>
4758
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4759<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4760
4761<h5>Syntax:</h5>
4762<pre>
4763 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4764</pre>
4765
4766<h5>Overview:</h5>
4767<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4768
4769<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4770<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
4771 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4772 of the same number of integers.
4773 The bit size of the <tt>value</tt> must be smaller than
4774 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4775 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4776
4777<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4778<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4779 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4780 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4781
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4782<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]4783
4784<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4785<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4786 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4787 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4788 %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]4789</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4790
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4791</div>
4792
4793<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4794<h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4795 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4796</h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4797
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4798<div>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4799
4800<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4801<pre>
4802 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4803</pre>
4804
4805<h5>Overview:</h5>
4806<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4807 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4808
4809<h5>Arguments:</h5>
4810<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4811 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4812 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]4813 <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]4814 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4815
4816<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4817<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4818 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4819 <a href="#t_floating">floating point</a> type. If the value cannot fit
4820 within the destination type, <tt>ty2</tt>, then the results are
4821 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4822
4823<h5>Example:</h5>
4824<pre>
4825 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4826 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4827</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4828
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4829</div>
4830
4831<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4832<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4833 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4834</h4>
4835
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4836<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4837
4838<h5>Syntax:</h5>
4839<pre>
4840 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4841</pre>
4842
4843<h5>Overview:</h5>
4844<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]4845 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4846
4847<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4848<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4849 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4850 a <a href="#t_floating">floating point</a> type to cast it to. The source
4851 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4852
4853<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4854<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4855 <a href="#t_floating">floating point</a> type to a larger
4856 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4857 used to make a <i>no-op cast</i> because it always changes bits. Use
4858 <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]4859
4860<h5>Example:</h5>
4861<pre>
Nick Lewycky9feca672011-03-31 18:20:19 +0000[diff] [blame]4862 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
4863 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4864</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4865
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4866</div>
4867
4868<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4869<h4>
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]4870 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4871</h4>
4872
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4873<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4874
4875<h5>Syntax:</h5>
4876<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4877 &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]4878</pre>
4879
4880<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4881<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4882 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4883
4884<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4885<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4886 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4887 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4888 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4889 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4890
4891<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4892<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4893 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4894 towards zero) unsigned integer value. If the value cannot fit
4895 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4896
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4897<h5>Example:</h5>
4898<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4899 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4900 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4901 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4902</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4903
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4904</div>
4905
4906<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4907<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4908 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4909</h4>
4910
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4911<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4912
4913<h5>Syntax:</h5>
4914<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4915 &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]4916</pre>
4917
4918<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4919<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4920 <a href="#t_floating">floating point</a> <tt>value</tt> to
4921 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4922
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4923<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4924<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4925 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4926 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4927 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4928 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4929
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4930<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4931<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4932 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4933 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4934 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4935
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4936<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4937<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4938 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4939 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4940 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4941</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4942
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4943</div>
4944
4945<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4946<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4947 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4948</h4>
4949
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4950<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4951
4952<h5>Syntax:</h5>
4953<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4954 &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]4955</pre>
4956
4957<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4958<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4959 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4960
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4961<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4962<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]4963 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4964 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4965 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4966 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4967
4968<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4969<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4970 integer quantity and converts it to the corresponding floating point
4971 value. If the value cannot fit in the floating point value, the results are
4972 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4973
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4974<h5>Example:</h5>
4975<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4976 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4977 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4978</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4979
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4980</div>
4981
4982<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4983<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4984 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4985</h4>
4986
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4987<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4988
4989<h5>Syntax:</h5>
4990<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4991 &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]4992</pre>
4993
4994<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4995<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4996 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4997
4998<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4999<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]5000 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5001 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5002 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5003 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5004
5005<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5006<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5007 quantity and converts it to the corresponding floating point value. If the
5008 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5009
5010<h5>Example:</h5>
5011<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5012 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5013 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5014</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5015
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5016</div>
5017
5018<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5019<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5020 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5021</h4>
5022
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5023<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5024
5025<h5>Syntax:</h5>
5026<pre>
5027 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5028</pre>
5029
5030<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5031<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5032 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5033
5034<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5035<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5036 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5037 <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]5038
5039<h5>Semantics:</h5>
5040<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5041 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5042 truncating or zero extending that value to the size of the integer type. If
5043 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5044 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5045 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5046 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5047
5048<h5>Example:</h5>
5049<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5050 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5051 %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]5052</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5053
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5054</div>
5055
5056<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5057<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5058 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5059</h4>
5060
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5061<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5062
5063<h5>Syntax:</h5>
5064<pre>
5065 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5066</pre>
5067
5068<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5069<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5070 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5071
5072<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]5073<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5074 value to cast, and a type to cast it to, which must be a
5075 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5076
5077<h5>Semantics:</h5>
5078<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5079 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5080 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5081 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5082 than the size of a pointer then a zero extension is done. If they are the
5083 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5084
5085<h5>Example:</h5>
5086<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5087 %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]5088 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5089 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5090</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5091
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5092</div>
5093
5094<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5095<h4>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5096 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5097</h4>
5098
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5099<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5100
5101<h5>Syntax:</h5>
5102<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5103 &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]5104</pre>
5105
5106<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5107<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5108 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5109
5110<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5111<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5112 non-aggregate first class value, and a type to cast it to, which must also be
5113 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5114 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5115 identical. If the source type is a pointer, the destination type must also be
5116 a pointer. This instruction supports bitwise conversion of vectors to
5117 integers and to vectors of other types (as long as they have the same
5118 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5119
5120<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5121<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5122 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5123 this conversion. The conversion is done as if the <tt>value</tt> had been
5124 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5125 be converted to other pointer types with this instruction. To convert
5126 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5127 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5128
5129<h5>Example:</h5>
5130<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5131 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5132 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5133 %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]5134</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5135
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5136</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5137
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5138</div>
5139
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5140<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5141<h3>
5142 <a name="otherops">Other Operations</a>
5143</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5144
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5145<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5146
5147<p>The instructions in this category are the "miscellaneous" instructions, which
5148 defy better classification.</p>
5149
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5150<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5151<h4>
5152 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5153</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5154
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5155<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5156
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5157<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5158<pre>
5159 &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]5160</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5161
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5162<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5163<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5164 boolean values based on comparison of its two integer, integer vector, or
5165 pointer operands.</p>
5166
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5167<h5>Arguments:</h5>
5168<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5169 the condition code indicating the kind of comparison to perform. It is not a
5170 value, just a keyword. The possible condition code are:</p>
5171
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5172<ol>
5173 <li><tt>eq</tt>: equal</li>
5174 <li><tt>ne</tt>: not equal </li>
5175 <li><tt>ugt</tt>: unsigned greater than</li>
5176 <li><tt>uge</tt>: unsigned greater or equal</li>
5177 <li><tt>ult</tt>: unsigned less than</li>
5178 <li><tt>ule</tt>: unsigned less or equal</li>
5179 <li><tt>sgt</tt>: signed greater than</li>
5180 <li><tt>sge</tt>: signed greater or equal</li>
5181 <li><tt>slt</tt>: signed less than</li>
5182 <li><tt>sle</tt>: signed less or equal</li>
5183</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5184
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]5185<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5186 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5187 typed. They must also be identical types.</p>
5188
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5189<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5190<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5191 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5192 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]5193 result, as follows:</p>
5194
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5195<ol>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5196 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5197 <tt>false</tt> otherwise. No sign interpretation is necessary or
5198 performed.</li>
5199
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5200 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5201 <tt>false</tt> otherwise. No sign interpretation is necessary or
5202 performed.</li>
5203
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5204 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5205 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5206
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5207 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5208 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5209 to <tt>op2</tt>.</li>
5210
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5211 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5212 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5213
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5214 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5215 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5216
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5217 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5218 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5219
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5220 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5221 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5222 to <tt>op2</tt>.</li>
5223
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5224 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5225 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5226
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5227 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5228 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5229</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5230
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5231<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5232 values are compared as if they were integers.</p>
5233
5234<p>If the operands are integer vectors, then they are compared element by
5235 element. The result is an <tt>i1</tt> vector with the same number of elements
5236 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5237
5238<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5239<pre>
5240 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5241 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5242 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5243 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5244 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5245 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5246</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5247
