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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 6762dc1fb38f7579b33143c80f057319e1537678 / . / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
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7 <meta name="author" content="Chris Lattner">
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]8 <meta name="description"
Reid Spencer3921c742004-08-26 20:44:00 +0000[diff] [blame]9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]14
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]15<h1>LLVM Language Reference Manual</h1>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman9d0919f2003-11-08 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 Lattnerfa730212004-12-09 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 Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling987e7eb2009-07-20 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 Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]27 <li><a href="#linkage_linker_private_weak">'<tt>linker_private_weak</tt>' Linkage</a></li>
Bill Wendling55ae5152010-08-20 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 Wendling987e7eb2009-07-20 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 Lattner5a2d8752009-10-10 18:26:06 +0000[diff] [blame]36 <li><a href="#linkage_linkonce_odr">'<tt>linkonce_odr</tt>' Linkage</a></li>
Bill Wendling987e7eb2009-07-20 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 Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]41 </ol>
42 </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]43 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]44 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]45 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]46 <li><a href="#functionstructure">Functions</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]47 <li><a href="#aliasstructure">Aliases</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]48 <li><a href="#namedmetadatastructure">Named Metadata</a></li>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]49 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]50 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]51 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]52 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]53 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]54 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]55 <li><a href="#volatile">Volatile Memory Accesses</a></li>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]56 <li><a href="#memmodel">Memory Model for Concurrent Operations</a></li>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]57 <li><a href="#ordering">Atomic Memory Ordering Constraints</a></li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]58 </ol>
59 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]60 <li><a href="#typesystem">Type System</a>
61 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]62 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]63 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]64 <ol>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]65 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]66 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]67 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]68 <li><a href="#t_void">Void Type</a></li>
69 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]70 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]71 </ol>
72 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]73 <li><a href="#t_derived">Derived Types</a>
74 <ol>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]75 <li><a href="#t_aggregate">Aggregate Types</a>
76 <ol>
77 <li><a href="#t_array">Array Type</a></li>
78 <li><a href="#t_struct">Structure Type</a></li>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]79 <li><a href="#t_opaque">Opaque Structure Types</a></li>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]80 <li><a href="#t_vector">Vector Type</a></li>
81 </ol>
82 </li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]83 <li><a href="#t_function">Function Type</a></li>
84 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]85 </ol>
86 </li>
87 </ol>
88 </li>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]89 <li><a href="#constants">Constants</a>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]90 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]91 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]92 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman0e451ce2008-10-14 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 Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]95 <li><a href="#trapvalues">Trap Values</a></li>
Chris Lattnerf9d078e2009-10-27 21:19:13 +0000[diff] [blame]96 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]97 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]98 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]99 </li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]100 <li><a href="#othervalues">Other Values</a>
101 <ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]102 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]103 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]104 </ol>
105 </li>
Chris Lattner857755c2009-07-20 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 Lattner401e10c2009-07-20 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 Lattner857755c2009-07-20 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 Lattner00950542001-06-06 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 Lattner261efe92003-11-25 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 Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]123 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]124 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]125 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]126 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]127 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]128 </ol>
129 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]130 <li><a href="#binaryops">Binary Operations</a>
131 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]132 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]133 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]134 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]135 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]136 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]137 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer1628cec2006-10-26 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 Spencer0a783f72006-11-02 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 Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]144 </ol>
145 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]146 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
147 <ol>
Reid Spencer8e11bf82007-02-02 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 Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]151 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]152 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]153 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]154 </ol>
155 </li>
Chris Lattner3df241e2006-04-08 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 Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]161 </ol>
162 </li>
Dan Gohmana334d5f2008-05-12 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 Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]169 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]170 <ol>
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]171 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
172 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
173 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
174 <li><a href="#i_fence">'<tt>fence</tt>' Instruction</a></li>
175 <li><a href="#i_cmpxchg">'<tt>cmpxchg</tt>' Instruction</a></li>
176 <li><a href="#i_atomicrmw">'<tt>atomicrmw</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]177 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]178 </ol>
179 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]180 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]181 <ol>
182 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
183 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
184 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
185 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
186 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]187 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
188 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
189 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
190 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]191 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
192 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]193 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]194 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]195 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]196 <li><a href="#otherops">Other Operations</a>
197 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]198 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
199 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]200 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]201 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]202 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]203 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]204 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]205 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]206 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]207 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]208 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]209 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]210 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
211 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]212 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
213 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
214 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]215 </ol>
216 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]217 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
218 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]219 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
220 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
221 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]222 </ol>
223 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]224 <li><a href="#int_codegen">Code Generator Intrinsics</a>
225 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]226 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
227 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
228 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
229 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
230 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
231 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohman31f1af12010-05-26 21:56:15 +0000[diff] [blame]232 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]233 </ol>
234 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]235 <li><a href="#int_libc">Standard C Library Intrinsics</a>
236 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]237 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
238 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
239 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
240 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
241 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]242 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
243 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
244 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohman08b280b2011-05-27 00:36:31 +0000[diff] [blame]245 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
246 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]247 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]248 </ol>
249 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]250 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]251 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]252 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]253 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
254 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
255 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]256 </ol>
257 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]258 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
259 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]260 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
261 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
262 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
263 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
264 <li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]265 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]266 </ol>
267 </li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]268 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
269 <ol>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]270 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
271 <li><a href="#int_convert_from_fp16">'<tt>llvm.convert.from.fp16</tt>' Intrinsic</a></li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]272 </ol>
273 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]274 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]275 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]276 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]277 <ol>
278 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]279 </ol>
280 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]281 <li><a href="#int_atomics">Atomic intrinsics</a>
282 <ol>
283 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
284 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
285 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
286 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
287 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
288 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
289 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
290 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
291 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
292 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
293 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
294 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
295 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
296 </ol>
297 </li>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]298 <li><a href="#int_memorymarkers">Memory Use Markers</a>
299 <ol>
300 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
301 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
302 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
303 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
304 </ol>
305 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]306 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]307 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]308 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]309 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]310 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]311 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]312 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]313 '<tt>llvm.trap</tt>' Intrinsic</a></li>
314 <li><a href="#int_stackprotector">
315 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]316 <li><a href="#int_objectsize">
317 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]318 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]319 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]320 </ol>
321 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]322</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]323
324<div class="doc_author">
325 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
326 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]327</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]328
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]329<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]330<h2><a name="abstract">Abstract</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]331<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]332
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]333<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]334
335<p>This document is a reference manual for the LLVM assembly language. LLVM is
336 a Static Single Assignment (SSA) based representation that provides type
337 safety, low-level operations, flexibility, and the capability of representing
338 'all' high-level languages cleanly. It is the common code representation
339 used throughout all phases of the LLVM compilation strategy.</p>
340
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]341</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]342
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]343<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]344<h2><a name="introduction">Introduction</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]345<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]346
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]347<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]348
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]349<p>The LLVM code representation is designed to be used in three different forms:
350 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
351 for fast loading by a Just-In-Time compiler), and as a human readable
352 assembly language representation. This allows LLVM to provide a powerful
353 intermediate representation for efficient compiler transformations and
354 analysis, while providing a natural means to debug and visualize the
355 transformations. The three different forms of LLVM are all equivalent. This
356 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]357
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]358<p>The LLVM representation aims to be light-weight and low-level while being
359 expressive, typed, and extensible at the same time. It aims to be a
360 "universal IR" of sorts, by being at a low enough level that high-level ideas
361 may be cleanly mapped to it (similar to how microprocessors are "universal
362 IR's", allowing many source languages to be mapped to them). By providing
363 type information, LLVM can be used as the target of optimizations: for
364 example, through pointer analysis, it can be proven that a C automatic
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]365 variable is never accessed outside of the current function, allowing it to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]366 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]367
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]368<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]369<h4>
370 <a name="wellformed">Well-Formedness</a>
371</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]372
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]373<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]374
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]375<p>It is important to note that this document describes 'well formed' LLVM
376 assembly language. There is a difference between what the parser accepts and
377 what is considered 'well formed'. For example, the following instruction is
378 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]379
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]380<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]381%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]382</pre>
383
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]384<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
385 LLVM infrastructure provides a verification pass that may be used to verify
386 that an LLVM module is well formed. This pass is automatically run by the
387 parser after parsing input assembly and by the optimizer before it outputs
388 bitcode. The violations pointed out by the verifier pass indicate bugs in
389 transformation passes or input to the parser.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]390
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]391</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]392
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]393</div>
394
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]395<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]396
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]397<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]398<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]399<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]400
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]401<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]402
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]403<p>LLVM identifiers come in two basic types: global and local. Global
404 identifiers (functions, global variables) begin with the <tt>'@'</tt>
405 character. Local identifiers (register names, types) begin with
406 the <tt>'%'</tt> character. Additionally, there are three different formats
407 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]408
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]409<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]410 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]411 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
412 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
413 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
414 other characters in their names can be surrounded with quotes. Special
415 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
416 ASCII code for the character in hexadecimal. In this way, any character
417 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]418
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]419 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]420 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]421
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]422 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]423 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]424</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]425
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]426<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]427 don't need to worry about name clashes with reserved words, and the set of
428 reserved words may be expanded in the future without penalty. Additionally,
429 unnamed identifiers allow a compiler to quickly come up with a temporary
430 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]431
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]432<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]433 languages. There are keywords for different opcodes
434 ('<tt><a href="#i_add">add</a></tt>',
435 '<tt><a href="#i_bitcast">bitcast</a></tt>',
436 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
437 ('<tt><a href="#t_void">void</a></tt>',
438 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
439 reserved words cannot conflict with variable names, because none of them
440 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]441
442<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]443 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]444
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]445<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]446
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]447<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]448%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]449</pre>
450
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]451<p>After strength reduction:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]452
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]453<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]454%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]455</pre>
456
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]457<p>And the hard way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]458
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]459<pre class="doc_code">
Gabor Greifec58f752009-10-28 13:05:07 +0000[diff] [blame]460%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
461%1 = <a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]462%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]463</pre>
464
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]465<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
466 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]467
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]468<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]469 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]470 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]471
472 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]473 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]474
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]475 <li>Unnamed temporaries are numbered sequentially</li>
476</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]477
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]478<p>It also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]479 demonstrating instructions, we will follow an instruction with a comment that
480 defines the type and name of value produced. Comments are shown in italic
481 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]482
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]483</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]484
485<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]486<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]487<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]488<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]489<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]490<h3>
491 <a name="modulestructure">Module Structure</a>
492</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]493
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]494<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]495
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]496<p>LLVM programs are composed of "Module"s, each of which is a translation unit
497 of the input programs. Each module consists of functions, global variables,
498 and symbol table entries. Modules may be combined together with the LLVM
499 linker, which merges function (and global variable) definitions, resolves
500 forward declarations, and merges symbol table entries. Here is an example of
501 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]502
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]503<pre class="doc_code">
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]504<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckydb9cd762011-01-29 01:09:53 +0000[diff] [blame]505<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a>&nbsp;<a href="#globalvars">constant</a>&nbsp;<a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]506
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]507<i>; External declaration of the puts function</i>&nbsp;
508<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]509
510<i>; Definition of main function</i>
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]511define i32 @main() { <i>; i32()* </i>&nbsp;
512 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
513 %cast210 = <a href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8*</i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]514
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]515 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
516 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
517 <a href="#i_ret">ret</a> i32 0&nbsp;
518}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]519
520<i>; Named metadata</i>
521!1 = metadata !{i32 41}
522!foo = !{!1, null}
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]523</pre>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]524
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]525<p>This example is made up of a <a href="#globalvars">global variable</a> named
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]526 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]527 a <a href="#functionstructure">function definition</a> for
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]528 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
529 "<tt>foo"</tt>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]530
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]531<p>In general, a module is made up of a list of global values, where both
532 functions and global variables are global values. Global values are
533 represented by a pointer to a memory location (in this case, a pointer to an
534 array of char, and a pointer to a function), and have one of the
535 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]536
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]537</div>
538
539<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]540<h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]541 <a name="linkage">Linkage Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]542</h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]543
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]544<div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]545
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]546<p>All Global Variables and Functions have one of the following types of
547 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]548
549<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]550 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]551 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
552 by objects in the current module. In particular, linking code into a
553 module with an private global value may cause the private to be renamed as
554 necessary to avoid collisions. Because the symbol is private to the
555 module, all references can be updated. This doesn't show up in any symbol
556 table in the object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]557
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]558 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]559 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
560 assembler and evaluated by the linker. Unlike normal strong symbols, they
561 are removed by the linker from the final linked image (executable or
562 dynamic library).</dd>
563
564 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
565 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
566 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
567 linker. The symbols are removed by the linker from the final linked image
568 (executable or dynamic library).</dd>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]569
Bill Wendling55ae5152010-08-20 22:05:50 +0000[diff] [blame]570 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
571 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
572 of the object is not taken. For instance, functions that had an inline
573 definition, but the compiler decided not to inline it. Note,
574 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
575 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
576 visibility. The symbols are removed by the linker from the final linked
577 image (executable or dynamic library).</dd>
578
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]579 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling07d31772010-06-29 22:34:52 +0000[diff] [blame]580 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]581 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
582 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]583
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]584 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]585 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]586 into the object file corresponding to the LLVM module. They exist to
587 allow inlining and other optimizations to take place given knowledge of
588 the definition of the global, which is known to be somewhere outside the
589 module. Globals with <tt>available_externally</tt> linkage are allowed to
590 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
591 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]592
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]593 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]594 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner873187c2010-01-09 19:15:14 +0000[diff] [blame]595 the same name when linkage occurs. This can be used to implement
596 some forms of inline functions, templates, or other code which must be
597 generated in each translation unit that uses it, but where the body may
598 be overridden with a more definitive definition later. Unreferenced
599 <tt>linkonce</tt> globals are allowed to be discarded. Note that
600 <tt>linkonce</tt> linkage does not actually allow the optimizer to
601 inline the body of this function into callers because it doesn't know if
602 this definition of the function is the definitive definition within the
603 program or whether it will be overridden by a stronger definition.
604 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
605 linkage.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]606
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]607 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]608 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
609 <tt>linkonce</tt> linkage, except that unreferenced globals with
610 <tt>weak</tt> linkage may not be discarded. This is used for globals that
611 are declared "weak" in C source code.</dd>
612
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]613 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]614 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
615 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
616 global scope.
617 Symbols with "<tt>common</tt>" linkage are merged in the same way as
618 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]619 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]620 must have a zero initializer, and may not be marked '<a
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]621 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
622 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]623
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]624
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]625 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]626 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]627 pointer to array type. When two global variables with appending linkage
628 are linked together, the two global arrays are appended together. This is
629 the LLVM, typesafe, equivalent of having the system linker append together
630 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]631
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]632 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]633 <dd>The semantics of this linkage follow the ELF object file model: the symbol
634 is weak until linked, if not linked, the symbol becomes null instead of
635 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]636
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]637 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
638 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]639 <dd>Some languages allow differing globals to be merged, such as two functions
640 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]641 that only equivalent globals are ever merged (the "one definition rule"
642 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]643 and <tt>weak_odr</tt> linkage types to indicate that the global will only
644 be merged with equivalent globals. These linkage types are otherwise the
645 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]646
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]647 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]648 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]649 visible, meaning that it participates in linkage and can be used to
650 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]651</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]652
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]653<p>The next two types of linkage are targeted for Microsoft Windows platform
654 only. They are designed to support importing (exporting) symbols from (to)
655 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]656
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]657<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]658 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]659 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]660 or variable via a global pointer to a pointer that is set up by the DLL
661 exporting the symbol. On Microsoft Windows targets, the pointer name is
662 formed by combining <code>__imp_</code> and the function or variable
663 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]664
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]665 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]666 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]667 pointer to a pointer in a DLL, so that it can be referenced with the
668 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
669 name is formed by combining <code>__imp_</code> and the function or
670 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]671</dl>
672
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]673<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
674 another module defined a "<tt>.LC0</tt>" variable and was linked with this
675 one, one of the two would be renamed, preventing a collision. Since
676 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
677 declarations), they are accessible outside of the current module.</p>
678
679<p>It is illegal for a function <i>declaration</i> to have any linkage type
680 other than "externally visible", <tt>dllimport</tt>
681 or <tt>extern_weak</tt>.</p>
682
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]683<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]684 or <tt>weak_odr</tt> linkages.</p>
685
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]686</div>
687
688<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]689<h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]690 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]691</h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]692
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]693<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]694
695<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]696 and <a href="#i_invoke">invokes</a> can all have an optional calling
697 convention specified for the call. The calling convention of any pair of
698 dynamic caller/callee must match, or the behavior of the program is
699 undefined. The following calling conventions are supported by LLVM, and more
700 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]701
702<dl>
703 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]704 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]705 specified) matches the target C calling conventions. This calling
706 convention supports varargs function calls and tolerates some mismatch in
707 the declared prototype and implemented declaration of the function (as
708 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]709
710 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]711 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]712 (e.g. by passing things in registers). This calling convention allows the
713 target to use whatever tricks it wants to produce fast code for the
714 target, without having to conform to an externally specified ABI
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]715 (Application Binary Interface).
716 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]717 when this or the GHC convention is used.</a> This calling convention
718 does not support varargs and requires the prototype of all callees to
719 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]720
721 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]722 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]723 as possible under the assumption that the call is not commonly executed.
724 As such, these calls often preserve all registers so that the call does
725 not break any live ranges in the caller side. This calling convention
726 does not support varargs and requires the prototype of all callees to
727 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]728
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]729 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
730 <dd>This calling convention has been implemented specifically for use by the
731 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
732 It passes everything in registers, going to extremes to achieve this by
733 disabling callee save registers. This calling convention should not be
734 used lightly but only for specific situations such as an alternative to
735 the <em>register pinning</em> performance technique often used when
736 implementing functional programming languages.At the moment only X86
737 supports this convention and it has the following limitations:
738 <ul>
739 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
740 floating point types are supported.</li>
741 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
742 6 floating point parameters.</li>
743 </ul>
744 This calling convention supports
745 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
746 requires both the caller and callee are using it.
747 </dd>
748
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]749 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]750 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]751 target-specific calling conventions to be used. Target specific calling
752 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]753</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]754
755<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]756 support Pascal conventions or any other well-known target-independent
757 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]758
759</div>
760
761<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]762<h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]763 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]764</h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]765
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]766<div>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]767
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]768<p>All Global Variables and Functions have one of the following visibility
769 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]770
771<dl>
772 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]773 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]774 that the declaration is visible to other modules and, in shared libraries,
775 means that the declared entity may be overridden. On Darwin, default
776 visibility means that the declaration is visible to other modules. Default
777 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]778
779 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]780 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]781 object if they are in the same shared object. Usually, hidden visibility
782 indicates that the symbol will not be placed into the dynamic symbol
783 table, so no other module (executable or shared library) can reference it
784 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]785
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]786 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]787 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]788 the dynamic symbol table, but that references within the defining module
789 will bind to the local symbol. That is, the symbol cannot be overridden by
790 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]791</dl>
792
793</div>
794
795<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]796<h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]797 <a name="namedtypes">Named Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]798</h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]799
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]800<div>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]801
802<p>LLVM IR allows you to specify name aliases for certain types. This can make
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]803 it easier to read the IR and make the IR more condensed (particularly when
804 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]805
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]806<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]807%mytype = type { %mytype*, i32 }
808</pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]809
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]810<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattnerdc65f222010-08-17 23:26:04 +0000[diff] [blame]811 "<a href="#t_void">void</a>". Type name aliases may be used anywhere a type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]812 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]813
814<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]815 and that you can therefore specify multiple names for the same type. This
816 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
817 uses structural typing, the name is not part of the type. When printing out
818 LLVM IR, the printer will pick <em>one name</em> to render all types of a
819 particular shape. This means that if you have code where two different
820 source types end up having the same LLVM type, that the dumper will sometimes
821 print the "wrong" or unexpected type. This is an important design point and
822 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]823
824</div>
825
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]826<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]827<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]828 <a name="globalvars">Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]829</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]830
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]831<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]832
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]833<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]834 instead of run-time. Global variables may optionally be initialized, may
835 have an explicit section to be placed in, and may have an optional explicit
836 alignment specified. A variable may be defined as "thread_local", which
837 means that it will not be shared by threads (each thread will have a
838 separated copy of the variable). A variable may be defined as a global
839 "constant," which indicates that the contents of the variable
840 will <b>never</b> be modified (enabling better optimization, allowing the
841 global data to be placed in the read-only section of an executable, etc).
842 Note that variables that need runtime initialization cannot be marked
843 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]844
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]845<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
846 constant, even if the final definition of the global is not. This capability
847 can be used to enable slightly better optimization of the program, but
848 requires the language definition to guarantee that optimizations based on the
849 'constantness' are valid for the translation units that do not include the
850 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]851
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]852<p>As SSA values, global variables define pointer values that are in scope
853 (i.e. they dominate) all basic blocks in the program. Global variables
854 always define a pointer to their "content" type because they describe a
855 region of memory, and all memory objects in LLVM are accessed through
856 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]857
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]858<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
859 that the address is not significant, only the content. Constants marked
Rafael Espindolaa5eaa862011-01-15 08:20:57 +0000[diff] [blame]860 like this can be merged with other constants if they have the same
861 initializer. Note that a constant with significant address <em>can</em>
862 be merged with a <tt>unnamed_addr</tt> constant, the result being a
863 constant whose address is significant.</p>
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]864
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]865<p>A global variable may be declared to reside in a target-specific numbered
866 address space. For targets that support them, address spaces may affect how
867 optimizations are performed and/or what target instructions are used to
868 access the variable. The default address space is zero. The address space
869 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]870
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]871<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]872 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]873
Chris Lattnerce99fa92010-04-28 00:13:42 +0000[diff] [blame]874<p>An explicit alignment may be specified for a global, which must be a power
875 of 2. If not present, or if the alignment is set to zero, the alignment of
876 the global is set by the target to whatever it feels convenient. If an
877 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner2d4b8ee2010-04-28 00:31:12 +0000[diff] [blame]878 alignment. Targets and optimizers are not allowed to over-align the global
879 if the global has an assigned section. In this case, the extra alignment
880 could be observable: for example, code could assume that the globals are
881 densely packed in their section and try to iterate over them as an array,
882 alignment padding would break this iteration.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]883
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]884<p>For example, the following defines a global in a numbered address space with
885 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]886
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]887<pre class="doc_code">
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]888@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]889</pre>
890
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]891</div>
892
893
894<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]895<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]896 <a name="functionstructure">Functions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]897</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]898
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]899<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]900
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]901<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]902 optional <a href="#linkage">linkage type</a>, an optional
903 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]904 <a href="#callingconv">calling convention</a>,
905 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]906 <a href="#paramattrs">parameter attribute</a> for the return type, a function
907 name, a (possibly empty) argument list (each with optional
908 <a href="#paramattrs">parameter attributes</a>), optional
909 <a href="#fnattrs">function attributes</a>, an optional section, an optional
910 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
911 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]912
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]913<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
914 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]915 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]916 <a href="#callingconv">calling convention</a>,
917 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]918 <a href="#paramattrs">parameter attribute</a> for the return type, a function
919 name, a possibly empty list of arguments, an optional alignment, and an
920 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]921
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]922<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]923 (Control Flow Graph) for the function. Each basic block may optionally start
924 with a label (giving the basic block a symbol table entry), contains a list
925 of instructions, and ends with a <a href="#terminators">terminator</a>
926 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]927
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]928<p>The first basic block in a function is special in two ways: it is immediately
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]929 executed on entrance to the function, and it is not allowed to have
930 predecessor basic blocks (i.e. there can not be any branches to the entry
931 block of a function). Because the block can have no predecessors, it also
932 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]933
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]934<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]935 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]936
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]937<p>An explicit alignment may be specified for a function. If not present, or if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]938 the alignment is set to zero, the alignment of the function is set by the
939 target to whatever it feels convenient. If an explicit alignment is
940 specified, the function is forced to have at least that much alignment. All
941 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]942
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]943<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
944 be significant and two identical functions can be merged</p>.
945
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]946<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]947<pre class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]948define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]949 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
950 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
951 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
952 [<a href="#gc">gc</a>] { ... }
953</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]954
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]955</div>
956
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]957<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]958<h3>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]959 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]960</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]961
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]962<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]963
964<p>Aliases act as "second name" for the aliasee value (which can be either
965 function, global variable, another alias or bitcast of global value). Aliases
966 may have an optional <a href="#linkage">linkage type</a>, and an
967 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]968
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]969<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]970<pre class="doc_code">
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]971@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]972</pre>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]973
974</div>
975
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]976<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]977<h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]978 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]979</h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]980
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]981<div>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]982
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]983<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]984 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]985 a named metadata.</p>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]986
987<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]988<pre class="doc_code">
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]989; Some unnamed metadata nodes, which are referenced by the named metadata.
990!0 = metadata !{metadata !"zero"}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]991!1 = metadata !{metadata !"one"}
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]992!2 = metadata !{metadata !"two"}
Dan Gohman1005bc52010-07-13 19:48:13 +0000[diff] [blame]993; A named metadata.
