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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 8645d1acc0c8504fd99690ef8ba6dedd73381fa9 / . / docs / LangRef.html
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5 <title>LLVM Assembly Language Reference Manual</title>
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7 <meta name="author" content="Chris Lattner">
Eric 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>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]56 </ol>
57 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]58 <li><a href="#typesystem">Type System</a>
59 <ol>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]60 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]61 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]62 <ol>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]63 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]64 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]65 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]66 <li><a href="#t_void">Void Type</a></li>
67 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]68 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]69 </ol>
70 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]71 <li><a href="#t_derived">Derived Types</a>
72 <ol>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]73 <li><a href="#t_aggregate">Aggregate Types</a>
74 <ol>
75 <li><a href="#t_array">Array Type</a></li>
76 <li><a href="#t_struct">Structure Type</a></li>
77 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]78 <li><a href="#t_vector">Vector Type</a></li>
79 </ol>
80 </li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]81 <li><a href="#t_function">Function Type</a></li>
82 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]83 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]84 </ol>
85 </li>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]86 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]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>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]171 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]172 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
173 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
174 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]175 </ol>
176 </li>
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]177 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]178 <ol>
179 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
180 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
181 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
182 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
183 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]184 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
185 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
186 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
187 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]188 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
189 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]190 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]191 </ol>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]192 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]193 <li><a href="#otherops">Other Operations</a>
194 <ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]195 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
196 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]197 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]198 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]199 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]200 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]201 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]202 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]203 </ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]204 </li>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]205 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]206 <ol>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]207 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
208 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]209 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
210 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
211 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]212 </ol>
213 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]214 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
215 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]216 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
217 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
218 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]219 </ol>
220 </li>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]221 <li><a href="#int_codegen">Code Generator Intrinsics</a>
222 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]223 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
224 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
225 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
226 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
227 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
228 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohman31f1af12010-05-26 21:56:15 +0000[diff] [blame]229 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell7123e272004-04-09 16:43:20 +0000[diff] [blame]230 </ol>
231 </li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]232 <li><a href="#int_libc">Standard C Library Intrinsics</a>
233 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]234 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
235 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
236 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
237 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
238 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]239 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
240 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
241 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]242 </ol>
243 </li>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]244 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]245 <ol>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]246 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]247 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
248 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
249 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]250 </ol>
251 </li>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]252 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
253 <ol>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]254 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
255 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
256 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
257 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
258 <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]259 <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]260 </ol>
261 </li>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]262 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
263 <ol>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]264 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
265 <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]266 </ol>
267 </li>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]268 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]269 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]270 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]271 <ol>
272 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]273 </ol>
274 </li>
Bill Wendling3c44f5b2008-11-18 22:10:53 +0000[diff] [blame]275 <li><a href="#int_atomics">Atomic intrinsics</a>
276 <ol>
277 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
278 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
279 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
280 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
281 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
282 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
283 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
284 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
285 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
286 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
287 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
288 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
289 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
290 </ol>
291 </li>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]292 <li><a href="#int_memorymarkers">Memory Use Markers</a>
293 <ol>
294 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
295 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
296 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
297 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
298 </ol>
299 </li>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]300 <li><a href="#int_general">General intrinsics</a>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]301 <ol>
Reid Spencer20677642007-07-20 19:59:11 +0000[diff] [blame]302 <li><a href="#int_var_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]303 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]304 <li><a href="#int_annotation">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]305 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]306 <li><a href="#int_trap">
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]307 '<tt>llvm.trap</tt>' Intrinsic</a></li>
308 <li><a href="#int_stackprotector">
309 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]310 <li><a href="#int_objectsize">
311 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]312 </ol>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]313 </li>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]314 </ol>
315 </li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]316</ol>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]317
318<div class="doc_author">
319 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
320 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]321</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]322
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]323<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]324<h2><a name="abstract">Abstract</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]325<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]326
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]327<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]328
329<p>This document is a reference manual for the LLVM assembly language. LLVM is
330 a Static Single Assignment (SSA) based representation that provides type
331 safety, low-level operations, flexibility, and the capability of representing
332 'all' high-level languages cleanly. It is the common code representation
333 used throughout all phases of the LLVM compilation strategy.</p>
334
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]335</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]336
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]337<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]338<h2><a name="introduction">Introduction</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]339<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]340
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]341<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]342
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]343<p>The LLVM code representation is designed to be used in three different forms:
344 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
345 for fast loading by a Just-In-Time compiler), and as a human readable
346 assembly language representation. This allows LLVM to provide a powerful
347 intermediate representation for efficient compiler transformations and
348 analysis, while providing a natural means to debug and visualize the
349 transformations. The three different forms of LLVM are all equivalent. This
350 document describes the human readable representation and notation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]351
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]352<p>The LLVM representation aims to be light-weight and low-level while being
353 expressive, typed, and extensible at the same time. It aims to be a
354 "universal IR" of sorts, by being at a low enough level that high-level ideas
355 may be cleanly mapped to it (similar to how microprocessors are "universal
356 IR's", allowing many source languages to be mapped to them). By providing
357 type information, LLVM can be used as the target of optimizations: for
358 example, through pointer analysis, it can be proven that a C automatic
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]359 variable is never accessed outside of the current function, allowing it to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]360 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]361
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]362<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]363<h4>
364 <a name="wellformed">Well-Formedness</a>
365</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]366
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]367<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]368
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]369<p>It is important to note that this document describes 'well formed' LLVM
370 assembly language. There is a difference between what the parser accepts and
371 what is considered 'well formed'. For example, the following instruction is
372 syntactically okay, but not well formed:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]373
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]374<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]375%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]376</pre>
377
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]378<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
379 LLVM infrastructure provides a verification pass that may be used to verify
380 that an LLVM module is well formed. This pass is automatically run by the
381 parser after parsing input assembly and by the optimizer before it outputs
382 bitcode. The violations pointed out by the verifier pass indicate bugs in
383 transformation passes or input to the parser.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]384
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]385</div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]386
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]387</div>
388
Chris Lattnercc689392007-10-03 17:34:29 +0000[diff] [blame]389<!-- Describe the typesetting conventions here. -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]390
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]391<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]392<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]393<!-- *********************************************************************** -->
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]394
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]395<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]396
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]397<p>LLVM identifiers come in two basic types: global and local. Global
398 identifiers (functions, global variables) begin with the <tt>'@'</tt>
399 character. Local identifiers (register names, types) begin with
400 the <tt>'%'</tt> character. Additionally, there are three different formats
401 for identifiers, for different purposes:</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]402
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]403<ol>
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]404 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]405 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
406 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
407 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
408 other characters in their names can be surrounded with quotes. Special
409 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
410 ASCII code for the character in hexadecimal. In this way, any character
411 can be used in a name value, even quotes themselves.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]412
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]413 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]414 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]415
Reid Spencercc16dc32004-12-09 18:02:53 +0000[diff] [blame]416 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]417 constants</a>, below.</li>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]418</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]419
Reid Spencer2c452282007-08-07 14:34:28 +0000[diff] [blame]420<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]421 don't need to worry about name clashes with reserved words, and the set of
422 reserved words may be expanded in the future without penalty. Additionally,
423 unnamed identifiers allow a compiler to quickly come up with a temporary
424 variable without having to avoid symbol table conflicts.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]425
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]426<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]427 languages. There are keywords for different opcodes
428 ('<tt><a href="#i_add">add</a></tt>',
429 '<tt><a href="#i_bitcast">bitcast</a></tt>',
430 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
431 ('<tt><a href="#t_void">void</a></tt>',
432 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
433 reserved words cannot conflict with variable names, because none of them
434 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]435
436<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]437 '<tt>%X</tt>' by 8:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]438
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]439<p>The easy way:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]440
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]441<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]442%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]443</pre>
444
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]445<p>After strength reduction:</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_shl">shl</a> i32 %X, i8 3
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>And the hard way:</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">
Gabor Greifec58f752009-10-28 13:05:07 +0000[diff] [blame]454%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
455%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]456%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]457</pre>
458
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]459<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
460 lexical features of LLVM:</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]461
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]462<ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]463 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]464 line.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]465
466 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]467 assigned to a named value.</li>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]468
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]469 <li>Unnamed temporaries are numbered sequentially</li>
470</ol>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]471
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]472<p>It also shows a convention that we follow in this document. When
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]473 demonstrating instructions, we will follow an instruction with a comment that
474 defines the type and name of value produced. Comments are shown in italic
475 text.</p>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]476
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]477</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]478
479<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]480<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]481<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]482<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]483<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]484<h3>
485 <a name="modulestructure">Module Structure</a>
486</h3>
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
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]490<p>LLVM programs are composed of "Module"s, each of which is a translation unit
491 of the input programs. Each module consists of functions, global variables,
492 and symbol table entries. Modules may be combined together with the LLVM
493 linker, which merges function (and global variable) definitions, resolves
494 forward declarations, and merges symbol table entries. Here is an example of
495 the "hello world" module:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]496
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]497<pre class="doc_code">
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]498<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckydb9cd762011-01-29 01:09:53 +0000[diff] [blame]499<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]500
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]501<i>; External declaration of the puts function</i>&nbsp;
502<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]503
504<i>; Definition of main function</i>
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]505define i32 @main() { <i>; i32()* </i>&nbsp;
506 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
507 %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]508
Chris Lattner63e4ccb2010-08-17 17:13:42 +0000[diff] [blame]509 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
510 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
511 <a href="#i_ret">ret</a> i32 0&nbsp;
512}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]513
514<i>; Named metadata</i>
515!1 = metadata !{i32 41}
516!foo = !{!1, null}
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]517</pre>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]518
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]519<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]520 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]521 a <a href="#functionstructure">function definition</a> for
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]522 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
523 "<tt>foo"</tt>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]524
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]525<p>In general, a module is made up of a list of global values, where both
526 functions and global variables are global values. Global values are
527 represented by a pointer to a memory location (in this case, a pointer to an
528 array of char, and a pointer to a function), and have one of the
529 following <a href="#linkage">linkage types</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]530
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]531</div>
532
533<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]534<h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]535 <a name="linkage">Linkage Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]536</h3>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]537
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]538<div>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]539
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]540<p>All Global Variables and Functions have one of the following types of
541 linkage:</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]542
543<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]544 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]545 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
546 by objects in the current module. In particular, linking code into a
547 module with an private global value may cause the private to be renamed as
548 necessary to avoid collisions. Because the symbol is private to the
549 module, all references can be updated. This doesn't show up in any symbol
550 table in the object file.</dd>
Rafael Espindolabb46f522009-01-15 20:18:42 +0000[diff] [blame]551
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]552 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]553 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
554 assembler and evaluated by the linker. Unlike normal strong symbols, they
555 are removed by the linker from the final linked image (executable or
556 dynamic library).</dd>
557
558 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
559 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
560 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
561 linker. The symbols are removed by the linker from the final linked image
562 (executable or dynamic library).</dd>
Bill Wendling3d10a5a2009-07-20 01:03:30 +0000[diff] [blame]563
Bill Wendling55ae5152010-08-20 22:05:50 +0000[diff] [blame]564 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
565 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
566 of the object is not taken. For instance, functions that had an inline
567 definition, but the compiler decided not to inline it. Note,
568 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
569 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
570 visibility. The symbols are removed by the linker from the final linked
571 image (executable or dynamic library).</dd>
572
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]573 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling07d31772010-06-29 22:34:52 +0000[diff] [blame]574 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]575 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
576 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]577
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]578 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]579 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]580 into the object file corresponding to the LLVM module. They exist to
581 allow inlining and other optimizations to take place given knowledge of
582 the definition of the global, which is known to be somewhere outside the
583 module. Globals with <tt>available_externally</tt> linkage are allowed to
584 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
585 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner266c7bb2009-04-13 05:44:34 +0000[diff] [blame]586
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]587 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattner4887bd82007-01-14 06:51:48 +0000[diff] [blame]588 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner873187c2010-01-09 19:15:14 +0000[diff] [blame]589 the same name when linkage occurs. This can be used to implement
590 some forms of inline functions, templates, or other code which must be
591 generated in each translation unit that uses it, but where the body may
592 be overridden with a more definitive definition later. Unreferenced
593 <tt>linkonce</tt> globals are allowed to be discarded. Note that
594 <tt>linkonce</tt> linkage does not actually allow the optimizer to
595 inline the body of this function into callers because it doesn't know if
596 this definition of the function is the definitive definition within the
597 program or whether it will be overridden by a stronger definition.
598 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
599 linkage.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]600
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]601 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]602 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
603 <tt>linkonce</tt> linkage, except that unreferenced globals with
604 <tt>weak</tt> linkage may not be discarded. This is used for globals that
605 are declared "weak" in C source code.</dd>
606
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]607 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]608 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
609 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
610 global scope.
611 Symbols with "<tt>common</tt>" linkage are merged in the same way as
612 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]613 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]614 must have a zero initializer, and may not be marked '<a
Chris Lattnercd81f5d2009-08-05 05:41:44 +0000[diff] [blame]615 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
616 have common linkage.</dd>
Chris Lattner26d054d2009-08-05 05:21:07 +0000[diff] [blame]617
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]618
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]619 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]620 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]621 pointer to array type. When two global variables with appending linkage
622 are linked together, the two global arrays are appended together. This is
623 the LLVM, typesafe, equivalent of having the system linker append together
624 "sections" with identical names when .o files are linked.</dd>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]625
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]626 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]627 <dd>The semantics of this linkage follow the ELF object file model: the symbol
628 is weak until linked, if not linked, the symbol becomes null instead of
629 being an undefined reference.</dd>
Anton Korobeynikov7f705592007-01-12 19:20:47 +0000[diff] [blame]630
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]631 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
632 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]633 <dd>Some languages allow differing globals to be merged, such as two functions
634 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling5e721d72010-07-01 21:55:59 +0000[diff] [blame]635 that only equivalent globals are ever merged (the "one definition rule"
636 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]637 and <tt>weak_odr</tt> linkage types to indicate that the global will only
638 be merged with equivalent globals. These linkage types are otherwise the
639 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]640
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]641 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnere5d947b2004-12-09 16:36:40 +0000[diff] [blame]642 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]643 visible, meaning that it participates in linkage and can be used to
644 resolve external symbol references.</dd>
Reid Spencerc8910842007-04-11 23:49:50 +0000[diff] [blame]645</dl>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]646
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]647<p>The next two types of linkage are targeted for Microsoft Windows platform
648 only. They are designed to support importing (exporting) symbols from (to)
649 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]650
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]651<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]652 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]653 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]654 or variable via a global pointer to a pointer that is set up by the DLL
655 exporting the symbol. On Microsoft Windows targets, the pointer name is
656 formed by combining <code>__imp_</code> and the function or variable
657 name.</dd>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]658
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]659 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovb74ed072006-09-14 18:23:27 +0000[diff] [blame]660 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]661 pointer to a pointer in a DLL, so that it can be referenced with the
662 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
663 name is formed by combining <code>__imp_</code> and the function or
664 variable name.</dd>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]665</dl>
666
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]667<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
668 another module defined a "<tt>.LC0</tt>" variable and was linked with this
669 one, one of the two would be renamed, preventing a collision. Since
670 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
671 declarations), they are accessible outside of the current module.</p>
672
673<p>It is illegal for a function <i>declaration</i> to have any linkage type
674 other than "externally visible", <tt>dllimport</tt>
675 or <tt>extern_weak</tt>.</p>
676
Duncan Sands667d4b82009-03-07 15:45:40 +0000[diff] [blame]677<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]678 or <tt>weak_odr</tt> linkages.</p>
679
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]680</div>
681
682<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]683<h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]684 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]685</h3>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]686
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]687<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]688
689<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]690 and <a href="#i_invoke">invokes</a> can all have an optional calling
691 convention specified for the call. The calling convention of any pair of
692 dynamic caller/callee must match, or the behavior of the program is
693 undefined. The following calling conventions are supported by LLVM, and more
694 may be added in the future:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]695
696<dl>
697 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]698 <dd>This calling convention (the default if no other calling convention is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]699 specified) matches the target C calling conventions. This calling
700 convention supports varargs function calls and tolerates some mismatch in
701 the declared prototype and implemented declaration of the function (as
702 does normal C).</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]703
704 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]705 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]706 (e.g. by passing things in registers). This calling convention allows the
707 target to use whatever tricks it wants to produce fast code for the
708 target, without having to conform to an externally specified ABI
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]709 (Application Binary Interface).
710 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]711 when this or the GHC convention is used.</a> This calling convention
712 does not support varargs and requires the prototype of all callees to
713 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]714
715 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]716 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]717 as possible under the assumption that the call is not commonly executed.
718 As such, these calls often preserve all registers so that the call does
719 not break any live ranges in the caller side. This calling convention
720 does not support varargs and requires the prototype of all callees to
721 exactly match the prototype of the function definition.</dd>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]722
Chris Lattner29689432010-03-11 00:22:57 +0000[diff] [blame]723 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
724 <dd>This calling convention has been implemented specifically for use by the
725 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
726 It passes everything in registers, going to extremes to achieve this by
727 disabling callee save registers. This calling convention should not be
728 used lightly but only for specific situations such as an alternative to
729 the <em>register pinning</em> performance technique often used when
730 implementing functional programming languages.At the moment only X86
731 supports this convention and it has the following limitations:
732 <ul>
733 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
734 floating point types are supported.</li>
735 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
736 6 floating point parameters.</li>
737 </ul>
738 This calling convention supports
739 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
740 requires both the caller and callee are using it.
741 </dd>
742
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]743 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]744 <dd>Any calling convention may be specified by number, allowing
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]745 target-specific calling conventions to be used. Target specific calling
746 conventions start at 64.</dd>
Chris Lattnercfe6b372005-05-07 01:46:40 +0000[diff] [blame]747</dl>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]748
749<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]750 support Pascal conventions or any other well-known target-independent
751 convention.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]752
753</div>
754
755<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]756<h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]757 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]758</h3>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]759
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]760<div>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]761
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]762<p>All Global Variables and Functions have one of the following visibility
763 styles:</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]764
765<dl>
766 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]767 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]768 that the declaration is visible to other modules and, in shared libraries,
769 means that the declared entity may be overridden. On Darwin, default
770 visibility means that the declaration is visible to other modules. Default
771 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]772
773 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]774 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]775 object if they are in the same shared object. Usually, hidden visibility
776 indicates that the symbol will not be placed into the dynamic symbol
777 table, so no other module (executable or shared library) can reference it
778 directly.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]779
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]780 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov6f9896f2007-04-29 18:35:00 +0000[diff] [blame]781 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]782 the dynamic symbol table, but that references within the defining module
783 will bind to the local symbol. That is, the symbol cannot be overridden by
784 another module.</dd>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]785</dl>
786
787</div>
788
789<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]790<h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]791 <a name="namedtypes">Named Types</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]792</h3>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]793
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]794<div>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]795
796<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]797 it easier to read the IR and make the IR more condensed (particularly when
798 recursive types are involved). An example of a name specification is:</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]799
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]800<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]801%mytype = type { %mytype*, i32 }
802</pre>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]803
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]804<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattnerdc65f222010-08-17 23:26:04 +0000[diff] [blame]805 "<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]806 is expected with the syntax "%mytype".</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]807
808<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]809 and that you can therefore specify multiple names for the same type. This
810 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
811 uses structural typing, the name is not part of the type. When printing out
812 LLVM IR, the printer will pick <em>one name</em> to render all types of a
813 particular shape. This means that if you have code where two different
814 source types end up having the same LLVM type, that the dumper will sometimes
815 print the "wrong" or unexpected type. This is an important design point and
816 isn't going to change.</p>
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]817
818</div>
819
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]820<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]821<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]822 <a name="globalvars">Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]823</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]824
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]825<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]826
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]827<p>Global variables define regions of memory allocated at compilation time
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]828 instead of run-time. Global variables may optionally be initialized, may
829 have an explicit section to be placed in, and may have an optional explicit
830 alignment specified. A variable may be defined as "thread_local", which
831 means that it will not be shared by threads (each thread will have a
832 separated copy of the variable). A variable may be defined as a global
833 "constant," which indicates that the contents of the variable
834 will <b>never</b> be modified (enabling better optimization, allowing the
835 global data to be placed in the read-only section of an executable, etc).
836 Note that variables that need runtime initialization cannot be marked
837 "constant" as there is a store to the variable.</p>
Chris Lattner3689a342005-02-12 19:30:21 +0000[diff] [blame]838
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]839<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
840 constant, even if the final definition of the global is not. This capability
841 can be used to enable slightly better optimization of the program, but
842 requires the language definition to guarantee that optimizations based on the
843 'constantness' are valid for the translation units that do not include the
844 definition.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]845
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]846<p>As SSA values, global variables define pointer values that are in scope
847 (i.e. they dominate) all basic blocks in the program. Global variables
848 always define a pointer to their "content" type because they describe a
849 region of memory, and all memory objects in LLVM are accessed through
850 pointers.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]851
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]852<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
853 that the address is not significant, only the content. Constants marked
Rafael Espindolaa5eaa862011-01-15 08:20:57 +0000[diff] [blame]854 like this can be merged with other constants if they have the same
855 initializer. Note that a constant with significant address <em>can</em>
856 be merged with a <tt>unnamed_addr</tt> constant, the result being a
857 constant whose address is significant.</p>
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]858
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]859<p>A global variable may be declared to reside in a target-specific numbered
860 address space. For targets that support them, address spaces may affect how
861 optimizations are performed and/or what target instructions are used to
862 access the variable. The default address space is zero. The address space
863 qualifier must precede any other attributes.</p>
Christopher Lamb284d9922007-12-11 09:31:00 +0000[diff] [blame]864
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]865<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]866 supports it, it will emit globals to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]867
Chris Lattnerce99fa92010-04-28 00:13:42 +0000[diff] [blame]868<p>An explicit alignment may be specified for a global, which must be a power
869 of 2. If not present, or if the alignment is set to zero, the alignment of
870 the global is set by the target to whatever it feels convenient. If an
871 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner2d4b8ee2010-04-28 00:31:12 +0000[diff] [blame]872 alignment. Targets and optimizers are not allowed to over-align the global
873 if the global has an assigned section. In this case, the extra alignment
874 could be observable: for example, code could assume that the globals are
875 densely packed in their section and try to iterate over them as an array,
876 alignment padding would break this iteration.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]877
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]878<p>For example, the following defines a global in a numbered address space with
879 an initializer, section, and alignment:</p>
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]880
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]881<pre class="doc_code">
Dan Gohman398873c2009-01-11 00:40:00 +0000[diff] [blame]882@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner68027ea2007-01-14 00:27:09 +0000[diff] [blame]883</pre>
884
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]885</div>
886
887
888<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]889<h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]890 <a name="functionstructure">Functions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]891</h3>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]892
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]893<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]894
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]895<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]896 optional <a href="#linkage">linkage type</a>, an optional
897 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]898 <a href="#callingconv">calling convention</a>,
899 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]900 <a href="#paramattrs">parameter attribute</a> for the return type, a function
901 name, a (possibly empty) argument list (each with optional
902 <a href="#paramattrs">parameter attributes</a>), optional
903 <a href="#fnattrs">function attributes</a>, an optional section, an optional
904 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
905 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikov8cea37b2007-01-23 12:35:46 +0000[diff] [blame]906
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]907<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
908 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]909 <a href="#visibility">visibility style</a>, an optional
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]910 <a href="#callingconv">calling convention</a>,
911 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]912 <a href="#paramattrs">parameter attribute</a> for the return type, a function
913 name, a possibly empty list of arguments, an optional alignment, and an
914 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]915
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]916<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]917 (Control Flow Graph) for the function. Each basic block may optionally start
918 with a label (giving the basic block a symbol table entry), contains a list
919 of instructions, and ends with a <a href="#terminators">terminator</a>
920 instruction (such as a branch or function return).</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]921
Chris Lattner4a3c9012007-06-08 16:52:14 +0000[diff] [blame]922<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]923 executed on entrance to the function, and it is not allowed to have
924 predecessor basic blocks (i.e. there can not be any branches to the entry
925 block of a function). Because the block can have no predecessors, it also
926 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]927
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]928<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]929 supports it, it will emit functions to the section specified.</p>
Chris Lattner88f6c462005-11-12 00:45:07 +0000[diff] [blame]930
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]931<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]932 the alignment is set to zero, the alignment of the function is set by the
933 target to whatever it feels convenient. If an explicit alignment is
934 specified, the function is forced to have at least that much alignment. All
935 alignments must be a power of 2.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]936
Rafael Espindolabea46262011-01-08 16:42:36 +0000[diff] [blame]937<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
938 be significant and two identical functions can be merged</p>.