5248<p>Note that the code generator does not yet support vector types with
5249 the <tt>icmp</tt> instruction.</p>
5250
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5251</div>
5252
5253<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5254<h4>
5255 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5256</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5257
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5258<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5259
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5260<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5261<pre>
5262 &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]5263</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5264
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5265<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5266<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5267 values based on comparison of its operands.</p>
5268
5269<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]5270(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5271
5272<p>If the operands are floating point vectors, then the result type is a vector
5273 of boolean with the same number of elements as the operands being
5274 compared.</p>
5275
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5276<h5>Arguments:</h5>
5277<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5278 the condition code indicating the kind of comparison to perform. It is not a
5279 value, just a keyword. The possible condition code are:</p>
5280
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5281<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5282 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5283 <li><tt>oeq</tt>: ordered and equal</li>
5284 <li><tt>ogt</tt>: ordered and greater than </li>
5285 <li><tt>oge</tt>: ordered and greater than or equal</li>
5286 <li><tt>olt</tt>: ordered and less than </li>
5287 <li><tt>ole</tt>: ordered and less than or equal</li>
5288 <li><tt>one</tt>: ordered and not equal</li>
5289 <li><tt>ord</tt>: ordered (no nans)</li>
5290 <li><tt>ueq</tt>: unordered or equal</li>
5291 <li><tt>ugt</tt>: unordered or greater than </li>
5292 <li><tt>uge</tt>: unordered or greater than or equal</li>
5293 <li><tt>ult</tt>: unordered or less than </li>
5294 <li><tt>ule</tt>: unordered or less than or equal</li>
5295 <li><tt>une</tt>: unordered or not equal</li>
5296 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5297 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5298</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5299
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5300<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5301 <i>unordered</i> means that either operand may be a QNAN.</p>
5302
5303<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5304 a <a href="#t_floating">floating point</a> type or
5305 a <a href="#t_vector">vector</a> of floating point type. They must have
5306 identical types.</p>
5307
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5308<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]5309<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5310 according to the condition code given as <tt>cond</tt>. If the operands are
5311 vectors, then the vectors are compared element by element. Each comparison
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5312 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5313 follows:</p>
5314
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5315<ol>
5316 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</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>oeq</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 equal to <tt>op2</tt>.</li>
5320
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5321 <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]5322 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5323
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5324 <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]5325 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5326
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5327 <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]5328 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5329
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5330 <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]5331 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5332
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5333 <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]5334 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5335
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5336 <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]5337
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5338 <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]5339 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5340
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5341 <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]5342 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5343
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5344 <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]5345 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5346
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5347 <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]5348 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5349
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5350 <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]5351 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5352
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5353 <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]5354 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5355
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5356 <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]5357
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5358 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5359</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5360
5361<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5362<pre>
5363 &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]5364 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5365 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5366 &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]5367</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5368
5369<p>Note that the code generator does not yet support vector types with
5370 the <tt>fcmp</tt> instruction.</p>
5371
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5372</div>
5373
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5374<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5375<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5376 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5377</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5378
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5379<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5380
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5381<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5382<pre>
5383 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5384</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5385
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5386<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5387<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5388 SSA graph representing the function.</p>
5389
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5390<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5391<p>The type of the incoming values is specified with the first type field. After
5392 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5393 one pair for each predecessor basic block of the current block. Only values
5394 of <a href="#t_firstclass">first class</a> type may be used as the value
5395 arguments to the PHI node. Only labels may be used as the label
5396 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5397
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5398<p>There must be no non-phi instructions between the start of a basic block and
5399 the PHI instructions: i.e. PHI instructions must be first in a basic
5400 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5401
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5402<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5403 occur on the edge from the corresponding predecessor block to the current
5404 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5405 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]5406
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5407<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5408<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5409 specified by the pair corresponding to the predecessor basic block that
5410 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5411
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5412<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5413<pre>
5414Loop: ; Infinite loop that counts from 0 on up...
5415 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5416 %nextindvar = add i32 %indvar, 1
5417 br label %Loop
5418</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5419
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5420</div>
5421
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5422<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5423<h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5424 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5425</h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5426
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5427<div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5428
5429<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5430<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]5431 &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>
5432
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5433 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5434</pre>
5435
5436<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5437<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5438 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5439
5440
5441<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5442<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5443 values indicating the condition, and two values of the
5444 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5445 vectors and the condition is a scalar, then entire vectors are selected, not
5446 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5447
5448<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5449<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5450 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5451
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5452<p>If the condition is a vector of i1, then the value arguments must be vectors
5453 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5454
5455<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5456<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5457 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5458</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5459
5460<p>Note that the code generator does not yet support conditions
5461 with vector type.</p>
5462
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5463</div>
5464
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]5465<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5466<h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5467 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5468</h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5469
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5470<div>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5471
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5472<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5473<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]5474 &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]5475</pre>
5476
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5477<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5478<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5479
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5480<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5481<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5482
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5483<ol>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5484 <li>The optional "tail" marker indicates that the callee function does not
5485 access any allocas or varargs in the caller. Note that calls may be
5486 marked "tail" even if they do not occur before
5487 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5488 present, the function call is eligible for tail call optimization,
5489 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Cheng59676492010-03-08 21:05:02 +0000[diff] [blame]5490 optimized into a jump</a>. The code generator may optimize calls marked
5491 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5492 sibling call optimization</a> when the caller and callee have
5493 matching signatures, or 2) forced tail call optimization when the
5494 following extra requirements are met:
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5495 <ul>
5496 <li>Caller and callee both have the calling
5497 convention <tt>fastcc</tt>.</li>
5498 <li>The call is in tail position (ret immediately follows call and ret
5499 uses value of call or is void).</li>
5500 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohman6232f732010-03-02 01:08:11 +0000[diff] [blame]5501 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5502 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5503 constraints are met.</a></li>
5504 </ul>
5505 </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 "cconv" marker indicates which <a href="#callingconv">calling
5508 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5509 defaults to using C calling conventions. The calling convention of the
5510 call must match the calling convention of the target function, or else the
5511 behavior is undefined.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5512
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5513 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5514 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5515 '<tt>inreg</tt>' attributes are valid here.</li>
5516
5517 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5518 type of the return value. Functions that return no value are marked
5519 <tt><a href="#t_void">void</a></tt>.</li>
5520
5521 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5522 being invoked. The argument types must match the types implied by this
5523 signature. This type can be omitted if the function is not varargs and if
5524 the function type does not return a pointer to a function.</li>
5525
5526 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5527 be invoked. In most cases, this is a direct function invocation, but
5528 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5529 to function value.</li>
5530
5531 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]5532 signature argument types and parameter attributes. All arguments must be
5533 of <a href="#t_firstclass">first class</a> type. If the function
5534 signature indicates the function accepts a variable number of arguments,
5535 the extra arguments can be specified.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5536
5537 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5538 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5539 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5540</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5541
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5542<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5543<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5544 a specified function, with its incoming arguments bound to the specified
5545 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5546 function, control flow continues with the instruction after the function
5547 call, and the return value of the function is bound to the result
5548 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5549
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5550<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5551<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]5552 %retval = call i32 @test(i32 %argc)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5553 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]5554 %X = tail call i32 @foo() <i>; yields i32</i>
5555 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5556 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]5557
5558 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5559 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]5560 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5561 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]5562 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]5563 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5564</pre>
5565
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5566<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen722212d2009-09-25 17:04:42 +0000[diff] [blame]5567standard C99 library as being the C99 library functions, and may perform
5568optimizations or generate code for them under that assumption. This is
5569something we'd like to change in the future to provide better support for
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5570freestanding environments and non-C-based languages.</p>
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5571
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5572</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5573
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5574<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5575<h4>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]5576 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5577</h4>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5578
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5579<div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5580
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5581<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5582<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5583 &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]5584</pre>
5585
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5586<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5587<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5588 the "variable argument" area of a function call. It is used to implement the
5589 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5590
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5591<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5592<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5593 argument. It returns a value of the specified argument type and increments
5594 the <tt>va_list</tt> to point to the next argument. The actual type
5595 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5596
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5597<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5598<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5599 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5600 to the next argument. For more information, see the variable argument
5601 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5602
5603<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]5604 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5605 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5606
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5607<p><tt>va_arg</tt> is an LLVM instruction instead of
5608 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5609 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5610
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5611<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5612<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5613
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5614<p>Note that the code generator does not yet fully support va_arg on many
5615 targets. Also, it does not currently support va_arg with aggregate types on
5616 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]5617
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5618</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5619
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5620</div>
5621
5622</div>
5623
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5624<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5625<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]5626<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5627
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5628<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5629
5630<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5631 well known names and semantics and are required to follow certain
5632 restrictions. Overall, these intrinsics represent an extension mechanism for
5633 the LLVM language that does not require changing all of the transformations
5634 in LLVM when adding to the language (or the bitcode reader/writer, the
5635 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5636
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5637<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5638 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5639 begin with this prefix. Intrinsic functions must always be external
5640 functions: you cannot define the body of intrinsic functions. Intrinsic
5641 functions may only be used in call or invoke instructions: it is illegal to
5642 take the address of an intrinsic function. Additionally, because intrinsic
5643 functions are part of the LLVM language, it is required if any are added that
5644 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5645
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5646<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5647 family of functions that perform the same operation but on different data
5648 types. Because LLVM can represent over 8 million different integer types,
5649 overloading is used commonly to allow an intrinsic function to operate on any
5650 integer type. One or more of the argument types or the result type can be