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]994!name = !{!0, !1, !2}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]995</pre>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]996
997</div>
998
999<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1000<h3>
1001 <a name="paramattrs">Parameter Attributes</a>
1002</h3>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1003
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1004<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1005
1006<p>The return type and each parameter of a function type may have a set of
1007 <i>parameter attributes</i> associated with them. Parameter attributes are
1008 used to communicate additional information about the result or parameters of
1009 a function. Parameter attributes are considered to be part of the function,
1010 not of the function type, so functions with different parameter attributes
1011 can have the same function type.</p>
1012
1013<p>Parameter attributes are simple keywords that follow the type specified. If
1014 multiple parameter attributes are needed, they are space separated. For
1015 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1016
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1017<pre class="doc_code">
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]1018declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]1019declare i32 @atoi(i8 zeroext)
1020declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1021</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1022
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1023<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1024 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1025
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1026<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1027
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1028<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1029 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1030 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichebe81732011-03-16 22:20:18 +0000[diff] [blame]1031 should be zero-extended to the extent required by the target's ABI (which
1032 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1033 parameter) or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1034
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1035 <dt><tt><b>signext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1036 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich9e69ff92011-03-17 14:21:58 +0000[diff] [blame]1037 should be sign-extended to the extent required by the target's ABI (which
1038 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1039 return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1040
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1041 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1042 <dd>This indicates that this parameter or return value should be treated in a
1043 special target-dependent fashion during while emitting code for a function
1044 call or return (usually, by putting it in a register as opposed to memory,
1045 though some targets use it to distinguish between two different kinds of
1046 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1047
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1048 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1049 <dd><p>This indicates that the pointer parameter should really be passed by
1050 value to the function. The attribute implies that a hidden copy of the
1051 pointee
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1052 is made between the caller and the callee, so the callee is unable to
1053 modify the value in the callee. This attribute is only valid on LLVM
1054 pointer arguments. It is generally used to pass structs and arrays by
1055 value, but is also valid on pointers to scalars. The copy is considered
1056 to belong to the caller not the callee (for example,
1057 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1058 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1059 values.</p>
1060
1061 <p>The byval attribute also supports specifying an alignment with
1062 the align attribute. It indicates the alignment of the stack slot to
1063 form and the known alignment of the pointer specified to the call site. If
1064 the alignment is not specified, then the code generator makes a
1065 target-specific assumption.</p></dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1066
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1067 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1068 <dd>This indicates that the pointer parameter specifies the address of a
1069 structure that is the return value of the function in the source program.
1070 This pointer must be guaranteed by the caller to be valid: loads and
1071 stores to the structure may be assumed by the callee to not to trap. This
1072 may only be applied to the first parameter. This is not a valid attribute
1073 for return values. </dd>
1074
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1075 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1076 <dd>This indicates that pointer values
1077 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmanefca7f92010-07-02 23:46:54 +0000[diff] [blame]1078 value do not alias pointer values which are not <i>based</i> on it,
1079 ignoring certain "irrelevant" dependencies.
1080 For a call to the parent function, dependencies between memory
1081 references from before or after the call and from those during the call
1082 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1083 return value used in that call.
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1084 The caller shares the responsibility with the callee for ensuring that
1085 these requirements are met.
1086 For further details, please see the discussion of the NoAlias response in
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1087 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1088<br>
John McCall191d4ee2010-07-06 21:07:14 +0000[diff] [blame]1089 Note that this definition of <tt>noalias</tt> is intentionally
1090 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner211244a2010-07-06 20:51:35 +0000[diff] [blame]1091 arguments, though it is slightly weaker.
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1092<br>
1093 For function return values, C99's <tt>restrict</tt> is not meaningful,
1094 while LLVM's <tt>noalias</tt> is.
1095 </dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1096
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1097 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1098 <dd>This indicates that the callee does not make any copies of the pointer
1099 that outlive the callee itself. This is not a valid attribute for return
1100 values.</dd>
1101
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1102 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1103 <dd>This indicates that the pointer parameter can be excised using the
1104 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1105 attribute for return values.</dd>
1106</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1107
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1108</div>
1109
1110<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1111<h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1112 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1113</h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1114
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1115<div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1116
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1117<p>Each function may specify a garbage collector name, which is simply a
1118 string:</p>
1119
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1120<pre class="doc_code">
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1121define void @f() gc "name" { ... }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1122</pre>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1123
1124<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1125 collector which will cause the compiler to alter its output in order to
1126 support the named garbage collection algorithm.</p>
1127
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1128</div>
1129
1130<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1131<h3>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1132 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1133</h3>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1134
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1135<div>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1136
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1137<p>Function attributes are set to communicate additional information about a
1138 function. Function attributes are considered to be part of the function, not
1139 of the function type, so functions with different parameter attributes can
1140 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1141
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1142<p>Function attributes are simple keywords that follow the type specified. If
1143 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1144
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1145<pre class="doc_code">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1146define void @f() noinline { ... }
1147define void @f() alwaysinline { ... }
1148define void @f() alwaysinline optsize { ... }
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1149define void @f() optsize { ... }
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1150</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1151
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1152<dl>
Charles Davis1e063d12010-02-12 00:31:15 +0000[diff] [blame]1153 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1154 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1155 the backend should forcibly align the stack pointer. Specify the
1156 desired alignment, which must be a power of two, in parentheses.
1157
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1158 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1159 <dd>This attribute indicates that the inliner should attempt to inline this
1160 function into callers whenever possible, ignoring any active inlining size
1161 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1162
Charles Davis970bfcc2010-10-25 15:37:09 +0000[diff] [blame]1163 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis6f12e292010-10-25 16:29:03 +0000[diff] [blame]1164 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis0076d202010-10-25 19:07:39 +0000[diff] [blame]1165 meaning the function can be patched and/or hooked even while it is
1166 loaded into memory. On x86, the function prologue will be preceded
1167 by six bytes of padding and will begin with a two-byte instruction.
1168 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1169 higher were compiled in this fashion.</dd>
Charles Davis970bfcc2010-10-25 15:37:09 +0000[diff] [blame]1170
Dan Gohman129bd562011-06-16 16:03:13 +0000[diff] [blame]1171 <dt><tt><b>nonlazybind</b></tt></dt>
1172 <dd>This attribute suppresses lazy symbol binding for the function. This
1173 may make calls to the function faster, at the cost of extra program
1174 startup time if the function is not called during program startup.</dd>
1175
Jakob Stoklund Olesen570a4a52010-02-06 01:16:28 +0000[diff] [blame]1176 <dt><tt><b>inlinehint</b></tt></dt>
1177 <dd>This attribute indicates that the source code contained a hint that inlining
1178 this function is desirable (such as the "inline" keyword in C/C++). It
1179 is just a hint; it imposes no requirements on the inliner.</dd>
1180
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1181 <dt><tt><b>naked</b></tt></dt>
1182 <dd>This attribute disables prologue / epilogue emission for the function.
1183 This can have very system-specific consequences.</dd>
1184
1185 <dt><tt><b>noimplicitfloat</b></tt></dt>
1186 <dd>This attributes disables implicit floating point instructions.</dd>
1187
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1188 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1189 <dd>This attribute indicates that the inliner should never inline this
1190 function in any situation. This attribute may not be used together with
1191 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1192
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1193 <dt><tt><b>noredzone</b></tt></dt>
1194 <dd>This attribute indicates that the code generator should not use a red
1195 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1196
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1197 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1198 <dd>This function attribute indicates that the function never returns
1199 normally. This produces undefined behavior at runtime if the function
1200 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1201
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1202 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1203 <dd>This function attribute indicates that the function never returns with an
1204 unwind or exceptional control flow. If the function does unwind, its
1205 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1206
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1207 <dt><tt><b>optsize</b></tt></dt>
1208 <dd>This attribute suggests that optimization passes and code generator passes
1209 make choices that keep the code size of this function low, and otherwise
1210 do optimizations specifically to reduce code size.</dd>
1211
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1212 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1213 <dd>This attribute indicates that the function computes its result (or decides
1214 to unwind an exception) based strictly on its arguments, without
1215 dereferencing any pointer arguments or otherwise accessing any mutable
1216 state (e.g. memory, control registers, etc) visible to caller functions.
1217 It does not write through any pointer arguments
1218 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1219 changes any state visible to callers. This means that it cannot unwind
1220 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1221 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1222
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1223 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1224 <dd>This attribute indicates that the function does not write through any
1225 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1226 arguments) or otherwise modify any state (e.g. memory, control registers,
1227 etc) visible to caller functions. It may dereference pointer arguments
1228 and read state that may be set in the caller. A readonly function always
1229 returns the same value (or unwinds an exception identically) when called
1230 with the same set of arguments and global state. It cannot unwind an
1231 exception by calling the <tt>C++</tt> exception throwing methods, but may
1232 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1233
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1234 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1235 <dd>This attribute indicates that the function should emit a stack smashing
1236 protector. It is in the form of a "canary"&mdash;a random value placed on
1237 the stack before the local variables that's checked upon return from the
1238 function to see if it has been overwritten. A heuristic is used to
1239 determine if a function needs stack protectors or not.<br>
1240<br>
1241 If a function that has an <tt>ssp</tt> attribute is inlined into a
1242 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1243 function will have an <tt>ssp</tt> attribute.</dd>
1244
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1245 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1246 <dd>This attribute indicates that the function should <em>always</em> emit a
1247 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1248 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1249<br>
1250 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1251 function that doesn't have an <tt>sspreq</tt> attribute or which has
1252 an <tt>ssp</tt> attribute, then the resulting function will have
1253 an <tt>sspreq</tt> attribute.</dd>
Rafael Espindolafbff0ec2011-07-25 15:27:59 +0000[diff] [blame]1254
1255 <dt><tt><b><a name="uwtable">uwtable</a></b></tt></dt>
1256 <dd>This attribute indicates that the ABI being targeted requires that
1257 an unwind table entry be produce for this function even if we can
1258 show that no exceptions passes by it. This is normally the case for
1259 the ELF x86-64 abi, but it can be disabled for some compilation
1260 units.</dd>
1261
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1262</dl>
1263
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1264</div>
1265
1266<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1267<h3>
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1268 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1269</h3>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1270
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1271<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1272
1273<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1274 the GCC "file scope inline asm" blocks. These blocks are internally
1275 concatenated by LLVM and treated as a single unit, but may be separated in
1276 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1277
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1278<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1279module asm "inline asm code goes here"
1280module asm "more can go here"
1281</pre>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1282
1283<p>The strings can contain any character by escaping non-printable characters.
1284 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1285 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1286
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1287<p>The inline asm code is simply printed to the machine code .s file when
1288 assembly code is generated.</p>
1289
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1290</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1291
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1292<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1293<h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1294 <a name="datalayout">Data Layout</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1295</h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1296
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1297<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1298
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1299<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1300 data is to be laid out in memory. The syntax for the data layout is
1301 simply:</p>
1302
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1303<pre class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1304target datalayout = "<i>layout specification</i>"
1305</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1306
1307<p>The <i>layout specification</i> consists of a list of specifications
1308 separated by the minus sign character ('-'). Each specification starts with
1309 a letter and may include other information after the letter to define some
1310 aspect of the data layout. The specifications accepted are as follows:</p>
1311
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1312<dl>
1313 <dt><tt>E</tt></dt>
1314 <dd>Specifies that the target lays out data in big-endian form. That is, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1315 bits with the most significance have the lowest address location.</dd>
1316
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1317 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1318 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1319 the bits with the least significance have the lowest address
1320 location.</dd>
1321
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1322 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1323 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1324 <i>preferred</i> alignments. All sizes are in bits. Specifying
1325 the <i>pref</i> alignment is optional. If omitted, the
1326 preceding <tt>:</tt> should be omitted too.</dd>
1327
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1328 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1329 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1330 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1331
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1332 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1333 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1334 <i>size</i>.</dd>
1335
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1336 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1337 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesen9d8d2212010-05-28 18:54:47 +0000[diff] [blame]1338 <i>size</i>. Only values of <i>size</i> that are supported by the target
1339 will work. 32 (float) and 64 (double) are supported on all targets;
1340 80 or 128 (different flavors of long double) are also supported on some
1341 targets.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1342
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1343 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1344 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1345 <i>size</i>.</dd>
1346
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1347 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1348 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1349 <i>size</i>.</dd>
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1350
1351 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1352 <dd>This specifies a set of native integer widths for the target CPU
1353 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1354 "n32:64" for PowerPC 64, or "n8:16:32:64" for X86-64. Elements of
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1355 this set are considered to support most general arithmetic
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1356 operations efficiently.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1357</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1358
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1359<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]1360 default set of specifications which are then (possibly) overridden by the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1361 specifications in the <tt>datalayout</tt> keyword. The default specifications
1362 are given in this list:</p>
1363
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1364<ul>
1365 <li><tt>E</tt> - big endian</li>
Dan Gohmanfdf2e8c2010-02-23 02:44:03 +0000[diff] [blame]1366 <li><tt>p:64:64:64</tt> - 64-bit pointers with 64-bit alignment</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1367 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1368 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1369 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1370 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1371 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1372 alignment of 64-bits</li>
1373 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1374 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1375 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1376 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1377 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1378 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1379</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1380
1381<p>When LLVM is determining the alignment for a given type, it uses the
1382 following rules:</p>
1383
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1384<ol>
1385 <li>If the type sought is an exact match for one of the specifications, that
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1386 specification is used.</li>
1387
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1388 <li>If no match is found, and the type sought is an integer type, then the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1389 smallest integer type that is larger than the bitwidth of the sought type
1390 is used. If none of the specifications are larger than the bitwidth then
1391 the the largest integer type is used. For example, given the default
1392 specifications above, the i7 type will use the alignment of i8 (next
1393 largest) while both i65 and i256 will use the alignment of i64 (largest
1394 specified).</li>
1395
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1396 <li>If no match is found, and the type sought is a vector type, then the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1397 largest vector type that is smaller than the sought vector type will be
1398 used as a fall back. This happens because &lt;128 x double&gt; can be
1399 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1400</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1401
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1402</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1403
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1404<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1405<h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1406 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1407</h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1408
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1409<div>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1410
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1411<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1412with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1413is undefined. Pointer values are associated with address ranges
1414according to the following rules:</p>
1415
1416<ul>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1417 <li>A pointer value is associated with the addresses associated with
1418 any value it is <i>based</i> on.
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1419 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1420 range of the variable's storage.</li>
1421 <li>The result value of an allocation instruction is associated with
1422 the address range of the allocated storage.</li>
1423 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1424 no address.</li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1425 <li>An integer constant other than zero or a pointer value returned
1426 from a function not defined within LLVM may be associated with address
1427 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1428 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1429 allocated by mechanisms provided by LLVM.</li>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1430</ul>
1431
1432<p>A pointer value is <i>based</i> on another pointer value according
1433 to the following rules:</p>
1434
1435<ul>
1436 <li>A pointer value formed from a
1437 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1438 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1439 <li>The result value of a
1440 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1441 of the <tt>bitcast</tt>.</li>
1442 <li>A pointer value formed by an
1443 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1444 pointer values that contribute (directly or indirectly) to the
1445 computation of the pointer's value.</li>
1446 <li>The "<i>based</i> on" relationship is transitive.</li>
1447</ul>
1448
1449<p>Note that this definition of <i>"based"</i> is intentionally
1450 similar to the definition of <i>"based"</i> in C99, though it is
1451 slightly weaker.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1452
1453<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1454<tt><a href="#i_load">load</a></tt> merely indicates the size and
1455alignment of the memory from which to load, as well as the
Dan Gohmanc22c0f32010-06-17 19:23:50 +0000[diff] [blame]1456interpretation of the value. The first operand type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1457<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1458and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1459
1460<p>Consequently, type-based alias analysis, aka TBAA, aka
1461<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1462LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1463additional information which specialized optimization passes may use
1464to implement type-based alias analysis.</p>
1465
1466</div>
1467
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1468<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1469<h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1470 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1471</h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1472
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1473<div>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1474
1475<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1476href="#i_store"><tt>store</tt></a>s, and <a
1477href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1478The optimizers must not change the number of volatile operations or change their
1479order of execution relative to other volatile operations. The optimizers
1480<i>may</i> change the order of volatile operations relative to non-volatile
1481operations. This is not Java's "volatile" and has no cross-thread
1482synchronization behavior.</p>
1483
1484</div>
1485
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1486<!-- ======================================================================= -->
1487<h3>
1488 <a name="memmodel">Memory Model for Concurrent Operations</a>
1489</h3>
1490
1491<div>
1492
1493<p>The LLVM IR does not define any way to start parallel threads of execution
1494or to register signal handlers. Nonetheless, there are platform-specific
1495ways to create them, and we define LLVM IR's behavior in their presence. This
1496model is inspired by the C++0x memory model.</p>
1497
1498<p>We define a <i>happens-before</i> partial order as the least partial order
1499that</p>
1500<ul>
1501 <li>Is a superset of single-thread program order, and</li>
1502 <li>When a <i>synchronizes-with</i> <tt>b</tt>, includes an edge from
1503 <tt>a</tt> to <tt>b</tt>. <i>Synchronizes-with</i> pairs are introduced
1504 by platform-specific techniques, like pthread locks, thread
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1505 creation, thread joining, etc., and by atomic instructions.
1506 (See also <a href="#ordering">Atomic Memory Ordering Constraints</a>).
1507 </li>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1508</ul>
1509
1510<p>Note that program order does not introduce <i>happens-before</i> edges
1511between a thread and signals executing inside that thread.</p>
1512
1513<p>Every (defined) read operation (load instructions, memcpy, atomic
1514loads/read-modify-writes, etc.) <var>R</var> reads a series of bytes written by
1515(defined) write operations (store instructions, atomic
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1516stores/read-modify-writes, memcpy, etc.). For the purposes of this section,
1517initialized globals are considered to have a write of the initializer which is
1518atomic and happens before any other read or write of the memory in question.
1519For each byte of a read <var>R</var>, <var>R<sub>byte</sub></var> may see
1520any write to the same byte, except:</p>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1521
1522<ul>
1523 <li>If <var>write<sub>1</sub></var> happens before
1524 <var>write<sub>2</sub></var>, and <var>write<sub>2</sub></var> happens
1525 before <var>R<sub>byte</sub></var>, then <var>R<sub>byte</sub></var>
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1526 does not see <var>write<sub>1</sub></var>.
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1527 <li>If <var>R<sub>byte</sub></var> happens before <var>write<sub>3</var>,
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1528 then <var>R<sub>byte</sub></var> does not see
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1529 <var>write<sub>3</sub></var>.
1530</ul>
1531
1532<p>Given that definition, <var>R<sub>byte</sub></var> is defined as follows:
1533<ul>
1534 <li>If there is no write to the same byte that happens before
1535 <var>R<sub>byte</sub></var>, <var>R<sub>byte</sub></var> returns
1536 <tt>undef</tt> for that byte.
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1537 <li>Otherwise, if <var>R<sub>byte</sub></var> may see exactly one write,
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1538 <var>R<sub>byte</sub></var> returns the value written by that
1539 write.</li>
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1540 <li>Otherwise, if <var>R</var> is atomic, and all the writes
1541 <var>R<sub>byte</sub></var> may see are atomic, it chooses one of the
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1542 values written. See the <a href="#ordering">Atomic Memory Ordering
1543 Constraints</a> section for additional constraints on how the choice
1544 is made.
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1545 <li>Otherwise <var>R<sub>byte</sub></var> returns <tt>undef</tt>.</li>
1546</ul>
1547
1548<p><var>R</var> returns the value composed of the series of bytes it read.
1549This implies that some bytes within the value may be <tt>undef</tt>
1550<b>without</b> the entire value being <tt>undef</tt>. Note that this only
1551defines the semantics of the operation; it doesn't mean that targets will
1552emit more than one instruction to read the series of bytes.</p>
1553
1554<p>Note that in cases where none of the atomic intrinsics are used, this model
1555places only one restriction on IR transformations on top of what is required
1556for single-threaded execution: introducing a store to a byte which might not
Eli Friedman118973a2011-07-22 03:04:45 +0000[diff] [blame]1557otherwise be stored to can introduce undefined behavior. (Specifically, in
1558the case where another thread might write to and read from an address,
1559introducing a store can change a load that may see exactly one write into
1560a load that may see multiple writes.)</p>
Eli Friedman5b60e1b2011-07-20 21:35:53 +0000[diff] [blame]1561
1562<!-- FIXME: This model assumes all targets where concurrency is relevant have
1563a byte-size store which doesn't affect adjacent bytes. As far as I can tell,
1564none of the backends currently in the tree fall into this category; however,
1565there might be targets which care. If there are, we want a paragraph
1566like the following:
1567
1568Targets may specify that stores narrower than a certain width are not
1569available; on such a target, for the purposes of this model, treat any
1570non-atomic write with an alignment or width less than the minimum width
1571as if it writes to the relevant surrounding bytes.
1572-->
1573
1574</div>
1575
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]1576<!-- ======================================================================= -->
1577<div class="doc_subsection">
1578 <a name="ordering">Atomic Memory Ordering Constraints</a>
1579</div>
1580
1581<div class="doc_text">
1582
1583<p>Atomic instructions (<a href="#i_cmpxchg"><code>cmpxchg</code></a>,
1584<a href="#i_atomicrmw"><code>atomicrmw</code></a>, and
1585<a href="#i_fence"><code>fence</code></a>) take an ordering parameter
1586that determines which other atomic instructions on the same address they
1587<i>synchronize with</i>. These semantics are borrowed from Java and C++0x,
1588but are somewhat more colloquial. If these descriptions aren't precise enough,
1589check those specs. <a href="#i_fence"><code>fence</code></a> instructions
1590treat these orderings somewhat differently since they don't take an address.
1591See that instruction's documentation for details.</p>
1592
1593<!-- FIXME Note atomic load+store here once those get added. -->
1594
1595<dl>
1596<!-- FIXME: unordered is intended to be used for atomic load and store;
1597it isn't allowed for any instruction yet. -->
1598<dt><code>unordered</code></dt>
1599<dd>The set of values that can be read is governed by the happens-before
1600partial order. A value cannot be read unless some operation wrote it.