939
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]940<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]941<pre class="doc_code">
Chris Lattner50ad45c2008-10-13 16:55:18 +0000[diff] [blame]942define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]943 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
944 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
945 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
946 [<a href="#gc">gc</a>] { ... }
947</pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]948
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]949</div>
950
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]951<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]952<h3>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]953 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]954</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]955
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]956<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]957
958<p>Aliases act as "second name" for the aliasee value (which can be either
959 function, global variable, another alias or bitcast of global value). Aliases
960 may have an optional <a href="#linkage">linkage type</a>, and an
961 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]962
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]963<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]964<pre class="doc_code">
Duncan Sands0b23ac12008-09-12 20:48:21 +0000[diff] [blame]965@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]966</pre>
Anton Korobeynikov8b0a8c82007-04-25 14:27:10 +0000[diff] [blame]967
968</div>
969
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]970<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]971<h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]972 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]973</h3>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]974
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]975<div>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]976
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]977<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]978 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]979 a named metadata.</p>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]980
981<h5>Syntax:</h5>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]982<pre class="doc_code">
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]983; Some unnamed metadata nodes, which are referenced by the named metadata.
984!0 = metadata !{metadata !"zero"}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]985!1 = metadata !{metadata !"one"}
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]986!2 = metadata !{metadata !"two"}
Dan Gohman1005bc52010-07-13 19:48:13 +0000[diff] [blame]987; A named metadata.
Dan Gohman872814a2010-07-21 18:54:18 +0000[diff] [blame]988!name = !{!0, !1, !2}
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]989</pre>
Devang Patelcd1fd252010-01-11 19:35:55 +0000[diff] [blame]990
991</div>
992
993<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]994<h3>
995 <a name="paramattrs">Parameter Attributes</a>
996</h3>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]997
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]998<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]999
1000<p>The return type and each parameter of a function type may have a set of
1001 <i>parameter attributes</i> associated with them. Parameter attributes are
1002 used to communicate additional information about the result or parameters of
1003 a function. Parameter attributes are considered to be part of the function,
1004 not of the function type, so functions with different parameter attributes
1005 can have the same function type.</p>
1006
1007<p>Parameter attributes are simple keywords that follow the type specified. If
1008 multiple parameter attributes are needed, they are space separated. For
1009 example:</p>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1010
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1011<pre class="doc_code">
Nick Lewyckyb6a7d252009-02-15 23:06:14 +0000[diff] [blame]1012declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner66d922c2008-10-04 18:33:34 +0000[diff] [blame]1013declare i32 @atoi(i8 zeroext)
1014declare signext i8 @returns_signed_char()
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1015</pre>
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1016
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1017<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1018 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1019
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1020<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1021
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1022<dl>
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1023 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1024 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichebe81732011-03-16 22:20:18 +0000[diff] [blame]1025 should be zero-extended to the extent required by the target's ABI (which
1026 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1027 parameter) or the callee (for a return value).</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1028
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1029 <dt><tt><b>signext</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 Zwarich9e69ff92011-03-17 14:21:58 +0000[diff] [blame]1031 should be sign-extended to the extent required by the target's ABI (which
1032 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1033 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>inreg</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1036 <dd>This indicates that this parameter or return value should be treated in a
1037 special target-dependent fashion during while emitting code for a function
1038 call or return (usually, by putting it in a register as opposed to memory,
1039 though some targets use it to distinguish between two different kinds of
1040 registers). Use of this attribute is target-specific.</dd>
Chris Lattner47507de2008-01-11 06:20:47 +0000[diff] [blame]1041
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1042 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1043 <dd><p>This indicates that the pointer parameter should really be passed by
1044 value to the function. The attribute implies that a hidden copy of the
1045 pointee
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1046 is made between the caller and the callee, so the callee is unable to
1047 modify the value in the callee. This attribute is only valid on LLVM
1048 pointer arguments. It is generally used to pass structs and arrays by
1049 value, but is also valid on pointers to scalars. The copy is considered
1050 to belong to the caller not the callee (for example,
1051 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1052 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnera6fd81d2010-11-20 23:49:06 +0000[diff] [blame]1053 values.</p>
1054
1055 <p>The byval attribute also supports specifying an alignment with
1056 the align attribute. It indicates the alignment of the stack slot to
1057 form and the known alignment of the pointer specified to the call site. If
1058 the alignment is not specified, then the code generator makes a
1059 target-specific assumption.</p></dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1060
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1061 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1062 <dd>This indicates that the pointer parameter specifies the address of a
1063 structure that is the return value of the function in the source program.
1064 This pointer must be guaranteed by the caller to be valid: loads and
1065 stores to the structure may be assumed by the callee to not to trap. This
1066 may only be applied to the first parameter. This is not a valid attribute
1067 for return values. </dd>
1068
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1069 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1070 <dd>This indicates that pointer values
1071 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmanefca7f92010-07-02 23:46:54 +0000[diff] [blame]1072 value do not alias pointer values which are not <i>based</i> on it,
1073 ignoring certain "irrelevant" dependencies.
1074 For a call to the parent function, dependencies between memory
1075 references from before or after the call and from those during the call
1076 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1077 return value used in that call.
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1078 The caller shares the responsibility with the callee for ensuring that
1079 these requirements are met.
1080 For further details, please see the discussion of the NoAlias response in
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1081 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1082<br>
John McCall191d4ee2010-07-06 21:07:14 +0000[diff] [blame]1083 Note that this definition of <tt>noalias</tt> is intentionally
1084 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner211244a2010-07-06 20:51:35 +0000[diff] [blame]1085 arguments, though it is slightly weaker.
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]1086<br>
1087 For function return values, C99's <tt>restrict</tt> is not meaningful,
1088 while LLVM's <tt>noalias</tt> is.
1089 </dd>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1090
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1091 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1092 <dd>This indicates that the callee does not make any copies of the pointer
1093 that outlive the callee itself. This is not a valid attribute for return
1094 values.</dd>
1095
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]1096 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1097 <dd>This indicates that the pointer parameter can be excised using the
1098 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1099 attribute for return values.</dd>
1100</dl>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1101
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1102</div>
1103
1104<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1105<h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1106 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1107</h3>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1108
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1109<div>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1110
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1111<p>Each function may specify a garbage collector name, which is simply a
1112 string:</p>
1113
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1114<pre class="doc_code">
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1115define void @f() gc "name" { ... }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1116</pre>
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1117
1118<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1119 collector which will cause the compiler to alter its output in order to
1120 support the named garbage collection algorithm.</p>
1121
Gordon Henriksen80a75bf2007-12-10 03:18:06 +0000[diff] [blame]1122</div>
1123
1124<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1125<h3>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1126 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1127</h3>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1128
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1129<div>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1130
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1131<p>Function attributes are set to communicate additional information about a
1132 function. Function attributes are considered to be part of the function, not
1133 of the function type, so functions with different parameter attributes can
1134 have the same function type.</p>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1135
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1136<p>Function attributes are simple keywords that follow the type specified. If
1137 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1138
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1139<pre class="doc_code">
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1140define void @f() noinline { ... }
1141define void @f() alwaysinline { ... }
1142define void @f() alwaysinline optsize { ... }
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1143define void @f() optsize { ... }
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1144</pre>
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1145
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1146<dl>
Charles Davis1e063d12010-02-12 00:31:15 +0000[diff] [blame]1147 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1148 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1149 the backend should forcibly align the stack pointer. Specify the
1150 desired alignment, which must be a power of two, in parentheses.
1151
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1152 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1153 <dd>This attribute indicates that the inliner should attempt to inline this
1154 function into callers whenever possible, ignoring any active inlining size
1155 threshold for this caller.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1156
Charles Davis970bfcc2010-10-25 15:37:09 +0000[diff] [blame]1157 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis6f12e292010-10-25 16:29:03 +0000[diff] [blame]1158 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis0076d202010-10-25 19:07:39 +0000[diff] [blame]1159 meaning the function can be patched and/or hooked even while it is
1160 loaded into memory. On x86, the function prologue will be preceded
1161 by six bytes of padding and will begin with a two-byte instruction.
1162 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1163 higher were compiled in this fashion.</dd>
Charles Davis970bfcc2010-10-25 15:37:09 +0000[diff] [blame]1164
Jakob Stoklund Olesen570a4a52010-02-06 01:16:28 +0000[diff] [blame]1165 <dt><tt><b>inlinehint</b></tt></dt>
1166 <dd>This attribute indicates that the source code contained a hint that inlining
1167 this function is desirable (such as the "inline" keyword in C/C++). It
1168 is just a hint; it imposes no requirements on the inliner.</dd>
1169
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1170 <dt><tt><b>naked</b></tt></dt>
1171 <dd>This attribute disables prologue / epilogue emission for the function.
1172 This can have very system-specific consequences.</dd>
1173
1174 <dt><tt><b>noimplicitfloat</b></tt></dt>
1175 <dd>This attributes disables implicit floating point instructions.</dd>
1176
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1177 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1178 <dd>This attribute indicates that the inliner should never inline this
1179 function in any situation. This attribute may not be used together with
1180 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1181
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1182 <dt><tt><b>noredzone</b></tt></dt>
1183 <dd>This attribute indicates that the code generator should not use a red
1184 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel2c9c3e72008-09-26 23:51:19 +0000[diff] [blame]1185
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1186 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1187 <dd>This function attribute indicates that the function never returns
1188 normally. This produces undefined behavior at runtime if the function
1189 ever does dynamically return.</dd>
Bill Wendling31359ba2008-11-13 01:02:51 +0000[diff] [blame]1190
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1191 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1192 <dd>This function attribute indicates that the function never returns with an
1193 unwind or exceptional control flow. If the function does unwind, its
1194 runtime behavior is undefined.</dd>
Bill Wendlingfbaa7ed2008-11-26 19:07:40 +0000[diff] [blame]1195
Nick Lewycky76ec37a2010-07-06 18:24:09 +0000[diff] [blame]1196 <dt><tt><b>optsize</b></tt></dt>
1197 <dd>This attribute suggests that optimization passes and code generator passes
1198 make choices that keep the code size of this function low, and otherwise
1199 do optimizations specifically to reduce code size.</dd>
1200
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1201 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1202 <dd>This attribute indicates that the function computes its result (or decides
1203 to unwind an exception) based strictly on its arguments, without
1204 dereferencing any pointer arguments or otherwise accessing any mutable
1205 state (e.g. memory, control registers, etc) visible to caller functions.
1206 It does not write through any pointer arguments
1207 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1208 changes any state visible to callers. This means that it cannot unwind
1209 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1210 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel5d96fda2009-06-12 19:45:19 +0000[diff] [blame]1211
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1212 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1213 <dd>This attribute indicates that the function does not write through any
1214 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1215 arguments) or otherwise modify any state (e.g. memory, control registers,
1216 etc) visible to caller functions. It may dereference pointer arguments
1217 and read state that may be set in the caller. A readonly function always
1218 returns the same value (or unwinds an exception identically) when called
1219 with the same set of arguments and global state. It cannot unwind an
1220 exception by calling the <tt>C++</tt> exception throwing methods, but may
1221 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc5ec8a72009-07-17 18:07:26 +0000[diff] [blame]1222
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1223 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1224 <dd>This attribute indicates that the function should emit a stack smashing
1225 protector. It is in the form of a "canary"&mdash;a random value placed on
1226 the stack before the local variables that's checked upon return from the
1227 function to see if it has been overwritten. A heuristic is used to
1228 determine if a function needs stack protectors or not.<br>
1229<br>
1230 If a function that has an <tt>ssp</tt> attribute is inlined into a
1231 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1232 function will have an <tt>ssp</tt> attribute.</dd>
1233
Bill Wendlingf82d40a2009-11-02 00:24:16 +0000[diff] [blame]1234 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1235 <dd>This attribute indicates that the function should <em>always</em> emit a
1236 stack smashing protector. This overrides
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1237 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1238<br>
1239 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1240 function that doesn't have an <tt>sspreq</tt> attribute or which has
1241 an <tt>ssp</tt> attribute, then the resulting function will have
1242 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1243</dl>
1244
Devang Patelf8b94812008-09-04 23:05:13 +0000[diff] [blame]1245</div>
1246
1247<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1248<h3>
Chris Lattner1eeeb0c2006-04-08 04:40:53 +0000[diff] [blame]1249 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1250</h3>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1251
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1252<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1253
1254<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1255 the GCC "file scope inline asm" blocks. These blocks are internally
1256 concatenated by LLVM and treated as a single unit, but may be separated in
1257 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1258
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1259<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]1260module asm "inline asm code goes here"
1261module asm "more can go here"
1262</pre>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1263
1264<p>The strings can contain any character by escaping non-printable characters.
1265 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]1266 for the number.</p>
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1267
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1268<p>The inline asm code is simply printed to the machine code .s file when
1269 assembly code is generated.</p>
1270
Chris Lattner4e9aba72006-01-23 23:23:47 +0000[diff] [blame]1271</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1272
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1273<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1274<h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1275 <a name="datalayout">Data Layout</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1276</h3>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1277
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1278<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1279
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1280<p>A module may specify a target specific data layout string that specifies how
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1281 data is to be laid out in memory. The syntax for the data layout is
1282 simply:</p>
1283
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]1284<pre class="doc_code">
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1285target datalayout = "<i>layout specification</i>"
1286</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1287
1288<p>The <i>layout specification</i> consists of a list of specifications
1289 separated by the minus sign character ('-'). Each specification starts with
1290 a letter and may include other information after the letter to define some
1291 aspect of the data layout. The specifications accepted are as follows:</p>
1292
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1293<dl>
1294 <dt><tt>E</tt></dt>
1295 <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]1296 bits with the most significance have the lowest address location.</dd>
1297
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1298 <dt><tt>e</tt></dt>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1299 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1300 the bits with the least significance have the lowest address
1301 location.</dd>
1302
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1303 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1304 <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]1305 <i>preferred</i> alignments. All sizes are in bits. Specifying
1306 the <i>pref</i> alignment is optional. If omitted, the
1307 preceding <tt>:</tt> should be omitted too.</dd>
1308
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1309 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1310 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1311 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1312
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1313 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1314 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1315 <i>size</i>.</dd>
1316
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1317 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1318 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesen9d8d2212010-05-28 18:54:47 +0000[diff] [blame]1319 <i>size</i>. Only values of <i>size</i> that are supported by the target
1320 will work. 32 (float) and 64 (double) are supported on all targets;
1321 80 or 128 (different flavors of long double) are also supported on some
1322 targets.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1323
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1324 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1325 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1326 <i>size</i>.</dd>
1327
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1328 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1329 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1330 <i>size</i>.</dd>
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1331
1332 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1333 <dd>This specifies a set of native integer widths for the target CPU
1334 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1335 "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]1336 this set are considered to support most general arithmetic
Chris Lattnere82bdc42009-11-07 09:35:34 +0000[diff] [blame]1337 operations efficiently.</dd>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1338</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1339
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1340<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]1341 default set of specifications which are then (possibly) overridden by the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1342 specifications in the <tt>datalayout</tt> keyword. The default specifications
1343 are given in this list:</p>
1344
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1345<ul>
1346 <li><tt>E</tt> - big endian</li>
Dan Gohmanfdf2e8c2010-02-23 02:44:03 +0000[diff] [blame]1347 <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]1348 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1349 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1350 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1351 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]1352 <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]1353 alignment of 64-bits</li>
1354 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1355 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1356 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1357 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1358 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar87bde0b2009-06-08 22:17:53 +0000[diff] [blame]1359 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1360</ul>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1361
1362<p>When LLVM is determining the alignment for a given type, it uses the
1363 following rules:</p>
1364
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1365<ol>
1366 <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]1367 specification is used.</li>
1368
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1369 <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]1370 smallest integer type that is larger than the bitwidth of the sought type
1371 is used. If none of the specifications are larger than the bitwidth then
1372 the the largest integer type is used. For example, given the default
1373 specifications above, the i7 type will use the alignment of i8 (next
1374 largest) while both i65 and i256 will use the alignment of i64 (largest
1375 specified).</li>
1376
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1377 <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]1378 largest vector type that is smaller than the sought vector type will be
1379 used as a fall back. This happens because &lt;128 x double&gt; can be
1380 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1381</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1382
Reid Spencerde151942007-02-19 23:54:10 +0000[diff] [blame]1383</div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1384
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1385<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1386<h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1387 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1388</h3>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1389
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1390<div>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1391
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1392<p>Any memory access must be done through a pointer value associated
Andreas Bolka99a82052009-07-27 20:37:10 +0000[diff] [blame]1393with an address range of the memory access, otherwise the behavior
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1394is undefined. Pointer values are associated with address ranges
1395according to the following rules:</p>
1396
1397<ul>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1398 <li>A pointer value is associated with the addresses associated with
1399 any value it is <i>based</i> on.
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1400 <li>An address of a global variable is associated with the address
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1401 range of the variable's storage.</li>
1402 <li>The result value of an allocation instruction is associated with
1403 the address range of the allocated storage.</li>
1404 <li>A null pointer in the default address-space is associated with
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1405 no address.</li>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1406 <li>An integer constant other than zero or a pointer value returned
1407 from a function not defined within LLVM may be associated with address
1408 ranges allocated through mechanisms other than those provided by
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1409 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1410 allocated by mechanisms provided by LLVM.</li>
Dan Gohman1e109622010-07-02 18:41:32 +0000[diff] [blame]1411</ul>
1412
1413<p>A pointer value is <i>based</i> on another pointer value according
1414 to the following rules:</p>
1415
1416<ul>
1417 <li>A pointer value formed from a
1418 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1419 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1420 <li>The result value of a
1421 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1422 of the <tt>bitcast</tt>.</li>
1423 <li>A pointer value formed by an
1424 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1425 pointer values that contribute (directly or indirectly) to the
1426 computation of the pointer's value.</li>
1427 <li>The "<i>based</i> on" relationship is transitive.</li>
1428</ul>
1429
1430<p>Note that this definition of <i>"based"</i> is intentionally
1431 similar to the definition of <i>"based"</i> in C99, though it is
1432 slightly weaker.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1433
1434<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1435<tt><a href="#i_load">load</a></tt> merely indicates the size and
1436alignment of the memory from which to load, as well as the
Dan Gohmanc22c0f32010-06-17 19:23:50 +0000[diff] [blame]1437interpretation of the value. The first operand type of a
Andreas Bolka55e459a2009-07-29 00:02:05 +0000[diff] [blame]1438<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1439and alignment of the store.</p>
Dan Gohman556ca272009-07-27 18:07:55 +0000[diff] [blame]1440
1441<p>Consequently, type-based alias analysis, aka TBAA, aka
1442<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1443LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1444additional information which specialized optimization passes may use
1445to implement type-based alias analysis.</p>
1446
1447</div>
1448
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1449<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1450<h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1451 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1452</h3>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1453
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1454<div>
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]1455
1456<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1457href="#i_store"><tt>store</tt></a>s, and <a
1458href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1459The optimizers must not change the number of volatile operations or change their
1460order of execution relative to other volatile operations. The optimizers
1461<i>may</i> change the order of volatile operations relative to non-volatile
1462operations. This is not Java's "volatile" and has no cross-thread
1463synchronization behavior.</p>
1464
1465</div>
1466
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1467</div>
1468
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1469<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1470<h2><a name="typesystem">Type System</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1471<!-- *********************************************************************** -->
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1472
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1473<div>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1474
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1475<p>The LLVM type system is one of the most important features of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1476 intermediate representation. Being typed enables a number of optimizations
1477 to be performed on the intermediate representation directly, without having
1478 to do extra analyses on the side before the transformation. A strong type
1479 system makes it easier to read the generated code and enables novel analyses
1480 and transformations that are not feasible to perform on normal three address
1481 code representations.</p>
Chris Lattnerfa730212004-12-09 16:11:40 +0000[diff] [blame]1482
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1483<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1484<h3>
1485 <a name="t_classifications">Type Classifications</a>
1486</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1487
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1488<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1489
1490<p>The types fall into a few useful classifications:</p>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1491
1492<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1493 <tbody>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1494 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1495 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1496 <td><a href="#t_integer">integer</a></td>
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1497 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1498 </tr>
1499 <tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1500 <td><a href="#t_floating">floating point</a></td>
1501 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1502 </tr>
1503 <tr>
1504 <td><a name="t_firstclass">first class</a></td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1505 <td><a href="#t_integer">integer</a>,
1506 <a href="#t_floating">floating point</a>,
1507 <a href="#t_pointer">pointer</a>,
Dan Gohman0066db62008-06-18 18:42:13 +0000[diff] [blame]1508 <a href="#t_vector">vector</a>,
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]1509 <a href="#t_struct">structure</a>,
1510 <a href="#t_array">array</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1511 <a href="#t_label">label</a>,
1512 <a href="#t_metadata">metadata</a>.
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1513 </td>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1514 </tr>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1515 <tr>
1516 <td><a href="#t_primitive">primitive</a></td>
1517 <td><a href="#t_label">label</a>,
1518 <a href="#t_void">void</a>,
Tobias Grosser05387292010-12-28 20:29:31 +0000[diff] [blame]1519 <a href="#t_integer">integer</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1520 <a href="#t_floating">floating point</a>,
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1521 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1522 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1523 </tr>
1524 <tr>
1525 <td><a href="#t_derived">derived</a></td>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1526 <td><a href="#t_array">array</a>,
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1527 <a href="#t_function">function</a>,
1528 <a href="#t_pointer">pointer</a>,
1529 <a href="#t_struct">structure</a>,
1530 <a href="#t_pstruct">packed structure</a>,
1531 <a href="#t_vector">vector</a>,
1532 <a href="#t_opaque">opaque</a>.
Dan Gohman01ac1012008-10-14 16:32:04 +0000[diff] [blame]1533 </td>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1534 </tr>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]1535 </tbody>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1536</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1537
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1538<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1539 important. Values of these types are the only ones which can be produced by
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1540 instructions.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1541
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1542</div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1543
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1544<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1545<h3>
1546 <a name="t_primitive">Primitive Types</a>
1547</h3>
Chris Lattner8f8c7b72008-01-04 04:34:14 +0000[diff] [blame]1548
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1549<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1550
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1551<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1552 system.</p>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1553
1554<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1555<h4>
1556 <a name="t_integer">Integer Type</a>
1557</h4>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1558
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1559<div>
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1560
1561<h5>Overview:</h5>
1562<p>The integer type is a very simple type that simply specifies an arbitrary
1563 bit width for the integer type desired. Any bit width from 1 bit to
1564 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1565
1566<h5>Syntax:</h5>
1567<pre>
1568 iN
1569</pre>
1570
1571<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1572 value.</p>
1573
1574<h5>Examples:</h5>
1575<table class="layout">
1576 <tr class="layout">
1577 <td class="left"><tt>i1</tt></td>
1578 <td class="left">a single-bit integer.</td>
1579 </tr>
1580 <tr class="layout">
1581 <td class="left"><tt>i32</tt></td>
1582 <td class="left">a 32-bit integer.</td>
1583 </tr>
1584 <tr class="layout">
1585 <td class="left"><tt>i1942652</tt></td>
1586 <td class="left">a really big integer of over 1 million bits.</td>
1587 </tr>
1588</table>
1589
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1590</div>
1591
1592<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1593<h4>
1594 <a name="t_floating">Floating Point Types</a>
1595</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1596
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1597<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1598
1599<table>
1600 <tbody>
1601 <tr><th>Type</th><th>Description</th></tr>
1602 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1603 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1604 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1605 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1606 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1607 </tbody>
1608</table>
1609
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1610</div>
1611
1612<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1613<h4>
1614 <a name="t_x86mmx">X86mmx Type</a>
1615</h4>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1616
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1617<div>
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1618
1619<h5>Overview:</h5>
1620<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>
1621
1622<h5>Syntax:</h5>
1623<pre>
Dale Johannesen473a8c82010-10-01 01:07:02 +0000[diff] [blame]1624 x86mmx
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]1625</pre>
1626
1627</div>
1628
1629<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1630<h4>
1631 <a name="t_void">Void Type</a>
1632</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1633
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1634<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1635
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1636<h5>Overview:</h5>
1637<p>The void type does not represent any value and has no size.</p>
1638
1639<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1640<pre>
1641 void
1642</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1643
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1644</div>
1645
1646<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1647<h4>
1648 <a name="t_label">Label Type</a>
1649</h4>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1650
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1651<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1652
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1653<h5>Overview:</h5>
1654<p>The label type represents code labels.</p>
1655
1656<h5>Syntax:</h5>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1657<pre>
1658 label
1659</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1660
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1661</div>
1662
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1663<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1664<h4>
1665 <a name="t_metadata">Metadata Type</a>
1666</h4>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1667
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1668<div>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1669
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1670<h5>Overview:</h5>
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1671<p>The metadata type represents embedded metadata. No derived types may be
1672 created from metadata except for <a href="#t_function">function</a>
1673 arguments.