5651 overloaded to accept any integer type. Argument types may also be defined as
5652 exactly matching a previous argument's type or the result type. This allows
5653 an intrinsic function which accepts multiple arguments, but needs all of them
5654 to be of the same type, to only be overloaded with respect to a single
5655 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5656
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5657<p>Overloaded intrinsics will have the names of its overloaded argument types
5658 encoded into its function name, each preceded by a period. Only those types
5659 which are overloaded result in a name suffix. Arguments whose type is matched
5660 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5661 can take an integer of any width and returns an integer of exactly the same
5662 integer width. This leads to a family of functions such as
5663 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5664 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5665 suffix is required. Because the argument's type is matched against the return
5666 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5667
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5668<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5669 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5670
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5671<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5672<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5673 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5674</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5675
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5676<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5677
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5678<p>Variable argument support is defined in LLVM with
5679 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5680 intrinsic functions. These functions are related to the similarly named
5681 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5682
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5683<p>All of these functions operate on arguments that use a target-specific value
5684 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5685 not define what this type is, so all transformations should be prepared to
5686 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5687
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]5688<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]5689 instruction and the variable argument handling intrinsic functions are
5690 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5691
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]5692<pre class="doc_code">
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5693define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5694 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5695 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5696 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5697 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5698
5699 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5700 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5701
5702 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5703 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5704 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5705 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5706 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5707
5708 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5709 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5710 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5711}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5712
5713declare void @llvm.va_start(i8*)
5714declare void @llvm.va_copy(i8*, i8*)
5715declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5716</pre>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5717
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5718<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5719<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5720 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5721</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5722
5723
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5724<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5725
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5726<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5727<pre>
5728 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5729</pre>
5730
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5731<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5732<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5733 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]5734
5735<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5736<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]5737
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5738<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5739<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]5740 macro available in C. In a target-dependent way, it initializes
5741 the <tt>va_list</tt> element to which the argument points, so that the next
5742 call to <tt>va_arg</tt> will produce the first variable argument passed to
5743 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5744 need to know the last argument of the function as the compiler can figure
5745 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5746
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5747</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5748
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5749<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5750<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5751 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5752</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5753
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5754<div>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5755
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5756<h5>Syntax:</h5>
5757<pre>
5758 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5759</pre>
5760
5761<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5762<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5763 which has been initialized previously
5764 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5765 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5766
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5767<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5768<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]5769
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5770<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5771<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]5772 macro available in C. In a target-dependent way, it destroys
5773 the <tt>va_list</tt> element to which the argument points. Calls
5774 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5775 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5776 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5777
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5778</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5779
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5780<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5781<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5782 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5783</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5784
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5785<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5786
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5787<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5788<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5789 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5790</pre>
5791
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5792<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5793<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5794 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5795
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5796<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5797<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]5798 The second argument is a pointer to a <tt>va_list</tt> element to copy
5799 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5800
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5801<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5802<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]5803 macro available in C. In a target-dependent way, it copies the
5804 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5805 element. This intrinsic is necessary because
5806 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5807 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5808
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5809</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5810
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5811</div>
5812
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5813<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5814<h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5815 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5816</h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5817
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5818<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5819
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5820<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5821Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5822intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5823roots on the stack</a>, as well as garbage collector implementations that
5824require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5825barriers. Front-ends for type-safe garbage collected languages should generate
5826these intrinsics to make use of the LLVM garbage collectors. For more details,
5827see <a href="GarbageCollection.html">Accurate Garbage Collection with
5828LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5829
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5830<p>The garbage collection intrinsics only operate on objects in the generic
5831 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5832
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5833<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5834<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5835 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5836</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5837
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5838<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5839
5840<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5841<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5842 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5843</pre>
5844
5845<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]5846<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]5847 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5848
5849<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5850<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5851 root pointer. The second pointer (which must be either a constant or a
5852 global value address) contains the meta-data to be associated with the
5853 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5854
5855<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]5856<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]5857 location. At compile-time, the code generator generates information to allow
5858 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5859 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5860 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5861
5862</div>
5863
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5864<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5865<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5866 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5867</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5868
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5869<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5870
5871<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5872<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5873 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5874</pre>
5875
5876<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5877<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5878 locations, allowing garbage collector implementations that require read
5879 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5880
5881<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5882<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]5883 allocated from the garbage collector. The first object is a pointer to the
5884 start of the referenced object, if needed by the language runtime (otherwise
5885 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5886
5887<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5888<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5889 instruction, but may be replaced with substantially more complex code by the
5890 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5891 may only be used in a function which <a href="#gc">specifies a GC
5892 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5893
5894</div>
5895
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5896<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5897<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5898 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5899</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5900
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5901<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5902
5903<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5904<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5905 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5906</pre>
5907
5908<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5909<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5910 locations, allowing garbage collector implementations that require write
5911 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5912
5913<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5914<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]5915 object to store it to, and the third is the address of the field of Obj to
5916 store to. If the runtime does not require a pointer to the object, Obj may
5917 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5918
5919<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5920<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5921 instruction, but may be replaced with substantially more complex code by the
5922 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5923 may only be used in a function which <a href="#gc">specifies a GC
5924 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5925
5926</div>
5927
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5928</div>
5929
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5930<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5931<h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5932 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5933</h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5934
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5935<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5936
5937<p>These intrinsics are provided by LLVM to expose special features that may
5938 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5939
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5940<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5941<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5942 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5943</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5944
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5945<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5946
5947<h5>Syntax:</h5>
5948<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5949 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5950</pre>
5951
5952<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5953<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5954 target-specific value indicating the return address of the current function
5955 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5956
5957<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5958<p>The argument to this intrinsic indicates which function to return the address
5959 for. Zero indicates the calling function, one indicates its caller, etc.
5960 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5961
5962<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5963<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5964 indicating the return address of the specified call frame, or zero if it
5965 cannot be identified. The value returned by this intrinsic is likely to be
5966 incorrect or 0 for arguments other than zero, so it should only be used for
5967 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5968
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5969<p>Note that calling this intrinsic does not prevent function inlining or other
5970 aggressive transformations, so the value returned may not be that of the
5971 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5972
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5973</div>
5974
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5975<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5976<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5977 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5978</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5979
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5980<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5981
5982<h5>Syntax:</h5>
5983<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5984 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5985</pre>
5986
5987<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5988<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5989 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5990
5991<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5992<p>The argument to this intrinsic indicates which function to return the frame
5993 pointer for. Zero indicates the calling function, one indicates its caller,
5994 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5995
5996<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5997<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5998 indicating the frame address of the specified call frame, or zero if it
5999 cannot be identified. The value returned by this intrinsic is likely to be
6000 incorrect or 0 for arguments other than zero, so it should only be used for
6001 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6002
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6003<p>Note that calling this intrinsic does not prevent function inlining or other
6004 aggressive transformations, so the value returned may not be that of the
6005 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6006
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6007</div>
6008
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6009<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6010<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6011 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6012</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6013
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6014<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6015
6016<h5>Syntax:</h5>
6017<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6018 declare i8* @llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6019</pre>
6020
6021<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6022<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6023 of the function stack, for use
6024 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6025 useful for implementing language features like scoped automatic variable
6026 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6027
6028<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6029<p>This intrinsic returns a opaque pointer value that can be passed
6030 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6031 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6032 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6033 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6034 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6035 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6036
6037</div>
6038
6039<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6040<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6041 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6042</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6043
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6044<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6045
6046<h5>Syntax:</h5>
6047<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6048 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6049</pre>
6050
6051<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6052<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6053 the function stack to the state it was in when the
6054 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6055 executed. This is useful for implementing language features like scoped
6056 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6057
6058<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6059<p>See the description
6060 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6061
6062</div>
6063
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]6064<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6065<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6066 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6067</h4>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6068
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6069<div>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6070
6071<h5>Syntax:</h5>
6072<pre>
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6073 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;, i32 &lt;cache type&gt;)
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6074</pre>
6075
6076<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6077<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6078 insert a prefetch instruction if supported; otherwise, it is a noop.