1601This is intended to provide a guarantee strong enough to model Java's
1602non-volatile shared variables. This ordering cannot be specified for
1603read-modify-write operations; it is not strong enough to make them atomic
1604in any interesting way.</dd>
1605<dt><code>monotonic</code></dt>
1606<dd>In addition to the guarantees of <code>unordered</code>, there is a single
1607total order for modifications by <code>monotonic</code> operations on each
1608address. All modification orders must be compatible with the happens-before
1609order. There is no guarantee that the modification orders can be combined to
1610a global total order for the whole program (and this often will not be
1611possible). The read in an atomic read-modify-write operation
1612(<a href="#i_cmpxchg"><code>cmpxchg</code></a> and
1613<a href="#i_atomicrmw"><code>atomicrmw</code></a>)
1614reads the value in the modification order immediately before the value it
1615writes. If one atomic read happens before another atomic read of the same
1616address, the later read must see the same value or a later value in the
1617address's modification order. This disallows reordering of
1618<code>monotonic</code> (or stronger) operations on the same address. If an
1619address is written <code>monotonic</code>ally by one thread, and other threads
1620<code>monotonic</code>ally read that address repeatedly, the other threads must
1621eventually see the write. This is intended to model C++'s relaxed atomic
1622variables.</dd>
1623<dt><code>acquire</code></dt>
1624<dd>In addition to the guarantees of <code>monotonic</code>, if this operation
1625reads a value written by a <code>release</code> atomic operation, it
1626<i>synchronizes-with</i> that operation.</dd>
1627<dt><code>release</code></dt>
1628<dd>In addition to the guarantees of <code>monotonic</code>,
1629a <i>synchronizes-with</i> edge may be formed by an <code>acquire</code>
1630operation.</dd>
1631<dt><code>acq_rel</code> (acquire+release)</dt><dd>Acts as both an
1632<code>acquire</code> and <code>release</code> operation on its address.</dd>
1633<dt><code>seq_cst</code> (sequentially consistent)</dt><dd>
1634<dd>In addition to the guarantees of <code>acq_rel</code>
1635(<code>acquire</code> for an operation which only reads, <code>release</code>
1636for an operation which only writes), there is a global total order on all
1637sequentially-consistent operations on all addresses, which is consistent with
1638the <i>happens-before</i> partial order and with the modification orders of
1639all the affected addresses. Each sequentially-consistent read sees the last
1640preceding write to the same address in this global order. This is intended
1641to model C++'s sequentially-consistent atomic variables and Java's volatile
1642shared variables.</dd>
1643</dl>
1644
1645<p id="singlethread">If an atomic operation is marked <code>singlethread</code>,
1646it only <i>synchronizes with</i> or participates in modification and seq_cst
1647total orderings with other operations running in the same thread (for example,
1648in signal handlers).</p>
1649
1650</div>
1651
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1652</div>
1653
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1654<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1655<h2><a name="typesystem">Type System</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1656<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1657
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1658<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1659
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1660<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1661 intermediate representation. Being typed enables a number of optimizations
1662 to be performed on the intermediate representation directly, without having
1663 to do extra analyses on the side before the transformation. A strong type
1664 system makes it easier to read the generated code and enables novel analyses
1665 and transformations that are not feasible to perform on normal three address
1666 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1667
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1668<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1669<h3>
1670 <a name="t_classifications">Type Classifications</a>
1671</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1672
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1673<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1674
1675<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1676
1677<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1678 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1679 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1680 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1681 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1682 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1683 </tr>
1684 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1685 <td><a href="#t_floating">floating point</a></td>
1686 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1687 </tr>
1688 <tr>
1689 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1690 <td><a href="#t_integer">integer</a>,
1691 <a href="#t_floating">floating point</a>,
1692 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1693 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1694 <a href="#t_struct">structure</a>,
1695 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1696 <a href="#t_label">label</a>,
1697 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1698 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1699 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1700 <tr>
1701 <td><a href="#t_primitive">primitive</a></td>
1702 <td><a href="#t_label">label</a>,
1703 <a href="#t_void">void</a>,
Tobias Grosser05387292010-12-28 20:29:31 +0000[diff] [blame]1704 <a href="#t_integer">integer</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1705 <a href="#t_floating">floating point</a>,
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1706 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1707 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1708 </tr>
1709 <tr>
1710 <td><a href="#t_derived">derived</a></td>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1711 <td><a href="#t_array">array</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1712 <a href="#t_function">function</a>,
1713 <a href="#t_pointer">pointer</a>,
1714 <a href="#t_struct">structure</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1715 <a href="#t_vector">vector</a>,
1716 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1717 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1718 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1719 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1720</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1721
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1722<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1723 important. Values of these types are the only ones which can be produced by
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1724 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1725
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1726</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1727
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1728<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1729<h3>
1730 <a name="t_primitive">Primitive Types</a>
1731</h3>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1732
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1733<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1734
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1735<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1736 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1737
1738<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1739<h4>
1740 <a name="t_integer">Integer Type</a>
1741</h4>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1742
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1743<div>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1744
1745<h5>Overview:</h5>
1746<p>The integer type is a very simple type that simply specifies an arbitrary
1747 bit width for the integer type desired. Any bit width from 1 bit to
1748 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1749
1750<h5>Syntax:</h5>
1751<pre>
1752 iN
1753</pre>
1754
1755<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1756 value.</p>
1757
1758<h5>Examples:</h5>
1759<table class="layout">
1760 <tr class="layout">
1761 <td class="left"><tt>i1</tt></td>
1762 <td class="left">a single-bit integer.</td>
1763 </tr>
1764 <tr class="layout">
1765 <td class="left"><tt>i32</tt></td>
1766 <td class="left">a 32-bit integer.</td>
1767 </tr>
1768 <tr class="layout">
1769 <td class="left"><tt>i1942652</tt></td>
1770 <td class="left">a really big integer of over 1 million bits.</td>
1771 </tr>
1772</table>
1773
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1774</div>
1775
1776<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1777<h4>
1778 <a name="t_floating">Floating Point Types</a>
1779</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1780
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1781<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1782
1783<table>
1784 <tbody>
1785 <tr><th>Type</th><th>Description</th></tr>
1786 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1787 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1788 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1789 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1790 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1791 </tbody>
1792</table>
1793
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1794</div>
1795
1796<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1797<h4>
1798 <a name="t_x86mmx">X86mmx Type</a>
1799</h4>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1800
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1801<div>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1802
1803<h5>Overview:</h5>
1804<p>The x86mmx type represents a value held in an MMX register on an x86 machine. The operations allowed on it are quite limited: parameters and return values, load and store, and bitcast. User-specified MMX instructions are represented as intrinsic or asm calls with arguments and/or results of this type. There are no arrays, vectors or constants of this type.</p>
1805
1806<h5>Syntax:</h5>
1807<pre>
Dale Johannesen473a8c82010-10-01 01:07:02 +0000[diff] [blame]1808 x86mmx
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1809</pre>
1810
1811</div>
1812
1813<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1814<h4>
1815 <a name="t_void">Void Type</a>
1816</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1817
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1818<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1819
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1820<h5>Overview:</h5>
1821<p>The void type does not represent any value and has no size.</p>
1822
1823<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1824<pre>
1825 void
1826</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1827
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1828</div>
1829
1830<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1831<h4>
1832 <a name="t_label">Label Type</a>
1833</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1834
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1835<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1836
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1837<h5>Overview:</h5>
1838<p>The label type represents code labels.</p>
1839
1840<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1841<pre>
1842 label
1843</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1844
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1845</div>
1846
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1847<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1848<h4>
1849 <a name="t_metadata">Metadata Type</a>
1850</h4>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1851
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1852<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1853
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1854<h5>Overview:</h5>
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1855<p>The metadata type represents embedded metadata. No derived types may be
1856 created from metadata except for <a href="#t_function">function</a>
1857 arguments.
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1858
1859<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1860<pre>
1861 metadata
1862</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1863
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1864</div>
1865
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1866</div>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1867
1868<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1869<h3>
1870 <a name="t_derived">Derived Types</a>
1871</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1872
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1873<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1874
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1875<p>The real power in LLVM comes from the derived types in the system. This is
1876 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1877 useful types. Each of these types contain one or more element types which
1878 may be a primitive type, or another derived type. For example, it is
1879 possible to have a two dimensional array, using an array as the element type
1880 of another array.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1881
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]1882</div>
1883
1884
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1885<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1886<h4>
1887 <a name="t_aggregate">Aggregate Types</a>
1888</h4>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1889
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1890<div>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1891
1892<p>Aggregate Types are a subset of derived types that can contain multiple
1893 member types. <a href="#t_array">Arrays</a>,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]1894 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1895 aggregate types.</p>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1896
1897</div>
1898
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1899<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1900<h4>
1901 <a name="t_array">Array Type</a>
1902</h4>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1903
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1904<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1905
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1906<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1907<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1908 sequentially in memory. The array type requires a size (number of elements)
1909 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1910
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1911<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1912<pre>
1913 [&lt;# elements&gt; x &lt;elementtype&gt;]
1914</pre>
1915
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1916<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1917 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1918
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1919<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1920<table class="layout">
1921 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1922 <td class="left"><tt>[40 x i32]</tt></td>
1923 <td class="left">Array of 40 32-bit integer values.</td>
1924 </tr>
1925 <tr class="layout">
1926 <td class="left"><tt>[41 x i32]</tt></td>
1927 <td class="left">Array of 41 32-bit integer values.</td>
1928 </tr>
1929 <tr class="layout">
1930 <td class="left"><tt>[4 x i8]</tt></td>
1931 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1932 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1933</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1934<p>Here are some examples of multidimensional arrays:</p>
1935<table class="layout">
1936 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1937 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1938 <td class="left">3x4 array of 32-bit integer values.</td>
1939 </tr>
1940 <tr class="layout">
1941 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1942 <td class="left">12x10 array of single precision floating point values.</td>
1943 </tr>
1944 <tr class="layout">
1945 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1946 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1947 </tr>
1948</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1949
Dan Gohman7657f6b2009-11-09 19:01:53 +0000[diff] [blame]1950<p>There is no restriction on indexing beyond the end of the array implied by
1951 a static type (though there are restrictions on indexing beyond the bounds
1952 of an allocated object in some cases). This means that single-dimension
1953 'variable sized array' addressing can be implemented in LLVM with a zero
1954 length array type. An implementation of 'pascal style arrays' in LLVM could
1955 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1956
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1957</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1958
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1959<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1960<h4>
1961 <a name="t_function">Function Type</a>
1962</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1963
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1964<div>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1965
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1966<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1967<p>The function type can be thought of as a function signature. It consists of
1968 a return type and a list of formal parameter types. The return type of a
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]1969 function type is a first class type or a void type.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1970
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1971<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1972<pre>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1973 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1974</pre>
1975
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1976<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1977 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1978 which indicates that the function takes a variable number of arguments.
1979 Variable argument functions can access their arguments with
1980 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1981 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1982 <a href="#t_label">label</a>.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1983
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1984<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1985<table class="layout">
1986 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1987 <td class="left"><tt>i32 (i32)</tt></td>
1988 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1989 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1990 </tr><tr class="layout">
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1991 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1992 </tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1993 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1994 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1995 returning <tt>float</tt>.
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1996 </td>
1997 </tr><tr class="layout">
1998 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1999 <td class="left">A vararg function that takes at least one
2000 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
2001 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]2002 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2003 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]2004 </tr><tr class="layout">
2005 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]2006 <td class="left">A function taking an <tt>i32</tt>, returning a
2007 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]2008 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2009 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2010</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]2011
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2012</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2013
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2014<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2015<h4>
2016 <a name="t_struct">Structure Type</a>
2017</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2018
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2019<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2020
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2021<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2022<p>The structure type is used to represent a collection of data members together
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2023 in memory. The elements of a structure may be any type that has a size.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2024
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]2025<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
2026 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
2027 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
2028 Structures in registers are accessed using the
2029 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
2030 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2031
2032<p>Structures may optionally be "packed" structures, which indicate that the
2033 alignment of the struct is one byte, and that there is no padding between
2034 the elements. In non-packed structs, padding between field types is defined
2035 by the target data string to match the underlying processor.</p>
2036
2037<p>Structures can either be "anonymous" or "named". An anonymous structure is
2038 defined inline with other types (e.g. <tt>{i32, i32}*</tt>) and a named types
2039 are always defined at the top level with a name. Anonmyous types are uniqued
2040 by their contents and can never be recursive since there is no way to write
2041 one. Named types can be recursive.
2042</p>
2043
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2044<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2045<pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2046 %T1 = type { &lt;type list&gt; } <i>; Named normal struct type</i>
2047 %T2 = type &lt;{ &lt;type list&gt; }&gt; <i>; Named packed struct type</i>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2048</pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2049
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2050<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2051<table class="layout">
2052 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2053 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
2054 <td class="left">A triple of three <tt>i32</tt> values</td>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2055 </tr>
2056 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]2057 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
2058 <td class="left">A pair, where the first element is a <tt>float</tt> and the
2059 second element is a <a href="#t_pointer">pointer</a> to a
2060 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
2061 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2062 </tr>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2063 <tr class="layout">
2064 <td class="left"><tt>&lt;{ i8, i32 }&gt;</tt></td>
2065 <td class="left">A packed struct known to be 5 bytes in size.</td>
2066 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2067</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2068
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2069</div>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2070
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2071<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2072<h4>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]2073 <a name="t_opaque">Opaque Structure Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2074</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2075
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2076<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2077
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2078<h5>Overview:</h5>
Chris Lattner628ed392011-07-23 19:59:08 +0000[diff] [blame]2079<p>Opaque structure types are used to represent named structure types that do
2080 not have a body specified. This corresponds (for example) to the C notion of
2081 a forward declared structure.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2082
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2083<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2084<pre>
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2085 %X = type opaque
2086 %52 = type opaque
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2087</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2088
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2089<h5>Examples:</h5>
2090<table class="layout">
2091 <tr class="layout">
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2092 <td class="left"><tt>opaque</tt></td>
2093 <td class="left">An opaque type.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2094 </tr>
2095</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2096
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2097</div>
2098
Chris Lattner1afcace2011-07-09 17:41:24 +0000[diff] [blame]2099
2100
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]2101<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2102<h4>
2103 <a name="t_pointer">Pointer Type</a>
2104</h4>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]2105
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2106<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2107
2108<h5>Overview:</h5>
Dan Gohmanff3ef322010-02-25 16:50:07 +0000[diff] [blame]2109<p>The pointer type is used to specify memory locations.
2110 Pointers are commonly used to reference objects in memory.</p>
2111
2112<p>Pointer types may have an optional address space attribute defining the
2113 numbered address space where the pointed-to object resides. The default
2114 address space is number zero. The semantics of non-zero address
2115 spaces are target-specific.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2116
2117<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
2118 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]2119
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2120<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]2121<pre>
2122 &lt;type&gt; *
2123</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2124
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2125<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2126<table class="layout">
2127 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]2128 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2129 <td class="left">A <a href="#t_pointer">pointer</a> to <a
2130 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
2131 </tr>
2132 <tr class="layout">
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]2133 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2134 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]2135 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2136 <tt>i32</tt>.</td>
2137 </tr>
2138 <tr class="layout">
2139 <td class="left"><tt>i32 addrspace(5)*</tt></td>
2140 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
2141 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2142 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2143</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2144
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2145</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2146
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2147<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2148<h4>
2149 <a name="t_vector">Vector Type</a>
2150</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2151
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2152<div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2153
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2154<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2155<p>A vector type is a simple derived type that represents a vector of elements.
2156 Vector types are used when multiple primitive data are operated in parallel
2157 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sandsd40d14e2009-11-27 13:38:03 +0000[diff] [blame]2158 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2159 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2160
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2161<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2162<pre>
2163 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
2164</pre>
2165
Chris Lattner7d2e7be2010-10-10 18:20:35 +0000[diff] [blame]2166<p>The number of elements is a constant integer value larger than 0; elementtype
2167 may be any integer or floating point type. Vectors of size zero are not
2168 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2169
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]2170<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2171<table class="layout">
2172 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2173 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
2174 <td class="left">Vector of 4 32-bit integer values.</td>
2175 </tr>
2176 <tr class="layout">
2177 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
2178 <td class="left">Vector of 8 32-bit floating-point values.</td>
2179 </tr>
2180 <tr class="layout">
2181 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
2182 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]2183 </tr>
2184</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]2185
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2186</div>
2187
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2188<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2189<h2><a name="constants">Constants</a></h2>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2190<!-- *********************************************************************** -->
2191
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2192<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2193
2194<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2195 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2196
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2197<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2198<h3>
2199 <a name="simpleconstants">Simple Constants</a>
2200</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2201
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2202<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2203
2204<dl>
2205 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2206 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]2207 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2208
2209 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2210 <dd>Standard integers (such as '4') are constants of
2211 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2212 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2213
2214 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2215 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2216 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2217 notation (see below). The assembler requires the exact decimal value of a
2218 floating-point constant. For example, the assembler accepts 1.25 but
2219 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2220 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2221
2222 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2223 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2224 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2225</dl>
2226
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2227<p>The one non-intuitive notation for constants is the hexadecimal form of
2228 floating point constants. For example, the form '<tt>double
2229 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2230 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2231 constants are required (and the only time that they are generated by the
2232 disassembler) is when a floating point constant must be emitted but it cannot
2233 be represented as a decimal floating point number in a reasonable number of
2234 digits. For example, NaN's, infinities, and other special values are
2235 represented in their IEEE hexadecimal format so that assembly and disassembly
2236 do not cause any bits to change in the constants.</p>
2237
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]2238<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2239 represented using the 16-digit form shown above (which matches the IEEE754
2240 representation for double); float values must, however, be exactly
2241 representable as IEE754 single precision. Hexadecimal format is always used
2242 for long double, and there are three forms of long double. The 80-bit format
2243 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2244 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2245 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2246 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2247 currently supported target uses this format. Long doubles will only work if
2248 they match the long double format on your target. All hexadecimal formats
2249 are big-endian (sign bit at the left).</p>
2250
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]2251<p>There are no constants of type x86mmx.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2252</div>
2253
2254<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2255<h3>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2256<a name="aggregateconstants"></a> <!-- old anchor -->
2257<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2258</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2259
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2260<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2261
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2262<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2263 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2264
2265<dl>
2266 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2267 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2268 type definitions (a comma separated list of elements, surrounded by braces
2269 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2270 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2271 Structure constants must have <a href="#t_struct">structure type</a>, and
2272 the number and types of elements must match those specified by the
2273 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2274
2275 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2276 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2277 definitions (a comma separated list of elements, surrounded by square
2278 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2279 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2280 the number and types of elements must match those specified by the
2281 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2282
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2283 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2284 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2285 definitions (a comma separated list of elements, surrounded by
2286 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2287 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2288 have <a href="#t_vector">vector type</a>, and the number and types of
2289 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2290
2291 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2292 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2293 value to zero of <em>any</em> type, including scalar and
2294 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2295 This is often used to avoid having to print large zero initializers
2296 (e.g. for large arrays) and is always exactly equivalent to using explicit
2297 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2298
2299 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]2300 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2301 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2302 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2303 be interpreted as part of the instruction stream, metadata is a place to
2304 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2305</dl>
2306
2307</div>
2308
2309<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2310<h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2311 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2312</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2313
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2314<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2315
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2316<p>The addresses of <a href="#globalvars">global variables</a>
2317 and <a href="#functionstructure">functions</a> are always implicitly valid
2318 (link-time) constants. These constants are explicitly referenced when
2319 the <a href="#identifiers">identifier for the global</a> is used and always
2320 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2321 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2322
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2323<pre class="doc_code">
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2324@X = global i32 17
2325@Y = global i32 42
2326@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2327</pre>
2328
2329</div>
2330
2331<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2332<h3>
2333 <a name="undefvalues">Undefined Values</a>
2334</h3>
2335
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2336<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2337
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2338<p>The string '<tt>undef</tt>' can be used anywhere a constant is expected, and
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]2339 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2340 Undefined values may be of any type (other than '<tt>label</tt>'
2341 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2342
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2343<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2344 program is well defined no matter what value is used. This gives the
2345 compiler more freedom to optimize. Here are some examples of (potentially
2346 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2347
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2348
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2349<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2350 %A = add %X, undef
2351 %B = sub %X, undef
2352 %C = xor %X, undef
2353Safe:
2354 %A = undef
2355 %B = undef
2356 %C = undef
2357</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2358
2359<p>This is safe because all of the output bits are affected by the undef bits.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2360 Any output bit can have a zero or one depending on the input bits.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2361
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2362<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2363 %A = or %X, undef
2364 %B = and %X, undef
2365Safe:
2366 %A = -1
2367 %B = 0
2368Unsafe:
2369 %A = undef
2370 %B = undef
2371</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2372
2373<p>These logical operations have bits that are not always affected by the input.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2374 For example, if <tt>%X</tt> has a zero bit, then the output of the
2375 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2376 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2377 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2378 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2379 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2380 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2381 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2382
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2383<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2384 %A = select undef, %X, %Y
2385 %B = select undef, 42, %Y
2386 %C = select %X, %Y, undef
2387Safe:
2388 %A = %X (or %Y)
2389 %B = 42 (or %Y)
2390 %C = %Y
2391Unsafe:
2392 %A = undef
2393 %B = undef
2394 %C = undef
2395</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2396
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2397<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2398 branch) conditions can go <em>either way</em>, but they have to come from one
2399 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2400 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2401 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2402 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2403 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2404 eliminated.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2405
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2406<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2407 %A = xor undef, undef
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2408
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2409 %B = undef
2410 %C = xor %B, %B
2411
2412 %D = undef
2413 %E = icmp lt %D, 4
2414 %F = icmp gte %D, 4
2415
2416Safe:
2417 %A = undef
2418 %B = undef
2419 %C = undef
2420 %D = undef
2421 %E = undef
2422 %F = undef
2423</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2424
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2425<p>This example points out that two '<tt>undef</tt>' operands are not
2426 necessarily the same. This can be surprising to people (and also matches C
2427 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2428 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2429 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2430 its value over its "live range". This is true because the variable doesn't
2431 actually <em>have a live range</em>. Instead, the value is logically read
2432 from arbitrary registers that happen to be around when needed, so the value
2433 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2434 need to have the same semantics or the core LLVM "replace all uses with"
2435 concept would not hold.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2436
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2437<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2438 %A = fdiv undef, %X
2439 %B = fdiv %X, undef
2440Safe:
2441 %A = undef
2442b: unreachable
2443</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2444
2445<p>These examples show the crucial difference between an <em>undefined
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2446 value</em> and <em>undefined behavior</em>. An undefined value (like
2447 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2448 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2449 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2450 defined on SNaN's. However, in the second example, we can make a more
2451 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2452 arbitrary value, we are allowed to assume that it could be zero. Since a
2453 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2454 the operation does not execute at all. This allows us to delete the divide and
2455 all code after it. Because the undefined operation "can't happen", the
2456 optimizer can assume that it occurs in dead code.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2457
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2458<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2459a: store undef -> %X
2460b: store %X -> undef
2461Safe:
2462a: &lt;deleted&gt;
2463b: unreachable
2464</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2465
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2466<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2467 undefined value can be assumed to not have any effect; we can assume that the
2468 value is overwritten with bits that happen to match what was already there.
2469 However, a store <em>to</em> an undefined location could clobber arbitrary
2470 memory, therefore, it has undefined behavior.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2471
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2472</div>
2473
2474<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2475<h3>
2476 <a name="trapvalues">Trap Values</a>
2477</h3>
2478
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2479<div>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2480
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2481<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2482 instead of representing an unspecified bit pattern, they represent the
2483 fact that an instruction or constant expression which cannot evoke side
2484 effects has nevertheless detected a condition which results in undefined
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2485 behavior.</p>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2486
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2487<p>There is currently no way of representing a trap value in the IR; they
Dan Gohman855abed2010-05-03 14:51:43 +0000[diff] [blame]2488 only exist when produced by operations such as
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2489 <a href="#i_add"><tt>add</tt></a> with the <tt>nsw</tt> flag.</p>
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2490
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2491<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2492
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2493<ul>
2494<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2495 their operands.</li>
2496
2497<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2498 to their dynamic predecessor basic block.</li>
2499
2500<li>Function arguments depend on the corresponding actual argument values in
2501 the dynamic callers of their functions.</li>
2502
2503<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2504 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2505 control back to them.</li>
2506
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2507<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2508 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2509 or exception-throwing call instructions that dynamically transfer control
2510 back to them.</li>
2511
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2512<li>Non-volatile loads and stores depend on the most recent stores to all of the
2513 referenced memory addresses, following the order in the IR
2514 (including loads and stores implied by intrinsics such as
2515 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2516
Dan Gohman7c24ff12010-05-03 14:59:34 +0000[diff] [blame]2517<!-- TODO: In the case of multiple threads, this only applies if the store
2518 "happens-before" the load or store. -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2519
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2520<!-- TODO: floating-point exception state -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2521
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2522<li>An instruction with externally visible side effects depends on the most
2523 recent preceding instruction with externally visible side effects, following
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]2524 the order in the IR. (This includes
2525 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2526
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2527<li>An instruction <i>control-depends</i> on a
2528 <a href="#terminators">terminator instruction</a>
2529 if the terminator instruction has multiple successors and the instruction
2530 is always executed when control transfers to one of the successors, and
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2531 may not be executed when control is transferred to another.</li>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2532
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2533<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2534 instruction if the set of instructions it otherwise depends on would be
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2535 different if the terminator had transferred control to a different
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2536 successor.</li>
2537
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2538<li>Dependence is transitive.</li>
2539
2540</ul>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2541
2542<p>Whenever a trap value is generated, all values which depend on it evaluate
2543 to trap. If they have side effects, the evoke their side effects as if each
2544 operand with a trap value were undef. If they have externally-visible side
2545 effects, the behavior is undefined.</p>
2546
2547<p>Here are some examples:</p>
Dan Gohmanc30f6e12010-04-26 20:54:53 +0000[diff] [blame]2548
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2549<pre class="doc_code">
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2550entry:
2551 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2552 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2553 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2554 store i32 0, i32* %trap_yet_again ; undefined behavior
2555
2556 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2557 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2558
2559 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2560
2561 %narrowaddr = bitcast i32* @g to i16*
2562 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2563 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2564 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2565
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2566 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2567 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2568
2569true:
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2570 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2571 ; it has undefined behavior.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2572 br label %end
2573
2574end:
2575 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2576 ; Both edges into this PHI are
2577 ; control-dependent on %cmp, so this
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2578 ; always results in a trap value.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2579
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2580 volatile store i32 0, i32* @g ; This would depend on the store in %true
2581 ; if %cmp is true, or the store in %entry
2582 ; otherwise, so this is undefined behavior.
2583
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2584 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2585 ; The same branch again, but this time the
2586 ; true block doesn't have side effects.
2587
2588second_true:
2589 ; No side effects!
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2590 ret void
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2591
2592second_end:
2593 volatile store i32 0, i32* @g ; This time, the instruction always depends
2594 ; on the store in %end. Also, it is
2595 ; control-equivalent to %end, so this is
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2596 ; well-defined (again, ignoring earlier
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2597 ; undefined behavior in this example).