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1674
1675<h5>Syntax:</h5>
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1676<pre>
1677 metadata
1678</pre>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1679
Nick Lewycky7a0370f2009-05-30 05:06:04 +0000[diff] [blame]1680</div>
1681
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1682</div>
Chris Lattner4f69f462008-01-04 04:32:38 +0000[diff] [blame]1683
1684<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1685<h3>
1686 <a name="t_derived">Derived Types</a>
1687</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1688
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1689<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1690
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1691<p>The real power in LLVM comes from the derived types in the system. This is
1692 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]1693 useful types. Each of these types contain one or more element types which
1694 may be a primitive type, or another derived type. For example, it is
1695 possible to have a two dimensional array, using an array as the element type
1696 of another array.</p>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1697
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1698
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1699<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1700<h4>
1701 <a name="t_aggregate">Aggregate Types</a>
1702</h4>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1703
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1704<div>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1705
1706<p>Aggregate Types are a subset of derived types that can contain multiple
1707 member types. <a href="#t_array">Arrays</a>,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]1708 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1709 aggregate types.</p>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]1710
1711</div>
1712
Reid Spencer2b916312007-05-16 18:44:01 +0000[diff] [blame]1713<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1714<h4>
1715 <a name="t_array">Array Type</a>
1716</h4>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1717
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1718<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1719
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1720<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1721<p>The array type is a very simple derived type that arranges elements
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1722 sequentially in memory. The array type requires a size (number of elements)
1723 and an underlying data type.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1724
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1725<h5>Syntax:</h5>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1726<pre>
1727 [&lt;# elements&gt; x &lt;elementtype&gt;]
1728</pre>
1729
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1730<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1731 be any type with a size.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]1732
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1733<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1734<table class="layout">
1735 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1736 <td class="left"><tt>[40 x i32]</tt></td>
1737 <td class="left">Array of 40 32-bit integer values.</td>
1738 </tr>
1739 <tr class="layout">
1740 <td class="left"><tt>[41 x i32]</tt></td>
1741 <td class="left">Array of 41 32-bit integer values.</td>
1742 </tr>
1743 <tr class="layout">
1744 <td class="left"><tt>[4 x i8]</tt></td>
1745 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1746 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1747</table>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1748<p>Here are some examples of multidimensional arrays:</p>
1749<table class="layout">
1750 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1751 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1752 <td class="left">3x4 array of 32-bit integer values.</td>
1753 </tr>
1754 <tr class="layout">
1755 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1756 <td class="left">12x10 array of single precision floating point values.</td>
1757 </tr>
1758 <tr class="layout">
1759 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1760 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1761 </tr>
1762</table>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1763
Dan Gohman7657f6b2009-11-09 19:01:53 +0000[diff] [blame]1764<p>There is no restriction on indexing beyond the end of the array implied by
1765 a static type (though there are restrictions on indexing beyond the bounds
1766 of an allocated object in some cases). This means that single-dimension
1767 'variable sized array' addressing can be implemented in LLVM with a zero
1768 length array type. An implementation of 'pascal style arrays' in LLVM could
1769 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]1770
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1771</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1772
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1773<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1774<h4>
1775 <a name="t_function">Function Type</a>
1776</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1777
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1778<div>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1779
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1780<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1781<p>The function type can be thought of as a function signature. It consists of
1782 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]1783 function type is a first class type or a void type.</p>
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]1784
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1785<h5>Syntax:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1786<pre>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1787 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1788</pre>
1789
John Criswell0ec250c2005-10-24 16:17:18 +0000[diff] [blame]1790<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]1791 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1792 which indicates that the function takes a variable number of arguments.
1793 Variable argument functions can access their arguments with
1794 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1795 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewyckyc261df92009-09-27 23:27:42 +0000[diff] [blame]1796 <a href="#t_label">label</a>.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]1797
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1798<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1799<table class="layout">
1800 <tr class="layout">
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1801 <td class="left"><tt>i32 (i32)</tt></td>
1802 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1803 </td>
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1804 </tr><tr class="layout">
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1805 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencerf17a0b72006-12-31 07:20:23 +0000[diff] [blame]1806 </tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1807 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]1808 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1809 returning <tt>float</tt>.
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1810 </td>
1811 </tr><tr class="layout">
1812 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]1813 <td class="left">A vararg function that takes at least one
1814 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1815 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer92f82302006-12-31 07:18:34 +0000[diff] [blame]1816 LLVM.
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1817 </td>
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1818 </tr><tr class="layout">
1819 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky51386942009-09-27 07:55:32 +0000[diff] [blame]1820 <td class="left">A function taking an <tt>i32</tt>, returning a
1821 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patela582f402008-03-24 05:35:41 +0000[diff] [blame]1822 </td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1823 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1824</table>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]1825
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1826</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1827
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1828<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1829<h4>
1830 <a name="t_struct">Structure Type</a>
1831</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1832
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1833<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1834
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1835<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1836<p>The structure type is used to represent a collection of data members together
1837 in memory. The packing of the field types is defined to match the ABI of the
1838 underlying processor. The elements of a structure may be any type that has a
1839 size.</p>
1840
Jeffrey Yasskin7a088cf2010-01-11 19:19:26 +0000[diff] [blame]1841<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1842 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1843 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1844 Structures in registers are accessed using the
1845 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1846 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1847<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1848<pre>
1849 { &lt;type list&gt; }
1850</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1851
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1852<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1853<table class="layout">
1854 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1855 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1856 <td class="left">A triple of three <tt>i32</tt> values</td>
1857 </tr><tr class="layout">
1858 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1859 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1860 second element is a <a href="#t_pointer">pointer</a> to a
1861 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1862 an <tt>i32</tt>.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1863 </tr>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1864</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1865
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1866</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1867
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]1868<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1869<h4>
1870 <a name="t_pstruct">Packed Structure Type</a>
1871</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1872
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1873<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1874
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1875<h5>Overview:</h5>
1876<p>The packed structure type is used to represent a collection of data members
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1877 together in memory. There is no padding between fields. Further, the
1878 alignment of a packed structure is 1 byte. The elements of a packed
1879 structure may be any type that has a size.</p>
1880
1881<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1882 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1883 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1884
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1885<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1886<pre>
1887 &lt; { &lt;type list&gt; } &gt;
1888</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1889
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1890<h5>Examples:</h5>
1891<table class="layout">
1892 <tr class="layout">
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1893 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1894 <td class="left">A triple of three <tt>i32</tt> values</td>
1895 </tr><tr class="layout">
Bill Wendlinge36dccc2008-09-07 10:26:33 +0000[diff] [blame]1896 <td class="left">
1897<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]1898 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1899 second element is a <a href="#t_pointer">pointer</a> to a
1900 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1901 an <tt>i32</tt>.</td>
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1902 </tr>
1903</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1904
Andrew Lenharth75e10682006-12-08 17:13:00 +0000[diff] [blame]1905</div>
1906
1907<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1908<h4>
1909 <a name="t_pointer">Pointer Type</a>
1910</h4>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1911
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1912<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1913
1914<h5>Overview:</h5>
Dan Gohmanff3ef322010-02-25 16:50:07 +0000[diff] [blame]1915<p>The pointer type is used to specify memory locations.
1916 Pointers are commonly used to reference objects in memory.</p>
1917
1918<p>Pointer types may have an optional address space attribute defining the
1919 numbered address space where the pointed-to object resides. The default
1920 address space is number zero. The semantics of non-zero address
1921 spaces are target-specific.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1922
1923<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1924 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner0fd4a272009-02-08 19:53:29 +0000[diff] [blame]1925
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1926<h5>Syntax:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]1927<pre>
1928 &lt;type&gt; *
1929</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1930
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]1931<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1932<table class="layout">
1933 <tr class="layout">
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]1934 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1935 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1936 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1937 </tr>
1938 <tr class="layout">
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]1939 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1940 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]1941 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1942 <tt>i32</tt>.</td>
1943 </tr>
1944 <tr class="layout">
1945 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1946 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1947 that resides in address space #5.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1948 </tr>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1949</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1950
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1951</div>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1952
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1953<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1954<h4>
1955 <a name="t_vector">Vector Type</a>
1956</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1957
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1958<div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1959
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1960<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1961<p>A vector type is a simple derived type that represents a vector of elements.
1962 Vector types are used when multiple primitive data are operated in parallel
1963 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sandsd40d14e2009-11-27 13:38:03 +0000[diff] [blame]1964 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]1965 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1966
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1967<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1968<pre>
1969 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1970</pre>
1971
Chris Lattner7d2e7be2010-10-10 18:20:35 +0000[diff] [blame]1972<p>The number of elements is a constant integer value larger than 0; elementtype
1973 may be any integer or floating point type. Vectors of size zero are not
1974 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1975
Chris Lattnera58561b2004-08-12 19:12:28 +0000[diff] [blame]1976<h5>Examples:</h5>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1977<table class="layout">
1978 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]1979 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1980 <td class="left">Vector of 4 32-bit integer values.</td>
1981 </tr>
1982 <tr class="layout">
1983 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1984 <td class="left">Vector of 8 32-bit floating-point values.</td>
1985 </tr>
1986 <tr class="layout">
1987 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1988 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerd3f876c2004-11-01 08:19:36 +0000[diff] [blame]1989 </tr>
1990</table>
Dan Gohmand8791e52009-01-24 15:58:40 +0000[diff] [blame]1991
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]1992</div>
1993
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]1994<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]1995<h4>
1996 <a name="t_opaque">Opaque Type</a>
1997</h4>
1998
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]1999<div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2000
2001<h5>Overview:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2002<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2003 corresponds (for example) to the C notion of a forward declared structure
2004 type. In LLVM, opaque types can eventually be resolved to any type (not just
2005 a structure type).</p>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2006
2007<h5>Syntax:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2008<pre>
2009 opaque
2010</pre>
2011
2012<h5>Examples:</h5>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2013<table class="layout">
2014 <tr class="layout">
Chris Lattner23ff1f92007-12-19 05:04:11 +0000[diff] [blame]2015 <td class="left"><tt>opaque</tt></td>
2016 <td class="left">An opaque type.</td>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2017 </tr>
2018</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2019
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2020</div>
2021
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2022</div>
2023
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2024<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2025<h3>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2026 <a name="t_uprefs">Type Up-references</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2027</h3>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2028
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2029<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2030
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2031<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2032<p>An "up reference" allows you to refer to a lexically enclosing type without
2033 requiring it to have a name. For instance, a structure declaration may
2034 contain a pointer to any of the types it is lexically a member of. Example
2035 of up references (with their equivalent as named type declarations)
2036 include:</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2037
2038<pre>
Chris Lattner3060f5b2009-02-09 10:00:56 +0000[diff] [blame]2039 { \2 * } %x = type { %x* }
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2040 { \2 }* %y = type { %y }*
2041 \1* %z = type %z*
2042</pre>
2043
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2044<p>An up reference is needed by the asmprinter for printing out cyclic types
2045 when there is no declared name for a type in the cycle. Because the
2046 asmprinter does not want to print out an infinite type string, it needs a
2047 syntax to handle recursive types that have no names (all names are optional
2048 in llvm IR).</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2049
2050<h5>Syntax:</h5>
2051<pre>
2052 \&lt;level&gt;
2053</pre>
2054
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2055<p>The level is the count of the lexical type that is being referred to.</p>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2056
2057<h5>Examples:</h5>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2058<table class="layout">
2059 <tr class="layout">
2060 <td class="left"><tt>\1*</tt></td>
2061 <td class="left">Self-referential pointer.</td>
2062 </tr>
2063 <tr class="layout">
2064 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
2065 <td class="left">Recursive structure where the upref refers to the out-most
2066 structure.</td>
2067 </tr>
2068</table>
Chris Lattner242d61d2009-02-02 07:32:36 +0000[diff] [blame]2069
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2070</div>
Chris Lattner69c11bb2005-04-25 17:34:15 +0000[diff] [blame]2071
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2072</div>
2073
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2074<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2075<h2><a name="constants">Constants</a></h2>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2076<!-- *********************************************************************** -->
2077
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2078<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2079
2080<p>LLVM has several different basic types of constants. This section describes
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2081 them all and their syntax.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2082
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2083<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2084<h3>
2085 <a name="simpleconstants">Simple Constants</a>
2086</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2087
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2088<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2089
2090<dl>
2091 <dt><b>Boolean constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2092 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]2093 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2094
2095 <dt><b>Integer constants</b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2096 <dd>Standard integers (such as '4') are constants of
2097 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2098 with integer types.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2099
2100 <dt><b>Floating point constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2101 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2102 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2103 notation (see below). The assembler requires the exact decimal value of a
2104 floating-point constant. For example, the assembler accepts 1.25 but
2105 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2106 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2107
2108 <dt><b>Null pointer constants</b></dt>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]2109 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2110 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2111</dl>
2112
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2113<p>The one non-intuitive notation for constants is the hexadecimal form of
2114 floating point constants. For example, the form '<tt>double
2115 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2116 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2117 constants are required (and the only time that they are generated by the
2118 disassembler) is when a floating point constant must be emitted but it cannot
2119 be represented as a decimal floating point number in a reasonable number of
2120 digits. For example, NaN's, infinities, and other special values are
2121 represented in their IEEE hexadecimal format so that assembly and disassembly
2122 do not cause any bits to change in the constants.</p>
2123
Dale Johannesenbd5e5a82009-02-11 22:14:51 +0000[diff] [blame]2124<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2125 represented using the 16-digit form shown above (which matches the IEEE754
2126 representation for double); float values must, however, be exactly
2127 representable as IEE754 single precision. Hexadecimal format is always used
2128 for long double, and there are three forms of long double. The 80-bit format
2129 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2130 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2131 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2132 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2133 currently supported target uses this format. Long doubles will only work if
2134 they match the long double format on your target. All hexadecimal formats
2135 are big-endian (sign bit at the left).</p>
2136
Dale Johannesen21fe99b2010-10-01 00:48:59 +0000[diff] [blame]2137<p>There are no constants of type x86mmx.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2138</div>
2139
2140<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2141<h3>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]2142<a name="aggregateconstants"></a> <!-- old anchor -->
2143<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2144</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2145
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2146<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2147
Chris Lattner70882792009-02-28 18:32:25 +0000[diff] [blame]2148<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2149 constants and smaller complex constants.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2150
2151<dl>
2152 <dt><b>Structure constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2153 <dd>Structure constants are represented with notation similar to structure
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2154 type definitions (a comma separated list of elements, surrounded by braces
2155 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2156 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2157 Structure constants must have <a href="#t_struct">structure type</a>, and
2158 the number and types of elements must match those specified by the
2159 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2160
2161 <dt><b>Array constants</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2162 <dd>Array constants are represented with notation similar to array type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2163 definitions (a comma separated list of elements, surrounded by square
2164 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2165 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2166 the number and types of elements must match those specified by the
2167 type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2168
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2169 <dt><b>Vector constants</b></dt>
Reid Spencer485bad12007-02-15 03:07:05 +0000[diff] [blame]2170 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2171 definitions (a comma separated list of elements, surrounded by
2172 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2173 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2174 have <a href="#t_vector">vector type</a>, and the number and types of
2175 elements must match those specified by the type.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2176
2177 <dt><b>Zero initialization</b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2178 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]2179 value to zero of <em>any</em> type, including scalar and
2180 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2181 This is often used to avoid having to print large zero initializers
2182 (e.g. for large arrays) and is always exactly equivalent to using explicit
2183 zero initializers.</dd>
Nick Lewycky21cc4462009-04-04 07:22:01 +0000[diff] [blame]2184
2185 <dt><b>Metadata node</b></dt>
Nick Lewycky1e8c7a62009-05-30 16:08:30 +0000[diff] [blame]2186 <dd>A metadata node is a structure-like constant with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2187 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2188 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2189 be interpreted as part of the instruction stream, metadata is a place to
2190 attach additional information such as debug info.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2191</dl>
2192
2193</div>
2194
2195<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2196<h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2197 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2198</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2199
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2200<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2201
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2202<p>The addresses of <a href="#globalvars">global variables</a>
2203 and <a href="#functionstructure">functions</a> are always implicitly valid
2204 (link-time) constants. These constants are explicitly referenced when
2205 the <a href="#identifiers">identifier for the global</a> is used and always
2206 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2207 legal LLVM file:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2208
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2209<pre class="doc_code">
Chris Lattnera18a4242007-06-06 18:28:13 +0000[diff] [blame]2210@X = global i32 17
2211@Y = global i32 42
2212@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2213</pre>
2214
2215</div>
2216
2217<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2218<h3>
2219 <a name="undefvalues">Undefined Values</a>
2220</h3>
2221
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2222<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2223
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2224<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]2225 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2226 Undefined values may be of any type (other than '<tt>label</tt>'
2227 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2228
Chris Lattnerc608cb12009-09-11 01:49:31 +0000[diff] [blame]2229<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2230 program is well defined no matter what value is used. This gives the
2231 compiler more freedom to optimize. Here are some examples of (potentially
2232 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2233
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2234
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2235<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2236 %A = add %X, undef
2237 %B = sub %X, undef
2238 %C = xor %X, undef
2239Safe:
2240 %A = undef
2241 %B = undef
2242 %C = undef
2243</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2244
2245<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]2246 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]2247
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2248<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2249 %A = or %X, undef
2250 %B = and %X, undef
2251Safe:
2252 %A = -1
2253 %B = 0
2254Unsafe:
2255 %A = undef
2256 %B = undef
2257</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2258
2259<p>These logical operations have bits that are not always affected by the input.
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2260 For example, if <tt>%X</tt> has a zero bit, then the output of the
2261 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2262 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2263 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2264 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2265 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2266 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2267 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2268
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2269<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2270 %A = select undef, %X, %Y
2271 %B = select undef, 42, %Y
2272 %C = select %X, %Y, undef
2273Safe:
2274 %A = %X (or %Y)
2275 %B = 42 (or %Y)
2276 %C = %Y
2277Unsafe:
2278 %A = undef
2279 %B = undef
2280 %C = undef
2281</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2282
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2283<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2284 branch) conditions can go <em>either way</em>, but they have to come from one
2285 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2286 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2287 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2288 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2289 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2290 eliminated.</p>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2291
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2292<pre class="doc_code">
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2293 %A = xor undef, undef
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2294
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2295 %B = undef
2296 %C = xor %B, %B
2297
2298 %D = undef
2299 %E = icmp lt %D, 4
2300 %F = icmp gte %D, 4
2301
2302Safe:
2303 %A = undef
2304 %B = undef
2305 %C = undef
2306 %D = undef
2307 %E = undef
2308 %F = undef
2309</pre>
Chris Lattner48a109c2009-09-07 22:52:39 +0000[diff] [blame]2310
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2311<p>This example points out that two '<tt>undef</tt>' operands are not
2312 necessarily the same. This can be surprising to people (and also matches C
2313 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2314 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2315 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2316 its value over its "live range". This is true because the variable doesn't
2317 actually <em>have a live range</em>. Instead, the value is logically read
2318 from arbitrary registers that happen to be around when needed, so the value
2319 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2320 need to have the same semantics or the core LLVM "replace all uses with"
2321 concept would not hold.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2322
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2323<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2324 %A = fdiv undef, %X
2325 %B = fdiv %X, undef
2326Safe:
2327 %A = undef
2328b: unreachable
2329</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2330
2331<p>These examples show the crucial difference between an <em>undefined
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2332 value</em> and <em>undefined behavior</em>. An undefined value (like
2333 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2334 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2335 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2336 defined on SNaN's. However, in the second example, we can make a more
2337 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2338 arbitrary value, we are allowed to assume that it could be zero. Since a
2339 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2340 the operation does not execute at all. This allows us to delete the divide and
2341 all code after it. Because the undefined operation "can't happen", the
2342 optimizer can assume that it occurs in dead code.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2343
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2344<pre class="doc_code">
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2345a: store undef -> %X
2346b: store %X -> undef
2347Safe:
2348a: &lt;deleted&gt;
2349b: unreachable
2350</pre>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2351
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2352<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2353 undefined value can be assumed to not have any effect; we can assume that the
2354 value is overwritten with bits that happen to match what was already there.
2355 However, a store <em>to</em> an undefined location could clobber arbitrary
2356 memory, therefore, it has undefined behavior.</p>
Chris Lattner6e9057b2009-09-07 23:33:52 +0000[diff] [blame]2357
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2358</div>
2359
2360<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2361<h3>
2362 <a name="trapvalues">Trap Values</a>
2363</h3>
2364
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2365<div>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2366
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2367<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2368 instead of representing an unspecified bit pattern, they represent the
2369 fact that an instruction or constant expression which cannot evoke side
2370 effects has nevertheless detected a condition which results in undefined
Dan Gohmanc68ce062010-04-26 20:21:21 +0000[diff] [blame]2371 behavior.</p>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2372
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2373<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]2374 only exist when produced by operations such as
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2375 <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]2376
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2377<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2378
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2379<ul>
2380<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2381 their operands.</li>
2382
2383<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2384 to their dynamic predecessor basic block.</li>
2385
2386<li>Function arguments depend on the corresponding actual argument values in
2387 the dynamic callers of their functions.</li>
2388
2389<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2390 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2391 control back to them.</li>
2392
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2393<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2394 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2395 or exception-throwing call instructions that dynamically transfer control
2396 back to them.</li>
2397
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2398<li>Non-volatile loads and stores depend on the most recent stores to all of the
2399 referenced memory addresses, following the order in the IR
2400 (including loads and stores implied by intrinsics such as
2401 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2402
Dan Gohman7c24ff12010-05-03 14:59:34 +0000[diff] [blame]2403<!-- TODO: In the case of multiple threads, this only applies if the store
2404 "happens-before" the load or store. -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2405
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2406<!-- TODO: floating-point exception state -->
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2407
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2408<li>An instruction with externally visible side effects depends on the most
2409 recent preceding instruction with externally visible side effects, following
Dan Gohmanff70fe42010-07-06 15:26:33 +0000[diff] [blame]2410 the order in the IR. (This includes
2411 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2412
Dan Gohmanb5328162010-05-03 14:55:22 +0000[diff] [blame]2413<li>An instruction <i>control-depends</i> on a
2414 <a href="#terminators">terminator instruction</a>
2415 if the terminator instruction has multiple successors and the instruction
2416 is always executed when control transfers to one of the successors, and
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2417 may not be executed when control is transferred to another.</li>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2418
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2419<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2420 instruction if the set of instructions it otherwise depends on would be
Chris Lattner7a2bdde2011-04-15 05:18:47 +0000[diff] [blame]2421 different if the terminator had transferred control to a different
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2422 successor.</li>
2423
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2424<li>Dependence is transitive.</li>
2425
2426</ul>
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2427
2428<p>Whenever a trap value is generated, all values which depend on it evaluate
2429 to trap. If they have side effects, the evoke their side effects as if each
2430 operand with a trap value were undef. If they have externally-visible side
2431 effects, the behavior is undefined.</p>
2432
2433<p>Here are some examples:</p>
Dan Gohmanc30f6e12010-04-26 20:54:53 +0000[diff] [blame]2434
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2435<pre class="doc_code">
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2436entry:
2437 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2438 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2439 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2440 store i32 0, i32* %trap_yet_again ; undefined behavior
2441
2442 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2443 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2444
2445 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2446
2447 %narrowaddr = bitcast i32* @g to i16*
2448 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2449 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2450 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2451
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2452 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2453 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2454
2455true:
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2456 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2457 ; it has undefined behavior.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2458 br label %end
2459
2460end:
2461 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2462 ; Both edges into this PHI are
2463 ; control-dependent on %cmp, so this
Dan Gohman34b3d992010-04-28 00:49:41 +0000[diff] [blame]2464 ; always results in a trap value.
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2465
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2466 volatile store i32 0, i32* @g ; This would depend on the store in %true
2467 ; if %cmp is true, or the store in %entry
2468 ; otherwise, so this is undefined behavior.
2469
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2470 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2471 ; The same branch again, but this time the
2472 ; true block doesn't have side effects.
2473
2474second_true:
2475 ; No side effects!
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2476 ret void
Dan Gohmanca4cac42011-04-12 23:05:59 +0000[diff] [blame]2477
2478second_end:
2479 volatile store i32 0, i32* @g ; This time, the instruction always depends
2480 ; on the store in %end. Also, it is
2481 ; control-equivalent to %end, so this is
Nick Lewycky64f9fb12011-05-16 19:29:30 +0000[diff] [blame]2482 ; well-defined (again, ignoring earlier
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2483 ; undefined behavior in this example).