6079 Prefetches have no effect on the behavior of the program but can change its
6080 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6081
6082<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6083<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6084 specifier determining if the fetch should be for a read (0) or write (1),
6085 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6086 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6087 specifies whether the prefetch is performed on the data (1) or instruction (0)
6088 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6089 must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6090
6091<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6092<p>This intrinsic does not modify the behavior of the program. In particular,
6093 prefetches cannot trap and do not produce a value. On targets that support
6094 this intrinsic, the prefetch can provide hints to the processor cache for
6095 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6096
6097</div>
6098
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6099<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6100<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6101 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6102</h4>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6103
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6104<div>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6105
6106<h5>Syntax:</h5>
6107<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6108 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6109</pre>
6110
6111<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6112<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6113 Counter (PC) in a region of code to simulators and other tools. The method
6114 is target specific, but it is expected that the marker will use exported
6115 symbols to transmit the PC of the marker. The marker makes no guarantees
6116 that it will remain with any specific instruction after optimizations. It is
6117 possible that the presence of a marker will inhibit optimizations. The
6118 intended use is to be inserted after optimizations to allow correlations of
6119 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6120
6121<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6122<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6123
6124<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6125<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6126 not support this intrinsic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6127
6128</div>
6129
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6130<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6131<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6132 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6133</h4>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6134
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6135<div>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6136
6137<h5>Syntax:</h5>
6138<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]6139 declare i64 @llvm.readcyclecounter()
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6140</pre>
6141
6142<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6143<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6144 counter register (or similar low latency, high accuracy clocks) on those
6145 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6146 should map to RPCC. As the backing counters overflow quickly (on the order
6147 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6148
6149<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6150<p>When directly supported, reading the cycle counter should not modify any
6151 memory. Implementations are allowed to either return a application specific
6152 value or a system wide value. On backends without support, this is lowered
6153 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6154
6155</div>
6156
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6157</div>
6158
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6159<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6160<h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6161 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6162</h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6163
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6164<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6165
6166<p>LLVM provides intrinsics for a few important standard C library functions.
6167 These intrinsics allow source-language front-ends to pass information about
6168 the alignment of the pointer arguments to the code generator, providing
6169 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6170
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6171<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6172<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6173 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6174</h4>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6175
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6176<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6177
6178<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6179<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]6180 integer bit width and for different address spaces. Not all targets support
6181 all bit widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6182
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6183<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6184 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]6185 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6186 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]6187 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6188</pre>
6189
6190<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6191<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6192 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6193
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6194<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6195 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6196 and the pointers can be in specified address spaces.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6197
6198<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6199
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6200<p>The first argument is a pointer to the destination, the second is a pointer
6201 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6202 number of bytes to copy, the fourth argument is the alignment of the
6203 source and destination locations, and the fifth is a boolean indicating a
6204 volatile access.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6205
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6206<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]6207 then the caller guarantees that both the source and destination pointers are
6208 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6209
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6210<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6211 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6212 The detailed access behavior is not very cleanly specified and it is unwise
6213 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6214
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6215<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6216
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6217<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6218 source location to the destination location, which are not allowed to
6219 overlap. It copies "len" bytes of memory over. If the argument is known to
6220 be aligned to some boundary, this can be specified as the fourth argument,
6221 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6222
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6223</div>
6224
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6225<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6226<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6227 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6228</h4>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6229
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6230<div>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6231
6232<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6233<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]6234 width and for different address space. Not all targets support all bit
6235 widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6236
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6237<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6238 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]6239 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6240 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]6241 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6242</pre>
6243
6244<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6245<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6246 source location to the destination location. It is similar to the
6247 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6248 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6249
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6250<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6251 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6252 and the pointers can be in specified address spaces.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6253
6254<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6255
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6256<p>The first argument is a pointer to the destination, the second is a pointer
6257 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6258 number of bytes to copy, the fourth argument is the alignment of the
6259 source and destination locations, and the fifth is a boolean indicating a
6260 volatile access.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6261
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6262<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]6263 then the caller guarantees that the source and destination pointers are
6264 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6265
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6266<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6267 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6268 The detailed access behavior is not very cleanly specified and it is unwise
6269 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6270
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6271<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6272
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6273<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6274 source location to the destination location, which may overlap. It copies
6275 "len" bytes of memory over. If the argument is known to be aligned to some
6276 boundary, this can be specified as the fourth argument, otherwise it should
6277 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6278
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6279</div>
6280
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6281<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6282<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6283 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6284</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6285
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6286<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6287
6288<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6289<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]6290 width and for different address spaces. However, not all targets support all
6291 bit widths.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6292
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6293<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6294 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6295 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6296 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6297 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6298</pre>
6299
6300<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6301<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6302 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6303
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6304<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6305 intrinsic does not return a value and takes extra alignment/volatile
6306 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6307
6308<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6309<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]6310 byte value with which to fill it, the third argument is an integer argument
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6311 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6312 alignment of the destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6313
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6314<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]6315 then the caller guarantees that the destination pointer is aligned to that
6316 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6317
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6318<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6319 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6320 The detailed access behavior is not very cleanly specified and it is unwise
6321 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6322
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6323<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6324<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6325 at the destination location. If the argument is known to be aligned to some
6326 boundary, this can be specified as the fourth argument, otherwise it should
6327 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6328
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6329</div>
6330
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6331<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6332<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6333 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6334</h4>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6335
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6336<div>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6337
6338<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6339<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6340 floating point or vector of floating point type. Not all targets support all
6341 types however.</p>
6342
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6343<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6344 declare float @llvm.sqrt.f32(float %Val)
6345 declare double @llvm.sqrt.f64(double %Val)
6346 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6347 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6348 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6349</pre>
6350
6351<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6352<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6353 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6354 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6355 behavior for negative numbers other than -0.0 (which allows for better
6356 optimization, because there is no need to worry about errno being
6357 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]6358
6359<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6360<p>The argument and return value are floating point numbers of the same
6361 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6362
6363<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6364<p>This function returns the sqrt of the specified operand if it is a
6365 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6366
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6367</div>
6368
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6369<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6370<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6371 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6372</h4>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6373
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6374<div>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6375
6376<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6377<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6378 floating point or vector of floating point type. Not all targets support all
6379 types however.</p>
6380
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6381<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6382 declare float @llvm.powi.f32(float %Val, i32 %power)
6383 declare double @llvm.powi.f64(double %Val, i32 %power)
6384 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6385 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6386 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6387</pre>
6388
6389<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6390<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6391 specified (positive or negative) power. The order of evaluation of