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2598</pre>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2599
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2600</div>
2601
2602<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2603<h3>
2604 <a name="blockaddress">Addresses of Basic Blocks</a>
2605</h3>
2606
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2607<div>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2608
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2609<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2610
2611<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner2dfdf2a2009-10-27 21:49:40 +0000[diff] [blame]2612 basic block in the specified function, and always has an i8* type. Taking
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2613 the address of the entry block is illegal.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2614
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2615<p>This value only has defined behavior when used as an operand to the
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2616 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2617 comparisons against null. Pointer equality tests between labels addresses
2618 results in undefined behavior &mdash; though, again, comparison against null
2619 is ok, and no label is equal to the null pointer. This may be passed around
2620 as an opaque pointer sized value as long as the bits are not inspected. This
2621 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2622 long as the original value is reconstituted before the <tt>indirectbr</tt>
2623 instruction.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2624
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2625<p>Finally, some targets may provide defined semantics when using the value as
2626 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2627
2628</div>
2629
2630
2631<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2632<h3>
2633 <a name="constantexprs">Constant Expressions</a>
2634</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2635
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2636<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2637
2638<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2639 to be used as constants. Constant expressions may be of
2640 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2641 operation that does not have side effects (e.g. load and call are not
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2642 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2643
2644<dl>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2645 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2646 <dd>Truncate a constant to another type. The bit size of CST must be larger
2647 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2648
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2649 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2650 <dd>Zero extend a constant to another type. The bit size of CST must be
Duncan Sands28afd432010-07-13 12:06:14 +0000[diff] [blame]2651 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2652
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2653 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2654 <dd>Sign extend a constant to another type. The bit size of CST must be
Duncan Sands28afd432010-07-13 12:06:14 +0000[diff] [blame]2655 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2656
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2657 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2658 <dd>Truncate a floating point constant to another floating point type. The
2659 size of CST must be larger than the size of TYPE. Both types must be
2660 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2661
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2662 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2663 <dd>Floating point extend a constant to another type. The size of CST must be
2664 smaller or equal to the size of TYPE. Both types must be floating
2665 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2666
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2667 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2668 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2669 constant. TYPE must be a scalar or vector integer type. CST must be of
2670 scalar or vector floating point type. Both CST and TYPE must be scalars,
2671 or vectors of the same number of elements. If the value won't fit in the
2672 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2673
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2674 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2675 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2676 constant. TYPE must be a scalar or vector integer type. CST must be of
2677 scalar or vector floating point type. Both CST and TYPE must be scalars,
2678 or vectors of the same number of elements. If the value won't fit in the
2679 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2680
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2681 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2682 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2683 constant. TYPE must be a scalar or vector floating point type. CST must be
2684 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2685 vectors of the same number of elements. If the value won't fit in the
2686 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2687
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2688 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2689 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2690 constant. TYPE must be a scalar or vector floating point type. CST must be
2691 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2692 vectors of the same number of elements. If the value won't fit in the
2693 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2694
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2695 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2696 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2697 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2698 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2699 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2700
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2701 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2702 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2703 type. CST must be of integer type. The CST value is zero extended,
2704 truncated, or unchanged to make it fit in a pointer size. This one is
2705 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2706
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2707 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2708 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2709 are the same as those for the <a href="#i_bitcast">bitcast
2710 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2711
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2712 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2713 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2714 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2715 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2716 instruction, the index list may have zero or more indexes, which are
2717 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2718
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2719 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2720 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2721
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2722 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2723 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2724
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2725 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2726 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2727
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2728 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2729 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2730 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2731
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2732 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2733 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2734 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2735
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2736 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2737 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2738 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2739
Nick Lewycky9e130ce2010-05-29 06:44:15 +0000[diff] [blame]2740 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2741 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2742 constants. The index list is interpreted in a similar manner as indices in
2743 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2744 index value must be specified.</dd>
2745
2746 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2747 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2748 constants. The index list is interpreted in a similar manner as indices in
2749 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2750 index value must be specified.</dd>
2751
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2752 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2753 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2754 be any of the <a href="#binaryops">binary</a>
2755 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2756 on operands are the same as those for the corresponding instruction
2757 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2758</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2759
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2760</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2761
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2762</div>
2763
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2764<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2765<h2><a name="othervalues">Other Values</a></h2>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2766<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2767<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2768<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2769<h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2770<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2771</h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2772
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2773<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2774
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2775<p>LLVM supports inline assembler expressions (as opposed
2776 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2777 a special value. This value represents the inline assembler as a string
2778 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2779 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2780 expression has side effects, and a flag indicating whether the function
2781 containing the asm needs to align its stack conservatively. An example
2782 inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2783
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2784<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2785i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2786</pre>
2787
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2788<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2789 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2790 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2791
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2792<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2793%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2794</pre>
2795
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2796<p>Inline asms with side effects not visible in the constraint list must be
2797 marked as having side effects. This is done through the use of the
2798 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2799
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2800<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2801call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2802</pre>
2803
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2804<p>In some cases inline asms will contain code that will not work unless the
2805 stack is aligned in some way, such as calls or SSE instructions on x86,
2806 yet will not contain code that does that alignment within the asm.
2807 The compiler should make conservative assumptions about what the asm might
2808 contain and should generate its usual stack alignment code in the prologue
2809 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2810
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2811<pre class="doc_code">
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2812call void asm alignstack "eieio", ""()
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2813</pre>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2814
2815<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2816 first.</p>
2817
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2818<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2819 documented here. Constraints on what can be done (e.g. duplication, moving,
2820 etc need to be documented). This is probably best done by reference to
2821 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2822
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2823<h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2824<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2825</h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2826
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2827<div>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2828
2829<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattnerce1b9ad2010-11-17 08:20:42 +0000[diff] [blame]2830 attached to it that contains a list of constant integers. If present, the
2831 code generator will use the integer as the location cookie value when report
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2832 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]2833 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2834 source code that produced it. For example:</p>
2835
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2836<pre class="doc_code">
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2837call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2838...
2839!42 = !{ i32 1234567 }
2840</pre>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2841
2842<p>It is up to the front-end to make sense of the magic numbers it places in the
Chris Lattnerce1b9ad2010-11-17 08:20:42 +0000[diff] [blame]2843 IR. If the MDNode contains multiple constants, the code generator will use
2844 the one that corresponds to the line of the asm that the error occurs on.</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2845
2846</div>
2847
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2848</div>
2849
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2850<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2851<h3>
2852 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2853</h3>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2854
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2855<div>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2856
2857<p>LLVM IR allows metadata to be attached to instructions in the program that
2858 can convey extra information about the code to the optimizers and code
2859 generator. One example application of metadata is source-level debug
2860 information. There are two metadata primitives: strings and nodes. All
2861 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2862 preceding exclamation point ('<tt>!</tt>').</p>
2863
2864<p>A metadata string is a string surrounded by double quotes. It can contain
2865 any character by escaping non-printable characters with "\xx" where "xx" is
2866 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2867
2868<p>Metadata nodes are represented with notation similar to structure constants
2869 (a comma separated list of elements, surrounded by braces and preceded by an
2870 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2871 10}</tt>". Metadata nodes can have any values as their operand.</p>
2872
2873<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2874 metadata nodes, which can be looked up in the module symbol table. For
2875 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2876
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2877<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2878 function is using two metadata arguments.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2879
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2880<div class="doc_code">
2881<pre>
2882call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2883</pre>
2884</div>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2885
2886<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2887 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2888
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2889<div class="doc_code">
2890<pre>
2891%indvar.next = add i64 %indvar, 1, !dbg !21
2892</pre>
2893</div>
2894
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2895</div>
2896
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2897</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2898
2899<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2900<h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2901 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2902</h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2903<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2904<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2905<p>LLVM has a number of "magic" global variables that contain data that affect
2906code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2907of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2908section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2909by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2910
2911<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2912<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2913<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2914</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2915
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2916<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2917
2918<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2919href="#linkage_appending">appending linkage</a>. This array contains a list of
2920pointers to global variables and functions which may optionally have a pointer
2921cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2922
2923<pre>
2924 @X = global i8 4
2925 @Y = global i32 123
2926
2927 @llvm.used = appending global [2 x i8*] [
2928 i8* @X,
2929 i8* bitcast (i32* @Y to i8*)
2930 ], section "llvm.metadata"
2931</pre>
2932
2933<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2934compiler, assembler, and linker are required to treat the symbol as if there is
2935a reference to the global that it cannot see. For example, if a variable has
2936internal linkage and no references other than that from the <tt>@llvm.used</tt>
2937list, it cannot be deleted. This is commonly used to represent references from
2938inline asms and other things the compiler cannot "see", and corresponds to
2939"attribute((used))" in GNU C.</p>
2940
2941<p>On some targets, the code generator must emit a directive to the assembler or
2942object file to prevent the assembler and linker from molesting the symbol.</p>
2943
2944</div>
2945
2946<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2947<h3>
2948 <a name="intg_compiler_used">
2949 The '<tt>llvm.compiler.used</tt>' Global Variable
2950 </a>
2951</h3>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2952
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2953<div>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2954
2955<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2956<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2957touching the symbol. On targets that support it, this allows an intelligent
2958linker to optimize references to the symbol without being impeded as it would be
2959by <tt>@llvm.used</tt>.</p>
2960
2961<p>This is a rare construct that should only be used in rare circumstances, and
2962should not be exposed to source languages.</p>
2963
2964</div>
2965
2966<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2967<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2968<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2969</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2970
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2971<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2972<pre>
2973%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2974@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2975</pre>
2976<p>The <tt>@llvm.global_ctors</tt> array contains a list of constructor functions and associated priorities. The functions referenced by this array will be called in ascending order of priority (i.e. lowest first) when the module is loaded. The order of functions with the same priority is not defined.
2977</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2978
2979</div>
2980
2981<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2982<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2983<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2984</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2985
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2986<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2987<pre>
2988%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2989@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2990</pre>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2991
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2992<p>The <tt>@llvm.global_dtors</tt> array contains a list of destructor functions and associated priorities. The functions referenced by this array will be called in descending order of priority (i.e. highest first) when the module is loaded. The order of functions with the same priority is not defined.
2993</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2994
2995</div>
2996
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2997</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2998
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2999<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3000<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3001<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3002
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3003<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3004
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3005<p>The LLVM instruction set consists of several different classifications of
3006 instructions: <a href="#terminators">terminator
3007 instructions</a>, <a href="#binaryops">binary instructions</a>,
3008 <a href="#bitwiseops">bitwise binary instructions</a>,
3009 <a href="#memoryops">memory instructions</a>, and
3010 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3011
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3012<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3013<h3>
3014 <a name="terminators">Terminator Instructions</a>
3015</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3016
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3017<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3018
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3019<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
3020 in a program ends with a "Terminator" instruction, which indicates which
3021 block should be executed after the current block is finished. These
3022 terminator instructions typically yield a '<tt>void</tt>' value: they produce
3023 control flow, not values (the one exception being the
3024 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
3025
Bill Wendling10c6d122011-07-30 05:42:50 +0000[diff] [blame]3026<p>There are seven different terminator instructions: the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3027 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
3028 '<a href="#i_br"><tt>br</tt></a>' instruction, the
3029 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling21c346e2009-11-02 00:25:26 +0000[diff] [blame]3030 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3031 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
Bill Wendling10c6d122011-07-30 05:42:50 +0000[diff] [blame]3032 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3033 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]3034
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3035<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3036<h4>
3037 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
3038</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3039
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3040<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3041
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3042<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]3043<pre>
3044 ret &lt;type&gt; &lt;value&gt; <i>; Return a value from a non-void function</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3045 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3046</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3047
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3048<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3049<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
3050 a value) from a function back to the caller.</p>
3051
3052<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
3053 value and then causes control flow, and one that just causes control flow to
3054 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3055
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3056<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3057<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
3058 return value. The type of the return value must be a
3059 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]3060
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3061<p>A function is not <a href="#wellformed">well formed</a> if it it has a
3062 non-void return type and contains a '<tt>ret</tt>' instruction with no return
3063 value or a return value with a type that does not match its type, or if it
3064 has a void return type and contains a '<tt>ret</tt>' instruction with a
3065 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3066
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3067<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3068<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
3069 the calling function's context. If the caller is a
3070 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
3071 instruction after the call. If the caller was an
3072 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
3073 the beginning of the "normal" destination block. If the instruction returns
3074 a value, that value shall set the call or invoke instruction's return
3075 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3076
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3077<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]3078<pre>
3079 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]3080 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]3081 ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3082</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]3083
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3084</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3085<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3086<h4>
3087 <a name="i_br">'<tt>br</tt>' Instruction</a>
3088</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3089
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3090<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3091
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3092<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3093<pre>
Bill Wendlingb3aa4712011-07-26 10:41:15 +0000[diff] [blame]3094 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;
3095 br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3096</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3097
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3098<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3099<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
3100 different basic block in the current function. There are two forms of this
3101 instruction, corresponding to a conditional branch and an unconditional
3102 branch.</p>
3103
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3104<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3105<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
3106 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
3107 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
3108 target.</p>
3109
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3110<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3111<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3112 argument is evaluated. If the value is <tt>true</tt>, control flows to the
3113 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
3114 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3115
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3116<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]3117<pre>
3118Test:
3119 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3120 br i1 %cond, label %IfEqual, label %IfUnequal
3121IfEqual:
3122 <a href="#i_ret">ret</a> i32 1
3123IfUnequal:
3124 <a href="#i_ret">ret</a> i32 0
3125</pre>
3126
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3127</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3128
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3129<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3130<h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3131 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3132</h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3133
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3134<div>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3135
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3136<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3137<pre>
3138 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3139</pre>
3140
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3141<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3142<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3143 several different places. It is a generalization of the '<tt>br</tt>'
3144 instruction, allowing a branch to occur to one of many possible
3145 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3146
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3147<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3148<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3149 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3150 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3151 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3152
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3153<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3154<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3155 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3156 is searched for the given value. If the value is found, control flow is
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]3157 transferred to the corresponding destination; otherwise, control flow is
3158 transferred to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3159
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3160<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3161<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3162 <tt>switch</tt> instruction, this instruction may be code generated in
3163 different ways. For example, it could be generated as a series of chained
3164 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3165
3166<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3167<pre>
3168 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3169 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3170 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3171
3172 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3173 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3174
3175 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3176 switch i32 %val, label %otherwise [ i32 0, label %onzero
3177 i32 1, label %onone
3178 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3179</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3180
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3181</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3182
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3183
3184<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3185<h4>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3186 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3187</h4>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3188
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3189<div>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3190
3191<h5>Syntax:</h5>
3192<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3193 indirectbr &lt;somety&gt;* &lt;address&gt;, [ label &lt;dest1&gt;, label &lt;dest2&gt;, ... ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3194</pre>
3195
3196<h5>Overview:</h5>
3197
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3198<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3199 within the current function, whose address is specified by
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]3200 "<tt>address</tt>". Address must be derived from a <a
3201 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3202
3203<h5>Arguments:</h5>
3204
3205<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3206 rest of the arguments indicate the full set of possible destinations that the
3207 address may point to. Blocks are allowed to occur multiple times in the
3208 destination list, though this isn't particularly useful.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3209
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3210<p>This destination list is required so that dataflow analysis has an accurate
3211 understanding of the CFG.</p>
3212
3213<h5>Semantics:</h5>
3214
3215<p>Control transfers to the block specified in the address argument. All
3216 possible destination blocks must be listed in the label list, otherwise this
3217 instruction has undefined behavior. This implies that jumps to labels
3218 defined in other functions have undefined behavior as well.</p>
3219
3220<h5>Implementation:</h5>
3221
3222<p>This is typically implemented with a jump through a register.</p>
3223
3224<h5>Example:</h5>
3225<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3226 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3227</pre>
3228
3229</div>
3230
3231
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3232<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3233<h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3234 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3235</h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3236
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3237<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3238
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3239<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3240<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3241 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ptr to function ty&gt; &lt;function ptr val&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner76b8a332006-05-14 18:23:06 +0000[diff] [blame]3242 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3243</pre>
3244
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3245<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3246<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3247 function, with the possibility of control flow transfer to either the
3248 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3249 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3250 control flow will return to the "normal" label. If the callee (or any
3251 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3252 instruction, control is interrupted and continued at the dynamically nearest
3253 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3254
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3255<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3256<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3257
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3258<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3259 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3260 convention</a> the call should use. If none is specified, the call
3261 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3262
3263 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3264 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3265 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3266
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3267 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3268 function value being invoked. In most cases, this is a direct function
3269 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3270 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3271
3272 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3273 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3274
3275 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]3276 signature argument types and parameter attributes. All arguments must be
3277 of <a href="#t_firstclass">first class</a> type. If the function
3278 signature indicates the function accepts a variable number of arguments,
3279 the extra arguments can be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3280
3281 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3282 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3283
3284 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3285 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3286
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3287 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3288 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3289 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3290</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3291
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3292<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3293<p>This instruction is designed to operate as a standard
3294 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3295 primary difference is that it establishes an association with a label, which
3296 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3297
3298<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3299 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3300 exception. Additionally, this is important for implementation of
3301 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3302
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3303<p>For the purposes of the SSA form, the definition of the value returned by the
3304 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3305 block to the "normal" label. If the callee unwinds then no return value is
3306 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]3307
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3308<p>Note that the code generator does not yet completely support unwind, and
3309that the invoke/unwind semantics are likely to change in future versions.</p>
3310
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3311<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3312<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3313 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3314 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3315 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3316 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3317</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3318
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3319</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3320
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3321<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3322
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3323<h4>
3324 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3325</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3326
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3327<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3328
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3329<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3330<pre>
3331 unwind
3332</pre>
3333
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3334<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3335<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3336 at the first callee in the dynamic call stack which used
3337 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3338 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3339
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3340<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3341<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3342 immediately halt. The dynamic call stack is then searched for the
3343 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3344 Once found, execution continues at the "exceptional" destination block
3345 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3346 instruction in the dynamic call chain, undefined behavior results.</p>
3347
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3348<p>Note that the code generator does not yet completely support unwind, and
3349that the invoke/unwind semantics are likely to change in future versions.</p>
3350
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3351</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3352
3353<!-- _______________________________________________________________________ -->
3354
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3355<h4>
3356 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3357</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3358
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3359<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3360
3361<h5>Syntax:</h5>
3362<pre>
3363 unreachable
3364</pre>
3365
3366<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3367<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3368 instruction is used to inform the optimizer that a particular portion of the
3369 code is not reachable. This can be used to indicate that the code after a
3370 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3371
3372<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3373<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3374
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3375</div>
3376
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3377</div>
3378
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3379<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3380<h3>
3381 <a name="binaryops">Binary Operations</a>
3382</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3383
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3384<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3385
3386<p>Binary operators are used to do most of the computation in a program. They
3387 require two operands of the same type, execute an operation on them, and
3388 produce a single value. The operands might represent multiple data, as is
3389 the case with the <a href="#t_vector">vector</a> data type. The result value
3390 has the same type as its operands.</p>
3391
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3392<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3393
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3394<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3395<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3396 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3397</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3398
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3399<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3400
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3401<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3402<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3403 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanfdfca792009-09-02 17:31:42 +0000[diff] [blame]3404 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3405 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3406 &lt;result&gt; = add nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3407</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3408
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3409<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3410<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3411
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3412<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3413<p>The two arguments to the '<tt>add</tt>' instruction must
3414 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3415 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3416
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3417<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3418<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3419
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3420<p>If the sum has unsigned overflow, the result returned is the mathematical
3421 result modulo 2<sup>n</sup>, where n is the bit width of the result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3422
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3423<p>Because LLVM integers use a two's complement representation, this instruction
3424 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3425
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3426<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3427 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3428 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3429 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3430 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3431
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3432<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3433<pre>
3434 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3435</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3436
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3437</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3438
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3439<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3440<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3441 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3442</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3443
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3444<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3445
3446<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3447<pre>
3448 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3449</pre>
3450
3451<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3452<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3453
3454<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3455<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3456 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3457 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3458
3459<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3460<p>The value produced is the floating point sum of the two operands.</p>
3461
3462<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3463<pre>
3464 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3465</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3466
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3467</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3468
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3469<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3470<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3471 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3472</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3473
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3474<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3475
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3476<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3477<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3478 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanfdfca792009-09-02 17:31:42 +0000[diff] [blame]3479 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3480 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3481 &lt;result&gt; = sub nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3482</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3483
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3484<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3485<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3486 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3487
3488<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3489 '<tt>neg</tt>' instruction present in most other intermediate
3490 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3491
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3492<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3493<p>The two arguments to the '<tt>sub</tt>' instruction must
3494 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3495 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3496
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3497<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3498<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3499
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3500<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3501 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3502 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3503
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3504<p>Because LLVM integers use a two's complement representation, this instruction
3505 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3506
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3507<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3508 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3509 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3510 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3511 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3512
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3513<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3514<pre>
3515 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3516 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3517</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3518
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3519</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3520
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3521<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3522<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3523 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3524</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3525
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3526<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3527
3528<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3529<pre>
3530 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3531</pre>
3532
3533<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3534<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3535 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3536
3537<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3538 '<tt>fneg</tt>' instruction present in most other intermediate
3539 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3540
3541<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]3542<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3543 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3544 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3545
3546<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3547<p>The value produced is the floating point difference of the two operands.</p>
3548
3549<h5>Example:</h5>
3550<pre>
3551 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3552 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3553</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3554
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3555</div>
3556
3557<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3558<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3559 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3560</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3561
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3562<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3563
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3564<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3565<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3566 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanfdfca792009-09-02 17:31:42 +0000[diff] [blame]3567 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3568 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3569 &lt;result&gt; = mul nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3570</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3571
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3572<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3573<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3574
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3575<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3576<p>The two arguments to the '<tt>mul</tt>' instruction must
3577 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3578 integer values. Both arguments must have identical types.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3579
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3580<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3581<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3582
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3583<p>If the result of the multiplication has unsigned overflow, the result
3584 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3585 width of the result.</p>
3586
3587<p>Because LLVM integers use a two's complement representation, and the result
3588 is the same width as the operands, this instruction returns the correct
3589 result for both signed and unsigned integers. If a full product
3590 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3591 be sign-extended or zero-extended as appropriate to the width of the full
3592 product.</p>
3593
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3594<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3595 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3596 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3597 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3598 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3599
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3600<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3601<pre>
3602 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3603</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3604
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3605</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3606
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3607<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3608<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3609 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3610</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3611
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3612<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3613
3614<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3615<pre>
3616 &lt;result&gt; = fmul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3617</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3618
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3619<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3620<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3621
3622<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3623<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3624 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3625 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3626
3627<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3628<p>The value produced is the floating point product of the two operands.</p>
3629
3630<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3631<pre>
3632 &lt;result&gt; = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3633</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3634
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3635</div>
3636
3637<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3638<h4>
3639 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3640</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3641
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3642<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3643
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3644<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3645<pre>
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3646 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3647 &lt;result&gt; = udiv exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3648</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3649
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3650<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3651<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3652
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3653<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3654<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3655 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3656 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3657
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3658<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3659<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3660
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3661<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3662 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3663
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3664<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3665
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3666<p>If the <tt>exact</tt> keyword is present, the result value of the
3667 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3668 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3669
3670
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3671<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3672<pre>
3673 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3674</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3675
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3676</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3677
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3678<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3679<h4>
3680 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3681</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3682
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3683<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3684
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3685<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3686<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3687 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanfdfca792009-09-02 17:31:42 +0000[diff] [blame]3688 &lt;result&gt; = sdiv exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3689</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3690
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3691<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3692<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3693
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3694<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3695<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3696 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3697 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3698
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3699<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3700<p>The value produced is the signed integer quotient of the two operands rounded
3701 towards zero.</p>
3702
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3703<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3704 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3705
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3706<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3707 undefined behavior; this is a rare case, but can occur, for example, by doing
3708 a 32-bit division of -2147483648 by -1.</p>
3709
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]3710<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]3711 <tt>sdiv</tt> is a <a href="#trapvalues">trap value</a> if the result would
Dan Gohman38da9272010-07-11 00:08:34 +0000[diff] [blame]3712 be rounded.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3713
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3714<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3715<pre>
3716 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3717</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3718
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3719</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3720
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3721<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3722<h4>
3723 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3724</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3725
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3726<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3727
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3728<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3729<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3730 &lt;result&gt; = fdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3731</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3732
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3733<h5>Overview:</h5>
3734<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3735
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3736<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3737<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3738 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3739 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3740
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3741<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3742<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3743
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3744<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3745<pre>
3746 &lt;result&gt; = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3747</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3748
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3749</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3750
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3751<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3752<h4>
3753 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3754</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3755
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3756<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3757
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3758<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3759<pre>
3760 &lt;result&gt; = urem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3761</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3762
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3763<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3764<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3765 division of its two arguments.</p>
3766
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3767<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3768<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3769 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3770 values. Both arguments must have identical types.</p>
3771
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3772<h5>Semantics:</h5>
3773<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3774 This instruction always performs an unsigned division to get the
3775 remainder.</p>
3776
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3777<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3778 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3779
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3780<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3781
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3782<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3783<pre>
3784 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3785</pre>
3786
3787</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3788
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3789<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3790<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3791 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3792</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3793
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3794<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3795
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3796<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3797<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3798 &lt;result&gt; = srem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3799</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3800
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3801<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3802<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3803 division of its two operands. This instruction can also take
3804 <a href="#t_vector">vector</a> versions of the values in which case the
3805 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3806
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3807<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3808<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3809 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3810 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3811
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3812<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3813<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sandsdea3a5e2011-03-07 09:12:24 +0000[diff] [blame]3814 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3815 <i>modulo</i> operator (where the result is either zero or has the same sign
3816 as the divisor, <tt>op2</tt>) of a value.