Dan Gohmanae11c3f2010-04-26 23:36:52 +0000[diff] [blame]2484</pre>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2485
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]2486</div>
2487
2488<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2489<h3>
2490 <a name="blockaddress">Addresses of Basic Blocks</a>
2491</h3>
2492
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2493<div>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2494
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2495<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2496
2497<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner2dfdf2a2009-10-27 21:49:40 +0000[diff] [blame]2498 basic block in the specified function, and always has an i8* type. Taking
Chris Lattnercdfc9402009-11-01 01:27:45 +0000[diff] [blame]2499 the address of the entry block is illegal.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2500
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2501<p>This value only has defined behavior when used as an operand to the
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2502 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2503 comparisons against null. Pointer equality tests between labels addresses
2504 results in undefined behavior &mdash; though, again, comparison against null
2505 is ok, and no label is equal to the null pointer. This may be passed around
2506 as an opaque pointer sized value as long as the bits are not inspected. This
2507 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2508 long as the original value is reconstituted before the <tt>indirectbr</tt>
2509 instruction.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]2510
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2511<p>Finally, some targets may provide defined semantics when using the value as
2512 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]2513
2514</div>
2515
2516
2517<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2518<h3>
2519 <a name="constantexprs">Constant Expressions</a>
2520</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2521
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2522<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2523
2524<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2525 to be used as constants. Constant expressions may be of
2526 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2527 operation that does not have side effects (e.g. load and call are not
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]2528 supported). The following is the syntax for constant expressions:</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2529
2530<dl>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2531 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2532 <dd>Truncate a constant to another type. The bit size of CST must be larger
2533 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2534
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2535 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2536 <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]2537 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2538
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2539 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2540 <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]2541 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2542
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2543 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2544 <dd>Truncate a floating point constant to another floating point type. The
2545 size of CST must be larger than the size of TYPE. Both types must be
2546 floating point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2547
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2548 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2549 <dd>Floating point extend a constant to another type. The size of CST must be
2550 smaller or equal to the size of TYPE. Both types must be floating
2551 point.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2552
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2553 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2554 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2555 constant. TYPE must be a scalar or vector integer type. CST must be of
2556 scalar or vector floating point type. Both CST and TYPE must be scalars,
2557 or vectors of the same number of elements. If the value won't fit in the
2558 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2559
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2560 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2561 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2562 constant. TYPE must be a scalar or vector integer type. CST must be of
2563 scalar or vector floating point type. Both CST and TYPE must be scalars,
2564 or vectors of the same number of elements. If the value won't fit in the
2565 integer type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2566
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2567 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2568 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2569 constant. TYPE must be a scalar or vector floating point type. CST must be
2570 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2571 vectors of the same number of elements. If the value won't fit in the
2572 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2573
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2574 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2575 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2576 constant. TYPE must be a scalar or vector floating point type. CST must be
2577 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2578 vectors of the same number of elements. If the value won't fit in the
2579 floating point type, the results are undefined.</dd>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]2580
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2581 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2582 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2583 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2584 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2585 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2586
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2587 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2588 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2589 type. CST must be of integer type. The CST value is zero extended,
2590 truncated, or unchanged to make it fit in a pointer size. This one is
2591 <i>really</i> dangerous!</dd>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]2592
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2593 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner03bbad62009-02-28 18:27:03 +0000[diff] [blame]2594 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2595 are the same as those for the <a href="#i_bitcast">bitcast
2596 instruction</a>.</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2597
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2598 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2599 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2600 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2601 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2602 instruction, the index list may have zero or more indexes, which are
2603 required to make sense for the type of "CSTPTR".</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2604
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2605 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2606 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2607
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2608 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2609 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2610
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2611 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer01c42592006-12-04 19:23:19 +0000[diff] [blame]2612 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2613
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2614 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2615 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2616 constants.</dd>
Robert Bocchino9fbe1452006-01-10 19:31:34 +0000[diff] [blame]2617
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2618 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2619 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2620 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2621
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2622 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2623 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2624 constants.</dd>
Chris Lattnerc1989542006-04-08 00:13:41 +0000[diff] [blame]2625
Nick Lewycky9e130ce2010-05-29 06:44:15 +0000[diff] [blame]2626 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2627 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2628 constants. The index list is interpreted in a similar manner as indices in
2629 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2630 index value must be specified.</dd>
2631
2632 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2633 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2634 constants. The index list is interpreted in a similar manner as indices in
2635 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2636 index value must be specified.</dd>
2637
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]2638 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2639 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2640 be any of the <a href="#binaryops">binary</a>
2641 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2642 on operands are the same as those for the corresponding instruction
2643 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2644</dl>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2645
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2646</div>
Chris Lattner9ee5d222004-03-08 16:49:10 +0000[diff] [blame]2647
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2648</div>
2649
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2650<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2651<h2><a name="othervalues">Other Values</a></h2>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2652<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2653<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2654<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2655<h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2656<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2657</h3>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2658
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2659<div>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2660
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2661<p>LLVM supports inline assembler expressions (as opposed
2662 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2663 a special value. This value represents the inline assembler as a string
2664 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2665 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2666 expression has side effects, and a flag indicating whether the function
2667 containing the asm needs to align its stack conservatively. An example
2668 inline assembler expression is:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2669
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2670<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2671i32 (i32) asm "bswap $0", "=r,r"
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2672</pre>
2673
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2674<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2675 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2676 have:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2677
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2678<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2679%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]2680</pre>
2681
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2682<p>Inline asms with side effects not visible in the constraint list must be
2683 marked as having side effects. This is done through the use of the
2684 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2685
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2686<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]2687call void asm sideeffect "eieio", ""()
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2688</pre>
2689
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2690<p>In some cases inline asms will contain code that will not work unless the
2691 stack is aligned in some way, such as calls or SSE instructions on x86,
2692 yet will not contain code that does that alignment within the asm.
2693 The compiler should make conservative assumptions about what the asm might
2694 contain and should generate its usual stack alignment code in the prologue
2695 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2696
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2697<pre class="doc_code">
Dale Johannesen8ba2d5b2009-10-21 23:28:00 +0000[diff] [blame]2698call void asm alignstack "eieio", ""()
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2699</pre>
Dale Johannesen09fed252009-10-13 21:56:55 +0000[diff] [blame]2700
2701<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2702 first.</p>
2703
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2704<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2705 documented here. Constraints on what can be done (e.g. duplication, moving,
2706 etc need to be documented). This is probably best done by reference to
2707 another document that covers inline asm from a holistic perspective.</p>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2708
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2709<h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2710<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2711</h4>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2712
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2713<div>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2714
2715<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattnerce1b9ad2010-11-17 08:20:42 +0000[diff] [blame]2716 attached to it that contains a list of constant integers. If present, the
2717 code generator will use the integer as the location cookie value when report
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2718 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman1c70c002010-04-28 00:36:01 +0000[diff] [blame]2719 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2720 source code that produced it. For example:</p>
2721
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2722<pre class="doc_code">
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2723call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2724...
2725!42 = !{ i32 1234567 }
2726</pre>
Chris Lattnercf9a4152010-04-07 05:38:05 +0000[diff] [blame]2727
2728<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]2729 IR. If the MDNode contains multiple constants, the code generator will use
2730 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]2731
2732</div>
2733
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2734</div>
2735
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2736<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2737<h3>
2738 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2739</h3>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2740
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2741<div>
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2742
2743<p>LLVM IR allows metadata to be attached to instructions in the program that
2744 can convey extra information about the code to the optimizers and code
2745 generator. One example application of metadata is source-level debug
2746 information. There are two metadata primitives: strings and nodes. All
2747 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2748 preceding exclamation point ('<tt>!</tt>').</p>
2749
2750<p>A metadata string is a string surrounded by double quotes. It can contain
2751 any character by escaping non-printable characters with "\xx" where "xx" is
2752 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2753
2754<p>Metadata nodes are represented with notation similar to structure constants
2755 (a comma separated list of elements, surrounded by braces and preceded by an
2756 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2757 10}</tt>". Metadata nodes can have any values as their operand.</p>
2758
2759<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2760 metadata nodes, which can be looked up in the module symbol table. For
2761 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2762
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2763<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2764 function is using two metadata arguments.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2765
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2766<div class="doc_code">
2767<pre>
2768call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2769</pre>
2770</div>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2771
2772<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]2773 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patele1d50cd2010-03-04 23:44:48 +0000[diff] [blame]2774
Bill Wendling9ff5de92011-03-02 02:17:11 +0000[diff] [blame]2775<div class="doc_code">
2776<pre>
2777%indvar.next = add i64 %indvar, 1, !dbg !21
2778</pre>
2779</div>
2780
Chris Lattnere6a5ddd2010-01-15 21:50:19 +0000[diff] [blame]2781</div>
2782
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2783</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2784
2785<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2786<h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2787 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2788</h2>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2789<!-- *********************************************************************** -->
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2790<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2791<p>LLVM has a number of "magic" global variables that contain data that affect
2792code generation or other IR semantics. These are documented here. All globals
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2793of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2794section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2795by LLVM.</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2796
2797<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2798<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2799<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2800</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2801
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2802<div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2803
2804<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2805href="#linkage_appending">appending linkage</a>. This array contains a list of
2806pointers to global variables and functions which may optionally have a pointer
2807cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2808
2809<pre>
2810 @X = global i8 4
2811 @Y = global i32 123
2812
2813 @llvm.used = appending global [2 x i8*] [
2814 i8* @X,
2815 i8* bitcast (i32* @Y to i8*)
2816 ], section "llvm.metadata"
2817</pre>
2818
2819<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2820compiler, assembler, and linker are required to treat the symbol as if there is
2821a reference to the global that it cannot see. For example, if a variable has
2822internal linkage and no references other than that from the <tt>@llvm.used</tt>
2823list, it cannot be deleted. This is commonly used to represent references from
2824inline asms and other things the compiler cannot "see", and corresponds to
2825"attribute((used))" in GNU C.</p>
2826
2827<p>On some targets, the code generator must emit a directive to the assembler or
2828object file to prevent the assembler and linker from molesting the symbol.</p>
2829
2830</div>
2831
2832<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2833<h3>
2834 <a name="intg_compiler_used">
2835 The '<tt>llvm.compiler.used</tt>' Global Variable
2836 </a>
2837</h3>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2838
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2839<div>
Chris Lattner401e10c2009-07-20 06:14:25 +0000[diff] [blame]2840
2841<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2842<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2843touching the symbol. On targets that support it, this allows an intelligent
2844linker to optimize references to the symbol without being impeded as it would be
2845by <tt>@llvm.used</tt>.</p>
2846
2847<p>This is a rare construct that should only be used in rare circumstances, and
2848should not be exposed to source languages.</p>
2849
2850</div>
2851
2852<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2853<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2854<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2855</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2856
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2857<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2858<pre>
2859%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2860@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2861</pre>
2862<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.
2863</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2864
2865</div>
2866
2867<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2868<h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2869<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2870</h3>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2871
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2872<div>
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2873<pre>
2874%0 = type { i32, void ()* }
David Chisnall27195a52010-04-30 19:27:35 +0000[diff] [blame]2875@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2876</pre>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2877
David Chisnalle31e9962010-04-30 19:23:49 +0000[diff] [blame]2878<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.
2879</p>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2880
2881</div>
2882
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2883</div>
Chris Lattner857755c2009-07-20 05:55:19 +0000[diff] [blame]2884
Chris Lattnere87d6532006-01-25 23:47:57 +0000[diff] [blame]2885<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2886<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]2887<!-- *********************************************************************** -->
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2888
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2889<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2890
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2891<p>The LLVM instruction set consists of several different classifications of
2892 instructions: <a href="#terminators">terminator
2893 instructions</a>, <a href="#binaryops">binary instructions</a>,
2894 <a href="#bitwiseops">bitwise binary instructions</a>,
2895 <a href="#memoryops">memory instructions</a>, and
2896 <a href="#otherops">other instructions</a>.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2897
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2898<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2899<h3>
2900 <a name="terminators">Terminator Instructions</a>
2901</h3>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2902
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2903<div>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2904
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2905<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2906 in a program ends with a "Terminator" instruction, which indicates which
2907 block should be executed after the current block is finished. These
2908 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2909 control flow, not values (the one exception being the
2910 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2911
Duncan Sands83821c82010-04-15 20:35:54 +0000[diff] [blame]2912<p>There are seven different terminator instructions: the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2913 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2914 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2915 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling21c346e2009-11-02 00:25:26 +0000[diff] [blame]2916 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2917 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2918 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2919 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattnerc3f59762004-12-09 17:30:23 +0000[diff] [blame]2920
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2921<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2922<h4>
2923 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
2924</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2925
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2926<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2927
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2928<h5>Syntax:</h5>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2929<pre>
2930 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]2931 ret void <i>; Return from void function</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2932</pre>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2933
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2934<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2935<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2936 a value) from a function back to the caller.</p>
2937
2938<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2939 value and then causes control flow, and one that just causes control flow to
2940 occur.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2941
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2942<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2943<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2944 return value. The type of the return value must be a
2945 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]2946
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2947<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2948 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2949 value or a return value with a type that does not match its type, or if it
2950 has a void return type and contains a '<tt>ret</tt>' instruction with a
2951 return value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2952
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2953<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2954<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2955 the calling function's context. If the caller is a
2956 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2957 instruction after the call. If the caller was an
2958 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2959 the beginning of the "normal" destination block. If the instruction returns
2960 a value, that value shall set the call or invoke instruction's return
2961 value.</p>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2962
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2963<h5>Example:</h5>
Chris Lattnerf4cde4e2008-04-23 04:59:35 +0000[diff] [blame]2964<pre>
2965 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]2966 ret void <i>; Return from a void function</i>
Bill Wendling0a4bbbf2009-02-28 22:12:54 +0000[diff] [blame]2967 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]2968</pre>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]2969
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]2970</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2971<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]2972<h4>
2973 <a name="i_br">'<tt>br</tt>' Instruction</a>
2974</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2975
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]2976<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2977
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2978<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2979<pre>
2980 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2981</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2982
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2983<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2984<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2985 different basic block in the current function. There are two forms of this
2986 instruction, corresponding to a conditional branch and an unconditional
2987 branch.</p>
2988
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2989<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2990<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2991 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2992 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2993 target.</p>
2994
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]2995<h5>Semantics:</h5>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]2996<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]2997 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2998 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2999 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
3000
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3001<h5>Example:</h5>
Bill Wendlingc39e3e02009-07-20 02:39:26 +0000[diff] [blame]3002<pre>
3003Test:
3004 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
3005 br i1 %cond, label %IfEqual, label %IfUnequal
3006IfEqual:
3007 <a href="#i_ret">ret</a> i32 1
3008IfUnequal:
3009 <a href="#i_ret">ret</a> i32 0
3010</pre>
3011
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3012</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3013
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3014<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3015<h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3016 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3017</h4>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3018
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3019<div>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3020
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3021<h5>Syntax:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3022<pre>
3023 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
3024</pre>
3025
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3026<h5>Overview:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3027<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]3028 several different places. It is a generalization of the '<tt>br</tt>'
3029 instruction, allowing a branch to occur to one of many possible
3030 destinations.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3031
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3032<h5>Arguments:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3033<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3034 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
3035 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
3036 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3037
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3038<h5>Semantics:</h5>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3039<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3040 destinations. When the '<tt>switch</tt>' instruction is executed, this table
3041 is searched for the given value. If the value is found, control flow is
Benjamin Kramer8040cd32009-10-12 14:46:08 +0000[diff] [blame]3042 transferred to the corresponding destination; otherwise, control flow is
3043 transferred to the default destination.</p>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3044
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3045<h5>Implementation:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3046<p>Depending on properties of the target machine and the particular
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3047 <tt>switch</tt> instruction, this instruction may be code generated in
3048 different ways. For example, it could be generated as a series of chained
3049 conditional branches or with a lookup table.</p>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3050
3051<h5>Example:</h5>
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3052<pre>
3053 <i>; Emulate a conditional br instruction</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]3054 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3055 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3056
3057 <i>; Emulate an unconditional br instruction</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3058 switch i32 0, label %dest [ ]
Chris Lattnerc88c17b2004-02-24 04:54:45 +0000[diff] [blame]3059
3060 <i>; Implement a jump table:</i>
Dan Gohman2a08c532009-01-04 23:44:43 +0000[diff] [blame]3061 switch i32 %val, label %otherwise [ i32 0, label %onzero
3062 i32 1, label %onone
3063 i32 2, label %ontwo ]
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3064</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3065
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3066</div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3067
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3068
3069<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3070<h4>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3071 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3072</h4>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3073
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3074<div>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3075
3076<h5>Syntax:</h5>
3077<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3078 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]3079</pre>
3080
3081<h5>Overview:</h5>
3082
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3083<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3084 within the current function, whose address is specified by
Chris Lattnerc6f44362009-10-27 21:01:34 +0000[diff] [blame]3085 "<tt>address</tt>". Address must be derived from a <a
3086 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3087
3088<h5>Arguments:</h5>
3089
3090<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3091 rest of the arguments indicate the full set of possible destinations that the
3092 address may point to. Blocks are allowed to occur multiple times in the
3093 destination list, though this isn't particularly useful.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3094
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3095<p>This destination list is required so that dataflow analysis has an accurate
3096 understanding of the CFG.</p>
3097
3098<h5>Semantics:</h5>
3099
3100<p>Control transfers to the block specified in the address argument. All
3101 possible destination blocks must be listed in the label list, otherwise this
3102 instruction has undefined behavior. This implies that jumps to labels
3103 defined in other functions have undefined behavior as well.</p>
3104
3105<h5>Implementation:</h5>
3106
3107<p>This is typically implemented with a jump through a register.</p>
3108
3109<h5>Example:</h5>
3110<pre>
Chris Lattnerab21db72009-10-28 00:19:10 +0000[diff] [blame]3111 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattnerf9be95f2009-10-27 19:13:16 +0000[diff] [blame]3112</pre>
3113
3114</div>
3115
3116
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3117<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3118<h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3119 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3120</h4>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3121
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3122<div>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3123
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3124<h5>Syntax:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3125<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3126 &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]3127 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3128</pre>
3129
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]3130<h5>Overview:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3131<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3132 function, with the possibility of control flow transfer to either the
3133 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3134 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3135 control flow will return to the "normal" label. If the callee (or any
3136 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3137 instruction, control is interrupted and continued at the dynamically nearest
3138 "exception" label.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3139
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3140<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3141<p>This instruction requires several arguments:</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3142
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3143<ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3144 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3145 convention</a> the call should use. If none is specified, the call
3146 defaults to using C calling conventions.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3147
3148 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3149 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3150 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]3151
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3152 <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]3153 function value being invoked. In most cases, this is a direct function
3154 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3155 off an arbitrary pointer to function value.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3156
3157 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3158 function to be invoked. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3159
3160 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]3161 signature argument types and parameter attributes. All arguments must be
3162 of <a href="#t_firstclass">first class</a> type. If the function
3163 signature indicates the function accepts a variable number of arguments,
3164 the extra arguments can be specified.</li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3165
3166 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3167 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3168
3169 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3170 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3171
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]3172 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3173 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3174 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3175</ol>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3176
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3177<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3178<p>This instruction is designed to operate as a standard
3179 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3180 primary difference is that it establishes an association with a label, which
3181 is used by the runtime library to unwind the stack.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3182
3183<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3184 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3185 exception. Additionally, this is important for implementation of
3186 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3187
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3188<p>For the purposes of the SSA form, the definition of the value returned by the
3189 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3190 block to the "normal" label. If the callee unwinds then no return value is
3191 available.</p>
Dan Gohmanf96a4992009-05-22 21:47:08 +0000[diff] [blame]3192
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3193<p>Note that the code generator does not yet completely support unwind, and
3194that the invoke/unwind semantics are likely to change in future versions.</p>
3195
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3196<h5>Example:</h5>
Chris Lattnerbad10ee2005-05-06 22:57:40 +0000[diff] [blame]3197<pre>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3198 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3199 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckyd703f652008-03-16 07:18:12 +0000[diff] [blame]3200 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3201 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3202</pre>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3203
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3204</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3205
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3206<!-- _______________________________________________________________________ -->
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3207
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3208<h4>
3209 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3210</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3211
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3212<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3213
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3214<h5>Syntax:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3215<pre>
3216 unwind
3217</pre>
3218
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3219<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3220<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3221 at the first callee in the dynamic call stack which used
3222 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3223 This is primarily used to implement exception handling.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3224
Chris Lattner27f71f22003-09-03 00:41:47 +0000[diff] [blame]3225<h5>Semantics:</h5>
Chris Lattner72ed2002008-04-19 21:01:16 +0000[diff] [blame]3226<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3227 immediately halt. The dynamic call stack is then searched for the
3228 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3229 Once found, execution continues at the "exceptional" destination block
3230 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3231 instruction in the dynamic call chain, undefined behavior results.</p>
3232
Chris Lattnerdf7a6802010-01-15 18:08:37 +0000[diff] [blame]3233<p>Note that the code generator does not yet completely support unwind, and
3234that the invoke/unwind semantics are likely to change in future versions.</p>
3235
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3236</div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3237
3238<!-- _______________________________________________________________________ -->
3239
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3240<h4>
3241 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3242</h4>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3243
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3244<div>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3245
3246<h5>Syntax:</h5>
3247<pre>
3248 unreachable
3249</pre>
3250
3251<h5>Overview:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3252<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3253 instruction is used to inform the optimizer that a particular portion of the
3254 code is not reachable. This can be used to indicate that the code after a
3255 no-return function cannot be reached, and other facts.</p>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3256
3257<h5>Semantics:</h5>
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3258<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3259
Chris Lattner35eca582004-10-16 18:04:13 +0000[diff] [blame]3260</div>
3261
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3262</div>
3263
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3264<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3265<h3>
3266 <a name="binaryops">Binary Operations</a>
3267</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3268
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3269<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3270
3271<p>Binary operators are used to do most of the computation in a program. They
3272 require two operands of the same type, execute an operation on them, and
3273 produce a single value. The operands might represent multiple data, as is
3274 the case with the <a href="#t_vector">vector</a> data type. The result value
3275 has the same type as its operands.</p>
3276
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3277<p>There are several different binary operators:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3278
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3279<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3280<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3281 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3282</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3283
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3284<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3285
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3286<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3287<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3288 &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]3289 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3290 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3291 &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]3292</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3293
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3294<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3295<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3296
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3297<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3298<p>The two arguments to the '<tt>add</tt>' instruction must
3299 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3300 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3301
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3302<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3303<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3304
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3305<p>If the sum has unsigned overflow, the result returned is the mathematical
3306 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]3307
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3308<p>Because LLVM integers use a two's complement representation, this instruction
3309 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3310
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3311<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3312 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3313 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3314 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3315 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3316
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3317<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3318<pre>
3319 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3320</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3321
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3322</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3323
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3324<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3325<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3326 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3327</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3328
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3329<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3330
3331<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3332<pre>
3333 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3334</pre>
3335
3336<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3337<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3338
3339<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3340<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3341 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3342 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3343
3344<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3345<p>The value produced is the floating point sum of the two operands.</p>
3346
3347<h5>Example:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3348<pre>
3349 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3350</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3351
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3352</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3353
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3354<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3355<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3356 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3357</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3358
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3359<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3360
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3361<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3362<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3363 &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]3364 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3365 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3366 &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]3367</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3368
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3369<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3370<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3371 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3372
3373<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3374 '<tt>neg</tt>' instruction present in most other intermediate
3375 representations.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3376
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3377<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3378<p>The two arguments to the '<tt>sub</tt>' instruction must
3379 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3380 integer values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3381
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3382<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3383<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3384
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3385<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3386 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3387 result.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3388
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3389<p>Because LLVM integers use a two's complement representation, this instruction
3390 is appropriate for both signed and unsigned integers.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3391
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3392<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3393 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3394 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3395 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3396 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3397
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3398<h5>Example:</h5>
Bill Wendlingaac388b2007-05-29 09:42:13 +0000[diff] [blame]3399<pre>
3400 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]3401 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3402</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3403
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3404</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3405
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3406<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3407<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3408 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3409</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3410
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3411<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3412
3413<h5>Syntax:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3414<pre>
3415 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3416</pre>
3417
3418<h5>Overview:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3419<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3420 operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3421
3422<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3423 '<tt>fneg</tt>' instruction present in most other intermediate
3424 representations.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3425
3426<h5>Arguments:</h5>
Bill Wendlingd9fe2982009-07-20 02:32:41 +0000[diff] [blame]3427<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3428 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3429 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3430
3431<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3432<p>The value produced is the floating point difference of the two operands.</p>
3433
3434<h5>Example:</h5>
3435<pre>
3436 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3437 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3438</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3439
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3440</div>
3441
3442<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3443<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3444 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3445</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3446
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3447<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3448
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3449<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3450<pre>
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3451 &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]3452 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3453 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3454 &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]3455</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3456
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3457<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3458<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3459
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3460<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3461<p>The two arguments to the '<tt>mul</tt>' instruction must
3462 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3463 integer values. Both arguments must have identical types.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3464
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3465<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3466<p>The value produced is the integer product of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3467
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3468<p>If the result of the multiplication has unsigned overflow, the result
3469 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3470 width of the result.</p>
3471
3472<p>Because LLVM integers use a two's complement representation, and the result
3473 is the same width as the operands, this instruction returns the correct
3474 result for both signed and unsigned integers. If a full product
3475 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3476 be sign-extended or zero-extended as appropriate to the width of the full
3477 product.</p>
3478
Dan Gohman08d012e2009-07-22 22:44:56 +0000[diff] [blame]3479<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3480 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3481 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanfff6c532010-04-22 23:14:21 +0000[diff] [blame]3482 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3483 respectively, occurs.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3484
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3485<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3486<pre>
3487 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3488</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3489
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3490</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3491
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3492<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3493<h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3494 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3495</h4>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3496
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3497<div>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3498
3499<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3500<pre>
3501 &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]3502</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3503
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3504<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3505<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3506
3507<h5>Arguments:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3508<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3509 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3510 floating point values. Both arguments must have identical types.</p>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3511
3512<h5>Semantics:</h5>
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3513<p>The value produced is the floating point product of the two operands.</p>
3514
3515<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3516<pre>
3517 &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]3518</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3519
Dan Gohmanae3a0be2009-06-04 22:49:04 +0000[diff] [blame]3520</div>
3521
3522<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3523<h4>
3524 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3525</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3526
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3527<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3528
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3529<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3530<pre>
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3531 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3532 &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]3533</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3534
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3535<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3536<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3537
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3538<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3539<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3540 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3541 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3542
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3543<h5>Semantics:</h5>
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3544<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3545
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3546<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3547 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3548
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3549<p>Division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3550
Chris Lattner35bda892011-02-06 21:44:57 +0000[diff] [blame]3551<p>If the <tt>exact</tt> keyword is present, the result value of the
3552 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3553 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3554
3555
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3556<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3557<pre>
3558 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3559</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3560
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3561</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3562
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3563<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3564<h4>
3565 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3566</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3567
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3568<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3569
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3570<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3571<pre>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3572 &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]3573 &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]3574</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3575
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3576<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3577<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3578
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3579<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3580<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3581 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3582 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3583
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3584<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3585<p>The value produced is the signed integer quotient of the two operands rounded
3586 towards zero.</p>
3587
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3588<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3589 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3590
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3591<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3592 undefined behavior; this is a rare case, but can occur, for example, by doing
3593 a 32-bit division of -2147483648 by -1.</p>
3594
Dan Gohman9c5beed2009-07-22 00:04:19 +0000[diff] [blame]3595<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]3596 <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]3597 be rounded.</p>
Dan Gohmancbb38f22009-07-20 22:41:19 +0000[diff] [blame]3598
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3599<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3600<pre>
3601 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3602</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3603
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3604</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3605
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3606<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3607<h4>
3608 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3609</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3610
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3611<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3612
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3613<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3614<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3615 &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]3616</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3617
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3618<h5>Overview:</h5>
3619<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3620
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3621<h5>Arguments:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]3622<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3623 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3624 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3625
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3626<h5>Semantics:</h5>
Reid Spencer1628cec2006-10-26 06:15:43 +0000[diff] [blame]3627<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3628
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3629<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3630<pre>
3631 &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]3632</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3633
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3634</div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3635
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3636<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3637<h4>
3638 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3639</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3640
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3641<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3642
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3643<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3644<pre>
3645 &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]3646</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3647
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3648<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3649<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3650 division of its two arguments.</p>
3651
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3652<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3653<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3654 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3655 values. Both arguments must have identical types.</p>
3656
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3657<h5>Semantics:</h5>
3658<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3659 This instruction always performs an unsigned division to get the
3660 remainder.</p>
3661
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3662<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3663 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3664
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3665<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3666
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3667<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3668<pre>
3669 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3670</pre>
3671
3672</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3673
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3674<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3675<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3676 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3677</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3678
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3679<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3680
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3681<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3682<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3683 &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]3684</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3685
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3686<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3687<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3688 division of its two operands. This instruction can also take
3689 <a href="#t_vector">vector</a> versions of the values in which case the
3690 elements must be integers.</p>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]3691
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3692<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3693<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3694 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3695 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3696
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3697<h5>Semantics:</h5>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3698<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sandsdea3a5e2011-03-07 09:12:24 +0000[diff] [blame]3699 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3700 <i>modulo</i> operator (where the result is either zero or has the same sign
3701 as the divisor, <tt>op2</tt>) of a value.