6392 multiplications is not defined. When a vector of floating point type is
6393 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6394
6395<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6396<p>The second argument is an integer power, and the first is a value to raise to
6397 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6398
6399<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6400<p>This function returns the first value raised to the second power with an
6401 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6402
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6403</div>
6404
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6405<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6406<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6407 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6408</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6409
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6410<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6411
6412<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6413<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6414 floating point or vector of floating point type. Not all targets support all
6415 types however.</p>
6416
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6417<pre>
6418 declare float @llvm.sin.f32(float %Val)
6419 declare double @llvm.sin.f64(double %Val)
6420 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6421 declare fp128 @llvm.sin.f128(fp128 %Val)
6422 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6423</pre>
6424
6425<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6426<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6427
6428<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6429<p>The argument and return value are floating point numbers of the same
6430 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6431
6432<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6433<p>This function returns the sine of the specified operand, returning the same
6434 values as the libm <tt>sin</tt> functions would, and handles error conditions
6435 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6436
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6437</div>
6438
6439<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6440<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6441 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6442</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6443
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6444<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6445
6446<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6447<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6448 floating point or vector of floating point type. Not all targets support all
6449 types however.</p>
6450
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6451<pre>
6452 declare float @llvm.cos.f32(float %Val)
6453 declare double @llvm.cos.f64(double %Val)
6454 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6455 declare fp128 @llvm.cos.f128(fp128 %Val)
6456 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6457</pre>
6458
6459<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6460<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6461
6462<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6463<p>The argument and return value are floating point numbers of the same
6464 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6465
6466<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6467<p>This function returns the cosine of the specified operand, returning the same
6468 values as the libm <tt>cos</tt> functions would, and handles error conditions
6469 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6470
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6471</div>
6472
6473<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6474<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6475 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6476</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6477
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6478<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6479
6480<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6481<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6482 floating point or vector of floating point type. Not all targets support all
6483 types however.</p>
6484
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6485<pre>
6486 declare float @llvm.pow.f32(float %Val, float %Power)
6487 declare double @llvm.pow.f64(double %Val, double %Power)
6488 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6489 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6490 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6491</pre>
6492
6493<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6494<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6495 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6496
6497<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6498<p>The second argument is a floating point power, and the first is a value to
6499 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6500
6501<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6502<p>This function returns the first value raised to the second power, returning
6503 the same values as the libm <tt>pow</tt> functions would, and handles error
6504 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6505
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6506</div>
6507
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6508</div>
6509
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6510<!-- _______________________________________________________________________ -->
6511<h4>
6512 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6513</h4>
6514
6515<div>
6516
6517<h5>Syntax:</h5>
6518<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6519 floating point or vector of floating point type. Not all targets support all
6520 types however.</p>
6521
6522<pre>
6523 declare float @llvm.exp.f32(float %Val)
6524 declare double @llvm.exp.f64(double %Val)
6525 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6526 declare fp128 @llvm.exp.f128(fp128 %Val)
6527 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6528</pre>
6529
6530<h5>Overview:</h5>
6531<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6532
6533<h5>Arguments:</h5>
6534<p>The argument and return value are floating point numbers of the same
6535 type.</p>
6536
6537<h5>Semantics:</h5>
6538<p>This function returns the same values as the libm <tt>exp</tt> functions
6539 would, and handles error conditions in the same way.</p>
6540
6541</div>
6542
6543<!-- _______________________________________________________________________ -->
6544<h4>
6545 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6546</h4>
6547
6548<div>
6549
6550<h5>Syntax:</h5>
6551<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6552 floating point or vector of floating point type. Not all targets support all
6553 types however.</p>
6554
6555<pre>
6556 declare float @llvm.log.f32(float %Val)
6557 declare double @llvm.log.f64(double %Val)
6558 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
6559 declare fp128 @llvm.log.f128(fp128 %Val)
6560 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
6561</pre>
6562
6563<h5>Overview:</h5>
6564<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
6565
6566<h5>Arguments:</h5>
6567<p>The argument and return value are floating point numbers of the same
6568 type.</p>
6569
6570<h5>Semantics:</h5>
6571<p>This function returns the same values as the libm <tt>log</tt> functions
6572 would, and handles error conditions in the same way.</p>
6573
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame^]6574<h4>
6575 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
6576</h4>
6577
6578<div>
6579
6580<h5>Syntax:</h5>
6581<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
6582 floating point or vector of floating point type. Not all targets support all
6583 types however.</p>
6584
6585<pre>
6586 declare float @llvm.fma.f32(float %a, float %b, float %c)
6587 declare double @llvm.fma.f64(double %a, double %b, double %c)
6588 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
6589 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
6590 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
6591</pre>
6592
6593<h5>Overview:</h5>
6594<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-accumulate
6595 operation.</p>
6596
6597<h5>Arguments:</h5>
6598<p>The argument and return value are floating point numbers of the same
6599 type.</p>
6600
6601<h5>Semantics:</h5>
6602<p>This function returns the same values as the libm <tt>fma</tt> functions
6603 would.</p>
6604
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6605</div>
6606
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6607<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6608<h3>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6609 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6610</h3>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6611
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6612<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6613
6614<p>LLVM provides intrinsics for a few important bit manipulation operations.
6615 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6616
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6617<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6618<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6619 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6620</h4>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6621
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6622<div>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6623
6624<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6625<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6626 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6627
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6628<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6629 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6630 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6631 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6632</pre>
6633
6634<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6635<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6636 values with an even number of bytes (positive multiple of 16 bits). These
6637 are useful for performing operations on data that is not in the target's
6638 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6639
6640<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6641<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6642 and low byte of the input i16 swapped. Similarly,
6643 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6644 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6645 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6646 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6647 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6648 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6649
6650</div>
6651
6652<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6653<h4>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]6654 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6655</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6656
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6657<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6658
6659<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6660<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6661 width, or on any vector with integer elements. Not all targets support all
6662 bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6663
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6664<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6665 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6666 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6667 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6668 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6669 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6670 declare &lt;2 x i32&gt; @llvm.ctpop.v2i32(&lt;2 x i32&gt; &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6671</pre>
6672
6673<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6674<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6675 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6676
6677<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6678<p>The only argument is the value to be counted. The argument may be of any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6679 integer type, or a vector with integer elements.
6680 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6681
6682<h5>Semantics:</h5>
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6683<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
6684 element of a vector.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6685
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6686</div>
6687
6688<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6689<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6690 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6691</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6692
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6693<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6694
6695<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6696<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6697 integer bit width, or any vector whose elements are integers. Not all
6698 targets support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6699
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6700<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6701 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6702 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6703 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6704 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6705 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6706 declare &lt;2 x i32&gt; @llvm.ctlz.v2i32(&lt;2 x i32&gt; &lt;src;gt)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6707</pre>
6708
6709<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6710<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6711 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6712
6713<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6714<p>The only argument is the value to be counted. The argument may be of any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6715 integer type, or any vector type with integer element type.
6716 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6717
6718<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6719<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6720 zeros in a variable, or within each element of the vector if the operation
6721 is of vector type. If the src == 0 then the result is the size in bits of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6722 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6723
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6724</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6725
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6726<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6727<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6728 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6729</h4>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6730
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6731<div>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6732
6733<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6734<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6735 integer bit width, or any vector of integer elements. Not all targets
6736 support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6737
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6738<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6739 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6740 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6741 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6742 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6743 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6744 declase &lt;2 x i32&gt; @llvm.cttz.v2i32(&lt;2 x i32&gt; &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6745</pre>
6746
6747<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6748<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6749 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6750
6751<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6752<p>The only argument is the value to be counted. The argument may be of any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6753 integer type, or a vectory with integer element type.. The return type
6754 must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6755
6756<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6757<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6758 zeros in a variable, or within each element of a vector.