3817 For more information about the difference,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3818 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3819 Math Forum</a>. For a table of how this is implemented in various languages,
3820 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3821 Wikipedia: modulo operation</a>.</p>
3822
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3823<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3824 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3825
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3826<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3827 Overflow also leads to undefined behavior; this is a rare case, but can
3828 occur, for example, by taking the remainder of a 32-bit division of
3829 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3830 lets srem be implemented using instructions that return both the result of
3831 the division and the remainder.)</p>
3832
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3833<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3834<pre>
3835 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3836</pre>
3837
3838</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3839
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3840<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3841<h4>
3842 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3843</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3844
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3845<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3846
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3847<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3848<pre>
3849 &lt;result&gt; = frem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3850</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3851
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3852<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3853<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3854 its two operands.</p>
3855
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3856<h5>Arguments:</h5>
3857<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3858 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3859 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3860
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3861<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3862<p>This instruction returns the <i>remainder</i> of a division. The remainder
3863 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3864
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3865<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3866<pre>
3867 &lt;result&gt; = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3868</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3869
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3870</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3871
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3872</div>
3873
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3874<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3875<h3>
3876 <a name="bitwiseops">Bitwise Binary Operations</a>
3877</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3878
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3879<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3880
3881<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3882 program. They are generally very efficient instructions and can commonly be
3883 strength reduced from other instructions. They require two operands of the
3884 same type, execute an operation on them, and produce a single value. The
3885 resulting value is the same type as its operands.</p>
3886
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3887<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3888<h4>
3889 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3890</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3891
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3892<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3893
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3894<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3895<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3896 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3897 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3898 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3899 &lt;result&gt; = shl nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3900</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3901
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3902<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3903<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3904 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3905
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3906<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3907<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3908 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3909 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3910
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3911<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3912<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3913 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3914 is (statically or dynamically) negative or equal to or larger than the number
3915 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3916 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3917 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3918
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3919<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3920 <a href="#trapvalues">trap value</a> if it shifts out any non-zero bits. If
Chris Lattner66298c12011-02-09 16:44:44 +0000[diff] [blame]3921 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3922 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3923 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3924 they would if the shift were expressed as a mul instruction with the same
3925 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3926
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3927<h5>Example:</h5>
3928<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3929 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3930 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3931 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3932 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3933 &lt;result&gt; = shl &lt;2 x i32&gt; &lt; i32 1, i32 1&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 2, i32 4&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3934</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3935
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3936</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3937
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3938<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3939<h4>
3940 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3941</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3942
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3943<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3944
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3945<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3946<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3947 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3948 &lt;result&gt; = lshr exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3949</pre>
3950
3951<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3952<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3953 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3954
3955<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3956<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3957 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3958 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3959
3960<h5>Semantics:</h5>
3961<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3962 significant bits of the result will be filled with zero bits after the shift.
3963 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3964 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3965 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3966 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3967
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3968<p>If the <tt>exact</tt> keyword is present, the result value of the
3969 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3970 shifted out are non-zero.</p>
3971
3972
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3973<h5>Example:</h5>
3974<pre>
3975 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3976 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3977 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3978 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3979 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3980 &lt;result&gt; = lshr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0x7FFFFFFF, i32 1&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3981</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3982
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3983</div>
3984
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3985<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3986<h4>
3987 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
3988</h4>
3989
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3990<div>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3991
3992<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3993<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3994 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3995 &lt;result&gt; = ashr exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3996</pre>
3997
3998<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3999<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
4000 operand shifted to the right a specified number of bits with sign
4001 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4002
4003<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4004<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4005 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4006 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4007
4008<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4009<p>This instruction always performs an arithmetic shift right operation, The
4010 most significant bits of the result will be filled with the sign bit
4011 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
4012 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
4013 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
4014 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4015
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]4016<p>If the <tt>exact</tt> keyword is present, the result value of the
4017 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
4018 shifted out are non-zero.</p>
4019
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4020<h5>Example:</h5>
4021<pre>
4022 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
4023 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
4024 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
4025 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]4026 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]4027 &lt;result&gt; = ashr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 3&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 -1, i32 0&gt;</i>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4028</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4029
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]4030</div>
4031
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4032<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4033<h4>
4034 <a name="i_and">'<tt>and</tt>' Instruction</a>
4035</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4036
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4037<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4038
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4039<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4040<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]4041 &lt;result&gt; = and &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4042</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4043
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4044<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4045<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
4046 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4047
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4048<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4049<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4050 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4051 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4052
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4053<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4054<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4055
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4056<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4057 <tbody>
4058 <tr>
4059 <td>In0</td>
4060 <td>In1</td>
4061 <td>Out</td>
4062 </tr>
4063 <tr>
4064 <td>0</td>
4065 <td>0</td>
4066 <td>0</td>
4067 </tr>
4068 <tr>
4069 <td>0</td>
4070 <td>1</td>
4071 <td>0</td>
4072 </tr>
4073 <tr>
4074 <td>1</td>
4075 <td>0</td>
4076 <td>0</td>
4077 </tr>
4078 <tr>
4079 <td>1</td>
4080 <td>1</td>
4081 <td>1</td>
4082 </tr>
4083 </tbody>
4084</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4085
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4086<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4087<pre>
4088 &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4089 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
4090 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4091</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4092</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4093<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4094<h4>
4095 <a name="i_or">'<tt>or</tt>' Instruction</a>
4096</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4097
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4098<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4099
4100<h5>Syntax:</h5>
4101<pre>
4102 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
4103</pre>
4104
4105<h5>Overview:</h5>
4106<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
4107 two operands.</p>
4108
4109<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4110<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4111 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4112 values. Both arguments must have identical types.</p>
4113
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4114<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4115<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4116
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4117<table border="1" cellspacing="0" cellpadding="4">
4118 <tbody>
4119 <tr>
4120 <td>In0</td>
4121 <td>In1</td>
4122 <td>Out</td>
4123 </tr>
4124 <tr>
4125 <td>0</td>
4126 <td>0</td>
4127 <td>0</td>
4128 </tr>
4129 <tr>
4130 <td>0</td>
4131 <td>1</td>
4132 <td>1</td>
4133 </tr>
4134 <tr>
4135 <td>1</td>
4136 <td>0</td>
4137 <td>1</td>
4138 </tr>
4139 <tr>
4140 <td>1</td>
4141 <td>1</td>
4142 <td>1</td>
4143 </tr>
4144 </tbody>
4145</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4146
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4147<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4148<pre>
4149 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4150 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4151 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4152</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4153
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4154</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4155
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4156<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4157<h4>
4158 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4159</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4160
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4161<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4162
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4163<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4164<pre>
4165 &lt;result&gt; = xor &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4166</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4167
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4168<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4169<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4170 its two operands. The <tt>xor</tt> is used to implement the "one's
4171 complement" operation, which is the "~" operator in C.</p>
4172
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4173<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4174<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4175 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4176 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4177
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4178<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4179<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4180
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4181<table border="1" cellspacing="0" cellpadding="4">
4182 <tbody>
4183 <tr>
4184 <td>In0</td>
4185 <td>In1</td>
4186 <td>Out</td>
4187 </tr>
4188 <tr>
4189 <td>0</td>
4190 <td>0</td>
4191 <td>0</td>
4192 </tr>
4193 <tr>
4194 <td>0</td>
4195 <td>1</td>
4196 <td>1</td>
4197 </tr>
4198 <tr>
4199 <td>1</td>
4200 <td>0</td>
4201 <td>1</td>
4202 </tr>
4203 <tr>
4204 <td>1</td>
4205 <td>1</td>
4206 <td>0</td>
4207 </tr>
4208 </tbody>
4209</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4210
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4211<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4212<pre>
4213 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4214 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4215 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4216 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4217</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4218
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4219</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4220
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4221</div>
4222
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4223<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4224<h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4225 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4226</h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4227
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4228<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4229
4230<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4231 target-independent manner. These instructions cover the element-access and
4232 vector-specific operations needed to process vectors effectively. While LLVM
4233 does directly support these vector operations, many sophisticated algorithms
4234 will want to use target-specific intrinsics to take full advantage of a
4235 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4236
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4237<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4238<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4239 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4240</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4241
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4242<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4243
4244<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4245<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4246 &lt;result&gt; = extractelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, i32 &lt;idx&gt; <i>; yields &lt;ty&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4247</pre>
4248
4249<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4250<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4251 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4252
4253
4254<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4255<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4256 of <a href="#t_vector">vector</a> type. The second operand is an index
4257 indicating the position from which to extract the element. The index may be
4258 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4259
4260<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4261<p>The result is a scalar of the same type as the element type of
4262 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4263 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4264 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4265
4266<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4267<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4268 &lt;result&gt; = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4269</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4270
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4271</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4272
4273<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4274<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4275 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4276</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4277
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4278<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4279
4280<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4281<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]4282 &lt;result&gt; = insertelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, i32 &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4283</pre>
4284
4285<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4286<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4287 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4288
4289<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4290<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4291 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4292 whose type must equal the element type of the first operand. The third
4293 operand is an index indicating the position at which to insert the value.
4294 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4295
4296<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4297<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4298 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4299 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4300 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4301
4302<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4303<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4304 &lt;result&gt; = insertelement &lt;4 x i32&gt; %vec, i32 1, i32 0 <i>; yields &lt;4 x i32&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4305</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4306
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4307</div>
4308
4309<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4310<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4311 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4312</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4313
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4314<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4315
4316<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4317<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4318 &lt;result&gt; = shufflevector &lt;n x &lt;ty&gt;&gt; &lt;v1&gt;, &lt;n x &lt;ty&gt;&gt; &lt;v2&gt;, &lt;m x i32&gt; &lt;mask&gt; <i>; yields &lt;m x &lt;ty&gt;&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4319</pre>
4320
4321<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4322<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4323 from two input vectors, returning a vector with the same element type as the
4324 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4325
4326<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4327<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4328 with types that match each other. The third argument is a shuffle mask whose
4329 element type is always 'i32'. The result of the instruction is a vector
4330 whose length is the same as the shuffle mask and whose element type is the
4331 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4332
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4333<p>The shuffle mask operand is required to be a constant vector with either
4334 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4335
4336<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4337<p>The elements of the two input vectors are numbered from left to right across
4338 both of the vectors. The shuffle mask operand specifies, for each element of
4339 the result vector, which element of the two input vectors the result element
4340 gets. The element selector may be undef (meaning "don't care") and the
4341 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4342
4343<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4344<pre>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4345 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4346 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4347 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4348 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i> - Identity shuffle.
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4349 &lt;result&gt; = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4350 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4351 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4352 &lt;8 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 &gt; <i>; yields &lt;8 x i32&gt;</i>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4353</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4354
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4355</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]4356
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4357</div>
4358
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4359<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4360<h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4361 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4362</h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4363
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4364<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4365
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4366<p>LLVM supports several instructions for working with
4367 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4368
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4369<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4370<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4371 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4372</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4373
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4374<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4375
4376<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4377<pre>
4378 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4379</pre>
4380
4381<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4382<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4383 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4384
4385<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4386<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4387 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4388 <a href="#t_array">array</a> type. The operands are constant indices to
4389 specify which value to extract in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4390 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel13242892010-12-05 20:54:38 +0000[diff] [blame]4391 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4392 <ul>
4393 <li>Since the value being indexed is not a pointer, the first index is
4394 omitted and assumed to be zero.</li>
4395 <li>At least one index must be specified.</li>
4396 <li>Not only struct indices but also array indices must be in
4397 bounds.</li>
4398 </ul>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4399
4400<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4401<p>The result is the value at the position in the aggregate specified by the
4402 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4403
4404<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4405<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4406 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4407</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4408
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4409</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4410
4411<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4412<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4413 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4414</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4415
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4416<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4417
4418<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4419<pre>
Bill Wendling194229e2011-07-26 20:42:28 +0000[diff] [blame]4420 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt;{, &lt;idx&gt;}* <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4421</pre>
4422
4423<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4424<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4425 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4426
4427<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4428<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4429 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4430 <a href="#t_array">array</a> type. The second operand is a first-class
4431 value to insert. The following operands are constant indices indicating
4432 the position at which to insert the value in a similar manner as indices in a
Frits van Bommel13242892010-12-05 20:54:38 +0000[diff] [blame]4433 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4434 value to insert must have the same type as the value identified by the
4435 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4436
4437<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4438<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4439 that of <tt>val</tt> except that the value at the position specified by the
4440 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4441
4442<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4443<pre>
Chris Lattner8645d1a2011-05-22 07:18:08 +0000[diff] [blame]4444 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4445 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4446 %agg3 = insertvalue {i32, {float}} %agg1, float %val, 1, 0 <i>; yields {i32 1, float %val}</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4447</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4448
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4449</div>
4450
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4451</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4452
4453<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4454<h3>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4455 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4456</h3>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4457
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4458<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4459
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4460<p>A key design point of an SSA-based representation is how it represents
4461 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]4462 very simple. This section describes how to read, write, and allocate
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4463 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4464
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4465<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4466<h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4467 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4468</h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4469
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4470<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4471
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4472<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4473<pre>
Dan Gohmanf75a7d32010-05-28 01:14:11 +0000[diff] [blame]4474 &lt;result&gt; = alloca &lt;type&gt;[, &lt;ty&gt; &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4475</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4476
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4477<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4478<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4479 currently executing function, to be automatically released when this function
4480 returns to its caller. The object is always allocated in the generic address
4481 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4482
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4483<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4484<p>The '<tt>alloca</tt>' instruction
4485 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4486 runtime stack, returning a pointer of the appropriate type to the program.
4487 If "NumElements" is specified, it is the number of elements allocated,
4488 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4489 specified, the value result of the allocation is guaranteed to be aligned to
4490 at least that boundary. If not specified, or if zero, the target can choose
4491 to align the allocation on any convenient boundary compatible with the
4492 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4493
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4494<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4495
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4496<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]4497<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4498 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4499 memory is automatically released when the function returns. The
4500 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4501 variables that must have an address available. When the function returns
4502 (either with the <tt><a href="#i_ret">ret</a></tt>
4503 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4504 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4505
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4506<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4507<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]4508 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4509 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4510 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4511 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4512</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4513
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4514</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4515
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4516<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4517<h4>
4518 <a name="i_load">'<tt>load</tt>' Instruction</a>
4519</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4520
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4521<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4522
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4523<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4524<pre>
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4525 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4526 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4527 !&lt;index&gt; = !{ i32 1 }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4528</pre>
4529
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4530<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4531<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4532
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4533<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4534<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4535 from which to load. The pointer must point to
4536 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4537 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4538 number or order of execution of this <tt>load</tt> with other <a
4539 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4540
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4541<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4542 operation (that is, the alignment of the memory address). A value of 0 or an
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4543 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4544 alignment for the target. It is the responsibility of the code emitter to
4545 ensure that the alignment information is correct. Overestimating the
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4546 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4547 produce less efficient code. An alignment of 1 is always safe.</p>
4548
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4549<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4550 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4551 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4552 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4553 and code generator that this load is not expected to be reused in the cache.
4554 The code generator may select special instructions to save cache bandwidth,
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4555 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4556
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4557<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4558<p>The location of memory pointed to is loaded. If the value being loaded is of
4559 scalar type then the number of bytes read does not exceed the minimum number
4560 of bytes needed to hold all bits of the type. For example, loading an
4561 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4562 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4563 is undefined if the value was not originally written using a store of the
4564 same type.</p>
4565
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4566<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4567<pre>
4568 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4569 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4570 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4571</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4572
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4573</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4574
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4575<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4576<h4>
4577 <a name="i_store">'<tt>store</tt>' Instruction</a>
4578</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4579
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4580<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4581
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4582<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4583<pre>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4584 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
4585 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4586</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4587
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4588<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4589<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4590
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4591<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4592<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4593 and an address at which to store it. The type of the
4594 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4595 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4596 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4597 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4598 order of execution of this <tt>store</tt> with other <a
4599 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4600
4601<p>The optional constant "align" argument specifies the alignment of the
4602 operation (that is, the alignment of the memory address). A value of 0 or an
4603 omitted "align" argument means that the operation has the preferential
4604 alignment for the target. It is the responsibility of the code emitter to
4605 ensure that the alignment information is correct. Overestimating the
4606 alignment results in an undefined behavior. Underestimating the alignment may
4607 produce less efficient code. An alignment of 1 is always safe.</p>
4608
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4609<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4610 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4611 value 1. The existence of the !nontemporal metatadata on the
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4612 instruction tells the optimizer and code generator that this load is
4613 not expected to be reused in the cache. The code generator may
4614 select special instructions to save cache bandwidth, such as the
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4615 MOVNT instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4616
4617
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4618<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4619<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4620 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4621 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4622 does not exceed the minimum number of bytes needed to hold all bits of the
4623 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4624 writing a value of a type like <tt>i20</tt> with a size that is not an
4625 integral number of bytes, it is unspecified what happens to the extra bits
4626 that do not belong to the type, but they will typically be overwritten.</p>
4627
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4628<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4629<pre>
4630 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]4631 store i32 3, i32* %ptr <i>; yields {void}</i>
4632 %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4633</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4634
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4635</div>
4636
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4637<!-- _______________________________________________________________________ -->
Eli Friedman47f35132011-07-25 23:16:38 +0000[diff] [blame]4638<div class="doc_subsubsection"> <a name="i_fence">'<tt>fence</tt>'
4639Instruction</a> </div>
4640
4641<div class="doc_text">
4642
4643<h5>Syntax:</h5>
4644<pre>
4645 fence [singlethread] &lt;ordering&gt; <i>; yields {void}</i>
4646</pre>
4647
4648<h5>Overview:</h5>
4649<p>The '<tt>fence</tt>' instruction is used to introduce happens-before edges
4650between operations.</p>
4651
4652<h5>Arguments:</h5> <p>'<code>fence</code>' instructions take an <a
4653href="#ordering">ordering</a> argument which defines what
4654<i>synchronizes-with</i> edges they add. They can only be given
4655<code>acquire</code>, <code>release</code>, <code>acq_rel</code>, and
4656<code>seq_cst</code> orderings.</p>
4657
4658<h5>Semantics:</h5>
4659<p>A fence <var>A</var> which has (at least) <code>release</code> ordering
4660semantics <i>synchronizes with</i> a fence <var>B</var> with (at least)
4661<code>acquire</code> ordering semantics if and only if there exist atomic
4662operations <var>X</var> and <var>Y</var>, both operating on some atomic object
4663<var>M</var>, such that <var>A</var> is sequenced before <var>X</var>,
4664<var>X</var> modifies <var>M</var> (either directly or through some side effect
4665of a sequence headed by <var>X</var>), <var>Y</var> is sequenced before
4666<var>B</var>, and <var>Y</var> observes <var>M</var>. This provides a
4667<i>happens-before</i> dependency between <var>A</var> and <var>B</var>. Rather
4668than an explicit <code>fence</code>, one (but not both) of the atomic operations
4669<var>X</var> or <var>Y</var> might provide a <code>release</code> or
4670<code>acquire</code> (resp.) ordering constraint and still
4671<i>synchronize-with</i> the explicit <code>fence</code> and establish the
4672<i>happens-before</i> edge.</p>
4673
4674<p>A <code>fence</code> which has <code>seq_cst</code> ordering, in addition to
4675having both <code>acquire</code> and <code>release</code> semantics specified
4676above, participates in the global program order of other <code>seq_cst</code>
4677operations and/or fences.</p>
4678
4679<p>The optional "<a href="#singlethread"><code>singlethread</code></a>" argument
4680specifies that the fence only synchronizes with other fences in the same
4681thread. (This is useful for interacting with signal handlers.)</p>
4682
4683<p>FIXME: This instruction is a work in progress; until it is finished, use
4684 llvm.memory.barrier.
4685
4686<h5>Example:</h5>
4687<pre>
4688 fence acquire <i>; yields {void}</i>
4689 fence singlethread seq_cst <i>; yields {void}</i>
4690</pre>
4691
4692</div>
4693
4694<!-- _______________________________________________________________________ -->
Eli Friedmanff030482011-07-28 21:48:00 +0000[diff] [blame]4695<div class="doc_subsubsection"> <a name="i_cmpxchg">'<tt>cmpxchg</tt>'
4696Instruction</a> </div>
4697
4698<div class="doc_text">
4699
4700<h5>Syntax:</h5>
4701<pre>
4702 [volatile] cmpxchg &lt;ty&gt;* &lt;pointer&gt;, &lt;ty&gt; &lt;cmp&gt;, &lt;ty&gt; &lt;new&gt; [singlethread] &lt;ordering&gt; <i>; yields {ty}</i>
4703</pre>
4704
4705<h5>Overview:</h5>
4706<p>The '<tt>cmpxchg</tt>' instruction is used to atomically modify memory.
4707It loads a value in memory and compares it to a given value. If they are
4708equal, it stores a new value into the memory.</p>
4709
4710<h5>Arguments:</h5>
4711<p>There are three arguments to the '<code>cmpxchg</code>' instruction: an
4712address to operate on, a value to compare to the value currently be at that
4713address, and a new value to place at that address if the compared values are
4714equal. The type of '<var>&lt;cmp&gt;</var>' must be an integer type whose
4715bit width is a power of two greater than or equal to eight and less than
4716or equal to a target-specific size limit. '<var>&lt;cmp&gt;</var>' and
4717'<var>&lt;new&gt;</var>' must have the same type, and the type of
4718'<var>&lt;pointer&gt;</var>' must be a pointer to that type. If the
4719<code>cmpxchg</code> is marked as <code>volatile</code>, then the
4720optimizer is not allowed to modify the number or order of execution
4721of this <code>cmpxchg</code> with other <a href="#volatile">volatile
4722operations</a>.</p>
4723
4724<!-- FIXME: Extend allowed types. -->
4725
4726<p>The <a href="#ordering"><var>ordering</var></a> argument specifies how this
4727<code>cmpxchg</code> synchronizes with other atomic operations.</p>
4728
4729<p>The optional "<code>singlethread</code>" argument declares that the
4730<code>cmpxchg</code> is only atomic with respect to code (usually signal
4731handlers) running in the same thread as the <code>cmpxchg</code>. Otherwise the
4732cmpxchg is atomic with respect to all other code in the system.</p>
4733
4734<p>The pointer passed into cmpxchg must have alignment greater than or equal to
4735the size in memory of the operand.
4736
4737<h5>Semantics:</h5>
4738<p>The contents of memory at the location specified by the
4739'<tt>&lt;pointer&gt;</tt>' operand is read and compared to
4740'<tt>&lt;cmp&gt;</tt>'; if the read value is the equal,
4741'<tt>&lt;new&gt;</tt>' is written. The original value at the location
4742is returned.
4743
4744<p>A successful <code>cmpxchg</code> is a read-modify-write instruction for the
4745purpose of identifying <a href="#release_sequence">release sequences</a>. A
4746failed <code>cmpxchg</code> is equivalent to an atomic load with an ordering
4747parameter determined by dropping any <code>release</code> part of the
4748<code>cmpxchg</code>'s ordering.</p>
4749
4750<!--
4751FIXME: Is compare_exchange_weak() necessary? (Consider after we've done
4752optimization work on ARM.)
4753
4754FIXME: Is a weaker ordering constraint on failure helpful in practice?
4755-->
4756
4757<h5>Example:</h5>
4758<pre>
4759entry:
4760 %orig = atomic <a href="#i_load">load</a> i32* %ptr unordered <i>; yields {i32}</i>
4761 <a href="#i_br">br</a> label %loop
4762
4763loop:
4764 %cmp = <a href="#i_phi">phi</a> i32 [ %orig, %entry ], [%old, %loop]
4765 %squared = <a href="#i_mul">mul</a> i32 %cmp, %cmp
4766 %old = cmpxchg i32* %ptr, i32 %cmp, i32 %squared <i>; yields {i32}</i>
4767 %success = <a href="#i_icmp">icmp</a> eq i32 %cmp, %old
4768 <a href="#i_br">br</a> i1 %success, label %done, label %loop
4769
4770done:
4771 ...
4772</pre>
4773
4774</div>
4775
4776<!-- _______________________________________________________________________ -->
4777<div class="doc_subsubsection"> <a name="i_atomicrmw">'<tt>atomicrmw</tt>'
4778Instruction</a> </div>
4779
4780<div class="doc_text">
4781
4782<h5>Syntax:</h5>
4783<pre>
4784 [volatile] atomicrmw &lt;operation&gt; &lt;ty&gt;* &lt;pointer&gt;, &lt;ty&gt; &lt;value&gt; [singlethread] &lt;ordering&gt; <i>; yields {ty}</i>
4785</pre>
4786
4787<h5>Overview:</h5>
4788<p>The '<tt>atomicrmw</tt>' instruction is used to atomically modify memory.</p>
4789
4790<h5>Arguments:</h5>
4791<p>There are three arguments to the '<code>atomicrmw</code>' instruction: an
4792operation to apply, an address whose value to modify, an argument to the
4793operation. The operation must be one of the following keywords:</p>
4794<ul>
4795 <li>xchg</li>
4796 <li>add</li>
4797 <li>sub</li>
4798 <li>and</li>
4799 <li>nand</li>
4800 <li>or</li>
4801 <li>xor</li>
4802 <li>max</li>
4803 <li>min</li>
4804 <li>umax</li>
4805 <li>umin</li>
4806</ul>
4807
4808<p>The type of '<var>&lt;value&gt;</var>' must be an integer type whose
4809bit width is a power of two greater than or equal to eight and less than
4810or equal to a target-specific size limit. The type of the
4811'<code>&lt;pointer&gt;</code>' operand must be a pointer to that type.