3702 For more information about the difference,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3703 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3704 Math Forum</a>. For a table of how this is implemented in various languages,
3705 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3706 Wikipedia: modulo operation</a>.</p>
3707
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3708<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3709 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3710
Chris Lattner5ec89832008-01-28 00:36:27 +0000[diff] [blame]3711<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3712 Overflow also leads to undefined behavior; this is a rare case, but can
3713 occur, for example, by taking the remainder of a 32-bit division of
3714 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3715 lets srem be implemented using instructions that return both the result of
3716 the division and the remainder.)</p>
3717
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3718<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3719<pre>
3720 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3721</pre>
3722
3723</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3724
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3725<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3726<h4>
3727 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3728</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3729
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3730<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3731
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3732<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3733<pre>
3734 &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]3735</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3736
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3737<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3738<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3739 its two operands.</p>
3740
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3741<h5>Arguments:</h5>
3742<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3743 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3744 floating point values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3745
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3746<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3747<p>This instruction returns the <i>remainder</i> of a division. The remainder
3748 has the same sign as the dividend.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3749
Reid Spencer0a783f72006-11-02 01:53:59 +0000[diff] [blame]3750<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3751<pre>
3752 &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]3753</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3754
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3755</div>
Robert Bocchino7b81c752006-02-17 21:18:08 +0000[diff] [blame]3756
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3757</div>
3758
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3759<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3760<h3>
3761 <a name="bitwiseops">Bitwise Binary Operations</a>
3762</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3763
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3764<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3765
3766<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3767 program. They are generally very efficient instructions and can commonly be
3768 strength reduced from other instructions. They require two operands of the
3769 same type, execute an operation on them, and produce a single value. The
3770 resulting value is the same type as its operands.</p>
3771
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3772<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3773<h4>
3774 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3775</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3776
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3777<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3778
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3779<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3780<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3781 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3782 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3783 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3784 &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]3785</pre>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3786
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3787<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3788<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3789 a specified number of bits.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3790
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3791<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3792<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3793 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3794 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3795
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3796<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3797<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3798 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3799 is (statically or dynamically) negative or equal to or larger than the number
3800 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3801 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3802 shift amount in <tt>op2</tt>.</p>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3803
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3804<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3805 <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]3806 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3807 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3808 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3809 they would if the shift were expressed as a mul instruction with the same
3810 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3811
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3812<h5>Example:</h5>
3813<pre>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3814 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3815 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3816 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3817 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3818 &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]3819</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3820
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3821</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3822
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3823<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3824<h4>
3825 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3826</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3827
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3828<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3829
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3830<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3831<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3832 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3833 &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]3834</pre>
3835
3836<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3837<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3838 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3839
3840<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3841<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3842 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3843 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3844
3845<h5>Semantics:</h5>
3846<p>This instruction always performs a logical shift right operation. The most
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3847 significant bits of the result will be filled with zero bits after the shift.
3848 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3849 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3850 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3851 shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3852
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3853<p>If the <tt>exact</tt> keyword is present, the result value of the
3854 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3855 shifted out are non-zero.</p>
3856
3857
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3858<h5>Example:</h5>
3859<pre>
3860 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3861 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3862 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3863 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3864 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3865 &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]3866</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3867
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3868</div>
3869
Reid Spencer8e11bf82007-02-02 13:57:07 +0000[diff] [blame]3870<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3871<h4>
3872 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
3873</h4>
3874
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3875<div>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3876
3877<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3878<pre>
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3879 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3880 &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]3881</pre>
3882
3883<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3884<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3885 operand shifted to the right a specified number of bits with sign
3886 extension.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3887
3888<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3889<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3890 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3891 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3892
3893<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3894<p>This instruction always performs an arithmetic shift right operation, The
3895 most significant bits of the result will be filled with the sign bit
3896 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3897 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3898 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3899 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3900
Chris Lattnerf067d582011-02-07 16:40:21 +0000[diff] [blame]3901<p>If the <tt>exact</tt> keyword is present, the result value of the
3902 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3903 shifted out are non-zero.</p>
3904
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3905<h5>Example:</h5>
3906<pre>
3907 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3908 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3909 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3910 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner6ccc2d52007-10-03 21:01:14 +0000[diff] [blame]3911 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wange9f10152008-12-09 05:46:39 +0000[diff] [blame]3912 &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]3913</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3914
Reid Spencer569f2fa2007-01-31 21:39:12 +0000[diff] [blame]3915</div>
3916
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3917<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3918<h4>
3919 <a name="i_and">'<tt>and</tt>' Instruction</a>
3920</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3921
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3922<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3923
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3924<h5>Syntax:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3925<pre>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]3926 &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]3927</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3928
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3929<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3930<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3931 operands.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3932
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3933<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3934<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3935 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3936 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3937
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3938<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3939<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3940
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3941<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]3942 <tbody>
3943 <tr>
3944 <td>In0</td>
3945 <td>In1</td>
3946 <td>Out</td>
3947 </tr>
3948 <tr>
3949 <td>0</td>
3950 <td>0</td>
3951 <td>0</td>
3952 </tr>
3953 <tr>
3954 <td>0</td>
3955 <td>1</td>
3956 <td>0</td>
3957 </tr>
3958 <tr>
3959 <td>1</td>
3960 <td>0</td>
3961 <td>0</td>
3962 </tr>
3963 <tr>
3964 <td>1</td>
3965 <td>1</td>
3966 <td>1</td>
3967 </tr>
3968 </tbody>
3969</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3970
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3971<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3972<pre>
3973 &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]3974 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3975 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3976</pre>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]3977</div>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3978<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]3979<h4>
3980 <a name="i_or">'<tt>or</tt>' Instruction</a>
3981</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]3982
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]3983<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3984
3985<h5>Syntax:</h5>
3986<pre>
3987 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3988</pre>
3989
3990<h5>Overview:</h5>
3991<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3992 two operands.</p>
3993
3994<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]3995<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]3996 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3997 values. Both arguments must have identical types.</p>
3998
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]3999<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4000<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4001
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4002<table border="1" cellspacing="0" cellpadding="4">
4003 <tbody>
4004 <tr>
4005 <td>In0</td>
4006 <td>In1</td>
4007 <td>Out</td>
4008 </tr>
4009 <tr>
4010 <td>0</td>
4011 <td>0</td>
4012 <td>0</td>
4013 </tr>
4014 <tr>
4015 <td>0</td>
4016 <td>1</td>
4017 <td>1</td>
4018 </tr>
4019 <tr>
4020 <td>1</td>
4021 <td>0</td>
4022 <td>1</td>
4023 </tr>
4024 <tr>
4025 <td>1</td>
4026 <td>1</td>
4027 <td>1</td>
4028 </tr>
4029 </tbody>
4030</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4031
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4032<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4033<pre>
4034 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4035 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
4036 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4037</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4038
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4039</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4040
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4041<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4042<h4>
4043 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
4044</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4045
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4046<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4047
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4048<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4049<pre>
4050 &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]4051</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4052
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4053<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4054<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
4055 its two operands. The <tt>xor</tt> is used to implement the "one's
4056 complement" operation, which is the "~" operator in C.</p>
4057
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4058<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4059<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4060 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
4061 values. Both arguments must have identical types.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]4062
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4063<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4064<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4065
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4066<table border="1" cellspacing="0" cellpadding="4">
4067 <tbody>
4068 <tr>
4069 <td>In0</td>
4070 <td>In1</td>
4071 <td>Out</td>
4072 </tr>
4073 <tr>
4074 <td>0</td>
4075 <td>0</td>
4076 <td>0</td>
4077 </tr>
4078 <tr>
4079 <td>0</td>
4080 <td>1</td>
4081 <td>1</td>
4082 </tr>
4083 <tr>
4084 <td>1</td>
4085 <td>0</td>
4086 <td>1</td>
4087 </tr>
4088 <tr>
4089 <td>1</td>
4090 <td>1</td>
4091 <td>0</td>
4092 </tr>
4093 </tbody>
4094</table>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4095
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4096<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4097<pre>
4098 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4099 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4100 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4101 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4102</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4103
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4104</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4105
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4106</div>
4107
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4108<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4109<h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4110 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4111</h3>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4112
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4113<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4114
4115<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4116 target-independent manner. These instructions cover the element-access and
4117 vector-specific operations needed to process vectors effectively. While LLVM
4118 does directly support these vector operations, many sophisticated algorithms
4119 will want to use target-specific intrinsics to take full advantage of a
4120 specific target.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4121
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4122<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4123<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4124 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4125</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4126
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4127<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4128
4129<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4130<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4131 &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]4132</pre>
4133
4134<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4135<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4136 from a vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4137
4138
4139<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4140<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4141 of <a href="#t_vector">vector</a> type. The second operand is an index
4142 indicating the position from which to extract the element. The index may be
4143 a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4144
4145<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4146<p>The result is a scalar of the same type as the element type of
4147 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4148 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4149 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4150
4151<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4152<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4153 &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]4154</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4155
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4156</div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4157
4158<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4159<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4160 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4161</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4162
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4163<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4164
4165<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4166<pre>
Dan Gohmanf3480b92008-05-12 23:38:42 +0000[diff] [blame]4167 &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]4168</pre>
4169
4170<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4171<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4172 vector at a specified index.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4173
4174<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4175<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4176 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4177 whose type must equal the element type of the first operand. The third
4178 operand is an index indicating the position at which to insert the value.
4179 The index may be a variable.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4180
4181<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4182<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4183 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4184 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4185 results are undefined.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4186
4187<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4188<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4189 &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]4190</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4191
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4192</div>
4193
4194<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4195<h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4196 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4197</h4>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4198
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4199<div>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4200
4201<h5>Syntax:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4202<pre>
Mon P Wangaeb06d22008-11-10 04:46:22 +0000[diff] [blame]4203 &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]4204</pre>
4205
4206<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4207<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4208 from two input vectors, returning a vector with the same element type as the
4209 input and length that is the same as the shuffle mask.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4210
4211<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4212<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4213 with types that match each other. The third argument is a shuffle mask whose
4214 element type is always 'i32'. The result of the instruction is a vector
4215 whose length is the same as the shuffle mask and whose element type is the
4216 same as the element type of the first two operands.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4217
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4218<p>The shuffle mask operand is required to be a constant vector with either
4219 constant integer or undef values.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4220
4221<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4222<p>The elements of the two input vectors are numbered from left to right across
4223 both of the vectors. The shuffle mask operand specifies, for each element of
4224 the result vector, which element of the two input vectors the result element
4225 gets. The element selector may be undef (meaning "don't care") and the
4226 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4227
4228<h5>Example:</h5>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4229<pre>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4230 &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]4231 &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]4232 &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]4233 &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]4234 &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]4235 &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]4236 &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]4237 &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]4238</pre>
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4239
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4240</div>
Tanya Lattner09474292006-04-14 19:24:33 +0000[diff] [blame]4241
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4242</div>
4243
Chris Lattner3df241e2006-04-08 23:07:04 +0000[diff] [blame]4244<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4245<h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4246 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4247</h3>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4248
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4249<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4250
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4251<p>LLVM supports several instructions for working with
4252 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4253
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4254<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4255<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4256 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4257</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4258
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4259<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4260
4261<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4262<pre>
4263 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4264</pre>
4265
4266<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4267<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4268 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4269
4270<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4271<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4272 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4273 <a href="#t_array">array</a> type. The operands are constant indices to
4274 specify which value to extract in a similar manner as indices in a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4275 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel13242892010-12-05 20:54:38 +0000[diff] [blame]4276 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4277 <ul>
4278 <li>Since the value being indexed is not a pointer, the first index is
4279 omitted and assumed to be zero.</li>
4280 <li>At least one index must be specified.</li>
4281 <li>Not only struct indices but also array indices must be in
4282 bounds.</li>
4283 </ul>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4284
4285<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4286<p>The result is the value at the position in the aggregate specified by the
4287 index operands.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4288
4289<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4290<pre>
Gabor Greifa5b6f452009-10-28 13:14:50 +0000[diff] [blame]4291 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4292</pre>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4293
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4294</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4295
4296<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4297<h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4298 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4299</h4>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4300
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4301<div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4302
4303<h5>Syntax:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4304<pre>
Chris Lattner8645d1a2011-05-22 07:18:08 +0000[diff] [blame^]4305 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt;{, <idx>}* <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4306</pre>
4307
4308<h5>Overview:</h5>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4309<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4310 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4311
4312<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4313<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4314 of <a href="#t_struct">struct</a> or
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4315 <a href="#t_array">array</a> type. The second operand is a first-class
4316 value to insert. The following operands are constant indices indicating
4317 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]4318 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4319 value to insert must have the same type as the value identified by the
4320 indices.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4321
4322<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4323<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4324 that of <tt>val</tt> except that the value at the position specified by the
4325 indices is that of <tt>elt</tt>.</p>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4326
4327<h5>Example:</h5>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4328<pre>
Chris Lattner8645d1a2011-05-22 07:18:08 +0000[diff] [blame^]4329 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4330 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4331 %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]4332</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4333
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4334</div>
4335
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4336</div>
Dan Gohmana334d5f2008-05-12 23:51:09 +0000[diff] [blame]4337
4338<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4339<h3>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4340 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4341</h3>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4342
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4343<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4344
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4345<p>A key design point of an SSA-based representation is how it represents
4346 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]4347 very simple. This section describes how to read, write, and allocate
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4348 memory in LLVM.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4349
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4350<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4351<h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4352 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4353</h4>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4354
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4355<div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4356
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4357<h5>Syntax:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4358<pre>
Dan Gohmanf75a7d32010-05-28 01:14:11 +0000[diff] [blame]4359 &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]4360</pre>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4361
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4362<h5>Overview:</h5>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4363<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4364 currently executing function, to be automatically released when this function
4365 returns to its caller. The object is always allocated in the generic address
4366 space (address space zero).</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4367
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4368<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4369<p>The '<tt>alloca</tt>' instruction
4370 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4371 runtime stack, returning a pointer of the appropriate type to the program.
4372 If "NumElements" is specified, it is the number of elements allocated,
4373 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4374 specified, the value result of the allocation is guaranteed to be aligned to
4375 at least that boundary. If not specified, or if zero, the target can choose
4376 to align the allocation on any convenient boundary compatible with the
4377 type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4378
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4379<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4380
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4381<h5>Semantics:</h5>
Bill Wendling871eb0a2009-05-08 20:49:29 +0000[diff] [blame]4382<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4383 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4384 memory is automatically released when the function returns. The
4385 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4386 variables that must have an address available. When the function returns
4387 (either with the <tt><a href="#i_ret">ret</a></tt>
4388 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4389 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4390
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4391<h5>Example:</h5>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4392<pre>
Dan Gohman81e21672009-01-04 23:49:44 +0000[diff] [blame]4393 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4394 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4395 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4396 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4397</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4398
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4399</div>
Chris Lattner2cbdc452005-11-06 08:02:57 +0000[diff] [blame]4400
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4401<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4402<h4>
4403 <a name="i_load">'<tt>load</tt>' Instruction</a>
4404</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4405
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4406<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4407
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4408<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4409<pre>
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4410 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4411 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4412 !&lt;index&gt; = !{ i32 1 }
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4413</pre>
4414
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4415<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4416<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4417
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4418<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4419<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4420 from which to load. The pointer must point to
4421 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4422 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4423 number or order of execution of this <tt>load</tt> with other <a
4424 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4425
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4426<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4427 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]4428 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4429 alignment for the target. It is the responsibility of the code emitter to
4430 ensure that the alignment information is correct. Overestimating the
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4431 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4432 produce less efficient code. An alignment of 1 is always safe.</p>
4433
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4434<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4435 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4436 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendling7c78dbb2010-02-25 21:23:24 +0000[diff] [blame]4437 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4438 and code generator that this load is not expected to be reused in the cache.
4439 The code generator may select special instructions to save cache bandwidth,
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4440 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4441
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4442<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4443<p>The location of memory pointed to is loaded. If the value being loaded is of
4444 scalar type then the number of bytes read does not exceed the minimum number
4445 of bytes needed to hold all bits of the type. For example, loading an
4446 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4447 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4448 is undefined if the value was not originally written using a store of the
4449 same type.</p>
4450
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4451<h5>Examples:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4452<pre>
4453 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4454 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4455 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4456</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4457
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4458</div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4459
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4460<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4461<h4>
4462 <a name="i_store">'<tt>store</tt>' Instruction</a>
4463</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4464
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4465<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4466
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4467<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4468<pre>
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4469 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>
4470 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]4471</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4472
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4473<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4474<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4475
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4476<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4477<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4478 and an address at which to store it. The type of the
4479 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4480 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]4481 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4482 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4483 order of execution of this <tt>store</tt> with other <a
4484 href="#volatile">volatile operations</a>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4485
4486<p>The optional constant "align" argument specifies the alignment of the
4487 operation (that is, the alignment of the memory address). A value of 0 or an
4488 omitted "align" argument means that the operation has the preferential
4489 alignment for the target. It is the responsibility of the code emitter to
4490 ensure that the alignment information is correct. Overestimating the
4491 alignment results in an undefined behavior. Underestimating the alignment may
4492 produce less efficient code. An alignment of 1 is always safe.</p>
4493
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4494<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4495 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4496 value 1. The existence of the !nontemporal metatadata on the
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4497 instruction tells the optimizer and code generator that this load is
4498 not expected to be reused in the cache. The code generator may
4499 select special instructions to save cache bandwidth, such as the
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]4500 MOVNT instruction on x86.</p>
David Greene8939b0d2010-02-16 20:50:18 +0000[diff] [blame]4501
4502
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]4503<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4504<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4505 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4506 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4507 does not exceed the minimum number of bytes needed to hold all bits of the
4508 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4509 writing a value of a type like <tt>i20</tt> with a size that is not an
4510 integral number of bytes, it is unspecified what happens to the extra bits
4511 that do not belong to the type, but they will typically be overwritten.</p>
4512
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4513<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4514<pre>
4515 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8c6c72d2007-10-22 05:10:05 +0000[diff] [blame]4516 store i32 3, i32* %ptr <i>; yields {void}</i>
4517 %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]4518</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4519
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4520</div>
4521
Chris Lattner2b7d3202002-05-06 03:03:22 +0000[diff] [blame]4522<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4523<h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4524 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4525</h4>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4526
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4527<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4528
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4529<h5>Syntax:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4530<pre>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4531 &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]4532 &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]4533</pre>
4534
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4535<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4536<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4537 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4538 It performs address calculation only and does not access memory.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4539
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4540<h5>Arguments:</h5>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4541<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnerc8eef442009-07-29 06:44:13 +0000[diff] [blame]4542 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4543 elements of the aggregate object are indexed. The interpretation of each
4544 index is dependent on the type being indexed into. The first index always
4545 indexes the pointer value given as the first argument, the second index
4546 indexes a value of the type pointed to (not necessarily the value directly
4547 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4548 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner61c70e92010-08-28 04:09:24 +0000[diff] [blame]4549 vectors, and structs. Note that subsequent types being indexed into
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4550 can never be pointers, since that would require loading the pointer before
4551 continuing calculation.</p>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4552
4553<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]4554 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattnerfdfeb692010-02-12 20:49:41 +0000[diff] [blame]4555 integer <b>constants</b> are allowed. When indexing into an array, pointer
4556 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]4557 constant.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4558
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4559<p>For example, let's consider a C code fragment and how it gets compiled to
4560 LLVM:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4561
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4562<pre class="doc_code">
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4563struct RT {
4564 char A;
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4565 int B[10][20];
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4566 char C;
4567};
4568struct ST {
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4569 int X;
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4570 double Y;
4571 struct RT Z;
4572};
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4573
Chris Lattnercabc8462007-05-29 15:43:56 +0000[diff] [blame]4574int *foo(struct ST *s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4575 return &amp;s[1].Z.B[5][13];
4576}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4577</pre>
4578
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4579<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4580
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]4581<pre class="doc_code">
Chris Lattnere7886e42009-01-11 20:53:49 +0000[diff] [blame]4582%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4583%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4584
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4585define i32* @foo(%ST* %s) {
Bill Wendling2f7a8b02007-05-29 09:04:49 +0000[diff] [blame]4586entry:
4587 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4588 ret i32* %reg
4589}
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4590</pre>
4591
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4592<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]4593<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]4594 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4595 }</tt>' type, a structure. The second index indexes into the third element
4596 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4597 i8 }</tt>' type, another structure. The third index indexes into the second
4598 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4599 array. The two dimensions of the array are subscripted into, yielding an
4600 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4601 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4602
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4603<p>Note that it is perfectly legal to index partially through a structure,
4604 returning a pointer to an inner element. Because of this, the LLVM code for
4605 the given testcase is equivalent to:</p>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4606
4607<pre>
Dan Gohman4df605b2009-07-25 02:23:48 +0000[diff] [blame]4608 define i32* @foo(%ST* %s) {
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4609 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen6f1cc772007-04-22 01:17:39 +0000[diff] [blame]4610 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4611 %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]4612 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4613 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4614 ret i32* %t5
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4615 }
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4616</pre>
Chris Lattnere67a9512005-06-24 17:22:57 +0000[diff] [blame]4617
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4618<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman27ef9972010-04-23 15:23:32 +0000[diff] [blame]4619 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4620 base pointer is not an <i>in bounds</i> address of an allocated object,
4621 or if any of the addresses that would be formed by successive addition of
4622 the offsets implied by the indices to the base address with infinitely
4623 precise arithmetic are not an <i>in bounds</i> address of that allocated
4624 object. The <i>in bounds</i> addresses for an allocated object are all
4625 the addresses that point into the object, plus the address one byte past
4626 the end.</p>
Dan Gohmandd8004d2009-07-27 21:53:46 +0000[diff] [blame]4627
4628<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4629 the base address with silently-wrapping two's complement arithmetic, and
4630 the result value of the <tt>getelementptr</tt> may be outside the object
4631 pointed to by the base pointer. The result value may not necessarily be
4632 used to access memory though, even if it happens to point into allocated
4633 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4634 section for more information.</p>
4635
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4636<p>The getelementptr instruction is often confusing. For some more insight into
4637 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner884a9702006-08-15 00:45:58 +0000[diff] [blame]4638
Chris Lattner7faa8832002-04-14 06:13:44 +0000[diff] [blame]4639<h5>Example:</h5>
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4640<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4641 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijmane49d0bc2008-10-13 13:44:15 +0000[diff] [blame]4642 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4643 <i>; yields i8*:vptr</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4644 %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]4645 <i>; yields i8*:eptr</i>
4646 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta9f805c22009-04-25 07:27:44 +0000[diff] [blame]4647 <i>; yields i32*:iptr</i>
Sanjiv Gupta16ffa802009-04-24 16:38:13 +0000[diff] [blame]4648 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4649</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4650
Chris Lattnerf74d5c72004-04-05 01:30:49 +0000[diff] [blame]4651</div>
Reid Spencer47ce1792006-11-09 21:15:49 +0000[diff] [blame]4652
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4653</div>
4654
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]4655<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4656<h3>
4657 <a name="convertops">Conversion Operations</a>
4658</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4659
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4660<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4661
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]4662<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4663 which all take a single operand and a type. They perform various bit
4664 conversions on the operand.</p>
4665
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4666<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4667<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4668 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4669</h4>
4670
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4671<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4672
4673<h5>Syntax:</h5>
4674<pre>
4675 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4676</pre>
4677
4678<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4679<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4680 type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4681
4682<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4683<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
4684 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4685 of the same number of integers.