6759 If the src == 0 then the result is the size in bits of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6760 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6761
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6762</div>
6763
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6764</div>
6765
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6766<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6767<h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6768 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6769</h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6770
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6771<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6772
6773<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6774
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6775<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6776<h4>
6777 <a name="int_sadd_overflow">
6778 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
6779 </a>
6780</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6781
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6782<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6783
6784<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6785<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]6786 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6787
6788<pre>
6789 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6790 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6791 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6792</pre>
6793
6794<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6795<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6796 a signed addition of the two arguments, and indicate whether an overflow
6797 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6798
6799<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6800<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]6801 be of integer types of any bit width, but they must have the same bit
6802 width. The second element of the result structure must be of
6803 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6804 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6805
6806<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6807<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6808 a signed addition of the two variables. They return a structure &mdash; the
6809 first element of which is the signed summation, and the second element of
6810 which is a bit specifying if the signed summation resulted in an
6811 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6812
6813<h5>Examples:</h5>
6814<pre>
6815 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6816 %sum = extractvalue {i32, i1} %res, 0
6817 %obit = extractvalue {i32, i1} %res, 1
6818 br i1 %obit, label %overflow, label %normal
6819</pre>
6820
6821</div>
6822
6823<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6824<h4>
6825 <a name="int_uadd_overflow">
6826 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
6827 </a>
6828</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6829
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6830<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6831
6832<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6833<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]6834 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6835
6836<pre>
6837 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6838 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6839 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6840</pre>
6841
6842<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6843<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6844 an unsigned addition of the two arguments, and indicate whether a carry
6845 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6846
6847<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6848<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]6849 be of integer types of any bit width, but they must have the same bit
6850 width. The second element of the result structure must be of
6851 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6852 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6853
6854<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6855<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6856 an unsigned addition of the two arguments. They return a structure &mdash;
6857 the first element of which is the sum, and the second element of which is a
6858 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6859
6860<h5>Examples:</h5>
6861<pre>
6862 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6863 %sum = extractvalue {i32, i1} %res, 0
6864 %obit = extractvalue {i32, i1} %res, 1
6865 br i1 %obit, label %carry, label %normal
6866</pre>
6867
6868</div>
6869
6870<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6871<h4>
6872 <a name="int_ssub_overflow">
6873 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
6874 </a>
6875</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6876
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6877<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6878
6879<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6880<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]6881 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6882
6883<pre>
6884 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6885 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6886 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6887</pre>
6888
6889<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6890<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6891 a signed subtraction of the two arguments, and indicate whether an overflow
6892 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6893
6894<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6895<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]6896 be of integer types of any bit width, but they must have the same bit
6897 width. The second element of the result structure must be of
6898 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6899 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6900
6901<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6902<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6903 a signed subtraction of the two arguments. They return a structure &mdash;
6904 the first element of which is the subtraction, and the second element of
6905 which is a bit specifying if the signed subtraction resulted in an
6906 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6907
6908<h5>Examples:</h5>
6909<pre>
6910 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6911 %sum = extractvalue {i32, i1} %res, 0
6912 %obit = extractvalue {i32, i1} %res, 1
6913 br i1 %obit, label %overflow, label %normal
6914</pre>
6915
6916</div>
6917
6918<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6919<h4>
6920 <a name="int_usub_overflow">
6921 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
6922 </a>
6923</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6924
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6925<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6926
6927<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6928<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]6929 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6930
6931<pre>
6932 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6933 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6934 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6935</pre>
6936
6937<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6938<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6939 an unsigned subtraction of the two arguments, and indicate whether an
6940 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6941
6942<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6943<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]6944 be of integer types of any bit width, but they must have the same bit
6945 width. The second element of the result structure must be of
6946 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6947 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6948
6949<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6950<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6951 an unsigned subtraction of the two arguments. They return a structure &mdash;
6952 the first element of which is the subtraction, and the second element of
6953 which is a bit specifying if the unsigned subtraction resulted in an
6954 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6955
6956<h5>Examples:</h5>
6957<pre>
6958 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6959 %sum = extractvalue {i32, i1} %res, 0
6960 %obit = extractvalue {i32, i1} %res, 1
6961 br i1 %obit, label %overflow, label %normal
6962</pre>
6963
6964</div>
6965
6966<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6967<h4>
6968 <a name="int_smul_overflow">
6969 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
6970 </a>
6971</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6972
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6973<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6974
6975<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6976<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]6977 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6978
6979<pre>
6980 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6981 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6982 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6983</pre>
6984
6985<h5>Overview:</h5>
6986
6987<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6988 a signed multiplication of the two arguments, and indicate whether an
6989 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6990
6991<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6992<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]6993 be of integer types of any bit width, but they must have the same bit
6994 width. The second element of the result structure must be of
6995 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6996 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6997
6998<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6999<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7000 a signed multiplication of the two arguments. They return a structure &mdash;
7001 the first element of which is the multiplication, and the second element of
7002 which is a bit specifying if the signed multiplication resulted in an
7003 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]7004
7005<h5>Examples:</h5>
7006<pre>
7007 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7008 %sum = extractvalue {i32, i1} %res, 0
7009 %obit = extractvalue {i32, i1} %res, 1
7010 br i1 %obit, label %overflow, label %normal
7011</pre>
7012
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]7013</div>
7014
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7015<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7016<h4>
7017 <a name="int_umul_overflow">
7018 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7019 </a>
7020</h4>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7021
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7022<div>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7023
7024<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7025<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]7026 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7027
7028<pre>
7029 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7030 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7031 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7032</pre>
7033
7034<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7035<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7036 a unsigned multiplication of the two arguments, and indicate whether an
7037 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7038
7039<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7040<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]7041 be of integer types of any bit width, but they must have the same bit
7042 width. The second element of the result structure must be of
7043 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7044 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7045
7046<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7047<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7048 an unsigned multiplication of the two arguments. They return a structure
7049 &mdash; the first element of which is the multiplication, and the second
7050 element of which is a bit specifying if the unsigned multiplication resulted
7051 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]7052
7053<h5>Examples:</h5>
7054<pre>
7055 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7056 %sum = extractvalue {i32, i1} %res, 0
7057 %obit = extractvalue {i32, i1} %res, 1
7058 br i1 %obit, label %overflow, label %normal
7059</pre>
7060
7061</div>
7062
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7063</div>
7064
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7065<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7066<h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7067 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7068</h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7069
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7070<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7071
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7072<p>Half precision floating point is a storage-only format. This means that it is
7073 a dense encoding (in memory) but does not support computation in the
7074 format.</p>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7075
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7076<p>This means that code must first load the half-precision floating point
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7077 value as an i16, then convert it to float with <a
7078 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7079 Computation can then be performed on the float value (including extending to
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7080 double etc). To store the value back to memory, it is first converted to
7081 float if needed, then converted to i16 with
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7082 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7083 storing as an i16 value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7084
7085<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7086<h4>
7087 <a name="int_convert_to_fp16">
7088 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7089 </a>
7090</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7091
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7092<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7093
7094<h5>Syntax:</h5>
7095<pre>
7096 declare i16 @llvm.convert.to.fp16(f32 %a)
7097</pre>
7098
7099<h5>Overview:</h5>
7100<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7101 a conversion from single precision floating point format to half precision
7102 floating point format.</p>
7103
7104<h5>Arguments:</h5>
7105<p>The intrinsic function contains single argument - the value to be
7106 converted.</p>
7107
7108<h5>Semantics:</h5>
7109<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7110 a conversion from single precision floating point format to half precision
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7111 floating point format. The return value is an <tt>i16</tt> which
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7112 contains the converted number.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7113
7114<h5>Examples:</h5>
7115<pre>
7116 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7117 store i16 %res, i16* @x, align 2
7118</pre>
7119
7120</div>
7121
7122<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7123<h4>
7124 <a name="int_convert_from_fp16">
7125 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7126 </a>
7127</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7128
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7129<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7130
7131<h5>Syntax:</h5>
7132<pre>
7133 declare f32 @llvm.convert.from.fp16(i16 %a)
7134</pre>
7135
7136<h5>Overview:</h5>
7137<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7138 a conversion from half precision floating point format to single precision
7139 floating point format.</p>
7140
7141<h5>Arguments:</h5>
7142<p>The intrinsic function contains single argument - the value to be
7143 converted.</p>
7144
7145<h5>Semantics:</h5>
7146<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7147 conversion from half single precision floating point format to single
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7148 precision floating point format. The input half-float value is represented by
7149 an <tt>i16</tt> value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7150
7151<h5>Examples:</h5>
7152<pre>
7153 %a = load i16* @x, align 2
7154 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7155</pre>
7156
7157</div>
7158
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7159</div>
7160
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7161<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7162<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7163 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7164</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7165
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7166<div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7167
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7168<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7169 prefix), are described in
7170 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7171 Level Debugging</a> document.</p>
7172
7173</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7174
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7175<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7176<h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7177 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7178</h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7179
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7180<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7181
7182<p>The LLVM exception handling intrinsics (which all start with
7183 <tt>llvm.eh.</tt> prefix), are described in
7184 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7185 Handling</a> document.</p>
7186
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7187</div>
7188
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7189<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7190<h3>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7191 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7192</h3>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7193
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7194<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7195
7196<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]7197 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7198 The result is a callable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7199 function pointer lacking the nest parameter - the caller does not need to
7200 provide a value for it. Instead, the value to use is stored in advance in a
7201 "trampoline", a block of memory usually allocated on the stack, which also
7202 contains code to splice the nest value into the argument list. This is used
7203 to implement the GCC nested function address extension.</p>
7204
7205<p>For example, if the function is
7206 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7207 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7208 follows:</p>
7209
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]7210<pre class="doc_code">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7211 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7212 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7213 %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]7214 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7215</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7216
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7217<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7218 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7219
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7220<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7221<h4>
7222 <a name="int_it">
7223 '<tt>llvm.init.trampoline</tt>' Intrinsic
7224 </a>
7225</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7226
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7227<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7228
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7229<h5>Syntax:</h5>
7230<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7231 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]7232</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7233
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7234<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7235<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7236 function pointer suitable for executing it.</p>
7237
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7238<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7239<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7240 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7241 sufficiently aligned block of memory; this memory is written to by the
7242 intrinsic. Note that the size and the alignment are target-specific - LLVM
7243 currently provides no portable way of determining them, so a front-end that
7244 generates this intrinsic needs to have some target-specific knowledge.