4812If the <code>atomicrmw</code> is marked as <code>volatile</code>, then the
4813optimizer is not allowed to modify the number or order of execution of this
4814<code>atomicrmw</code> with other <a href="#volatile">volatile
4815 operations</a>.</p>
4816
4817<!-- FIXME: Extend allowed types. -->
4818
4819<h5>Semantics:</h5>
4820<p>The contents of memory at the location specified by the
4821'<tt>&lt;pointer&gt;</tt>' operand are atomically read, modified, and written
4822back. The original value at the location is returned. The modification is
4823specified by the <var>operation</var> argument:</p>
4824
4825<ul>
4826 <li>xchg: <code>*ptr = val</code></li>
4827 <li>add: <code>*ptr = *ptr + val</code></li>
4828 <li>sub: <code>*ptr = *ptr - val</code></li>
4829 <li>and: <code>*ptr = *ptr &amp; val</code></li>
4830 <li>nand: <code>*ptr = ~(*ptr &amp; val)</code></li>
4831 <li>or: <code>*ptr = *ptr | val</code></li>
4832 <li>xor: <code>*ptr = *ptr ^ val</code></li>
4833 <li>max: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using a signed comparison)</li>
4834 <li>min: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using a signed comparison)</li>
4835 <li>umax: <code>*ptr = *ptr &gt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4836 <li>umin: <code>*ptr = *ptr &lt; val ? *ptr : val</code> (using an unsigned comparison)</li>
4837</ul>
4838
4839<h5>Example:</h5>
4840<pre>
4841 %old = atomicrmw add i32* %ptr, i32 1 acquire <i>; yields {i32}</i>
4842</pre>
4843
4844</div>
4845
4846<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4847<h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4848 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4849</h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4850
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4851<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4852
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4853<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4854<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4855 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4856 &lt;result&gt; = getelementptr inbounds &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4857</pre>
4858
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4859<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4860<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4861 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4862 It performs address calculation only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4863
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4864<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4865<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4866 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4867 elements of the aggregate object are indexed. The interpretation of each
4868 index is dependent on the type being indexed into. The first index always
4869 indexes the pointer value given as the first argument, the second index
4870 indexes a value of the type pointed to (not necessarily the value directly
4871 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4872 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4873 vectors, and structs. Note that subsequent types being indexed into
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4874 can never be pointers, since that would require loading the pointer before
4875 continuing calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4876
4877<p>The type of each index argument depends on the type it is indexing into.
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4878 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4879 integer <b>constants</b> are allowed. When indexing into an array, pointer
4880 or vector, integers of any width are allowed, and they are not required to be
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4881 constant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4882
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4883<p>For example, let's consider a C code fragment and how it gets compiled to
4884 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4885
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4886<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4887struct RT {
4888 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4889 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4890 char C;
4891};
4892struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4893 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4894 double Y;
4895 struct RT Z;
4896};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4897
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4898int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4899 return &amp;s[1].Z.B[5][13];
4900}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4901</pre>
4902
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4903<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4904
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4905<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]4906%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4907%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4908
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4909define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4910entry:
4911 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4912 ret i32* %reg
4913}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4914</pre>
4915
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4916<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4917<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4918 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4919 }</tt>' type, a structure. The second index indexes into the third element
4920 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4921 i8 }</tt>' type, another structure. The third index indexes into the second
4922 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4923 array. The two dimensions of the array are subscripted into, yielding an
4924 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4925 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4926
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4927<p>Note that it is perfectly legal to index partially through a structure,
4928 returning a pointer to an inner element. Because of this, the LLVM code for
4929 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4930
4931<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4932 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4933 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4934 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4935 %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4936 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4937 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4938 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4939 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4940</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]4941
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4942<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]4943 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4944 base pointer is not an <i>in bounds</i> address of an allocated object,
4945 or if any of the addresses that would be formed by successive addition of
4946 the offsets implied by the indices to the base address with infinitely
4947 precise arithmetic are not an <i>in bounds</i> address of that allocated
4948 object. The <i>in bounds</i> addresses for an allocated object are all
4949 the addresses that point into the object, plus the address one byte past
4950 the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4951
4952<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4953 the base address with silently-wrapping two's complement arithmetic, and
4954 the result value of the <tt>getelementptr</tt> may be outside the object
4955 pointed to by the base pointer. The result value may not necessarily be
4956 used to access memory though, even if it happens to point into allocated
4957 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4958 section for more information.</p>
4959
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4960<p>The getelementptr instruction is often confusing. For some more insight into
4961 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4962
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4963<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4964<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4965 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4966 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4967 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4968 %vptr = getelementptr {i32, &lt;2 x i8&gt;}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4969 <i>; yields i8*:eptr</i>
4970 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]4971 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]4972 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4973</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4974
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4975</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4976
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4977</div>
4978
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4979<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4980<h3>
4981 <a name="convertops">Conversion Operations</a>
4982</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4983
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4984<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4985
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4986<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4987 which all take a single operand and a type. They perform various bit
4988 conversions on the operand.</p>
4989
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4990<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4991<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4992 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4993</h4>
4994
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4995<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4996
4997<h5>Syntax:</h5>
4998<pre>
4999 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5000</pre>
5001
5002<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5003<p>The '<tt>trunc</tt>' instruction truncates its operand to the
5004 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5005
5006<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5007<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
5008 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5009 of the same number of integers.
5010 The bit size of the <tt>value</tt> must be larger than
5011 the bit size of the destination type, <tt>ty2</tt>.
5012 Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5013
5014<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5015<p>The '<tt>trunc</tt>' instruction truncates the high order bits
5016 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
5017 source size must be larger than the destination size, <tt>trunc</tt> cannot
5018 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5019
5020<h5>Example:</h5>
5021<pre>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5022 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
5023 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
5024 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
5025 %W = trunc &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i8&gt; <i>; yields &lt;i8 8, i8 7&gt;</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5026</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5027
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5028</div>
5029
5030<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5031<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5032 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5033</h4>
5034
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5035<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5036
5037<h5>Syntax:</h5>
5038<pre>
5039 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5040</pre>
5041
5042<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5043<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5044 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5045
5046
5047<h5>Arguments:</h5>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]5048<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
5049 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5050 of the same number of integers.
5051 The bit size of the <tt>value</tt> must be smaller than
5052 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5053 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5054
5055<h5>Semantics:</h5>
5056<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5057 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5058
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]5059<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5060
5061<h5>Example:</h5>
5062<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5063 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5064 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]5065 %Z = zext &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i32&gt; <i>; yields &lt;i32 8, i32 7&gt;</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5066</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5067
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5068</div>
5069
5070<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5071<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5072 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5073</h4>
5074
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5075<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5076
5077<h5>Syntax:</h5>
5078<pre>
5079 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5080</pre>
5081
5082<h5>Overview:</h5>
5083<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
5084
5085<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5086<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
5087 Both types must be of <a href="#t_integer">integer</a> types, or vectors
5088 of the same number of integers.
5089 The bit size of the <tt>value</tt> must be smaller than
5090 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5091 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5092
5093<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5094<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
5095 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
5096 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5097
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5098<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5099
5100<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5101<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5102 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5103 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]5104 %Z = sext &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i32&gt; <i>; yields &lt;i32 8, i32 7&gt;</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5105</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5106
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5107</div>
5108
5109<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5110<h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5111 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5112</h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5113
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5114<div>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5115
5116<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5117<pre>
5118 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5119</pre>
5120
5121<h5>Overview:</h5>
5122<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5123 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5124
5125<h5>Arguments:</h5>
5126<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5127 point</a> value to cast and a <a href="#t_floating">floating point</a> type
5128 to cast it to. The size of <tt>value</tt> must be larger than the size of
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5129 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5130 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5131
5132<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5133<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5134 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5135 <a href="#t_floating">floating point</a> type. If the value cannot fit
5136 within the destination type, <tt>ty2</tt>, then the results are
5137 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5138
5139<h5>Example:</h5>
5140<pre>
5141 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
5142 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
5143</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5144
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]5145</div>
5146
5147<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5148<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5149 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5150</h4>
5151
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5152<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5153
5154<h5>Syntax:</h5>
5155<pre>
5156 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5157</pre>
5158
5159<h5>Overview:</h5>
5160<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5161 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5162
5163<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5164<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5165 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
5166 a <a href="#t_floating">floating point</a> type to cast it to. The source
5167 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5168
5169<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5170<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5171 <a href="#t_floating">floating point</a> type to a larger
5172 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
5173 used to make a <i>no-op cast</i> because it always changes bits. Use
5174 <tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5175
5176<h5>Example:</h5>
5177<pre>
Nick Lewycky5bb3ece2011-03-31 18:20:19 +0000[diff] [blame]5178 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
5179 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5180</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5181
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5182</div>
5183
5184<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5185<h4>
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]5186 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5187</h4>
5188
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5189<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5190
5191<h5>Syntax:</h5>
5192<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5193 &lt;result&gt; = fptoui &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5194</pre>
5195
5196<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5197<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5198 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5199
5200<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5201<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
5202 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5203 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5204 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5205 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5206
5207<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5208<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5209 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5210 towards zero) unsigned integer value. If the value cannot fit
5211 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5212
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5213<h5>Example:</h5>
5214<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]5215 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]5216 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5217 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5218</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5219
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5220</div>
5221
5222<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5223<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5224 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5225</h4>
5226
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5227<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5228
5229<h5>Syntax:</h5>
5230<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5231 &lt;result&gt; = fptosi &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5232</pre>
5233
5234<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5235<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5236 <a href="#t_floating">floating point</a> <tt>value</tt> to
5237 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5238
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5239<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5240<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
5241 scalar or vector <a href="#t_floating">floating point</a> value, and a type
5242 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
5243 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
5244 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5245
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5246<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5247<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5248 <a href="#t_floating">floating point</a> operand into the nearest (rounding
5249 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
5250 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5251
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]5252<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5253<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5254 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]5255 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5256 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5257</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5258
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5259</div>
5260
5261<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5262<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5263 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5264</h4>
5265
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5266<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5267
5268<h5>Syntax:</h5>
5269<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5270 &lt;result&gt; = uitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5271</pre>
5272
5273<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5274<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5275 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5276
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5277<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]5278<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5279 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5280 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5281 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5282 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5283
5284<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5285<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5286 integer quantity and converts it to the corresponding floating point
5287 value. If the value cannot fit in the floating point value, the results are
5288 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5289
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5290<h5>Example:</h5>
5291<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5292 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5293 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5294</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5295
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5296</div>
5297
5298<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5299<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5300 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5301</h4>
5302
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5303<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5304
5305<h5>Syntax:</h5>
5306<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]5307 &lt;result&gt; = sitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5308</pre>
5309
5310<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5311<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
5312 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5313
5314<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]5315<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5316 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
5317 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
5318 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
5319 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5320
5321<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5322<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
5323 quantity and converts it to the corresponding floating point value. If the
5324 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5325
5326<h5>Example:</h5>
5327<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5328 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5329 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5330</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5331
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5332</div>
5333
5334<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5335<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5336 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5337</h4>
5338
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5339<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5340
5341<h5>Syntax:</h5>
5342<pre>
5343 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5344</pre>
5345
5346<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5347<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5348 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5349
5350<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5351<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5352 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5353 <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5354
5355<h5>Semantics:</h5>
5356<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5357 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5358 truncating or zero extending that value to the size of the integer type. If
5359 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5360 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5361 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5362 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5363
5364<h5>Example:</h5>
5365<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5366 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5367 %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5368</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5369
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5370</div>
5371
5372<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5373<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5374 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5375</h4>
5376
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5377<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5378
5379<h5>Syntax:</h5>
5380<pre>
5381 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5382</pre>
5383
5384<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5385<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5386 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5387
5388<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]5389<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5390 value to cast, and a type to cast it to, which must be a
5391 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5392
5393<h5>Semantics:</h5>
5394<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5395 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5396 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5397 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5398 than the size of a pointer then a zero extension is done. If they are the
5399 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5400
5401<h5>Example:</h5>
5402<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5403 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]5404 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5405 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5406</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5407
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5408</div>
5409
5410<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5411<h4>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5412 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5413</h4>
5414
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5415<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5416
5417<h5>Syntax:</h5>
5418<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5419 &lt;result&gt; = bitcast &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5420</pre>
5421
5422<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5423<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5424 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5425
5426<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5427<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5428 non-aggregate first class value, and a type to cast it to, which must also be
5429 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5430 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5431 identical. If the source type is a pointer, the destination type must also be
5432 a pointer. This instruction supports bitwise conversion of vectors to
5433 integers and to vectors of other types (as long as they have the same
5434 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5435
5436<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5437<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5438 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5439 this conversion. The conversion is done as if the <tt>value</tt> had been
5440 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5441 be converted to other pointer types with this instruction. To convert
5442 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5443 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5444
5445<h5>Example:</h5>
5446<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5447 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5448 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5449 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]5450</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5451
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5452</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5453
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5454</div>
5455
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5456<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5457<h3>
5458 <a name="otherops">Other Operations</a>
5459</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5460
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5461<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5462
5463<p>The instructions in this category are the "miscellaneous" instructions, which
5464 defy better classification.</p>
5465
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5466<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5467<h4>
5468 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5469</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5470
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5471<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5472
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5473<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5474<pre>
5475 &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5476</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5477
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5478<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5479<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5480 boolean values based on comparison of its two integer, integer vector, or
5481 pointer operands.</p>
5482
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5483<h5>Arguments:</h5>
5484<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5485 the condition code indicating the kind of comparison to perform. It is not a
5486 value, just a keyword. The possible condition code are:</p>
5487
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5488<ol>
5489 <li><tt>eq</tt>: equal</li>
5490 <li><tt>ne</tt>: not equal </li>
5491 <li><tt>ugt</tt>: unsigned greater than</li>
5492 <li><tt>uge</tt>: unsigned greater or equal</li>
5493 <li><tt>ult</tt>: unsigned less than</li>
5494 <li><tt>ule</tt>: unsigned less or equal</li>
5495 <li><tt>sgt</tt>: signed greater than</li>
5496 <li><tt>sge</tt>: signed greater or equal</li>
5497 <li><tt>slt</tt>: signed less than</li>
5498 <li><tt>sle</tt>: signed less or equal</li>
5499</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5500
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]5501<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5502 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5503 typed. They must also be identical types.</p>
5504
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5505<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5506<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5507 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5508 either an <a href="#t_integer"><tt>i1</tt></a> or vector of <tt>i1</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5509 result, as follows:</p>
5510
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5511<ol>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5512 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5513 <tt>false</tt> otherwise. No sign interpretation is necessary or
5514 performed.</li>
5515
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5516 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5517 <tt>false</tt> otherwise. No sign interpretation is necessary or
5518 performed.</li>
5519
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5520 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5521 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5522
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5523 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5524 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5525 to <tt>op2</tt>.</li>
5526
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5527 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5528 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5529
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5530 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5531 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5532
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5533 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5534 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5535
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5536 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5537 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5538 to <tt>op2</tt>.</li>
5539
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5540 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5541 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5542
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5543 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5544 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5545</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5546
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5547<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5548 values are compared as if they were integers.</p>
5549
5550<p>If the operands are integer vectors, then they are compared element by
5551 element. The result is an <tt>i1</tt> vector with the same number of elements
5552 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5553
5554<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5555<pre>
5556 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5557 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5558 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5559 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5560 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5561 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5562</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5563
5564<p>Note that the code generator does not yet support vector types with
5565 the <tt>icmp</tt> instruction.</p>
5566
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5567</div>
5568
5569<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5570<h4>
5571 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5572</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5573
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5574<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5575
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5576<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5577<pre>
5578 &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5579</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5580
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5581<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5582<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5583 values based on comparison of its operands.</p>
5584
5585<p>If the operands are floating point scalars, then the result type is a boolean
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5586(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5587
5588<p>If the operands are floating point vectors, then the result type is a vector
5589 of boolean with the same number of elements as the operands being
5590 compared.</p>
5591
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5592<h5>Arguments:</h5>
5593<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5594 the condition code indicating the kind of comparison to perform. It is not a
5595 value, just a keyword. The possible condition code are:</p>
5596
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5597<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5598 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5599 <li><tt>oeq</tt>: ordered and equal</li>
5600 <li><tt>ogt</tt>: ordered and greater than </li>
5601 <li><tt>oge</tt>: ordered and greater than or equal</li>
5602 <li><tt>olt</tt>: ordered and less than </li>
5603 <li><tt>ole</tt>: ordered and less than or equal</li>
5604 <li><tt>one</tt>: ordered and not equal</li>
5605 <li><tt>ord</tt>: ordered (no nans)</li>
5606 <li><tt>ueq</tt>: unordered or equal</li>
5607 <li><tt>ugt</tt>: unordered or greater than </li>
5608 <li><tt>uge</tt>: unordered or greater than or equal</li>
5609 <li><tt>ult</tt>: unordered or less than </li>
5610 <li><tt>ule</tt>: unordered or less than or equal</li>
5611 <li><tt>une</tt>: unordered or not equal</li>
5612 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5613 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5614</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5615
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5616<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5617 <i>unordered</i> means that either operand may be a QNAN.</p>
5618
5619<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5620 a <a href="#t_floating">floating point</a> type or
5621 a <a href="#t_vector">vector</a> of floating point type. They must have
5622 identical types.</p>
5623
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5624<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]5625<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5626 according to the condition code given as <tt>cond</tt>. If the operands are
5627 vectors, then the vectors are compared element by element. Each comparison
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5628 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5629 follows:</p>
5630
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5631<ol>
5632 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5633
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5634 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5635 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5636
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5637 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5638 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5639
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5640 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5641 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5642
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5643 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5644 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5645
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5646 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5647 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5648
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5649 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5650 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5651
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5652 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5653
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5654 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5655 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5656
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5657 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5658 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5659
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5660 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5661 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5662
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5663 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5664 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5665
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5666 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5667 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5668
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5669 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5670 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5671
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5672 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5673
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5674 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5675</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5676
5677<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5678<pre>
5679 &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5680 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5681 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5682 &lt;result&gt; = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5683</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5684
5685<p>Note that the code generator does not yet support vector types with
5686 the <tt>fcmp</tt> instruction.</p>
5687
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5688</div>
5689
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5690<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5691<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5692 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5693</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5694
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5695<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5696
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5697<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5698<pre>
5699 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5700</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5701
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5702<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5703<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5704 SSA graph representing the function.</p>
5705
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5706<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5707<p>The type of the incoming values is specified with the first type field. After
5708 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5709 one pair for each predecessor basic block of the current block. Only values
5710 of <a href="#t_firstclass">first class</a> type may be used as the value
5711 arguments to the PHI node. Only labels may be used as the label
5712 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5713
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5714<p>There must be no non-phi instructions between the start of a basic block and
5715 the PHI instructions: i.e. PHI instructions must be first in a basic
5716 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5717
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5718<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5719 occur on the edge from the corresponding predecessor block to the current
5720 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5721 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]5722
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5723<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5724<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5725 specified by the pair corresponding to the predecessor basic block that
5726 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5727
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5728<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5729<pre>
5730Loop: ; Infinite loop that counts from 0 on up...
5731 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5732 %nextindvar = add i32 %indvar, 1
5733 br label %Loop
5734</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5735
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5736</div>
5737
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5738<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5739<h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5740 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5741</h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5742
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5743<div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5744
5745<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5746<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5747 &lt;result&gt; = select <i>selty</i> &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
5748
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5749 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5750</pre>
5751
5752<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5753<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5754 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5755
5756
5757<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5758<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5759 values indicating the condition, and two values of the
5760 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5761 vectors and the condition is a scalar, then entire vectors are selected, not
5762 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5763
5764<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5765<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5766 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5767
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5768<p>If the condition is a vector of i1, then the value arguments must be vectors
5769 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5770
5771<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5772<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5773 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5774</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5775
5776<p>Note that the code generator does not yet support conditions
5777 with vector type.</p>
5778
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5779</div>
5780
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]5781<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5782<h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5783 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5784</h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5785
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5786<div>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5787
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5788<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5789<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]5790 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5791</pre>
5792
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5793<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5794<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5795
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5796<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5797<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5798
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5799<ol>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5800 <li>The optional "tail" marker indicates that the callee function does not
5801 access any allocas or varargs in the caller. Note that calls may be
5802 marked "tail" even if they do not occur before
5803 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5804 present, the function call is eligible for tail call optimization,
5805 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Chengdc444e92010-03-08 21:05:02 +0000[diff] [blame]5806 optimized into a jump</a>. The code generator may optimize calls marked
5807 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5808 sibling call optimization</a> when the caller and callee have
5809 matching signatures, or 2) forced tail call optimization when the
5810 following extra requirements are met:
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5811 <ul>
5812 <li>Caller and callee both have the calling
5813 convention <tt>fastcc</tt>.</li>
5814 <li>The call is in tail position (ret immediately follows call and ret
5815 uses value of call or is void).</li>
5816 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohmanfbbee8d2010-03-02 01:08:11 +0000[diff] [blame]5817 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5818 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5819 constraints are met.</a></li>
5820 </ul>
5821 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5822
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5823 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5824 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5825 defaults to using C calling conventions. The calling convention of the
5826 call must match the calling convention of the target function, or else the
5827 behavior is undefined.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5828
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5829 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5830 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5831 '<tt>inreg</tt>' attributes are valid here.</li>
5832
5833 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5834 type of the return value. Functions that return no value are marked
5835 <tt><a href="#t_void">void</a></tt>.</li>
5836
5837 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5838 being invoked. The argument types must match the types implied by this
5839 signature. This type can be omitted if the function is not varargs and if
5840 the function type does not return a pointer to a function.</li>
5841
5842 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5843 be invoked. In most cases, this is a direct function invocation, but
5844 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5845 to function value.</li>
5846
5847 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]5848 signature argument types and parameter attributes. All arguments must be
5849 of <a href="#t_firstclass">first class</a> type. If the function
5850 signature indicates the function accepts a variable number of arguments,
5851 the extra arguments can be specified.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5852
5853 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5854 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5855 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5856</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5857
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5858<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5859<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5860 a specified function, with its incoming arguments bound to the specified
5861 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5862 function, control flow continues with the instruction after the function
5863 call, and the return value of the function is bound to the result
5864 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5865
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5866<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5867<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]5868 %retval = call i32 @test(i32 %argc)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]5869 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]5870 %X = tail call i32 @foo() <i>; yields i32</i>
5871 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5872 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]5873
5874 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5875 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]5876 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5877 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]5878 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]5879 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5880</pre>
5881
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5882<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen9f8380b2009-09-25 17:04:42 +0000[diff] [blame]5883standard C99 library as being the C99 library functions, and may perform
5884optimizations or generate code for them under that assumption. This is
5885something we'd like to change in the future to provide better support for
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5886freestanding environments and non-C-based languages.</p>
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5887
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5888</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5889
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5890<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5891<h4>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]5892 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5893</h4>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5894
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5895<div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5896
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5897<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5898<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5899 &lt;resultval&gt; = va_arg &lt;va_list*&gt; &lt;arglist&gt;, &lt;argty&gt;
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5900</pre>
5901
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5902<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5903<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5904 the "variable argument" area of a function call. It is used to implement the
5905 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5906
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5907<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5908<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5909 argument. It returns a value of the specified argument type and increments
5910 the <tt>va_list</tt> to point to the next argument. The actual type
5911 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5912
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5913<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5914<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5915 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5916 to the next argument. For more information, see the variable argument
5917 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5918
5919<p>It is legal for this instruction to be called in a function which does not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5920 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5921 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5922
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5923<p><tt>va_arg</tt> is an LLVM instruction instead of
5924 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5925 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5926
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5927<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5928<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5929
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5930<p>Note that the code generator does not yet fully support va_arg on many
5931 targets. Also, it does not currently support va_arg with aggregate types on
5932 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]5933
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5934</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5935
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5936</div>
5937
5938</div>
5939
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5940<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5941<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]5942<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5943
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5944<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5945
5946<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5947 well known names and semantics and are required to follow certain
5948 restrictions. Overall, these intrinsics represent an extension mechanism for
5949 the LLVM language that does not require changing all of the transformations
5950 in LLVM when adding to the language (or the bitcode reader/writer, the
5951 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5952
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5953<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5954 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5955 begin with this prefix. Intrinsic functions must always be external
5956 functions: you cannot define the body of intrinsic functions. Intrinsic
5957 functions may only be used in call or invoke instructions: it is illegal to
5958 take the address of an intrinsic function. Additionally, because intrinsic
5959 functions are part of the LLVM language, it is required if any are added that
5960 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5961
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5962<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5963 family of functions that perform the same operation but on different data
5964 types. Because LLVM can represent over 8 million different integer types,
5965 overloading is used commonly to allow an intrinsic function to operate on any
5966 integer type. One or more of the argument types or the result type can be
5967 overloaded to accept any integer type. Argument types may also be defined as
5968 exactly matching a previous argument's type or the result type. This allows
5969 an intrinsic function which accepts multiple arguments, but needs all of them
5970 to be of the same type, to only be overloaded with respect to a single
5971 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5972
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5973<p>Overloaded intrinsics will have the names of its overloaded argument types
5974 encoded into its function name, each preceded by a period. Only those types
5975 which are overloaded result in a name suffix. Arguments whose type is matched
5976 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5977 can take an integer of any width and returns an integer of exactly the same
5978 integer width. This leads to a family of functions such as
5979 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5980 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5981 suffix is required. Because the argument's type is matched against the return
5982 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5983
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5984<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5985 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5986
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5987<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5988<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5989 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5990</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5991
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5992<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5993
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5994<p>Variable argument support is defined in LLVM with
5995 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5996 intrinsic functions. These functions are related to the similarly named
5997 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5998
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5999<p>All of these functions operate on arguments that use a target-specific value
6000 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
6001 not define what this type is, so all transformations should be prepared to
6002 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6003
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]6004<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6005 instruction and the variable argument handling intrinsic functions are
6006 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6007
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]6008<pre class="doc_code">
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6009define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6010 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6011 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6012 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6013 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6014
6015 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6016 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6017
6018 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6019 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6020 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6021 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6022 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6023
6024 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6025 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]6026 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6027}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]6028
6029declare void @llvm.va_start(i8*)
6030declare void @llvm.va_copy(i8*, i8*)
6031declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6032</pre>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6033
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6034<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6035<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6036 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6037</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6038
6039
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6040<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6041
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6042<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6043<pre>
6044 declare void %llvm.va_start(i8* &lt;arglist&gt;)
6045</pre>
6046
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6047<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6048<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
6049 for subsequent use by <tt><a href="#i_va_arg">va_arg</a></tt>.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6050
6051<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6052<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6053
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6054<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]6055<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6056 macro available in C. In a target-dependent way, it initializes
6057 the <tt>va_list</tt> element to which the argument points, so that the next
6058 call to <tt>va_arg</tt> will produce the first variable argument passed to
6059 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
6060 need to know the last argument of the function as the compiler can figure
6061 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6062
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6063</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6064
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6065<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6066<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6067 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6068</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6069
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6070<div>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6071
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6072<h5>Syntax:</h5>
6073<pre>
6074 declare void @llvm.va_end(i8* &lt;arglist&gt;)
6075</pre>
6076
6077<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6078<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6079 which has been initialized previously
6080 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
6081 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6082
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6083<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6084<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6085
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6086<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6087<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6088 macro available in C. In a target-dependent way, it destroys
6089 the <tt>va_list</tt> element to which the argument points. Calls
6090 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
6091 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
6092 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]6093
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6094</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6095
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6096<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6097<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6098 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6099</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6100
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6101<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6102
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6103<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6104<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6105 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6106</pre>
6107
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6108<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6109<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6110 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6111
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6112<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]6113<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6114 The second argument is a pointer to a <tt>va_list</tt> element to copy
6115 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6116
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]6117<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]6118<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6119 macro available in C. In a target-dependent way, it copies the
6120 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
6121 element. This intrinsic is necessary because
6122 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
6123 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6124
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]6125</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6126
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6127</div>
6128
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6129<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6130<h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6131 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6132</h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6133
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6134<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6135
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6136<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]6137Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6138intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
6139roots on the stack</a>, as well as garbage collector implementations that
6140require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
6141barriers. Front-ends for type-safe garbage collected languages should generate
6142these intrinsics to make use of the LLVM garbage collectors. For more details,
6143see <a href="GarbageCollection.html">Accurate Garbage Collection with
6144LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]6145
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6146<p>The garbage collection intrinsics only operate on objects in the generic
6147 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]6148
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6149<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6150<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6151 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6152</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6153
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6154<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6155
6156<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6157<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6158 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6159</pre>
6160
6161<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]6162<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6163 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6164
6165<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6166<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6167 root pointer. The second pointer (which must be either a constant or a
6168 global value address) contains the meta-data to be associated with the
6169 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6170
6171<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]6172<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6173 location. At compile-time, the code generator generates information to allow
6174 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
6175 intrinsic may only be used in a function which <a href="#gc">specifies a GC
6176 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6177
6178</div>
6179
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6180<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6181<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6182 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6183</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6184
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6185<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6186
6187<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6188<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6189 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6190</pre>
6191
6192<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6193<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6194 locations, allowing garbage collector implementations that require read
6195 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6196
6197<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]6198<p>The second argument is the address to read from, which should be an address
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6199 allocated from the garbage collector. The first object is a pointer to the
6200 start of the referenced object, if needed by the language runtime (otherwise
6201 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6202
6203<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6204<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6205 instruction, but may be replaced with substantially more complex code by the
6206 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
6207 may only be used in a function which <a href="#gc">specifies a GC
6208 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6209
6210</div>
6211
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6212<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6213<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6214 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6215</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6216
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6217<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6218
6219<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6220<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6221 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6222</pre>
6223
6224<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6225<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6226 locations, allowing garbage collector implementations that require write
6227 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6228
6229<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]6230<p>The first argument is the reference to store, the second is the start of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6231 object to store it to, and the third is the address of the field of Obj to
6232 store to. If the runtime does not require a pointer to the object, Obj may
6233 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6234
6235<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6236<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6237 instruction, but may be replaced with substantially more complex code by the
6238 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
6239 may only be used in a function which <a href="#gc">specifies a GC
6240 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6241
6242</div>
6243
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6244</div>
6245
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]6246<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6247<h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6248 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6249</h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6250
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6251<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6252
6253<p>These intrinsics are provided by LLVM to expose special features that may
6254 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6255
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6256<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6257<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6258 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6259</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6260
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6261<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6262
6263<h5>Syntax:</h5>
6264<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6265 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6266</pre>
6267
6268<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6269<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
6270 target-specific value indicating the return address of the current function
6271 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6272
6273<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6274<p>The argument to this intrinsic indicates which function to return the address
6275 for. Zero indicates the calling function, one indicates its caller, etc.