4686 The bit size of the <tt>value</tt> must be larger than
4687 the bit size of the destination type, <tt>ty2</tt>.
4688 Equal sized types are not allowed.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4689
4690<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4691<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4692 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4693 source size must be larger than the destination size, <tt>trunc</tt> cannot
4694 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4695
4696<h5>Example:</h5>
4697<pre>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4698 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
4699 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4700 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
4701 %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]4702</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4703
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4704</div>
4705
4706<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4707<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4708 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4709</h4>
4710
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4711<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4712
4713<h5>Syntax:</h5>
4714<pre>
4715 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4716</pre>
4717
4718<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4719<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4720 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4721
4722
4723<h5>Arguments:</h5>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]4724<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
4725 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4726 of the same number of integers.
4727 The bit size of the <tt>value</tt> must be smaller than
4728 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4729 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4730
4731<h5>Semantics:</h5>
4732<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]4733 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4734
Reid Spencerb5929522007-01-12 15:46:11 +0000[diff] [blame]4735<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]4736
4737<h5>Example:</h5>
4738<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4739 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4740 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotemed9b9342011-02-20 12:37:50 +0000[diff] [blame]4741 %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]4742</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4743
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4744</div>
4745
4746<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4747<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4748 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4749</h4>
4750
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4751<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4752
4753<h5>Syntax:</h5>
4754<pre>
4755 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4756</pre>
4757
4758<h5>Overview:</h5>
4759<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4760
4761<h5>Arguments:</h5>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4762<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
4763 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4764 of the same number of integers.
4765 The bit size of the <tt>value</tt> must be smaller than
4766 the bit size of the destination type,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4767 <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4768
4769<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4770<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4771 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4772 of the type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4773
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4774<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]4775
4776<h5>Example:</h5>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4777<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4778 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4779 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem8c20ec52011-02-24 21:01:34 +0000[diff] [blame]4780 %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]4781</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4782
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4783</div>
4784
4785<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4786<h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4787 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4788</h4>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4789
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4790<div>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4791
4792<h5>Syntax:</h5>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4793<pre>
4794 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4795</pre>
4796
4797<h5>Overview:</h5>
4798<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4799 <tt>ty2</tt>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4800
4801<h5>Arguments:</h5>
4802<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4803 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4804 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]4805 <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]4806 <i>no-op cast</i>.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4807
4808<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4809<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4810 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4811 <a href="#t_floating">floating point</a> type. If the value cannot fit
4812 within the destination type, <tt>ty2</tt>, then the results are
4813 undefined.</p>
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4814
4815<h5>Example:</h5>
4816<pre>
4817 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4818 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4819</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4820
Reid Spencer3fa91b02006-11-09 21:48:10 +0000[diff] [blame]4821</div>
4822
4823<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4824<h4>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4825 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4826</h4>
4827
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4828<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4829
4830<h5>Syntax:</h5>
4831<pre>
4832 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4833</pre>
4834
4835<h5>Overview:</h5>
4836<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]4837 floating point value.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4838
4839<h5>Arguments:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4840<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4841 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4842 a <a href="#t_floating">floating point</a> type to cast it to. The source
4843 type must be smaller than the destination type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4844
4845<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4846<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4847 <a href="#t_floating">floating point</a> type to a larger
4848 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4849 used to make a <i>no-op cast</i> because it always changes bits. Use
4850 <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]4851
4852<h5>Example:</h5>
4853<pre>
Nick Lewycky5bb3ece2011-03-31 18:20:19 +0000[diff] [blame]4854 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
4855 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4856</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4857
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4858</div>
4859
4860<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4861<h4>
Reid Spencer24d6da52007-01-21 00:29:26 +0000[diff] [blame]4862 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4863</h4>
4864
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4865<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4866
4867<h5>Syntax:</h5>
4868<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4869 &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]4870</pre>
4871
4872<h5>Overview:</h5>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4873<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4874 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4875
4876<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4877<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4878 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4879 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4880 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4881 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4882
4883<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4884<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4885 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4886 towards zero) unsigned integer value. If the value cannot fit
4887 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4888
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4889<h5>Example:</h5>
4890<pre>
Reid Spencer1539a1c2007-07-31 14:40:14 +0000[diff] [blame]4891 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4892 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4893 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4894</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4895
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4896</div>
4897
4898<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4899<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4900 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4901</h4>
4902
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4903<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4904
4905<h5>Syntax:</h5>
4906<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4907 &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]4908</pre>
4909
4910<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4911<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4912 <a href="#t_floating">floating point</a> <tt>value</tt> to
4913 type <tt>ty2</tt>.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4914
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4915<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4916<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4917 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4918 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4919 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4920 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4921
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]4922<h5>Semantics:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]4923<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4924 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4925 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4926 the results are undefined.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4927
Chris Lattner33ba0d92001-07-09 00:26:23 +0000[diff] [blame]4928<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]4929<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]4930 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner88519042007-09-22 03:17:52 +0000[diff] [blame]4931 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greif6a292012009-10-28 09:21:30 +0000[diff] [blame]4932 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4933</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4934
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4935</div>
4936
4937<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4938<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4939 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4940</h4>
4941
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4942<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4943
4944<h5>Syntax:</h5>
4945<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4946 &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]4947</pre>
4948
4949<h5>Overview:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4950<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4951 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4952
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4953<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4954<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]4955 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4956 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4957 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4958 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4959
4960<h5>Semantics:</h5>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4961<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4962 integer quantity and converts it to the corresponding floating point
4963 value. If the value cannot fit in the floating point value, the results are
4964 undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4965
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4966<h5>Example:</h5>
4967<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]4968 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]4969 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4970</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4971
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4972</div>
4973
4974<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4975<h4>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4976 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]4977</h4>
4978
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]4979<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4980
4981<h5>Syntax:</h5>
4982<pre>
Reid Spencerd4448792006-11-09 23:03:26 +0000[diff] [blame]4983 &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]4984</pre>
4985
4986<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4987<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4988 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4989
4990<h5>Arguments:</h5>
Nate Begemanb348d182007-11-17 03:58:34 +0000[diff] [blame]4991<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]4992 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4993 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4994 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4995 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]4996
4997<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]4998<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4999 quantity and converts it to the corresponding floating point value. If the
5000 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5001
5002<h5>Example:</h5>
5003<pre>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5004 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5005 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5006</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5007
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5008</div>
5009
5010<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5011<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5012 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5013</h4>
5014
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5015<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5016
5017<h5>Syntax:</h5>
5018<pre>
5019 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5020</pre>
5021
5022<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5023<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
5024 the integer type <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5025
5026<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5027<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
5028 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
5029 <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]5030
5031<h5>Semantics:</h5>
5032<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5033 <tt>ty2</tt> by interpreting the pointer value as an integer and either
5034 truncating or zero extending that value to the size of the integer type. If
5035 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
5036 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
5037 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
5038 change.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5039
5040<h5>Example:</h5>
5041<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5042 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
5043 %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]5044</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5045
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5046</div>
5047
5048<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5049<h4>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5050 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5051</h4>
5052
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5053<div>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5054
5055<h5>Syntax:</h5>
5056<pre>
5057 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
5058</pre>
5059
5060<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5061<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
5062 pointer type, <tt>ty2</tt>.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5063
5064<h5>Arguments:</h5>
Duncan Sands8036ca42007-03-30 12:22:09 +0000[diff] [blame]5065<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5066 value to cast, and a type to cast it to, which must be a
5067 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5068
5069<h5>Semantics:</h5>
5070<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5071 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5072 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5073 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5074 than the size of a pointer then a zero extension is done. If they are the
5075 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5076
5077<h5>Example:</h5>
5078<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5079 %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]5080 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5081 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5082</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5083
Reid Spencer72679252006-11-11 21:00:47 +0000[diff] [blame]5084</div>
5085
5086<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5087<h4>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5088 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5089</h4>
5090
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5091<div>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5092
5093<h5>Syntax:</h5>
5094<pre>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5095 &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]5096</pre>
5097
5098<h5>Overview:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5099<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5100 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5101
5102<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5103<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5104 non-aggregate first class value, and a type to cast it to, which must also be
5105 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5106 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5107 identical. If the source type is a pointer, the destination type must also be
5108 a pointer. This instruction supports bitwise conversion of vectors to
5109 integers and to vectors of other types (as long as they have the same
5110 size).</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5111
5112<h5>Semantics:</h5>
Reid Spencer5c0ef472006-11-11 23:08:07 +0000[diff] [blame]5113<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5114 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5115 this conversion. The conversion is done as if the <tt>value</tt> had been
5116 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5117 be converted to other pointer types with this instruction. To convert
5118 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5119 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer9dee3ac2006-11-08 01:11:31 +0000[diff] [blame]5120
5121<h5>Example:</h5>
5122<pre>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5123 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5124 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5125 %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]5126</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5127
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5128</div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5129
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5130</div>
5131
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5132<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5133<h3>
5134 <a name="otherops">Other Operations</a>
5135</h3>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5136
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5137<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5138
5139<p>The instructions in this category are the "miscellaneous" instructions, which
5140 defy better classification.</p>
5141
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5142<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5143<h4>
5144 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5145</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5146
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5147<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5148
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5149<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5150<pre>
5151 &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]5152</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5153
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5154<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5155<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5156 boolean values based on comparison of its two integer, integer vector, or
5157 pointer operands.</p>
5158
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5159<h5>Arguments:</h5>
5160<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5161 the condition code indicating the kind of comparison to perform. It is not a
5162 value, just a keyword. The possible condition code are:</p>
5163
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5164<ol>
5165 <li><tt>eq</tt>: equal</li>
5166 <li><tt>ne</tt>: not equal </li>
5167 <li><tt>ugt</tt>: unsigned greater than</li>
5168 <li><tt>uge</tt>: unsigned greater or equal</li>
5169 <li><tt>ult</tt>: unsigned less than</li>
5170 <li><tt>ule</tt>: unsigned less or equal</li>
5171 <li><tt>sgt</tt>: signed greater than</li>
5172 <li><tt>sge</tt>: signed greater or equal</li>
5173 <li><tt>slt</tt>: signed less than</li>
5174 <li><tt>sle</tt>: signed less or equal</li>
5175</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5176
Chris Lattner3b19d652007-01-15 01:54:13 +0000[diff] [blame]5177<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5178 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5179 typed. They must also be identical types.</p>
5180
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5181<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5182<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5183 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5184 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]5185 result, as follows:</p>
5186
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5187<ol>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5188 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5189 <tt>false</tt> otherwise. No sign interpretation is necessary or
5190 performed.</li>
5191
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5192 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5193 <tt>false</tt> otherwise. No sign interpretation is necessary or
5194 performed.</li>
5195
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5196 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5197 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5198
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5199 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5200 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5201 to <tt>op2</tt>.</li>
5202
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5203 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5204 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5205
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5206 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5207 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5208
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5209 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5210 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5211
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5212 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5213 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5214 to <tt>op2</tt>.</li>
5215
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5216 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5217 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5218
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5219 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5220 <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]5221</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5222
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5223<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5224 values are compared as if they were integers.</p>
5225
5226<p>If the operands are integer vectors, then they are compared element by
5227 element. The result is an <tt>i1</tt> vector with the same number of elements
5228 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5229
5230<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5231<pre>
5232 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5233 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5234 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5235 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5236 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5237 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5238</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5239
5240<p>Note that the code generator does not yet support vector types with
5241 the <tt>icmp</tt> instruction.</p>
5242
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5243</div>
5244
5245<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5246<h4>
5247 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5248</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5249
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5250<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5251
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5252<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5253<pre>
5254 &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]5255</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5256
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5257<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5258<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5259 values based on comparison of its operands.</p>
5260
5261<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]5262(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5263
5264<p>If the operands are floating point vectors, then the result type is a vector
5265 of boolean with the same number of elements as the operands being
5266 compared.</p>
5267
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5268<h5>Arguments:</h5>
5269<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5270 the condition code indicating the kind of comparison to perform. It is not a
5271 value, just a keyword. The possible condition code are:</p>
5272
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5273<ol>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5274 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5275 <li><tt>oeq</tt>: ordered and equal</li>
5276 <li><tt>ogt</tt>: ordered and greater than </li>
5277 <li><tt>oge</tt>: ordered and greater than or equal</li>
5278 <li><tt>olt</tt>: ordered and less than </li>
5279 <li><tt>ole</tt>: ordered and less than or equal</li>
5280 <li><tt>one</tt>: ordered and not equal</li>
5281 <li><tt>ord</tt>: ordered (no nans)</li>
5282 <li><tt>ueq</tt>: unordered or equal</li>
5283 <li><tt>ugt</tt>: unordered or greater than </li>
5284 <li><tt>uge</tt>: unordered or greater than or equal</li>
5285 <li><tt>ult</tt>: unordered or less than </li>
5286 <li><tt>ule</tt>: unordered or less than or equal</li>
5287 <li><tt>une</tt>: unordered or not equal</li>
5288 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5289 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5290</ol>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5291
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5292<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5293 <i>unordered</i> means that either operand may be a QNAN.</p>
5294
5295<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5296 a <a href="#t_floating">floating point</a> type or
5297 a <a href="#t_vector">vector</a> of floating point type. They must have
5298 identical types.</p>
5299
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5300<h5>Semantics:</h5>
Gabor Greiffb224a22008-08-07 21:46:00 +0000[diff] [blame]5301<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5302 according to the condition code given as <tt>cond</tt>. If the operands are
5303 vectors, then the vectors are compared element by element. Each comparison
Nick Lewyckyec38da42009-09-27 00:45:11 +0000[diff] [blame]5304 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5305 follows:</p>
5306
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5307<ol>
5308 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5309
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5310 <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]5311 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5312
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5313 <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]5314 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5315
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5316 <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]5317 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5318
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5319 <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]5320 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5321
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5322 <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]5323 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5324
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5325 <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]5326 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5327
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5328 <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]5329
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5330 <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]5331 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5332
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5333 <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]5334 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5335
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5336 <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]5337 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5338
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5339 <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]5340 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5341
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5342 <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]5343 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5344
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5345 <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]5346 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5347
Reid Spencerb7f26282006-11-19 03:00:14 +0000[diff] [blame]5348 <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]5349
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5350 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5351</ol>
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5352
5353<h5>Example:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5354<pre>
5355 &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]5356 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5357 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5358 &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]5359</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5360
5361<p>Note that the code generator does not yet support vector types with
5362 the <tt>fcmp</tt> instruction.</p>
5363
Reid Spencerf3a70a62006-11-18 21:50:54 +0000[diff] [blame]5364</div>
5365
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5366<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5367<h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5368 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5369</h4>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5370
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5371<div>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5372
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5373<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5374<pre>
5375 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5376</pre>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5377
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5378<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5379<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5380 SSA graph representing the function.</p>
5381
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5382<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5383<p>The type of the incoming values is specified with the first type field. After
5384 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5385 one pair for each predecessor basic block of the current block. Only values
5386 of <a href="#t_firstclass">first class</a> type may be used as the value
5387 arguments to the PHI node. Only labels may be used as the label
5388 arguments.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5389
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5390<p>There must be no non-phi instructions between the start of a basic block and
5391 the PHI instructions: i.e. PHI instructions must be first in a basic
5392 block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5393
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5394<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5395 occur on the edge from the corresponding predecessor block to the current
5396 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5397 value on the same edge).</p>
Jay Foadd2449092009-06-03 10:20:10 +0000[diff] [blame]5398
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5399<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5400<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5401 specified by the pair corresponding to the predecessor basic block that
5402 executed just prior to the current block.</p>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5403
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5404<h5>Example:</h5>
Chris Lattner5568e942008-05-20 20:48:21 +0000[diff] [blame]5405<pre>
5406Loop: ; Infinite loop that counts from 0 on up...
5407 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5408 %nextindvar = add i32 %indvar, 1
5409 br label %Loop
5410</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5411
Reid Spencer2fd21e62006-11-08 01:18:52 +0000[diff] [blame]5412</div>
5413
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5414<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5415<h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5416 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5417</h4>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5418
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5419<div>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5420
5421<h5>Syntax:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5422<pre>
Dan Gohmanf72fb672008-09-09 01:02:47 +0000[diff] [blame]5423 &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>
5424
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5425 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5426</pre>
5427
5428<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5429<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5430 condition, without branching.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5431
5432
5433<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5434<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5435 values indicating the condition, and two values of the
5436 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5437 vectors and the condition is a scalar, then entire vectors are selected, not
5438 individual elements.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5439
5440<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5441<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5442 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5443
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5444<p>If the condition is a vector of i1, then the value arguments must be vectors
5445 of the same size, and the selection is done element by element.</p>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5446
5447<h5>Example:</h5>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5448<pre>
Reid Spencerc78f3372007-01-12 03:35:51 +0000[diff] [blame]5449 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5450</pre>
Dan Gohmanc766f722009-01-22 01:39:38 +0000[diff] [blame]5451
5452<p>Note that the code generator does not yet support conditions
5453 with vector type.</p>
5454
Chris Lattnercc37aae2004-03-12 05:50:16 +0000[diff] [blame]5455</div>
5456
Robert Bocchino05ccd702006-01-15 20:48:27 +0000[diff] [blame]5457<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5458<h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5459 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5460</h4>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5461
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5462<div>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5463
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5464<h5>Syntax:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5465<pre>
Devang Patel307e8ab2008-10-07 17:48:33 +0000[diff] [blame]5466 &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]5467</pre>
5468
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5469<h5>Overview:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5470<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5471
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5472<h5>Arguments:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5473<p>This instruction requires several arguments:</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5474
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5475<ol>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5476 <li>The optional "tail" marker indicates that the callee function does not
5477 access any allocas or varargs in the caller. Note that calls may be
5478 marked "tail" even if they do not occur before
5479 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5480 present, the function call is eligible for tail call optimization,
5481 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Chengdc444e92010-03-08 21:05:02 +0000[diff] [blame]5482 optimized into a jump</a>. The code generator may optimize calls marked
5483 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5484 sibling call optimization</a> when the caller and callee have
5485 matching signatures, or 2) forced tail call optimization when the
5486 following extra requirements are met:
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5487 <ul>
5488 <li>Caller and callee both have the calling
5489 convention <tt>fastcc</tt>.</li>
5490 <li>The call is in tail position (ret immediately follows call and ret
5491 uses value of call or is void).</li>
5492 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohmanfbbee8d2010-03-02 01:08:11 +0000[diff] [blame]5493 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5494 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5495 constraints are met.</a></li>
5496 </ul>
5497 </li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5498
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5499 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5500 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskin95fa80a2010-01-09 19:44:16 +0000[diff] [blame]5501 defaults to using C calling conventions. The calling convention of the
5502 call must match the calling convention of the target function, or else the
5503 behavior is undefined.</li>
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5504
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5505 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5506 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5507 '<tt>inreg</tt>' attributes are valid here.</li>
5508
5509 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5510 type of the return value. Functions that return no value are marked
5511 <tt><a href="#t_void">void</a></tt>.</li>
5512
5513 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5514 being invoked. The argument types must match the types implied by this
5515 signature. This type can be omitted if the function is not varargs and if
5516 the function type does not return a pointer to a function.</li>
5517
5518 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5519 be invoked. In most cases, this is a direct function invocation, but
5520 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5521 to function value.</li>
5522
5523 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner0724fbd2010-03-02 06:36:51 +0000[diff] [blame]5524 signature argument types and parameter attributes. All arguments must be
5525 of <a href="#t_firstclass">first class</a> type. If the function
5526 signature indicates the function accepts a variable number of arguments,
5527 the extra arguments can be specified.</li>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5528
5529 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5530 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5531 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner6536cfe2002-05-06 22:08:29 +0000[diff] [blame]5532</ol>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5533
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5534<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5535<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5536 a specified function, with its incoming arguments bound to the specified
5537 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5538 function, control flow continues with the instruction after the function
5539 call, and the return value of the function is bound to the result
5540 argument.</p>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5541
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]5542<h5>Example:</h5>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5543<pre>
Nick Lewyckydb7e3c92007-09-08 13:57:50 +0000[diff] [blame]5544 %retval = call i32 @test(i32 %argc)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]5545 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattner772fccf2008-03-21 17:24:17 +0000[diff] [blame]5546 %X = tail call i32 @foo() <i>; yields i32</i>
5547 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5548 call void %foo(i8 97 signext)
Devang Patelc3fc6df2008-03-10 20:49:15 +0000[diff] [blame]5549
5550 %struct.A = type { i32, i8 }
Devang Patelf642f472008-10-06 18:50:38 +0000[diff] [blame]5551 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmanb1e6b962008-10-04 19:00:07 +0000[diff] [blame]5552 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5553 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner85a350f2008-10-08 06:26:11 +0000[diff] [blame]5554 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmancb73d192008-10-07 10:03:45 +0000[diff] [blame]5555 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner2bff5242005-05-06 05:47:36 +0000[diff] [blame]5556</pre>
5557
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5558<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen9f8380b2009-09-25 17:04:42 +0000[diff] [blame]5559standard C99 library as being the C99 library functions, and may perform
5560optimizations or generate code for them under that assumption. This is
5561something we'd like to change in the future to provide better support for
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]5562freestanding environments and non-C-based languages.</p>
Dale Johannesen07de8d12009-09-24 18:38:21 +0000[diff] [blame]5563
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5564</div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5565
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5566<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5567<h4>
Chris Lattnerfb6977d2006-01-13 23:26:01 +0000[diff] [blame]5568 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5569</h4>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5570
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5571<div>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5572
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5573<h5>Syntax:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5574<pre>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5575 &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]5576</pre>
5577
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5578<h5>Overview:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5579<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5580 the "variable argument" area of a function call. It is used to implement the
5581 <tt>va_arg</tt> macro in C.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5582
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5583<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5584<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5585 argument. It returns a value of the specified argument type and increments
5586 the <tt>va_list</tt> to point to the next argument. The actual type
5587 of <tt>va_list</tt> is target specific.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5588
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5589<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5590<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5591 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5592 to the next argument. For more information, see the variable argument
5593 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5594
5595<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]5596 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5597 function.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5598
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5599<p><tt>va_arg</tt> is an LLVM instruction instead of
5600 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5601 argument.</p>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5602
Chris Lattner8d1a81d2003-10-18 05:51:36 +0000[diff] [blame]5603<h5>Example:</h5>
Chris Lattnere19d7a72004-09-27 21:51:25 +0000[diff] [blame]5604<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5605
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5606<p>Note that the code generator does not yet fully support va_arg on many
5607 targets. Also, it does not currently support va_arg with aggregate types on
5608 any target.</p>
Dan Gohmanf3e60bd2009-01-12 23:12:39 +0000[diff] [blame]5609
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5610</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5611
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5612</div>
5613
5614</div>
5615
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5616<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5617<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner261efe92003-11-25 01:02:51 +0000[diff] [blame]5618<!-- *********************************************************************** -->
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5619
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5620<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5621
5622<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5623 well known names and semantics and are required to follow certain
5624 restrictions. Overall, these intrinsics represent an extension mechanism for
5625 the LLVM language that does not require changing all of the transformations
5626 in LLVM when adding to the language (or the bitcode reader/writer, the
5627 parser, etc...).</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5628
John Criswellfc6b8952005-05-16 16:17:45 +0000[diff] [blame]5629<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5630 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5631 begin with this prefix. Intrinsic functions must always be external
5632 functions: you cannot define the body of intrinsic functions. Intrinsic
5633 functions may only be used in call or invoke instructions: it is illegal to
5634 take the address of an intrinsic function. Additionally, because intrinsic
5635 functions are part of the LLVM language, it is required if any are added that
5636 they be documented here.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5637
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5638<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5639 family of functions that perform the same operation but on different data
5640 types. Because LLVM can represent over 8 million different integer types,
5641 overloading is used commonly to allow an intrinsic function to operate on any
5642 integer type. One or more of the argument types or the result type can be
5643 overloaded to accept any integer type. Argument types may also be defined as
5644 exactly matching a previous argument's type or the result type. This allows
5645 an intrinsic function which accepts multiple arguments, but needs all of them
5646 to be of the same type, to only be overloaded with respect to a single
5647 argument or the result.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5648
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5649<p>Overloaded intrinsics will have the names of its overloaded argument types
5650 encoded into its function name, each preceded by a period. Only those types
5651 which are overloaded result in a name suffix. Arguments whose type is matched
5652 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5653 can take an integer of any width and returns an integer of exactly the same
5654 integer width. This leads to a family of functions such as
5655 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5656 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5657 suffix is required. Because the argument's type is matched against the return
5658 type, it does not require its own name suffix.</p>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]5659
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]5660<p>To learn how to add an intrinsic function, please see the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5661 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5662
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5663<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5664<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5665 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5666</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5667
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5668<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5669
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5670<p>Variable argument support is defined in LLVM with
5671 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5672 intrinsic functions. These functions are related to the similarly named
5673 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5674
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5675<p>All of these functions operate on arguments that use a target-specific value
5676 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5677 not define what this type is, so all transformations should be prepared to
5678 handle these functions regardless of the type used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5679
Chris Lattner374ab302006-05-15 17:26:46 +0000[diff] [blame]5680<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]5681 instruction and the variable argument handling intrinsic functions are
5682 used.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5683
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]5684<pre class="doc_code">
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5685define i32 @test(i32 %X, ...) {
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5686 ; Initialize variable argument processing
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5687 %ap = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5688 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5689 call void @llvm.va_start(i8* %ap2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5690
5691 ; Read a single integer argument
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5692 %tmp = va_arg i8** %ap, i32
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5693
5694 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5695 %aq = alloca i8*
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5696 %aq2 = bitcast i8** %aq to i8*
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5697 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5698 call void @llvm.va_end(i8* %aq2)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5699
5700 ; Stop processing of arguments.