7245 The <tt>func</tt> argument must hold a function bitcast to
7246 an <tt>i8*</tt>.</p>
7247
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7248<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7249<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7250 dependent code, turning it into a function. A pointer to this function is
7251 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7252 function pointer type</a> before being called. The new function's signature
7253 is the same as that of <tt>func</tt> with any arguments marked with
7254 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7255 is allowed, and it must be of pointer type. Calling the new function is
7256 equivalent to calling <tt>func</tt> with the same argument list, but
7257 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7258 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7259 by <tt>tramp</tt> is modified, then the effect of any later call to the
7260 returned function pointer is undefined.</p>
7261
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7262</div>
7263
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7264</div>
7265
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7266<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7267<h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7268 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7269</h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7270
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7271<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7272
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7273<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7274 hardware constructs for atomic operations and memory synchronization. This
7275 provides an interface to the hardware, not an interface to the programmer. It
7276 is aimed at a low enough level to allow any programming models or APIs
7277 (Application Programming Interfaces) which need atomic behaviors to map
7278 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7279 hardware provides a "universal IR" for source languages, it also provides a
7280 starting point for developing a "universal" atomic operation and
7281 synchronization IR.</p>
7282
7283<p>These do <em>not</em> form an API such as high-level threading libraries,
7284 software transaction memory systems, atomic primitives, and intrinsic
7285 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7286 application libraries. The hardware interface provided by LLVM should allow
7287 a clean implementation of all of these APIs and parallel programming models.
7288 No one model or paradigm should be selected above others unless the hardware
7289 itself ubiquitously does so.</p>
7290
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7291<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7292<h4>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7293 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7294</h4>
7295
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7296<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7297<h5>Syntax:</h5>
7298<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7299 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]7300</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7301
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7302<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7303<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7304 specific pairs of memory access types.</p>
7305
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7306<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7307<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7308 The first four arguments enables a specific barrier as listed below. The
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]7309 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7310 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7311
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7312<ul>
7313 <li><tt>ll</tt>: load-load barrier</li>
7314 <li><tt>ls</tt>: load-store barrier</li>
7315 <li><tt>sl</tt>: store-load barrier</li>
7316 <li><tt>ss</tt>: store-store barrier</li>
7317 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7318</ul>
7319
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7320<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7321<p>This intrinsic causes the system to enforce some ordering constraints upon
7322 the loads and stores of the program. This barrier does not
7323 indicate <em>when</em> any events will occur, it only enforces
7324 an <em>order</em> in which they occur. For any of the specified pairs of load
7325 and store operations (f.ex. load-load, or store-load), all of the first
7326 operations preceding the barrier will complete before any of the second
7327 operations succeeding the barrier begin. Specifically the semantics for each
7328 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7329
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7330<ul>
7331 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7332 after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7333 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7334 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7335 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7336 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7337 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7338 load after the barrier begins.</li>
7339</ul>
7340
7341<p>These semantics are applied with a logical "and" behavior when more than one
7342 is enabled in a single memory barrier intrinsic.</p>
7343
7344<p>Backends may implement stronger barriers than those requested when they do
7345 not support as fine grained a barrier as requested. Some architectures do
7346 not need all types of barriers and on such architectures, these become
7347 noops.</p>
7348
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7349<h5>Example:</h5>
7350<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7351%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7352%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7353 store i32 4, %ptr
7354
7355%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0ac49c62011-06-29 17:14:00 +0000[diff] [blame]7356 call void @llvm.memory.barrier(i1 false, i1 true, i1 false, i1 false, i1 true)
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7357 <i>; guarantee the above finishes</i>
7358 store i32 8, %ptr <i>; before this begins</i>
7359</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7360
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7361</div>
7362
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7363<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7364<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7365 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7366</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7367
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7368<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7369
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7370<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7371<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7372 any integer bit width and for different address spaces. Not all targets
7373 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7374
7375<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7376 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7377 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7378 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7379 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]7380</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7381
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7382<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7383<p>This loads a value in memory and compares it to a given value. If they are
7384 equal, it stores a new value into the memory.</p>
7385
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7386<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7387<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7388 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7389 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7390 this integer type. While any bit width integer may be used, targets may only
7391 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7392
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7393<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7394<p>This entire intrinsic must be executed atomically. It first loads the value
7395 in memory pointed to by <tt>ptr</tt> and compares it with the
7396 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7397 memory. The loaded value is yielded in all cases. This provides the
7398 equivalent of an atomic compare-and-swap operation within the SSA
7399 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7400
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7401<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7402<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7403%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7404%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7405 store i32 4, %ptr
7406
7407%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7408%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7409 <i>; yields {i32}:result1 = 4</i>
7410%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7411%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7412
7413%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7414%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7415 <i>; yields {i32}:result2 = 8</i>
7416%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7417
7418%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7419</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7420
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7421</div>
7422
7423<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7424<h4>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7425 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7426</h4>
7427
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7428<div>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7429<h5>Syntax:</h5>
7430
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7431<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7432 integer bit width. Not all targets support all bit widths however.</p>
7433
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7434<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7435 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7436 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7437 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7438 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]7439</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7440
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7441<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7442<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7443 the value from memory. It then stores the value in <tt>val</tt> in the memory
7444 at <tt>ptr</tt>.</p>
7445
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7446<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7447<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7448 the <tt>val</tt> argument and the result must be integers of the same bit
7449 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7450 integer type. The targets may only lower integer representations they
7451 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7452
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7453<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7454<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7455 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7456 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7457
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7458<h5>Examples:</h5>
7459<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7460%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7461%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7462 store i32 4, %ptr
7463
7464%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7465%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7466 <i>; yields {i32}:result1 = 4</i>
7467%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7468%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7469
7470%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7471%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7472 <i>; yields {i32}:result2 = 8</i>
7473
7474%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7475%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7476</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7477
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7478</div>
7479
7480<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7481<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7482 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7483</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7484
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7485<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7486
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7487<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7488<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7489 any integer bit width. Not all targets support all bit widths however.</p>
7490
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7491<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7492 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7493 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7494 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7495 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]7496</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7497
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7498<h5>Overview:</h5>
7499<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7500 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7501
7502<h5>Arguments:</h5>
7503<p>The intrinsic takes two arguments, the first a pointer to an integer value
7504 and the second an integer value. The result is also an integer value. These
7505 integer types can have any bit width, but they must all have the same bit
7506 width. The targets may only lower integer representations they support.</p>
7507
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7508<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7509<p>This intrinsic does a series of operations atomically. It first loads the
7510 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7511 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]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 4, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7518%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7519 <i>; yields {i32}:result1 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7520%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7521 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7522%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7523 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7524%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7525</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7526
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7527</div>
7528
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7529<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7530<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7531 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7532</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7533
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7534<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7535
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7536<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7537<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7538 any integer bit width and for different address spaces. Not all targets
7539 support all bit widths however.</p>
7540
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7541<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7542 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7543 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7544 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7545 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]7546</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7547
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7548<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7549<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7550 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7551
7552<h5>Arguments:</h5>
7553<p>The intrinsic takes two arguments, the first a pointer to an integer value
7554 and the second an integer value. The result is also an integer value. These
7555 integer types can have any bit width, but they must all have the same bit
7556 width. The targets may only lower integer representations they support.</p>
7557
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7558<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7559<p>This intrinsic does a series of operations atomically. It first loads the
7560 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7561 result to <tt>ptr</tt>. It yields the original value stored
7562 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7563
7564<h5>Examples:</h5>
7565<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7566%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7567%ptr = bitcast i8* %mallocP to i32*
7568 store i32 8, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7569%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7570 <i>; yields {i32}:result1 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7571%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7572 <i>; yields {i32}:result2 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7573%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7574 <i>; yields {i32}:result3 = 2</i>
7575%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7576</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7577
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7578</div>
7579
7580<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7581<h4>
7582 <a name="int_atomic_load_and">
7583 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7584 </a>
7585 <br>
7586 <a name="int_atomic_load_nand">
7587 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7588 </a>
7589 <br>
7590 <a name="int_atomic_load_or">
7591 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7592 </a>
7593 <br>
7594 <a name="int_atomic_load_xor">
7595 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7596 </a>
7597</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7598
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7599<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7600
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7601<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7602<p>These are overloaded intrinsics. You can
7603 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7604 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7605 bit width and for different address spaces. Not all targets support all bit
7606 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7607
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7608<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7609 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7610 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7611 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7612 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]7613</pre>
7614
7615<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7616 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7617 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7618 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7619 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]7620</pre>
7621
7622<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7623 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7624 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7625 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7626 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]7627</pre>
7628
7629<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7630 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7631 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7632 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7633 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]7634</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7635
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7636<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7637<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7638 the value stored in memory at <tt>ptr</tt>. It yields the original value
7639 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7640