6276 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6277
6278<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6279<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
6280 indicating the return address of the specified call frame, or zero if it
6281 cannot be identified. The value returned by this intrinsic is likely to be
6282 incorrect or 0 for arguments other than zero, so it should only be used for
6283 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6284
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6285<p>Note that calling this intrinsic does not prevent function inlining or other
6286 aggressive transformations, so the value returned may not be that of the
6287 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6288
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6289</div>
6290
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6291<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6292<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6293 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6294</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6295
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6296<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6297
6298<h5>Syntax:</h5>
6299<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6300 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6301</pre>
6302
6303<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6304<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
6305 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6306
6307<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6308<p>The argument to this intrinsic indicates which function to return the frame
6309 pointer for. Zero indicates the calling function, one indicates its caller,
6310 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6311
6312<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6313<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
6314 indicating the frame address of the specified call frame, or zero if it
6315 cannot be identified. The value returned by this intrinsic is likely to be
6316 incorrect or 0 for arguments other than zero, so it should only be used for
6317 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6318
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6319<p>Note that calling this intrinsic does not prevent function inlining or other
6320 aggressive transformations, so the value returned may not be that of the
6321 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6322
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6323</div>
6324
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6325<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6326<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6327 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6328</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6329
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6330<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6331
6332<h5>Syntax:</h5>
6333<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6334 declare i8* @llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6335</pre>
6336
6337<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6338<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6339 of the function stack, for use
6340 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6341 useful for implementing language features like scoped automatic variable
6342 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6343
6344<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6345<p>This intrinsic returns a opaque pointer value that can be passed
6346 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6347 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6348 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6349 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6350 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6351 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6352
6353</div>
6354
6355<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6356<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6357 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6358</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6359
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6360<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6361
6362<h5>Syntax:</h5>
6363<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6364 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6365</pre>
6366
6367<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6368<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6369 the function stack to the state it was in when the
6370 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6371 executed. This is useful for implementing language features like scoped
6372 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6373
6374<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6375<p>See the description
6376 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6377
6378</div>
6379
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6380<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6381<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6382 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6383</h4>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6384
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6385<div>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6386
6387<h5>Syntax:</h5>
6388<pre>
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6389 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;, i32 &lt;cache type&gt;)
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6390</pre>
6391
6392<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6393<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6394 insert a prefetch instruction if supported; otherwise, it is a noop.
6395 Prefetches have no effect on the behavior of the program but can change its
6396 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6397
6398<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6399<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6400 specifier determining if the fetch should be for a read (0) or write (1),
6401 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopes9a767332011-06-14 04:58:37 +0000[diff] [blame]6402 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6403 specifies whether the prefetch is performed on the data (1) or instruction (0)
6404 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6405 must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6406
6407<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6408<p>This intrinsic does not modify the behavior of the program. In particular,
6409 prefetches cannot trap and do not produce a value. On targets that support
6410 this intrinsic, the prefetch can provide hints to the processor cache for
6411 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6412
6413</div>
6414
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6415<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6416<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6417 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6418</h4>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6419
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6420<div>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6421
6422<h5>Syntax:</h5>
6423<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6424 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6425</pre>
6426
6427<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6428<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6429 Counter (PC) in a region of code to simulators and other tools. The method
6430 is target specific, but it is expected that the marker will use exported
6431 symbols to transmit the PC of the marker. The marker makes no guarantees
6432 that it will remain with any specific instruction after optimizations. It is
6433 possible that the presence of a marker will inhibit optimizations. The
6434 intended use is to be inserted after optimizations to allow correlations of
6435 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6436
6437<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6438<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6439
6440<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6441<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6442 not support this intrinsic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6443
6444</div>
6445
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6446<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6447<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6448 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6449</h4>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6450
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6451<div>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6452
6453<h5>Syntax:</h5>
6454<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]6455 declare i64 @llvm.readcyclecounter()
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6456</pre>
6457
6458<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6459<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6460 counter register (or similar low latency, high accuracy clocks) on those
6461 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6462 should map to RPCC. As the backing counters overflow quickly (on the order
6463 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6464
6465<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6466<p>When directly supported, reading the cycle counter should not modify any
6467 memory. Implementations are allowed to either return a application specific
6468 value or a system wide value. On backends without support, this is lowered
6469 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6470
6471</div>
6472
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6473</div>
6474
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6475<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6476<h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6477 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6478</h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6479
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6480<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6481
6482<p>LLVM provides intrinsics for a few important standard C library functions.
6483 These intrinsics allow source-language front-ends to pass information about
6484 the alignment of the pointer arguments to the code generator, providing
6485 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6486
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6487<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6488<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6489 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6490</h4>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6491
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6492<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6493
6494<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6495<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
Mon P Wange88909b2010-04-07 06:35:53 +0000[diff] [blame]6496 integer bit width and for different address spaces. Not all targets support
6497 all bit widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6498
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6499<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6500 declare void @llvm.memcpy.p0i8.p0i8.i32(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6501 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6502 declare void @llvm.memcpy.p0i8.p0i8.i64(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6503 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6504</pre>
6505
6506<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6507<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6508 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6509
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6510<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6511 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6512 and the pointers can be in specified address spaces.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6513
6514<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6515
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6516<p>The first argument is a pointer to the destination, the second is a pointer
6517 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6518 number of bytes to copy, the fourth argument is the alignment of the
6519 source and destination locations, and the fifth is a boolean indicating a
6520 volatile access.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6521
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6522<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6523 then the caller guarantees that both the source and destination pointers are
6524 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6525
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6526<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6527 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6528 The detailed access behavior is not very cleanly specified and it is unwise
6529 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6530
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6531<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6532
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6533<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6534 source location to the destination location, which are not allowed to
6535 overlap. It copies "len" bytes of memory over. If the argument is known to
6536 be aligned to some boundary, this can be specified as the fourth argument,
6537 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6538
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6539</div>
6540
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6541<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6542<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6543 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6544</h4>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6545
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6546<div>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6547
6548<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6549<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Mon P Wange88909b2010-04-07 06:35:53 +0000[diff] [blame]6550 width and for different address space. Not all targets support all bit
6551 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6552
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6553<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6554 declare void @llvm.memmove.p0i8.p0i8.i32(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6555 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6556 declare void @llvm.memmove.p0i8.p0i8.i64(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6557 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6558</pre>
6559
6560<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6561<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6562 source location to the destination location. It is similar to the
6563 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6564 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6565
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6566<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6567 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6568 and the pointers can be in specified address spaces.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6569
6570<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6571
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6572<p>The first argument is a pointer to the destination, the second is a pointer
6573 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6574 number of bytes to copy, the fourth argument is the alignment of the
6575 source and destination locations, and the fifth is a boolean indicating a
6576 volatile access.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6577
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6578<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6579 then the caller guarantees that the source and destination pointers are
6580 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6581
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6582<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6583 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6584 The detailed access behavior is not very cleanly specified and it is unwise
6585 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6586
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6587<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6588
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6589<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6590 source location to the destination location, which may overlap. It copies
6591 "len" bytes of memory over. If the argument is known to be aligned to some
6592 boundary, this can be specified as the fourth argument, otherwise it should
6593 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6594
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6595</div>
6596
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6597<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6598<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6599 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6600</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6601
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6602<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6603
6604<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6605<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6606 width and for different address spaces. However, not all targets support all
6607 bit widths.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6608
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6609<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6610 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6611 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6612 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6613 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6614</pre>
6615
6616<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6617<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6618 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6619
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6620<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6621 intrinsic does not return a value and takes extra alignment/volatile
6622 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6623
6624<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6625<p>The first argument is a pointer to the destination to fill, the second is the
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6626 byte value with which to fill it, the third argument is an integer argument
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6627 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6628 alignment of the destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6629
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6630<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6631 then the caller guarantees that the destination pointer is aligned to that
6632 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6633
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6634<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6635 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6636 The detailed access behavior is not very cleanly specified and it is unwise
6637 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6638
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6639<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6640<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6641 at the destination location. If the argument is known to be aligned to some
6642 boundary, this can be specified as the fourth argument, otherwise it should
6643 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6644
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6645</div>
6646
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6647<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6648<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6649 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6650</h4>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6651
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6652<div>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6653
6654<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6655<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6656 floating point or vector of floating point type. Not all targets support all
6657 types however.</p>
6658
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6659<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6660 declare float @llvm.sqrt.f32(float %Val)
6661 declare double @llvm.sqrt.f64(double %Val)
6662 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6663 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6664 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6665</pre>
6666
6667<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6668<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6669 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6670 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6671 behavior for negative numbers other than -0.0 (which allows for better
6672 optimization, because there is no need to worry about errno being
6673 set). <tt>llvm.sqrt(-0.0)</tt> is defined to return -0.0 like IEEE sqrt.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6674
6675<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6676<p>The argument and return value are floating point numbers of the same
6677 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6678
6679<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6680<p>This function returns the sqrt of the specified operand if it is a
6681 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6682
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6683</div>
6684
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6685<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6686<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6687 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6688</h4>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6689
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6690<div>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6691
6692<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6693<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6694 floating point or vector of floating point type. Not all targets support all
6695 types however.</p>
6696
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6697<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6698 declare float @llvm.powi.f32(float %Val, i32 %power)
6699 declare double @llvm.powi.f64(double %Val, i32 %power)
6700 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6701 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6702 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6703</pre>
6704
6705<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6706<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6707 specified (positive or negative) power. The order of evaluation of
6708 multiplications is not defined. When a vector of floating point type is
6709 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6710
6711<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6712<p>The second argument is an integer power, and the first is a value to raise to
6713 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6714
6715<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6716<p>This function returns the first value raised to the second power with an
6717 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6718
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6719</div>
6720
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6721<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6722<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6723 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6724</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6725
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6726<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6727
6728<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6729<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6730 floating point or vector of floating point type. Not all targets support all
6731 types however.</p>
6732
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6733<pre>
6734 declare float @llvm.sin.f32(float %Val)
6735 declare double @llvm.sin.f64(double %Val)
6736 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6737 declare fp128 @llvm.sin.f128(fp128 %Val)
6738 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6739</pre>
6740
6741<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6742<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6743
6744<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6745<p>The argument and return value are floating point numbers of the same
6746 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6747
6748<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6749<p>This function returns the sine of the specified operand, returning the same
6750 values as the libm <tt>sin</tt> functions would, and handles error conditions
6751 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6752
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6753</div>
6754
6755<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6756<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6757 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6758</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6759
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6760<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6761
6762<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6763<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6764 floating point or vector of floating point type. Not all targets support all
6765 types however.</p>
6766
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6767<pre>
6768 declare float @llvm.cos.f32(float %Val)
6769 declare double @llvm.cos.f64(double %Val)
6770 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6771 declare fp128 @llvm.cos.f128(fp128 %Val)
6772 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6773</pre>
6774
6775<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6776<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6777
6778<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6779<p>The argument and return value are floating point numbers of the same
6780 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6781
6782<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6783<p>This function returns the cosine of the specified operand, returning the same
6784 values as the libm <tt>cos</tt> functions would, and handles error conditions
6785 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6786
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6787</div>
6788
6789<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6790<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6791 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6792</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6793
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6794<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6795
6796<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6797<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6798 floating point or vector of floating point type. Not all targets support all
6799 types however.</p>
6800
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6801<pre>
6802 declare float @llvm.pow.f32(float %Val, float %Power)
6803 declare double @llvm.pow.f64(double %Val, double %Power)
6804 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6805 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6806 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6807</pre>
6808
6809<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6810<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6811 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6812
6813<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6814<p>The second argument is a floating point power, and the first is a value to
6815 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6816
6817<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6818<p>This function returns the first value raised to the second power, returning
6819 the same values as the libm <tt>pow</tt> functions would, and handles error
6820 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6821
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6822</div>
6823
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6824</div>
6825
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]6826<!-- _______________________________________________________________________ -->
6827<h4>
6828 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6829</h4>
6830
6831<div>
6832
6833<h5>Syntax:</h5>
6834<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6835 floating point or vector of floating point type. Not all targets support all
6836 types however.</p>
6837
6838<pre>
6839 declare float @llvm.exp.f32(float %Val)
6840 declare double @llvm.exp.f64(double %Val)
6841 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6842 declare fp128 @llvm.exp.f128(fp128 %Val)
6843 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6844</pre>
6845
6846<h5>Overview:</h5>
6847<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6848
6849<h5>Arguments:</h5>
6850<p>The argument and return value are floating point numbers of the same
6851 type.</p>
6852
6853<h5>Semantics:</h5>
6854<p>This function returns the same values as the libm <tt>exp</tt> functions
6855 would, and handles error conditions in the same way.</p>
6856
6857</div>
6858
6859<!-- _______________________________________________________________________ -->
6860<h4>
6861 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6862</h4>
6863
6864<div>
6865
6866<h5>Syntax:</h5>
6867<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6868 floating point or vector of floating point type. Not all targets support all
6869 types however.</p>
6870
6871<pre>
6872 declare float @llvm.log.f32(float %Val)
6873 declare double @llvm.log.f64(double %Val)
6874 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
6875 declare fp128 @llvm.log.f128(fp128 %Val)
6876 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
6877</pre>
6878
6879<h5>Overview:</h5>
6880<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
6881
6882<h5>Arguments:</h5>
6883<p>The argument and return value are floating point numbers of the same
6884 type.</p>
6885
6886<h5>Semantics:</h5>
6887<p>This function returns the same values as the libm <tt>log</tt> functions
6888 would, and handles error conditions in the same way.</p>
6889
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]6890<h4>
6891 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
6892</h4>
6893
6894<div>
6895
6896<h5>Syntax:</h5>
6897<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
6898 floating point or vector of floating point type. Not all targets support all
6899 types however.</p>
6900
6901<pre>
6902 declare float @llvm.fma.f32(float %a, float %b, float %c)
6903 declare double @llvm.fma.f64(double %a, double %b, double %c)
6904 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
6905 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
6906 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
6907</pre>
6908
6909<h5>Overview:</h5>
Cameron Zwarichabc43e62011-07-08 22:13:55 +0000[diff] [blame]6910<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarich33390842011-07-08 21:39:21 +0000[diff] [blame]6911 operation.</p>
6912
6913<h5>Arguments:</h5>
6914<p>The argument and return value are floating point numbers of the same
6915 type.</p>
6916
6917<h5>Semantics:</h5>
6918<p>This function returns the same values as the libm <tt>fma</tt> functions
6919 would.</p>
6920
Dan Gohman4e9011c2011-05-23 21:13:03 +0000[diff] [blame]6921</div>
6922
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6923<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6924<h3>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6925 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6926</h3>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6927
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6928<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6929
6930<p>LLVM provides intrinsics for a few important bit manipulation operations.
6931 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6932
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6933<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6934<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6935 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6936</h4>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6937
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6938<div>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6939
6940<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6941<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6942 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6943
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6944<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6945 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6946 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6947 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6948</pre>
6949
6950<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6951<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6952 values with an even number of bytes (positive multiple of 16 bits). These
6953 are useful for performing operations on data that is not in the target's
6954 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6955
6956<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6957<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6958 and low byte of the input i16 swapped. Similarly,
6959 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6960 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6961 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6962 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6963 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6964 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6965
6966</div>
6967
6968<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6969<h4>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]6970 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6971</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6972
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6973<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6974
6975<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6976<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6977 width, or on any vector with integer elements. Not all targets support all
6978 bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6979
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6980<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6981 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6982 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6983 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6984 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6985 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6986 declare &lt;2 x i32&gt; @llvm.ctpop.v2i32(&lt;2 x i32&gt; &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6987</pre>
6988
6989<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6990<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6991 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6992
6993<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6994<p>The only argument is the value to be counted. The argument may be of any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6995 integer type, or a vector with integer elements.
6996 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6997
6998<h5>Semantics:</h5>
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]6999<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
7000 element of a vector.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7001
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7002</div>
7003
7004<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7005<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]7006 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7007</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7008
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7009<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7010
7011<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7012<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7013 integer bit width, or any vector whose elements are integers. Not all
7014 targets support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7015
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7016<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7017 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
7018 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7019 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7020 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
7021 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7022 declare &lt;2 x i32&gt; @llvm.ctlz.v2i32(&lt;2 x i32&gt; &lt;src;gt)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7023</pre>
7024
7025<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7026<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
7027 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7028
7029<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7030<p>The only argument is the value to be counted. The argument may be of any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7031 integer type, or any vector type with integer element type.
7032 The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7033
7034<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7035<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7036 zeros in a variable, or within each element of the vector if the operation
7037 is of vector type. If the src == 0 then the result is the size in bits of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7038 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7039
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]7040</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]7041
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7042<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7043<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]7044 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7045</h4>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7046
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7047<div>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7048
7049<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7050<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7051 integer bit width, or any vector of integer elements. Not all targets
7052 support all bit widths or vector types, however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7053
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7054<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7055 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
7056 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]7057 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]7058 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
7059 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7060 declase &lt;2 x i32&gt; @llvm.cttz.v2i32(&lt;2 x i32&gt; &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7061</pre>
7062
7063<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7064<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
7065 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7066
7067<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7068<p>The only argument is the value to be counted. The argument may be of any
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7069 integer type, or a vectory with integer element type.. The return type
7070 must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7071
7072<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7073<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Andersonf1ac4652011-07-01 21:52:38 +0000[diff] [blame]7074 zeros in a variable, or within each element of a vector.