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5701 call void @llvm.va_end(i8* %ap2)
Reid Spencerca86e162006-12-31 07:07:53 +0000[diff] [blame]5702 ret i32 %tmp
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5703}
Anton Korobeynikov5d522f32007-03-21 23:58:04 +0000[diff] [blame]5704
5705declare void @llvm.va_start(i8*)
5706declare void @llvm.va_copy(i8*, i8*)
5707declare void @llvm.va_end(i8*)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5708</pre>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5709
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5710<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5711<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5712 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5713</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5714
5715
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5716<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5717
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5718<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5719<pre>
5720 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5721</pre>
5722
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5723<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5724<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5725 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]5726
5727<h5>Arguments:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5728<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]5729
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5730<h5>Semantics:</h5>
Dan Gohman0e451ce2008-10-14 16:51:45 +0000[diff] [blame]5731<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]5732 macro available in C. In a target-dependent way, it initializes
5733 the <tt>va_list</tt> element to which the argument points, so that the next
5734 call to <tt>va_arg</tt> will produce the first variable argument passed to
5735 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5736 need to know the last argument of the function as the compiler can figure
5737 that out.</p>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5738
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5739</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5740
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5741<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5742<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5743 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5744</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5745
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5746<div>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5747
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5748<h5>Syntax:</h5>
5749<pre>
5750 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5751</pre>
5752
5753<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5754<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5755 which has been initialized previously
5756 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5757 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5758
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5759<h5>Arguments:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5760<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]5761
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5762<h5>Semantics:</h5>
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5763<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]5764 macro available in C. In a target-dependent way, it destroys
5765 the <tt>va_list</tt> element to which the argument points. Calls
5766 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5767 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5768 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerb75137d2007-01-08 07:55:15 +0000[diff] [blame]5769
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5770</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5771
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5772<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5773<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5774 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5775</h4>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5776
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5777<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5778
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5779<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5780<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5781 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5782</pre>
5783
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5784<h5>Overview:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5785<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5786 from the source argument list to the destination argument list.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5787
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5788<h5>Arguments:</h5>
Andrew Lenharth8bf607a2005-06-18 18:28:17 +0000[diff] [blame]5789<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]5790 The second argument is a pointer to a <tt>va_list</tt> element to copy
5791 from.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5792
Chris Lattnerd9ad5b32003-05-08 04:57:36 +0000[diff] [blame]5793<h5>Semantics:</h5>
Jeff Cohenb627eab2007-04-29 01:07:00 +0000[diff] [blame]5794<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]5795 macro available in C. In a target-dependent way, it copies the
5796 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5797 element. This intrinsic is necessary because
5798 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5799 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5800
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]5801</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]5802
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5803</div>
5804
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]5805<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5806<h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5807 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5808</h3>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5809
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5810<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5811
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5812<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattnerd3eda892008-08-05 18:29:16 +0000[diff] [blame]5813Collection</a> (GC) requires the implementation and generation of these
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5814intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5815roots on the stack</a>, as well as garbage collector implementations that
5816require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5817barriers. Front-ends for type-safe garbage collected languages should generate
5818these intrinsics to make use of the LLVM garbage collectors. For more details,
5819see <a href="GarbageCollection.html">Accurate Garbage Collection with
5820LLVM</a>.</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5821
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5822<p>The garbage collection intrinsics only operate on objects in the generic
5823 address space (address space zero).</p>
Christopher Lamb303dae92007-12-17 01:00:21 +0000[diff] [blame]5824
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5825<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5826<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5827 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5828</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5829
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5830<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5831
5832<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5833<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5834 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5835</pre>
5836
5837<h5>Overview:</h5>
John Criswell9e2485c2004-12-10 15:51:16 +0000[diff] [blame]5838<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]5839 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5840
5841<h5>Arguments:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5842<p>The first argument specifies the address of a stack object that contains the
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5843 root pointer. The second pointer (which must be either a constant or a
5844 global value address) contains the meta-data to be associated with the
5845 root.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5846
5847<h5>Semantics:</h5>
Chris Lattner05d67092008-04-24 05:59:56 +0000[diff] [blame]5848<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]5849 location. At compile-time, the code generator generates information to allow
5850 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5851 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5852 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5853
5854</div>
5855
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5856<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5857<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5858 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5859</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5860
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5861<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5862
5863<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5864<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5865 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5866</pre>
5867
5868<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5869<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5870 locations, allowing garbage collector implementations that require read
5871 barriers.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5872
5873<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5874<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]5875 allocated from the garbage collector. The first object is a pointer to the
5876 start of the referenced object, if needed by the language runtime (otherwise
5877 null).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5878
5879<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5880<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5881 instruction, but may be replaced with substantially more complex code by the
5882 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5883 may only be used in a function which <a href="#gc">specifies a GC
5884 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5885
5886</div>
5887
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5888<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5889<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5890 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5891</h4>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5892
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5893<div>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5894
5895<h5>Syntax:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5896<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]5897 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5898</pre>
5899
5900<h5>Overview:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5901<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5902 locations, allowing garbage collector implementations that require write
5903 barriers (such as generational or reference counting collectors).</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5904
5905<h5>Arguments:</h5>
Chris Lattner80626e92006-03-14 20:02:51 +0000[diff] [blame]5906<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]5907 object to store it to, and the third is the address of the field of Obj to
5908 store to. If the runtime does not require a pointer to the object, Obj may
5909 be null.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5910
5911<h5>Semantics:</h5>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5912<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5913 instruction, but may be replaced with substantially more complex code by the
5914 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5915 may only be used in a function which <a href="#gc">specifies a GC
5916 algorithm</a>.</p>
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5917
5918</div>
5919
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5920</div>
5921
Chris Lattnerd7923912004-05-23 21:06:01 +0000[diff] [blame]5922<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5923<h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5924 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5925</h3>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5926
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5927<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5928
5929<p>These intrinsics are provided by LLVM to expose special features that may
5930 only be implemented with code generator support.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5931
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5932<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5933<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5934 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5935</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5936
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5937<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5938
5939<h5>Syntax:</h5>
5940<pre>
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]5941 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5942</pre>
5943
5944<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5945<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5946 target-specific value indicating the return address of the current function
5947 or one of its callers.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5948
5949<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5950<p>The argument to this intrinsic indicates which function to return the address
5951 for. Zero indicates the calling function, one indicates its caller, etc.
5952 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5953
5954<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5955<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5956 indicating the return address of the specified call frame, or zero if it
5957 cannot be identified. The value returned by this intrinsic is likely to be
5958 incorrect or 0 for arguments other than zero, so it should only be used for
5959 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5960
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5961<p>Note that calling this intrinsic does not prevent function inlining or other
5962 aggressive transformations, so the value returned may not be that of the
5963 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5964
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5965</div>
5966
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5967<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5968<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]5969 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]5970</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5971
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]5972<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5973
5974<h5>Syntax:</h5>
5975<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]5976 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5977</pre>
5978
5979<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5980<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5981 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5982
5983<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5984<p>The argument to this intrinsic indicates which function to return the frame
5985 pointer for. Zero indicates the calling function, one indicates its caller,
5986 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5987
5988<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5989<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5990 indicating the frame address of the specified call frame, or zero if it
5991 cannot be identified. The value returned by this intrinsic is likely to be
5992 incorrect or 0 for arguments other than zero, so it should only be used for
5993 debugging purposes.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5994
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]5995<p>Note that calling this intrinsic does not prevent function inlining or other
5996 aggressive transformations, so the value returned may not be that of the
5997 obvious source-language caller.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5998
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]5999</div>
6000
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6001<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6002<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6003 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6004</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6005
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6006<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6007
6008<h5>Syntax:</h5>
6009<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6010 declare i8* @llvm.stacksave()
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6011</pre>
6012
6013<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6014<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
6015 of the function stack, for use
6016 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
6017 useful for implementing language features like scoped automatic variable
6018 sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6019
6020<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6021<p>This intrinsic returns a opaque pointer value that can be passed
6022 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
6023 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
6024 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
6025 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
6026 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
6027 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6028
6029</div>
6030
6031<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6032<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6033 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6034</h4>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6035
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6036<div>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6037
6038<h5>Syntax:</h5>
6039<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6040 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6041</pre>
6042
6043<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6044<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
6045 the function stack to the state it was in when the
6046 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
6047 executed. This is useful for implementing language features like scoped
6048 automatic variable sized arrays in C99.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6049
6050<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6051<p>See the description
6052 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6053
6054</div>
6055
Chris Lattner57e1f392006-01-13 02:03:13 +0000[diff] [blame]6056<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6057<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6058 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6059</h4>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6060
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6061<div>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6062
6063<h5>Syntax:</h5>
6064<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6065 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6066</pre>
6067
6068<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6069<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6070 insert a prefetch instruction if supported; otherwise, it is a noop.
6071 Prefetches have no effect on the behavior of the program but can change its
6072 performance characteristics.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6073
6074<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6075<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6076 specifier determining if the fetch should be for a read (0) or write (1),
6077 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
6078 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
6079 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6080
6081<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6082<p>This intrinsic does not modify the behavior of the program. In particular,
6083 prefetches cannot trap and do not produce a value. On targets that support
6084 this intrinsic, the prefetch can provide hints to the processor cache for
6085 better performance.</p>
Chris Lattner9a9d7ac2005-02-28 19:24:19 +0000[diff] [blame]6086
6087</div>
6088
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6089<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6090<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6091 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6092</h4>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6093
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6094<div>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6095
6096<h5>Syntax:</h5>
6097<pre>
Chris Lattner1df4f752007-09-21 17:30:40 +0000[diff] [blame]6098 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6099</pre>
6100
6101<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6102<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6103 Counter (PC) in a region of code to simulators and other tools. The method
6104 is target specific, but it is expected that the marker will use exported
6105 symbols to transmit the PC of the marker. The marker makes no guarantees
6106 that it will remain with any specific instruction after optimizations. It is
6107 possible that the presence of a marker will inhibit optimizations. The
6108 intended use is to be inserted after optimizations to allow correlations of
6109 simulation runs.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6110
6111<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6112<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6113
6114<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6115<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6116 not support this intrinsic may ignore it.</p>
Andrew Lenharth7f4ec3b2005-03-28 20:05:49 +0000[diff] [blame]6117
6118</div>
6119
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6120<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6121<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6122 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6123</h4>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6124
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6125<div>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6126
6127<h5>Syntax:</h5>
6128<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]6129 declare i64 @llvm.readcyclecounter()
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6130</pre>
6131
6132<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6133<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6134 counter register (or similar low latency, high accuracy clocks) on those
6135 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6136 should map to RPCC. As the backing counters overflow quickly (on the order
6137 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6138
6139<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6140<p>When directly supported, reading the cycle counter should not modify any
6141 memory. Implementations are allowed to either return a application specific
6142 value or a system wide value. On backends without support, this is lowered
6143 to a constant 0.</p>
Andrew Lenharth51b8d542005-11-11 16:47:30 +0000[diff] [blame]6144
6145</div>
6146
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6147</div>
6148
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6149<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6150<h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6151 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6152</h3>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6153
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6154<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6155
6156<p>LLVM provides intrinsics for a few important standard C library functions.
6157 These intrinsics allow source-language front-ends to pass information about
6158 the alignment of the pointer arguments to the code generator, providing
6159 opportunity for more efficient code generation.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6160
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6161<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6162<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6163 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6164</h4>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6165
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6166<div>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6167
6168<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6169<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]6170 integer bit width and for different address spaces. Not all targets support
6171 all bit widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6172
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6173<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6174 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]6175 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6176 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]6177 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6178</pre>
6179
6180<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6181<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6182 source location to the destination location.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6183
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6184<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6185 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6186 and the pointers can be in specified address spaces.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6187
6188<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6189
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6190<p>The first argument is a pointer to the destination, the second is a pointer
6191 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6192 number of bytes to copy, the fourth argument is the alignment of the
6193 source and destination locations, and the fifth is a boolean indicating a
6194 volatile access.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6195
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6196<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]6197 then the caller guarantees that both the source and destination pointers are
6198 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6199
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6200<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6201 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6202 The detailed access behavior is not very cleanly specified and it is unwise
6203 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6204
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6205<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6206
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6207<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6208 source location to the destination location, which are not allowed to
6209 overlap. It copies "len" bytes of memory over. If the argument is known to
6210 be aligned to some boundary, this can be specified as the fourth argument,
6211 otherwise it should be set to 0 or 1.</p>
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6212
Chris Lattner33aec9e2004-02-12 17:01:32 +0000[diff] [blame]6213</div>
6214
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6215<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6216<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6217 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6218</h4>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6219
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6220<div>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6221
6222<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6223<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]6224 width and for different address space. Not all targets support all bit
6225 widths however.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6226
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6227<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6228 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]6229 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6230 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]6231 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6232</pre>
6233
6234<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6235<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6236 source location to the destination location. It is similar to the
6237 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6238 overlap.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6239
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6240<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6241 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6242 and the pointers can be in specified address spaces.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6243
6244<h5>Arguments:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6245
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6246<p>The first argument is a pointer to the destination, the second is a pointer
6247 to the source. The third argument is an integer argument specifying the
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6248 number of bytes to copy, the fourth argument is the alignment of the
6249 source and destination locations, and the fifth is a boolean indicating a
6250 volatile access.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6251
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6252<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]6253 then the caller guarantees that the source and destination pointers are
6254 aligned to that boundary.</p>
Chris Lattner3301ced2004-02-12 21:18:15 +0000[diff] [blame]6255
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6256<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6257 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6258 The detailed access behavior is not very cleanly specified and it is unwise
6259 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6260
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6261<h5>Semantics:</h5>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6262
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6263<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6264 source location to the destination location, which may overlap. It copies
6265 "len" bytes of memory over. If the argument is known to be aligned to some
6266 boundary, this can be specified as the fourth argument, otherwise it should
6267 be set to 0 or 1.</p>
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6268
Chris Lattner0eb51b42004-02-12 18:10:10 +0000[diff] [blame]6269</div>
6270
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6271<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6272<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6273 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6274</h4>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6275
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6276<div>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6277
6278<h5>Syntax:</h5>
Chris Lattner824b9582008-11-21 16:42:48 +0000[diff] [blame]6279<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]6280 width and for different address spaces. However, not all targets support all
6281 bit widths.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6282
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6283<pre>
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6284 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6285 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanfe47aae2010-05-28 17:13:49 +0000[diff] [blame]6286 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattnerff35c3f2010-04-08 00:54:34 +0000[diff] [blame]6287 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6288</pre>
6289
6290<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6291<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6292 particular byte value.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6293
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6294<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6295 intrinsic does not return a value and takes extra alignment/volatile
6296 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6297
6298<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6299<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]6300 byte value with which to fill it, the third argument is an integer argument
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6301 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellcdcbbfc2010-07-30 16:30:28 +0000[diff] [blame]6302 alignment of the destination location.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6303
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]6304<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]6305 then the caller guarantees that the destination pointer is aligned to that
6306 boundary.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6307
Jeffrey Yasskin93e066d2010-04-26 21:21:24 +0000[diff] [blame]6308<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6309 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6310 The detailed access behavior is not very cleanly specified and it is unwise
6311 to depend on it.</p>
Chris Lattner9f636de2010-04-08 00:53:57 +0000[diff] [blame]6312
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6313<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6314<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6315 at the destination location. If the argument is known to be aligned to some
6316 boundary, this can be specified as the fourth argument, otherwise it should
6317 be set to 0 or 1.</p>
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6318
Chris Lattner10610642004-02-14 04:08:35 +0000[diff] [blame]6319</div>
6320
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6321<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6322<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6323 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6324</h4>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6325
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6326<div>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6327
6328<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6329<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6330 floating point or vector of floating point type. Not all targets support all
6331 types however.</p>
6332
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6333<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6334 declare float @llvm.sqrt.f32(float %Val)
6335 declare double @llvm.sqrt.f64(double %Val)
6336 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6337 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6338 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6339</pre>
6340
6341<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6342<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6343 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6344 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6345 behavior for negative numbers other than -0.0 (which allows for better
6346 optimization, because there is no need to worry about errno being
6347 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]6348
6349<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6350<p>The argument and return value are floating point numbers of the same
6351 type.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6352
6353<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6354<p>This function returns the sqrt of the specified operand if it is a
6355 nonnegative floating point number.</p>
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6356
Chris Lattnera4d74142005-07-21 01:29:16 +0000[diff] [blame]6357</div>
6358
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6359<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6360<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6361 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6362</h4>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6363
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6364<div>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6365
6366<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6367<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6368 floating point or vector of floating point type. Not all targets support all
6369 types however.</p>
6370
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6371<pre>
Dale Johannesen408f9c12007-10-02 17:47:38 +0000[diff] [blame]6372 declare float @llvm.powi.f32(float %Val, i32 %power)
6373 declare double @llvm.powi.f64(double %Val, i32 %power)
6374 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6375 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6376 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6377</pre>
6378
6379<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6380<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6381 specified (positive or negative) power. The order of evaluation of
6382 multiplications is not defined. When a vector of floating point type is
6383 used, the second argument remains a scalar integer value.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6384
6385<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6386<p>The second argument is an integer power, and the first is a value to raise to
6387 that power.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6388
6389<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6390<p>This function returns the first value raised to the second power with an
6391 unspecified sequence of rounding operations.</p>
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6392
Chris Lattnerf4d252d2006-09-08 06:34:02 +0000[diff] [blame]6393</div>
6394
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6395<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6396<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6397 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6398</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6399
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6400<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6401
6402<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6403<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6404 floating point or vector of floating point type. Not all targets support all
6405 types however.</p>
6406
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6407<pre>
6408 declare float @llvm.sin.f32(float %Val)
6409 declare double @llvm.sin.f64(double %Val)
6410 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6411 declare fp128 @llvm.sin.f128(fp128 %Val)
6412 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6413</pre>
6414
6415<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6416<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6417
6418<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6419<p>The argument and return value are floating point numbers of the same
6420 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6421
6422<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6423<p>This function returns the sine of the specified operand, returning the same
6424 values as the libm <tt>sin</tt> functions would, and handles error conditions
6425 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6426
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6427</div>
6428
6429<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6430<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6431 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6432</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6433
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6434<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6435
6436<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6437<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6438 floating point or vector of floating point type. Not all targets support all
6439 types however.</p>
6440
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6441<pre>
6442 declare float @llvm.cos.f32(float %Val)
6443 declare double @llvm.cos.f64(double %Val)
6444 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6445 declare fp128 @llvm.cos.f128(fp128 %Val)
6446 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6447</pre>
6448
6449<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6450<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6451
6452<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6453<p>The argument and return value are floating point numbers of the same
6454 type.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6455
6456<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6457<p>This function returns the cosine of the specified operand, returning the same
6458 values as the libm <tt>cos</tt> functions would, and handles error conditions
6459 in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6460
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6461</div>
6462
6463<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6464<h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6465 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6466</h4>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6467
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6468<div>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6469
6470<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6471<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6472 floating point or vector of floating point type. Not all targets support all
6473 types however.</p>
6474
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6475<pre>
6476 declare float @llvm.pow.f32(float %Val, float %Power)
6477 declare double @llvm.pow.f64(double %Val, double %Power)
6478 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6479 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6480 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6481</pre>
6482
6483<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6484<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6485 specified (positive or negative) power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6486
6487<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6488<p>The second argument is a floating point power, and the first is a value to
6489 raise to that power.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6490
6491<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6492<p>This function returns the first value raised to the second power, returning
6493 the same values as the libm <tt>pow</tt> functions would, and handles error
6494 conditions in the same way.</p>
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6495
Dan Gohman91c284c2007-10-15 20:30:11 +0000[diff] [blame]6496</div>
6497
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6498</div>
6499
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6500<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6501<h3>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6502 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6503</h3>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6504
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6505<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6506
6507<p>LLVM provides intrinsics for a few important bit manipulation operations.