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7641<h5>Arguments:</h5>
7642<p>These intrinsics take two arguments, the first a pointer to an integer value
7643 and the second an integer value. The result is also an integer value. These
7644 integer types can have any bit width, but they must all have the same bit
7645 width. The targets may only lower integer representations they support.</p>
7646
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7647<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7648<p>These intrinsics does a series of operations atomically. They first load the
7649 value stored at <tt>ptr</tt>. They then do the bitwise
7650 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7651 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7652
7653<h5>Examples:</h5>
7654<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7655%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7656%ptr = bitcast i8* %mallocP to i32*
7657 store i32 0x0F0F, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7658%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7659 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7660%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7661 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7662%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7663 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7664%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7665 <i>; yields {i32}:result3 = FF</i>
7666%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7667</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7668
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7669</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7670
7671<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7672<h4>
7673 <a name="int_atomic_load_max">
7674 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
7675 </a>
7676 <br>
7677 <a name="int_atomic_load_min">
7678 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
7679 </a>
7680 <br>
7681 <a name="int_atomic_load_umax">
7682 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
7683 </a>
7684 <br>
7685 <a name="int_atomic_load_umin">
7686 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
7687 </a>
7688</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7689
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7690<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7691
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7692<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7693<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7694 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7695 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7696 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7697
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7698<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7699 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7700 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7701 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7702 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]7703</pre>
7704
7705<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7706 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7707 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7708 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7709 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]7710</pre>
7711
7712<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7713 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7714 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7715 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7716 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]7717</pre>
7718
7719<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7720 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7721 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7722 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7723 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]7724</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7725
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7726<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7727<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7728 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7729 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7730
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7731<h5>Arguments:</h5>
7732<p>These intrinsics take two arguments, the first a pointer to an integer value
7733 and the second an integer value. The result is also an integer value. These
7734 integer types can have any bit width, but they must all have the same bit
7735 width. The targets may only lower integer representations they support.</p>
7736
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7737<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7738<p>These intrinsics does a series of operations atomically. They first load the
7739 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7740 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7741 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7742
7743<h5>Examples:</h5>
7744<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7745%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7746%ptr = bitcast i8* %mallocP to i32*
7747 store i32 7, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7748%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7749 <i>; yields {i32}:result0 = 7</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7750%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7751 <i>; yields {i32}:result1 = -2</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7752%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7753 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7754%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7755 <i>; yields {i32}:result3 = 8</i>
7756%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7757</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7758
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7759</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7760
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7761</div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7762
7763<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7764<h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7765 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7766</h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7767
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7768<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7769
7770<p>This class of intrinsics exists to information about the lifetime of memory
7771 objects and ranges where variables are immutable.</p>
7772
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7773<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7774<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7775 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7776</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7777
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7778<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7779
7780<h5>Syntax:</h5>
7781<pre>
7782 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7783</pre>
7784
7785<h5>Overview:</h5>
7786<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7787 object's lifetime.</p>
7788
7789<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7790<p>The first argument is a constant integer representing the size of the
7791 object, or -1 if it is variable sized. The second argument is a pointer to
7792 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7793
7794<h5>Semantics:</h5>
7795<p>This intrinsic indicates that before this point in the code, the value of the
7796 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]7797 never be used and has an undefined value. A load from the pointer that
7798 precedes this intrinsic can be replaced with
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7799 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7800
7801</div>
7802
7803<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7804<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7805 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7806</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7807
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7808<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7809
7810<h5>Syntax:</h5>
7811<pre>
7812 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7813</pre>
7814
7815<h5>Overview:</h5>
7816<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7817 object's lifetime.</p>
7818
7819<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7820<p>The first argument is a constant integer representing the size of the
7821 object, or -1 if it is variable sized. The second argument is a pointer to
7822 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7823
7824<h5>Semantics:</h5>
7825<p>This intrinsic indicates that after this point in the code, the value of the
7826 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7827 never be used and has an undefined value. Any stores into the memory object
7828 following this intrinsic may be removed as dead.
7829
7830</div>
7831
7832<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7833<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7834 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7835</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7836
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7837<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7838
7839<h5>Syntax:</h5>
7840<pre>
Nick Lewycky2965d3e2010-11-30 04:13:41 +0000[diff] [blame]7841 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7842</pre>
7843
7844<h5>Overview:</h5>
7845<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7846 a memory object will not change.</p>
7847
7848<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7849<p>The first argument is a constant integer representing the size of the
7850 object, or -1 if it is variable sized. The second argument is a pointer to
7851 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7852
7853<h5>Semantics:</h5>
7854<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7855 the return value, the referenced memory location is constant and
7856 unchanging.</p>
7857
7858</div>
7859
7860<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7861<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7862 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7863</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7864
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7865<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7866
7867<h5>Syntax:</h5>
7868<pre>
7869 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7870</pre>
7871
7872<h5>Overview:</h5>
7873<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7874 a memory object are mutable.</p>
7875
7876<h5>Arguments:</h5>
7877<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7878 The second argument is a constant integer representing the size of the
7879 object, or -1 if it is variable sized and the third argument is a pointer
7880 to the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7881
7882<h5>Semantics:</h5>
7883<p>This intrinsic indicates that the memory is mutable again.</p>
7884
7885</div>
7886
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7887</div>
7888
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7889<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7890<h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7891 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7892</h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7893
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7894<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7895
7896<p>This class of intrinsics is designed to be generic and has no specific
7897 purpose.</p>
7898
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7899<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7900<h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7901 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7902</h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7903
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7904<div>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7905
7906<h5>Syntax:</h5>
7907<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7908 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]7909</pre>
7910
7911<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7912<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7913
7914<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7915<p>The first argument is a pointer to a value, the second is a pointer to a
7916 global string, the third is a pointer to a global string which is the source
7917 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7918
7919<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7920<p>This intrinsic allows annotation of local variables with arbitrary strings.
7921 This can be useful for special purpose optimizations that want to look for
7922 these annotations. These have no other defined use, they are ignored by code
7923 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7924
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7925</div>
7926
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7927<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7928<h4>
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]7929 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7930</h4>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7931
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7932<div>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7933
7934<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7935<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7936 any integer bit width.</p>
7937
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7938<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7939 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7940 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7941 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7942 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7943 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]7944</pre>
7945
7946<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7947<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7948
7949<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7950<p>The first argument is an integer value (result of some expression), the
7951 second is a pointer to a global string, the third is a pointer to a global
7952 string which is the source file name, and the last argument is the line
7953 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7954
7955<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7956<p>This intrinsic allows annotations to be put on arbitrary expressions with
7957 arbitrary strings. This can be useful for special purpose optimizations that
7958 want to look for these annotations. These have no other defined use, they
7959 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7960
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7961</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7962
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7963<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7964<h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7965 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7966</h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7967
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7968<div>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7969
7970<h5>Syntax:</h5>
7971<pre>
7972 declare void @llvm.trap()
7973</pre>
7974
7975<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7976<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7977
7978<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7979<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7980
7981<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7982<p>This intrinsics is lowered to the target dependent trap instruction. If the
7983 target does not have a trap instruction, this intrinsic will be lowered to
7984 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7985
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7986</div>
7987
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7988<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7989<h4>
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]7990 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7991</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7992
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7993<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7994
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7995<h5>Syntax:</h5>
7996<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7997 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7998</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7999
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8000<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8001<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8002 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8003 ensure that it is placed on the stack before local variables.</p>
8004
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8005<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8006<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8007 arguments. The first argument is the value loaded from the stack
8008 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8009 that has enough space to hold the value of the guard.</p>
8010
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8011<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8012<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8013 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8014 stack. This is to ensure that if a local variable on the stack is
8015 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8016 the guard on the stack is checked against the original guard. If they are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]8017 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8018 function.</p>
8019
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]8020</div>
8021
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8022<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8023<h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8024 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]8025</h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8026
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8027<div>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8028
8029<h5>Syntax:</h5>
8030<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]8031 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
8032 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8033</pre>
8034
8035<h5>Overview:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8036<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8037 the optimizers to determine at compile time whether a) an operation (like
8038 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8039 runtime check for overflow isn't necessary. An object in this context means
8040 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8041
8042<h5>Arguments:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8043<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]8044 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8045 is a boolean 0 or 1. This argument determines whether you want the
8046 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]8047 1, variables are not allowed.</p>
8048
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8049<h5>Semantics:</h5>
8050<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]8051 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8052 depending on the <tt>type</tt> argument, if the size cannot be determined at
8053 compile time.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]8054
8055</div>
8056
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]8057</div>
8058
8059</div>
8060
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8061<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]8062<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8063<address>
8064 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8065 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8066 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]8067 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]8068
8069 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumica46f5a2011-04-09 02:13:37 +0000[diff] [blame]8070 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]8071 Last modified: $Date$
8072</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]8073
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]8074</body>
8075</html>