7075 If the src == 0 then the result is the size in bits of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7076 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7077
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]7078</div>
7079
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7080</div>
7081
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7082<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7083<h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7084 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7085</h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7086
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7087<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7088
7089<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]7090
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7091<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7092<h4>
7093 <a name="int_sadd_overflow">
7094 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
7095 </a>
7096</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7097
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7098<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7099
7100<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7101<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7102 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7103
7104<pre>
7105 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
7106 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7107 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
7108</pre>
7109
7110<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7111<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7112 a signed addition of the two arguments, and indicate whether an overflow
7113 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7114
7115<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7116<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7117 be of integer types of any bit width, but they must have the same bit
7118 width. The second element of the result structure must be of
7119 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7120 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7121
7122<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7123<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7124 a signed addition of the two variables. They return a structure &mdash; the
7125 first element of which is the signed summation, and the second element of
7126 which is a bit specifying if the signed summation resulted in an
7127 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7128
7129<h5>Examples:</h5>
7130<pre>
7131 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
7132 %sum = extractvalue {i32, i1} %res, 0
7133 %obit = extractvalue {i32, i1} %res, 1
7134 br i1 %obit, label %overflow, label %normal
7135</pre>
7136
7137</div>
7138
7139<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7140<h4>
7141 <a name="int_uadd_overflow">
7142 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
7143 </a>
7144</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7145
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7146<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7147
7148<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7149<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7150 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7151
7152<pre>
7153 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
7154 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7155 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
7156</pre>
7157
7158<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7159<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7160 an unsigned addition of the two arguments, and indicate whether a carry
7161 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7162
7163<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7164<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7165 be of integer types of any bit width, but they must have the same bit
7166 width. The second element of the result structure must be of
7167 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7168 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7169
7170<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7171<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7172 an unsigned addition of the two arguments. They return a structure &mdash;
7173 the first element of which is the sum, and the second element of which is a
7174 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7175
7176<h5>Examples:</h5>
7177<pre>
7178 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
7179 %sum = extractvalue {i32, i1} %res, 0
7180 %obit = extractvalue {i32, i1} %res, 1
7181 br i1 %obit, label %carry, label %normal
7182</pre>
7183
7184</div>
7185
7186<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7187<h4>
7188 <a name="int_ssub_overflow">
7189 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
7190 </a>
7191</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7192
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7193<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7194
7195<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7196<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7197 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7198
7199<pre>
7200 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
7201 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7202 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
7203</pre>
7204
7205<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7206<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7207 a signed subtraction of the two arguments, and indicate whether an overflow
7208 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7209
7210<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7211<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7212 be of integer types of any bit width, but they must have the same bit
7213 width. The second element of the result structure must be of
7214 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7215 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7216
7217<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7218<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7219 a signed subtraction of the two arguments. They return a structure &mdash;
7220 the first element of which is the subtraction, and the second element of
7221 which is a bit specifying if the signed subtraction resulted in an
7222 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7223
7224<h5>Examples:</h5>
7225<pre>
7226 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
7227 %sum = extractvalue {i32, i1} %res, 0
7228 %obit = extractvalue {i32, i1} %res, 1
7229 br i1 %obit, label %overflow, label %normal
7230</pre>
7231
7232</div>
7233
7234<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7235<h4>
7236 <a name="int_usub_overflow">
7237 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
7238 </a>
7239</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7240
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7241<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7242
7243<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7244<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7245 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7246
7247<pre>
7248 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
7249 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7250 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
7251</pre>
7252
7253<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7254<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7255 an unsigned subtraction of the two arguments, and indicate whether an
7256 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7257
7258<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7259<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7260 be of integer types of any bit width, but they must have the same bit
7261 width. The second element of the result structure must be of
7262 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7263 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7264
7265<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7266<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7267 an unsigned subtraction of the two arguments. They return a structure &mdash;
7268 the first element of which is the subtraction, and the second element of
7269 which is a bit specifying if the unsigned subtraction resulted in an
7270 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7271
7272<h5>Examples:</h5>
7273<pre>
7274 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
7275 %sum = extractvalue {i32, i1} %res, 0
7276 %obit = extractvalue {i32, i1} %res, 1
7277 br i1 %obit, label %overflow, label %normal
7278</pre>
7279
7280</div>
7281
7282<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7283<h4>
7284 <a name="int_smul_overflow">
7285 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
7286 </a>
7287</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7288
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7289<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7290
7291<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7292<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7293 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7294
7295<pre>
7296 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
7297 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7298 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
7299</pre>
7300
7301<h5>Overview:</h5>
7302
7303<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7304 a signed multiplication of the two arguments, and indicate whether an
7305 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7306
7307<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7308<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7309 be of integer types of any bit width, but they must have the same bit
7310 width. The second element of the result structure must be of
7311 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7312 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7313
7314<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7315<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7316 a signed multiplication of the two arguments. They return a structure &mdash;
7317 the first element of which is the multiplication, and the second element of
7318 which is a bit specifying if the signed multiplication resulted in an
7319 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]7320
7321<h5>Examples:</h5>
7322<pre>
7323 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
7324 %sum = extractvalue {i32, i1} %res, 0
7325 %obit = extractvalue {i32, i1} %res, 1
7326 br i1 %obit, label %overflow, label %normal
7327</pre>
7328
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]7329</div>
7330
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7331<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7332<h4>
7333 <a name="int_umul_overflow">
7334 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
7335 </a>
7336</h4>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7337
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7338<div>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7339
7340<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7341<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7342 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7343
7344<pre>
7345 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
7346 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7347 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
7348</pre>
7349
7350<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7351<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7352 a unsigned multiplication of the two arguments, and indicate whether an
7353 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7354
7355<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7356<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7357 be of integer types of any bit width, but they must have the same bit
7358 width. The second element of the result structure must be of
7359 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
7360 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7361
7362<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7363<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7364 an unsigned multiplication of the two arguments. They return a structure
7365 &mdash; the first element of which is the multiplication, and the second
7366 element of which is a bit specifying if the unsigned multiplication resulted
7367 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]7368
7369<h5>Examples:</h5>
7370<pre>
7371 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
7372 %sum = extractvalue {i32, i1} %res, 0
7373 %obit = extractvalue {i32, i1} %res, 1
7374 br i1 %obit, label %overflow, label %normal
7375</pre>
7376
7377</div>
7378
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7379</div>
7380
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7381<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7382<h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7383 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7384</h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7385
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7386<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7387
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7388<p>Half precision floating point is a storage-only format. This means that it is
7389 a dense encoding (in memory) but does not support computation in the
7390 format.</p>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7391
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7392<p>This means that code must first load the half-precision floating point
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7393 value as an i16, then convert it to float with <a
7394 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7395 Computation can then be performed on the float value (including extending to
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7396 double etc). To store the value back to memory, it is first converted to
7397 float if needed, then converted to i16 with
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7398 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7399 storing as an i16 value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7400
7401<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7402<h4>
7403 <a name="int_convert_to_fp16">
7404 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7405 </a>
7406</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7407
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7408<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7409
7410<h5>Syntax:</h5>
7411<pre>
7412 declare i16 @llvm.convert.to.fp16(f32 %a)
7413</pre>
7414
7415<h5>Overview:</h5>
7416<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7417 a conversion from single precision floating point format to half precision
7418 floating point format.</p>
7419
7420<h5>Arguments:</h5>
7421<p>The intrinsic function contains single argument - the value to be
7422 converted.</p>
7423
7424<h5>Semantics:</h5>
7425<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7426 a conversion from single precision floating point format to half precision
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7427 floating point format. The return value is an <tt>i16</tt> which
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7428 contains the converted number.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7429
7430<h5>Examples:</h5>
7431<pre>
7432 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7433 store i16 %res, i16* @x, align 2
7434</pre>
7435
7436</div>
7437
7438<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7439<h4>
7440 <a name="int_convert_from_fp16">
7441 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7442 </a>
7443</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7444
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7445<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7446
7447<h5>Syntax:</h5>
7448<pre>
7449 declare f32 @llvm.convert.from.fp16(i16 %a)
7450</pre>
7451
7452<h5>Overview:</h5>
7453<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7454 a conversion from half precision floating point format to single precision
7455 floating point format.</p>
7456
7457<h5>Arguments:</h5>
7458<p>The intrinsic function contains single argument - the value to be
7459 converted.</p>
7460
7461<h5>Semantics:</h5>
7462<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7463 conversion from half single precision floating point format to single
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7464 precision floating point format. The input half-float value is represented by
7465 an <tt>i16</tt> value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7466
7467<h5>Examples:</h5>
7468<pre>
7469 %a = load i16* @x, align 2
7470 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7471</pre>
7472
7473</div>
7474
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7475</div>
7476
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7477<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7478<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7479 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7480</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7481
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7482<div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7483
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7484<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7485 prefix), are described in
7486 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7487 Level Debugging</a> document.</p>
7488
7489</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7490
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7491<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7492<h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7493 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7494</h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7495
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7496<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7497
7498<p>The LLVM exception handling intrinsics (which all start with
7499 <tt>llvm.eh.</tt> prefix), are described in
7500 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7501 Handling</a> document.</p>
7502
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7503</div>
7504
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7505<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7506<h3>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7507 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7508</h3>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7509
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7510<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7511
7512<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]7513 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7514 The result is a callable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7515 function pointer lacking the nest parameter - the caller does not need to
7516 provide a value for it. Instead, the value to use is stored in advance in a
7517 "trampoline", a block of memory usually allocated on the stack, which also
7518 contains code to splice the nest value into the argument list. This is used
7519 to implement the GCC nested function address extension.</p>
7520
7521<p>For example, if the function is
7522 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7523 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7524 follows:</p>
7525
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]7526<pre class="doc_code">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7527 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7528 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7529 %p = call i8* @llvm.init.trampoline(i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval)
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7530 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7531</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7532
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7533<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7534 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7535
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7536<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7537<h4>
7538 <a name="int_it">
7539 '<tt>llvm.init.trampoline</tt>' Intrinsic
7540 </a>
7541</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7542
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7543<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7544
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7545<h5>Syntax:</h5>
7546<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7547 declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7548</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7549
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7550<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7551<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7552 function pointer suitable for executing it.</p>
7553
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7554<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7555<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7556 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7557 sufficiently aligned block of memory; this memory is written to by the
7558 intrinsic. Note that the size and the alignment are target-specific - LLVM
7559 currently provides no portable way of determining them, so a front-end that
7560 generates this intrinsic needs to have some target-specific knowledge.
7561 The <tt>func</tt> argument must hold a function bitcast to
7562 an <tt>i8*</tt>.</p>
7563
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7564<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7565<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7566 dependent code, turning it into a function. A pointer to this function is
7567 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7568 function pointer type</a> before being called. The new function's signature
7569 is the same as that of <tt>func</tt> with any arguments marked with
7570 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7571 is allowed, and it must be of pointer type. Calling the new function is
7572 equivalent to calling <tt>func</tt> with the same argument list, but
7573 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7574 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7575 by <tt>tramp</tt> is modified, then the effect of any later call to the
7576 returned function pointer is undefined.</p>
7577
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7578</div>
7579
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7580</div>
7581
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7582<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7583<h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7584 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7585</h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7586
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7587<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7588
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7589<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7590 hardware constructs for atomic operations and memory synchronization. This
7591 provides an interface to the hardware, not an interface to the programmer. It
7592 is aimed at a low enough level to allow any programming models or APIs
7593 (Application Programming Interfaces) which need atomic behaviors to map
7594 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7595 hardware provides a "universal IR" for source languages, it also provides a
7596 starting point for developing a "universal" atomic operation and
7597 synchronization IR.</p>
7598
7599<p>These do <em>not</em> form an API such as high-level threading libraries,
7600 software transaction memory systems, atomic primitives, and intrinsic
7601 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7602 application libraries. The hardware interface provided by LLVM should allow
7603 a clean implementation of all of these APIs and parallel programming models.
7604 No one model or paradigm should be selected above others unless the hardware
7605 itself ubiquitously does so.</p>
7606
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7607<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7608<h4>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7609 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7610</h4>
7611
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7612<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7613<h5>Syntax:</h5>
7614<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7615 declare void @llvm.memory.barrier(i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;, i1 &lt;device&gt;)
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7616</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7617
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7618<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7619<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7620 specific pairs of memory access types.</p>
7621
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7622<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7623<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7624 The first four arguments enables a specific barrier as listed below. The
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]7625 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7626 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7627
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7628<ul>
7629 <li><tt>ll</tt>: load-load barrier</li>
7630 <li><tt>ls</tt>: load-store barrier</li>
7631 <li><tt>sl</tt>: store-load barrier</li>
7632 <li><tt>ss</tt>: store-store barrier</li>
7633 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7634</ul>
7635
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7636<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7637<p>This intrinsic causes the system to enforce some ordering constraints upon
7638 the loads and stores of the program. This barrier does not
7639 indicate <em>when</em> any events will occur, it only enforces
7640 an <em>order</em> in which they occur. For any of the specified pairs of load
7641 and store operations (f.ex. load-load, or store-load), all of the first
7642 operations preceding the barrier will complete before any of the second
7643 operations succeeding the barrier begin. Specifically the semantics for each
7644 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7645
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7646<ul>
7647 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7648 after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7649 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7650 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7651 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7652 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7653 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7654 load after the barrier begins.</li>
7655</ul>
7656
7657<p>These semantics are applied with a logical "and" behavior when more than one
7658 is enabled in a single memory barrier intrinsic.</p>
7659
7660<p>Backends may implement stronger barriers than those requested when they do
7661 not support as fine grained a barrier as requested. Some architectures do
7662 not need all types of barriers and on such architectures, these become
7663 noops.</p>
7664
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7665<h5>Example:</h5>
7666<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7667%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7668%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7669 store i32 4, %ptr
7670
7671%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0b0669a2011-06-29 17:14:00 +0000[diff] [blame]7672 call void @llvm.memory.barrier(i1 false, i1 true, i1 false, i1 false, i1 true)
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7673 <i>; guarantee the above finishes</i>
7674 store i32 8, %ptr <i>; before this begins</i>
7675</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7676
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7677</div>
7678
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7679<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7680<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7681 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7682</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7683
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7684<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7685
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7686<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7687<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7688 any integer bit width and for different address spaces. Not all targets
7689 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7690
7691<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7692 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7693 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7694 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7695 declare i64 @llvm.atomic.cmp.swap.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt;)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7696</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7697
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7698<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7699<p>This loads a value in memory and compares it to a given value. If they are
7700 equal, it stores a new value into the memory.</p>
7701
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7702<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7703<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7704 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7705 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7706 this integer type. While any bit width integer may be used, targets may only
7707 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7708
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7709<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7710<p>This entire intrinsic must be executed atomically. It first loads the value
7711 in memory pointed to by <tt>ptr</tt> and compares it with the
7712 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7713 memory. The loaded value is yielded in all cases. This provides the
7714 equivalent of an atomic compare-and-swap operation within the SSA
7715 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7716
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7717<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7718<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7719%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7720%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7721 store i32 4, %ptr
7722
7723%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7724%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7725 <i>; yields {i32}:result1 = 4</i>
7726%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7727%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7728
7729%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7730%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7731 <i>; yields {i32}:result2 = 8</i>
7732%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7733
7734%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7735</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7736
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7737</div>
7738
7739<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7740<h4>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7741 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7742</h4>
7743
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7744<div>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7745<h5>Syntax:</h5>
7746
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7747<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7748 integer bit width. Not all targets support all bit widths however.</p>
7749
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7750<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7751 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7752 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7753 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7754 declare i64 @llvm.atomic.swap.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;val&gt;)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7755</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7756
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7757<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7758<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7759 the value from memory. It then stores the value in <tt>val</tt> in the memory
7760 at <tt>ptr</tt>.</p>
7761
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7762<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7763<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7764 the <tt>val</tt> argument and the result must be integers of the same bit
7765 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7766 integer type. The targets may only lower integer representations they
7767 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7768
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7769<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7770<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7771 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7772 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7773
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7774<h5>Examples:</h5>
7775<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7776%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7777%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7778 store i32 4, %ptr
7779
7780%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7781%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7782 <i>; yields {i32}:result1 = 4</i>
7783%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7784%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7785
7786%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7787%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7788 <i>; yields {i32}:result2 = 8</i>
7789
7790%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7791%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7792</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7793
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7794</div>
7795
7796<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7797<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7798 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7799</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7800
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7801<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7802
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7803<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7804<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7805 any integer bit width. Not all targets support all bit widths however.</p>
7806
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7807<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7808 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7809 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7810 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7811 declare i64 @llvm.atomic.load.add.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7812</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7813
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7814<h5>Overview:</h5>
7815<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7816 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7817
7818<h5>Arguments:</h5>
7819<p>The intrinsic takes two arguments, the first a pointer to an integer value
7820 and the second an integer value. The result is also an integer value. These
7821 integer types can have any bit width, but they must all have the same bit
7822 width. The targets may only lower integer representations they support.</p>
7823
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7824<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7825<p>This intrinsic does a series of operations atomically. It first loads the
7826 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7827 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7828
7829<h5>Examples:</h5>
7830<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7831%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7832%ptr = bitcast i8* %mallocP to i32*
7833 store i32 4, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7834%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7835 <i>; yields {i32}:result1 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7836%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7837 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7838%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7839 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7840%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7841</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7842
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7843</div>
7844
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7845<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7846<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7847 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7848</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7849
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7850<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7851
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7852<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7853<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7854 any integer bit width and for different address spaces. Not all targets
7855 support all bit widths however.</p>
7856
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7857<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7858 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7859 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7860 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7861 declare i64 @llvm.atomic.load.sub.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7862</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7863
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7864<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7865<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7866 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7867
7868<h5>Arguments:</h5>
7869<p>The intrinsic takes two arguments, the first a pointer to an integer value
7870 and the second an integer value. The result is also an integer value. These
7871 integer types can have any bit width, but they must all have the same bit
7872 width. The targets may only lower integer representations they support.</p>
7873
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7874<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7875<p>This intrinsic does a series of operations atomically. It first loads the
7876 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7877 result to <tt>ptr</tt>. It yields the original value stored
7878 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7879
7880<h5>Examples:</h5>
7881<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7882%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7883%ptr = bitcast i8* %mallocP to i32*
7884 store i32 8, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7885%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7886 <i>; yields {i32}:result1 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7887%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7888 <i>; yields {i32}:result2 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7889%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7890 <i>; yields {i32}:result3 = 2</i>
7891%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7892</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7893
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7894</div>
7895
7896<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7897<h4>
7898 <a name="int_atomic_load_and">
7899 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7900 </a>
7901 <br>
7902 <a name="int_atomic_load_nand">
7903 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7904 </a>
7905 <br>
7906 <a name="int_atomic_load_or">
7907 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7908 </a>
7909 <br>
7910 <a name="int_atomic_load_xor">
7911 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7912 </a>
7913</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7914
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7915<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7916
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7917<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7918<p>These are overloaded intrinsics. You can
7919 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7920 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7921 bit width and for different address spaces. Not all targets support all bit
7922 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7923
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7924<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7925 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7926 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7927 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7928 declare i64 @llvm.atomic.load.and.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7929</pre>
7930
7931<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7932 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7933 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7934 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7935 declare i64 @llvm.atomic.load.or.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7936</pre>
7937
7938<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7939 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7940 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7941 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7942 declare i64 @llvm.atomic.load.nand.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7943</pre>
7944
7945<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7946 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7947 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7948 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7949 declare i64 @llvm.atomic.load.xor.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7950</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7951
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7952<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7953<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7954 the value stored in memory at <tt>ptr</tt>. It yields the original value
7955 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7956
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7957<h5>Arguments:</h5>
7958<p>These intrinsics take two arguments, the first a pointer to an integer value
7959 and the second an integer value. The result is also an integer value. These
7960 integer types can have any bit width, but they must all have the same bit
7961 width. The targets may only lower integer representations they support.</p>
7962
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7963<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7964<p>These intrinsics does a series of operations atomically. They first load the
7965 value stored at <tt>ptr</tt>. They then do the bitwise
7966 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7967 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7968
7969<h5>Examples:</h5>
7970<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7971%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7972%ptr = bitcast i8* %mallocP to i32*
7973 store i32 0x0F0F, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7974%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7975 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7976%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7977 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7978%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7979 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7980%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7981 <i>; yields {i32}:result3 = FF</i>
7982%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7983</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7984
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7985</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7986
7987<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7988<h4>
7989 <a name="int_atomic_load_max">
7990 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
7991 </a>
7992 <br>
7993 <a name="int_atomic_load_min">
7994 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
7995 </a>
7996 <br>
7997 <a name="int_atomic_load_umax">
7998 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
7999 </a>
8000 <br>
8001 <a name="int_atomic_load_umin">
8002 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
8003 </a>
8004</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8005
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8006<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8007
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8008<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8009<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
8010 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
8011 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
8012 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8013
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8014<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8015 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8016 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8017 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8018 declare i64 @llvm.atomic.load.max.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8019</pre>
8020
8021<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8022 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8023 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8024 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8025 declare i64 @llvm.atomic.load.min.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8026</pre>
8027
8028<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8029 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8030 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8031 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8032 declare i64 @llvm.atomic.load.umax.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8033</pre>
8034
8035<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8036 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
8037 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
8038 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
8039 declare i64 @llvm.atomic.load.umin.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8040</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8041
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8042<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]8043<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8044 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
8045 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8046
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8047<h5>Arguments:</h5>
8048<p>These intrinsics take two arguments, the first a pointer to an integer value
8049 and the second an integer value. The result is also an integer value. These
8050 integer types can have any bit width, but they must all have the same bit
8051 width. The targets may only lower integer representations they support.</p>
8052
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8053<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8054<p>These intrinsics does a series of operations atomically. They first load the
8055 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
8056 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
8057 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8058
8059<h5>Examples:</h5>
8060<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]8061%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
8062%ptr = bitcast i8* %mallocP to i32*
8063 store i32 7, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8064%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8065 <i>; yields {i32}:result0 = 7</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8066%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8067 <i>; yields {i32}:result1 = -2</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8068%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8069 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8070%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8071 <i>; yields {i32}:result3 = 8</i>
8072%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
8073</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8074
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]8075</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]8076
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8077</div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8078
8079<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8080<h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8081 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8082</h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8083
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8084<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8085
8086<p>This class of intrinsics exists to information about the lifetime of memory
8087 objects and ranges where variables are immutable.</p>
8088
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8089<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8090<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8091 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8092</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8093
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8094<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8095
8096<h5>Syntax:</h5>
8097<pre>
8098 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8099</pre>
8100
8101<h5>Overview:</h5>
8102<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
8103 object's lifetime.</p>
8104
8105<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8106<p>The first argument is a constant integer representing the size of the
8107 object, or -1 if it is variable sized. The second argument is a pointer to
8108 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8109
8110<h5>Semantics:</h5>
8111<p>This intrinsic indicates that before this point in the code, the value of the
8112 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
Nick Lewycky8d336592009-10-27 16:56:58 +0000[diff] [blame]8113 never be used and has an undefined value. A load from the pointer that
8114 precedes this intrinsic can be replaced with
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8115 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
8116
8117</div>
8118
8119<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8120<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8121 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8122</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8123
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8124<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8125
8126<h5>Syntax:</h5>
8127<pre>
8128 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8129</pre>
8130
8131<h5>Overview:</h5>
8132<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
8133 object's lifetime.</p>
8134
8135<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8136<p>The first argument is a constant integer representing the size of the
8137 object, or -1 if it is variable sized. The second argument is a pointer to
8138 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8139
8140<h5>Semantics:</h5>
8141<p>This intrinsic indicates that after this point in the code, the value of the
8142 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
8143 never be used and has an undefined value. Any stores into the memory object
8144 following this intrinsic may be removed as dead.
8145
8146</div>
8147
8148<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8149<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8150 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8151</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8152
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8153<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8154
8155<h5>Syntax:</h5>
8156<pre>
Nick Lewycky29b6cb42010-11-30 04:13:41 +0000[diff] [blame]8157 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8158</pre>
8159
8160<h5>Overview:</h5>
8161<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
8162 a memory object will not change.</p>
8163
8164<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8165<p>The first argument is a constant integer representing the size of the
8166 object, or -1 if it is variable sized. The second argument is a pointer to
8167 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8168
8169<h5>Semantics:</h5>
8170<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
8171 the return value, the referenced memory location is constant and
8172 unchanging.</p>
8173
8174</div>
8175
8176<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8177<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8178 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8179</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8180
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8181<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8182
8183<h5>Syntax:</h5>
8184<pre>
8185 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
8186</pre>
8187
8188<h5>Overview:</h5>
8189<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
8190 a memory object are mutable.</p>
8191
8192<h5>Arguments:</h5>
8193<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]8194 The second argument is a constant integer representing the size of the
8195 object, or -1 if it is variable sized and the third argument is a pointer
8196 to the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]8197
8198<h5>Semantics:</h5>
8199<p>This intrinsic indicates that the memory is mutable again.</p>
8200
8201</div>
8202
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8203</div>
8204
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]8205<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8206<h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8207 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8208</h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8209
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8210<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8211
8212<p>This class of intrinsics is designed to be generic and has no specific
8213 purpose.</p>
8214
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8215<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8216<h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8217 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8218</h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8219
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8220<div>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8221
8222<h5>Syntax:</h5>
8223<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8224 declare void @llvm.var.annotation(i8* &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8225</pre>
8226
8227<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8228<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8229
8230<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8231<p>The first argument is a pointer to a value, the second is a pointer to a
8232 global string, the third is a pointer to a global string which is the source
8233 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8234
8235<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8236<p>This intrinsic allows annotation of local variables with arbitrary strings.
8237 This can be useful for special purpose optimizations that want to look for
8238 these annotations. These have no other defined use, they are ignored by code
8239 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8240
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]8241</div>
8242
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8243<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8244<h4>
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]8245 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8246</h4>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8247
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8248<div>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8249
8250<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8251<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
8252 any integer bit width.</p>
8253
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8254<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8255 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8256 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8257 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8258 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
8259 declare i256 @llvm.annotation.i256(i256 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8260</pre>
8261
8262<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8263<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8264
8265<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8266<p>The first argument is an integer value (result of some expression), the
8267 second is a pointer to a global string, the third is a pointer to a global
8268 string which is the source file name, and the last argument is the line
8269 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8270
8271<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8272<p>This intrinsic allows annotations to be put on arbitrary expressions with
8273 arbitrary strings. This can be useful for special purpose optimizations that
8274 want to look for these annotations. These have no other defined use, they
8275 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8276
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]8277</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]8278
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8279<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8280<h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8281 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8282</h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8283
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8284<div>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8285
8286<h5>Syntax:</h5>
8287<pre>
8288 declare void @llvm.trap()
8289</pre>
8290
8291<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8292<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8293
8294<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8295<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8296
8297<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8298<p>This intrinsics is lowered to the target dependent trap instruction. If the
8299 target does not have a trap instruction, this intrinsic will be lowered to
8300 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8301
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]8302</div>
8303
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8304<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8305<h4>
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]8306 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8307</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8308
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8309<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8310
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8311<h5>Syntax:</h5>
8312<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8313 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8314</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8315
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8316<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8317<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
8318 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
8319 ensure that it is placed on the stack before local variables.</p>
8320
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8321<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8322<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
8323 arguments. The first argument is the value loaded from the stack
8324 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
8325 that has enough space to hold the value of the guard.</p>
8326
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8327<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8328<p>This intrinsic causes the prologue/epilogue inserter to force the position of
8329 the <tt>AllocaInst</tt> stack slot to be before local variables on the
8330 stack. This is to ensure that if a local variable on the stack is
8331 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8332 the guard on the stack is checked against the original guard. If they are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]8333 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
8334 function.</p>
8335
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]8336</div>
8337
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8338<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8339<h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8340 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]8341</h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8342
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8343<div>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8344
8345<h5>Syntax:</h5>
8346<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]8347 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
8348 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8349</pre>
8350
8351<h5>Overview:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8352<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
8353 the optimizers to determine at compile time whether a) an operation (like
8354 memcpy) will overflow a buffer that corresponds to an object, or b) that a
8355 runtime check for overflow isn't necessary. An object in this context means
8356 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8357
8358<h5>Arguments:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8359<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]8360 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8361 is a boolean 0 or 1. This argument determines whether you want the
8362 maximum (0) or minimum (1) bytes remaining. This needs to be a literal 0 or
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]8363 1, variables are not allowed.</p>
8364
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8365<h5>Semantics:</h5>
8366<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]8367 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
8368 depending on the <tt>type</tt> argument, if the size cannot be determined at
8369 compile time.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]8370
8371</div>
8372
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]8373</div>
8374
8375</div>
8376
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8377<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]8378<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8379<address>
8380 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]8381 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8382 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]8383 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8384
8385 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]8386 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]8387 Last modified: $Date$
8388</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]8389
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]8390</body>
8391</html>