6508 These allow efficient code generation for some algorithms.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6509
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6510<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6511<h4>
Reid Spencera3e435f2007-04-04 02:42:35 +0000[diff] [blame]6512 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6513</h4>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6514
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6515<div>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6516
6517<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6518<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6519 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6520
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6521<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6522 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6523 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6524 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6525</pre>
6526
6527<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6528<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6529 values with an even number of bytes (positive multiple of 16 bits). These
6530 are useful for performing operations on data that is not in the target's
6531 native byte order.</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6532
6533<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6534<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6535 and low byte of the input i16 swapped. Similarly,
6536 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6537 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6538 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6539 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6540 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6541 more, respectively).</p>
Nate Begeman7e36c472006-01-13 23:26:38 +0000[diff] [blame]6542
6543</div>
6544
6545<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6546<h4>
Reid Spencer0b118202006-01-16 21:12:35 +0000[diff] [blame]6547 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6548</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6549
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6550<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6551
6552<h5>Syntax:</h5>
Reid Spencer409e28f2007-04-01 08:04:23 +0000[diff] [blame]6553<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6554 width. Not all targets support all bit widths however.</p>
6555
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6556<pre>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6557 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6558 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6559 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6560 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6561 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6562</pre>
6563
6564<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6565<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6566 in a value.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6567
6568<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6569<p>The only argument is the value to be counted. The argument may be of any
6570 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6571
6572<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6573<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6574
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6575</div>
6576
6577<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6578<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6579 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6580</h4>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6581
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6582<div>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6583
6584<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6585<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
6586 integer bit width. Not all targets support all bit widths however.</p>
6587
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6588<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6589 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6590 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6591 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6592 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6593 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6594</pre>
6595
6596<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6597<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6598 leading zeros in a variable.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6599
6600<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6601<p>The only argument is the value to be counted. The argument may be of any
6602 integer type. The return type must match the argument type.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6603
6604<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6605<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
6606 zeros in a variable. If the src == 0 then the result is the size in bits of
6607 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6608
Andrew Lenharthec370fd2005-05-03 18:01:48 +0000[diff] [blame]6609</div>
Chris Lattner32006282004-06-11 02:28:03 +0000[diff] [blame]6610
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6611<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6612<h4>
Chris Lattner8a886be2006-01-16 22:34:14 +0000[diff] [blame]6613 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6614</h4>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6615
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6616<div>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6617
6618<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6619<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
6620 integer bit width. Not all targets support all bit widths however.</p>
6621
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6622<pre>
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6623 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6624 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovec43a062007-03-22 00:02:17 +0000[diff] [blame]6625 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth69940402007-08-04 01:51:18 +0000[diff] [blame]6626 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6627 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6628</pre>
6629
6630<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6631<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6632 trailing zeros.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6633
6634<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6635<p>The only argument is the value to be counted. The argument may be of any
6636 integer type. The return type must match the argument type.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6637
6638<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6639<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
6640 zeros in a variable. If the src == 0 then the result is the size in bits of
6641 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6642
Chris Lattnereff29ab2005-05-15 19:39:26 +0000[diff] [blame]6643</div>
6644
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6645</div>
6646
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6647<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6648<h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6649 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6650</h3>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6651
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6652<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6653
6654<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingda01af72009-02-08 04:04:40 +0000[diff] [blame]6655
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6656<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6657<h4>
6658 <a name="int_sadd_overflow">
6659 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
6660 </a>
6661</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6662
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6663<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6664
6665<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6666<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]6667 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6668
6669<pre>
6670 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6671 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6672 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6673</pre>
6674
6675<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6676<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6677 a signed addition of the two arguments, and indicate whether an overflow
6678 occurred during the signed summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6679
6680<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6681<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]6682 be of integer types of any bit width, but they must have the same bit
6683 width. The second element of the result structure must be of
6684 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6685 undergo signed addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6686
6687<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6688<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6689 a signed addition of the two variables. They return a structure &mdash; the
6690 first element of which is the signed summation, and the second element of
6691 which is a bit specifying if the signed summation resulted in an
6692 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6693
6694<h5>Examples:</h5>
6695<pre>
6696 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6697 %sum = extractvalue {i32, i1} %res, 0
6698 %obit = extractvalue {i32, i1} %res, 1
6699 br i1 %obit, label %overflow, label %normal
6700</pre>
6701
6702</div>
6703
6704<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6705<h4>
6706 <a name="int_uadd_overflow">
6707 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
6708 </a>
6709</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6710
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6711<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6712
6713<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6714<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]6715 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6716
6717<pre>
6718 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6719 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6720 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6721</pre>
6722
6723<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6724<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6725 an unsigned addition of the two arguments, and indicate whether a carry
6726 occurred during the unsigned summation.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6727
6728<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6729<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]6730 be of integer types of any bit width, but they must have the same bit
6731 width. The second element of the result structure must be of
6732 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6733 undergo unsigned addition.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6734
6735<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6736<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6737 an unsigned addition of the two arguments. They return a structure &mdash;
6738 the first element of which is the sum, and the second element of which is a
6739 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6740
6741<h5>Examples:</h5>
6742<pre>
6743 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6744 %sum = extractvalue {i32, i1} %res, 0
6745 %obit = extractvalue {i32, i1} %res, 1
6746 br i1 %obit, label %carry, label %normal
6747</pre>
6748
6749</div>
6750
6751<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6752<h4>
6753 <a name="int_ssub_overflow">
6754 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
6755 </a>
6756</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6757
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6758<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6759
6760<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6761<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]6762 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6763
6764<pre>
6765 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6766 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6767 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6768</pre>
6769
6770<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6771<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6772 a signed subtraction of the two arguments, and indicate whether an overflow
6773 occurred during the signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6774
6775<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6776<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]6777 be of integer types of any bit width, but they must have the same bit
6778 width. The second element of the result structure must be of
6779 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6780 undergo signed subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6781
6782<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6783<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6784 a signed subtraction of the two arguments. They return a structure &mdash;
6785 the first element of which is the subtraction, and the second element of
6786 which is a bit specifying if the signed subtraction resulted in an
6787 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6788
6789<h5>Examples:</h5>
6790<pre>
6791 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6792 %sum = extractvalue {i32, i1} %res, 0
6793 %obit = extractvalue {i32, i1} %res, 1
6794 br i1 %obit, label %overflow, label %normal
6795</pre>
6796
6797</div>
6798
6799<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6800<h4>
6801 <a name="int_usub_overflow">
6802 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
6803 </a>
6804</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6805
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6806<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6807
6808<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6809<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]6810 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6811
6812<pre>
6813 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6814 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6815 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6816</pre>
6817
6818<h5>Overview:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6819<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6820 an unsigned subtraction of the two arguments, and indicate whether an
6821 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6822
6823<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6824<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]6825 be of integer types of any bit width, but they must have the same bit
6826 width. The second element of the result structure must be of
6827 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6828 undergo unsigned subtraction.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6829
6830<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6831<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6832 an unsigned subtraction of the two arguments. They return a structure &mdash;
6833 the first element of which is the subtraction, and the second element of
6834 which is a bit specifying if the unsigned subtraction resulted in an
6835 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6836
6837<h5>Examples:</h5>
6838<pre>
6839 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6840 %sum = extractvalue {i32, i1} %res, 0
6841 %obit = extractvalue {i32, i1} %res, 1
6842 br i1 %obit, label %overflow, label %normal
6843</pre>
6844
6845</div>
6846
6847<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6848<h4>
6849 <a name="int_smul_overflow">
6850 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
6851 </a>
6852</h4>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6853
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6854<div>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6855
6856<h5>Syntax:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6857<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]6858 on any integer bit width.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6859
6860<pre>
6861 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6862 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6863 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6864</pre>
6865
6866<h5>Overview:</h5>
6867
6868<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6869 a signed multiplication of the two arguments, and indicate whether an
6870 overflow occurred during the signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6871
6872<h5>Arguments:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6873<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]6874 be of integer types of any bit width, but they must have the same bit
6875 width. The second element of the result structure must be of
6876 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6877 undergo signed multiplication.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6878
6879<h5>Semantics:</h5>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6880<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6881 a signed multiplication of the two arguments. They return a structure &mdash;
6882 the first element of which is the multiplication, and the second element of
6883 which is a bit specifying if the signed multiplication resulted in an
6884 overflow.</p>
Bill Wendlingac1df8e2009-02-08 01:40:31 +0000[diff] [blame]6885
6886<h5>Examples:</h5>
6887<pre>
6888 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6889 %sum = extractvalue {i32, i1} %res, 0
6890 %obit = extractvalue {i32, i1} %res, 1
6891 br i1 %obit, label %overflow, label %normal
6892</pre>
6893
Reid Spencerf86037f2007-04-11 23:23:49 +0000[diff] [blame]6894</div>
6895
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6896<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6897<h4>
6898 <a name="int_umul_overflow">
6899 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
6900 </a>
6901</h4>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6902
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6903<div>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6904
6905<h5>Syntax:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6906<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]6907 on any integer bit width.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6908
6909<pre>
6910 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6911 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6912 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6913</pre>
6914
6915<h5>Overview:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6916<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6917 a unsigned multiplication of the two arguments, and indicate whether an
6918 overflow occurred during the unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6919
6920<h5>Arguments:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6921<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]6922 be of integer types of any bit width, but they must have the same bit
6923 width. The second element of the result structure must be of
6924 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6925 undergo unsigned multiplication.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6926
6927<h5>Semantics:</h5>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6928<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]6929 an unsigned multiplication of the two arguments. They return a structure
6930 &mdash; the first element of which is the multiplication, and the second
6931 element of which is a bit specifying if the unsigned multiplication resulted
6932 in an overflow.</p>
Bill Wendling41b485c2009-02-08 23:00:09 +0000[diff] [blame]6933
6934<h5>Examples:</h5>
6935<pre>
6936 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6937 %sum = extractvalue {i32, i1} %res, 0
6938 %obit = extractvalue {i32, i1} %res, 1
6939 br i1 %obit, label %overflow, label %normal
6940</pre>
6941
6942</div>
6943
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6944</div>
6945
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]6946<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6947<h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6948 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6949</h3>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6950
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6951<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6952
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6953<p>Half precision floating point is a storage-only format. This means that it is
6954 a dense encoding (in memory) but does not support computation in the
6955 format.</p>
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6956
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6957<p>This means that code must first load the half-precision floating point
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6958 value as an i16, then convert it to float with <a
6959 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
6960 Computation can then be performed on the float value (including extending to
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6961 double etc). To store the value back to memory, it is first converted to
6962 float if needed, then converted to i16 with
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6963 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
6964 storing as an i16 value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6965
6966<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]6967<h4>
6968 <a name="int_convert_to_fp16">
6969 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
6970 </a>
6971</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6972
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]6973<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6974
6975<h5>Syntax:</h5>
6976<pre>
6977 declare i16 @llvm.convert.to.fp16(f32 %a)
6978</pre>
6979
6980<h5>Overview:</h5>
6981<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
6982 a conversion from single precision floating point format to half precision
6983 floating point format.</p>
6984
6985<h5>Arguments:</h5>
6986<p>The intrinsic function contains single argument - the value to be
6987 converted.</p>
6988
6989<h5>Semantics:</h5>
6990<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
6991 a conversion from single precision floating point format to half precision
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]6992 floating point format. The return value is an <tt>i16</tt> which
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]6993 contains the converted number.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]6994
6995<h5>Examples:</h5>
6996<pre>
6997 %res = call i16 @llvm.convert.to.fp16(f32 %a)
6998 store i16 %res, i16* @x, align 2
6999</pre>
7000
7001</div>
7002
7003<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7004<h4>
7005 <a name="int_convert_from_fp16">
7006 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7007 </a>
7008</h4>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7009
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7010<div>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7011
7012<h5>Syntax:</h5>
7013<pre>
7014 declare f32 @llvm.convert.from.fp16(i16 %a)
7015</pre>
7016
7017<h5>Overview:</h5>
7018<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7019 a conversion from half precision floating point format to single precision
7020 floating point format.</p>
7021
7022<h5>Arguments:</h5>
7023<p>The intrinsic function contains single argument - the value to be
7024 converted.</p>
7025
7026<h5>Semantics:</h5>
7027<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner0cec9c82010-03-15 04:12:21 +0000[diff] [blame]7028 conversion from half single precision floating point format to single
Chris Lattner82c3dc62010-03-14 23:03:31 +0000[diff] [blame]7029 precision floating point format. The input half-float value is represented by
7030 an <tt>i16</tt> value.</p>
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7031
7032<h5>Examples:</h5>
7033<pre>
7034 %a = load i16* @x, align 2
7035 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7036</pre>
7037
7038</div>
7039
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7040</div>
7041
Anton Korobeynikovf02e7302010-03-14 18:42:47 +0000[diff] [blame]7042<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7043<h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7044 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7045</h3>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7046
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7047<div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7048
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7049<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7050 prefix), are described in
7051 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7052 Level Debugging</a> document.</p>
7053
7054</div>
Chris Lattner8ff75902004-01-06 05:31:32 +0000[diff] [blame]7055
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7056<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7057<h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7058 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7059</h3>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7060
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7061<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7062
7063<p>The LLVM exception handling intrinsics (which all start with
7064 <tt>llvm.eh.</tt> prefix), are described in
7065 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7066 Handling</a> document.</p>
7067
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7068</div>
7069
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7070<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7071<h3>
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7072 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7073</h3>
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7074
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7075<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7076
7077<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohmanff235352010-07-02 23:18:08 +0000[diff] [blame]7078 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7079 The result is a callable
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7080 function pointer lacking the nest parameter - the caller does not need to
7081 provide a value for it. Instead, the value to use is stored in advance in a
7082 "trampoline", a block of memory usually allocated on the stack, which also
7083 contains code to splice the nest value into the argument list. This is used
7084 to implement the GCC nested function address extension.</p>
7085
7086<p>For example, if the function is
7087 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7088 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7089 follows:</p>
7090
Benjamin Kramer26fe25f2010-07-13 12:26:09 +0000[diff] [blame]7091<pre class="doc_code">
Duncan Sandsf7331b32007-09-11 14:10:23 +0000[diff] [blame]7092 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7093 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7094 %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]7095 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7096</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7097
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7098<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7099 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7100
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7101<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7102<h4>
7103 <a name="int_it">
7104 '<tt>llvm.init.trampoline</tt>' Intrinsic
7105 </a>
7106</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7107
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7108<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7109
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7110<h5>Syntax:</h5>
7111<pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7112 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]7113</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7114
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7115<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7116<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7117 function pointer suitable for executing it.</p>
7118
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7119<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7120<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7121 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7122 sufficiently aligned block of memory; this memory is written to by the
7123 intrinsic. Note that the size and the alignment are target-specific - LLVM
7124 currently provides no portable way of determining them, so a front-end that
7125 generates this intrinsic needs to have some target-specific knowledge.
7126 The <tt>func</tt> argument must hold a function bitcast to
7127 an <tt>i8*</tt>.</p>
7128
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7129<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7130<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7131 dependent code, turning it into a function. A pointer to this function is
7132 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7133 function pointer type</a> before being called. The new function's signature
7134 is the same as that of <tt>func</tt> with any arguments marked with
7135 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7136 is allowed, and it must be of pointer type. Calling the new function is
7137 equivalent to calling <tt>func</tt> with the same argument list, but
7138 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7139 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7140 by <tt>tramp</tt> is modified, then the effect of any later call to the
7141 returned function pointer is undefined.</p>
7142
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7143</div>
7144
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7145</div>
7146
Duncan Sands36397f52007-07-27 12:58:54 +0000[diff] [blame]7147<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7148<h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7149 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7150</h3>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7151
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7152<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7153
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7154<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7155 hardware constructs for atomic operations and memory synchronization. This
7156 provides an interface to the hardware, not an interface to the programmer. It
7157 is aimed at a low enough level to allow any programming models or APIs
7158 (Application Programming Interfaces) which need atomic behaviors to map
7159 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7160 hardware provides a "universal IR" for source languages, it also provides a
7161 starting point for developing a "universal" atomic operation and
7162 synchronization IR.</p>
7163
7164<p>These do <em>not</em> form an API such as high-level threading libraries,
7165 software transaction memory systems, atomic primitives, and intrinsic
7166 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7167 application libraries. The hardware interface provided by LLVM should allow
7168 a clean implementation of all of these APIs and parallel programming models.
7169 No one model or paradigm should be selected above others unless the hardware
7170 itself ubiquitously does so.</p>
7171
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7172<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7173<h4>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7174 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7175</h4>
7176
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7177<div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7178<h5>Syntax:</h5>
7179<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7180 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]7181</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7182
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7183<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7184<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7185 specific pairs of memory access types.</p>
7186
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7187<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7188<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7189 The first four arguments enables a specific barrier as listed below. The
Dan Gohmanb55a1ee2010-03-01 17:41:39 +0000[diff] [blame]7190 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7191 memory.</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7192
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7193<ul>
7194 <li><tt>ll</tt>: load-load barrier</li>
7195 <li><tt>ls</tt>: load-store barrier</li>
7196 <li><tt>sl</tt>: store-load barrier</li>
7197 <li><tt>ss</tt>: store-store barrier</li>
7198 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7199</ul>
7200
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7201<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7202<p>This intrinsic causes the system to enforce some ordering constraints upon
7203 the loads and stores of the program. This barrier does not
7204 indicate <em>when</em> any events will occur, it only enforces
7205 an <em>order</em> in which they occur. For any of the specified pairs of load
7206 and store operations (f.ex. load-load, or store-load), all of the first
7207 operations preceding the barrier will complete before any of the second
7208 operations succeeding the barrier begin. Specifically the semantics for each
7209 pairing is as follows:</p>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7210
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7211<ul>
7212 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7213 after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7214 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7215 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7216 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7217 store after the barrier begins.</li>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7218 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7219 load after the barrier begins.</li>
7220</ul>
7221
7222<p>These semantics are applied with a logical "and" behavior when more than one
7223 is enabled in a single memory barrier intrinsic.</p>
7224
7225<p>Backends may implement stronger barriers than those requested when they do
7226 not support as fine grained a barrier as requested. Some architectures do
7227 not need all types of barriers and on such architectures, these become
7228 noops.</p>
7229
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7230<h5>Example:</h5>
7231<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7232%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7233%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7234 store i32 4, %ptr
7235
7236%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7237 call void @llvm.memory.barrier(i1 false, i1 true, i1 false, i1 false)
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7238 <i>; guarantee the above finishes</i>
7239 store i32 8, %ptr <i>; before this begins</i>
7240</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7241
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7242</div>
7243
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7244<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7245<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7246 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7247</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7248
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7249<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7250
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7251<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7252<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7253 any integer bit width and for different address spaces. Not all targets
7254 support all bit widths however.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7255
7256<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7257 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7258 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7259 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7260 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]7261</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7262
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7263<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7264<p>This loads a value in memory and compares it to a given value. If they are
7265 equal, it stores a new value into the memory.</p>
7266
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7267<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7268<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7269 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7270 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7271 this integer type. While any bit width integer may be used, targets may only
7272 lower representations they support in hardware.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7273
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7274<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7275<p>This entire intrinsic must be executed atomically. It first loads the value
7276 in memory pointed to by <tt>ptr</tt> and compares it with the
7277 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7278 memory. The loaded value is yielded in all cases. This provides the
7279 equivalent of an atomic compare-and-swap operation within the SSA
7280 framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7281
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7282<h5>Examples:</h5>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7283<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7284%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7285%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7286 store i32 4, %ptr
7287
7288%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7289%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7290 <i>; yields {i32}:result1 = 4</i>
7291%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7292%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7293
7294%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7295%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7296 <i>; yields {i32}:result2 = 8</i>
7297%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7298
7299%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7300</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7301
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7302</div>
7303
7304<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7305<h4>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7306 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7307</h4>
7308
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7309<div>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7310<h5>Syntax:</h5>
7311
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7312<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7313 integer bit width. Not all targets support all bit widths however.</p>
7314
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7315<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7316 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7317 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7318 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7319 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]7320</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7321
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7322<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7323<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7324 the value from memory. It then stores the value in <tt>val</tt> in the memory
7325 at <tt>ptr</tt>.</p>
7326
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7327<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7328<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7329 the <tt>val</tt> argument and the result must be integers of the same bit
7330 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7331 integer type. The targets may only lower integer representations they
7332 support.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7333
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7334<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7335<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7336 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7337 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7338
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7339<h5>Examples:</h5>
7340<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7341%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7342%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7343 store i32 4, %ptr
7344
7345%val1 = add i32 4, 4
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7346%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7347 <i>; yields {i32}:result1 = 4</i>
7348%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7349%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7350
7351%val2 = add i32 1, 1
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7352%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7353 <i>; yields {i32}:result2 = 8</i>
7354
7355%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7356%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7357</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7358
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7359</div>
7360
7361<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7362<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7363 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7364</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7365
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7366<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7367
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7368<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7369<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7370 any integer bit width. Not all targets support all bit widths however.</p>
7371
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7372<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7373 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7374 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7375 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7376 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]7377</pre>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7378
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7379<h5>Overview:</h5>
7380<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7381 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7382
7383<h5>Arguments:</h5>
7384<p>The intrinsic takes two arguments, the first a pointer to an integer value
7385 and the second an integer value. The result is also an integer value. These
7386 integer types can have any bit width, but they must all have the same bit
7387 width. The targets may only lower integer representations they support.</p>
7388
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7389<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7390<p>This intrinsic does a series of operations atomically. It first loads the
7391 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7392 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]7393
7394<h5>Examples:</h5>
7395<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7396%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7397%ptr = bitcast i8* %mallocP to i32*
7398 store i32 4, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7399%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7400 <i>; yields {i32}:result1 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7401%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7402 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7403%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7404 <i>; yields {i32}:result3 = 10</i>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7405%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7406</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7407
Andrew Lenharthab0b9492008-02-21 06:45:13 +0000[diff] [blame]7408</div>
7409
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7410<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7411<h4>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7412 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7413</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7414
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7415<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7416
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7417<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7418<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7419 any integer bit width and for different address spaces. Not all targets
7420 support all bit widths however.</p>
7421
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7422<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7423 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7424 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7425 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7426 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]7427</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7428
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7429<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7430<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7431 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7432
7433<h5>Arguments:</h5>
7434<p>The intrinsic takes two arguments, the first a pointer to an integer value
7435 and the second an integer value. The result is also an integer value. These
7436 integer types can have any bit width, but they must all have the same bit
7437 width. The targets may only lower integer representations they support.</p>
7438
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7439<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7440<p>This intrinsic does a series of operations atomically. It first loads the
7441 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7442 result to <tt>ptr</tt>. It yields the original value stored
7443 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7444
7445<h5>Examples:</h5>
7446<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7447%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7448%ptr = bitcast i8* %mallocP to i32*
7449 store i32 8, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7450%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7451 <i>; yields {i32}:result1 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7452%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7453 <i>; yields {i32}:result2 = 4</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7454%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7455 <i>; yields {i32}:result3 = 2</i>
7456%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7457</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7458
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7459</div>
7460
7461<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7462<h4>
7463 <a name="int_atomic_load_and">
7464 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7465 </a>
7466 <br>
7467 <a name="int_atomic_load_nand">
7468 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7469 </a>
7470 <br>
7471 <a name="int_atomic_load_or">
7472 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7473 </a>
7474 <br>
7475 <a name="int_atomic_load_xor">
7476 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7477 </a>
7478</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7479
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7480<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7481
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7482<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7483<p>These are overloaded intrinsics. You can
7484 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7485 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7486 bit width and for different address spaces. Not all targets support all bit
7487 widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7488
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7489<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7490 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7491 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7492 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7493 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]7494</pre>
7495
7496<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7497 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7498 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7499 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7500 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]7501</pre>
7502
7503<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7504 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7505 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7506 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7507 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]7508</pre>
7509
7510<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7511 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7512 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7513 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7514 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]7515</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7516
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7517<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7518<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7519 the value stored in memory at <tt>ptr</tt>. It yields the original value
7520 at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7521
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7522<h5>Arguments:</h5>
7523<p>These intrinsics take two arguments, the first a pointer to an integer value
7524 and the second an integer value. The result is also an integer value. These
7525 integer types can have any bit width, but they must all have the same bit
7526 width. The targets may only lower integer representations they support.</p>
7527
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7528<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7529<p>These intrinsics does a series of operations atomically. They first load the
7530 value stored at <tt>ptr</tt>. They then do the bitwise
7531 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7532 original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7533
7534<h5>Examples:</h5>
7535<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7536%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7537%ptr = bitcast i8* %mallocP to i32*
7538 store i32 0x0F0F, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7539%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7540 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7541%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7542 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7543%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7544 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7545%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7546 <i>; yields {i32}:result3 = FF</i>
7547%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7548</pre>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7549
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7550</div>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7551
7552<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7553<h4>
7554 <a name="int_atomic_load_max">
7555 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
7556 </a>
7557 <br>
7558 <a name="int_atomic_load_min">
7559 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
7560 </a>
7561 <br>
7562 <a name="int_atomic_load_umax">
7563 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
7564 </a>
7565 <br>
7566 <a name="int_atomic_load_umin">
7567 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
7568 </a>
7569</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7570
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7571<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7572
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7573<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7574<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7575 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7576 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7577 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7578
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7579<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7580 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7581 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7582 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7583 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]7584</pre>
7585
7586<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7587 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7588 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7589 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7590 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]7591</pre>
7592
7593<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7594 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7595 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7596 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7597 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]7598</pre>
7599
7600<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7601 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7602 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7603 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7604 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]7605</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7606
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7607<h5>Overview:</h5>
Eric Christopher6c7e8a02009-12-05 02:46:03 +0000[diff] [blame]7608<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7609 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7610 original value at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7611
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7612<h5>Arguments:</h5>
7613<p>These intrinsics take two arguments, the first a pointer to an integer value
7614 and the second an integer value. The result is also an integer value. These
7615 integer types can have any bit width, but they must all have the same bit
7616 width. The targets may only lower integer representations they support.</p>
7617
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7618<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7619<p>These intrinsics does a series of operations atomically. They first load the
7620 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7621 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7622 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7623
7624<h5>Examples:</h5>
7625<pre>
Victor Hernandez2fee2942009-10-26 23:44:29 +0000[diff] [blame]7626%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7627%ptr = bitcast i8* %mallocP to i32*
7628 store i32 7, %ptr
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7629%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7630 <i>; yields {i32}:result0 = 7</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7631%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7632 <i>; yields {i32}:result1 = -2</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7633%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7634 <i>; yields {i32}:result2 = 8</i>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7635%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7636 <i>; yields {i32}:result3 = 8</i>
7637%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7638</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7639
Mon P Wang28873102008-06-25 08:15:39 +0000[diff] [blame]7640</div>
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7641
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7642</div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7643
7644<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7645<h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7646 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7647</h3>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7648
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7649<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7650
7651<p>This class of intrinsics exists to information about the lifetime of memory
7652 objects and ranges where variables are immutable.</p>
7653
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7654<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7655<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7656 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7657</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7658
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7659<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7660
7661<h5>Syntax:</h5>
7662<pre>
7663 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7664</pre>
7665
7666<h5>Overview:</h5>
7667<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7668 object's lifetime.</p>
7669
7670<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7671<p>The first argument is a constant integer representing the size of the
7672 object, or -1 if it is variable sized. The second argument is a pointer to
7673 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7674
7675<h5>Semantics:</h5>
7676<p>This intrinsic indicates that before this point in the code, the value of the
7677 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]7678 never be used and has an undefined value. A load from the pointer that
7679 precedes this intrinsic can be replaced with
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7680 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7681
7682</div>
7683
7684<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7685<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7686 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7687</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7688
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7689<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7690
7691<h5>Syntax:</h5>
7692<pre>
7693 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7694</pre>
7695
7696<h5>Overview:</h5>
7697<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7698 object's lifetime.</p>
7699
7700<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7701<p>The first argument is a constant integer representing the size of the
7702 object, or -1 if it is variable sized. The second argument is a pointer to
7703 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7704
7705<h5>Semantics:</h5>
7706<p>This intrinsic indicates that after this point in the code, the value of the
7707 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7708 never be used and has an undefined value. Any stores into the memory object
7709 following this intrinsic may be removed as dead.
7710
7711</div>
7712
7713<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7714<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7715 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7716</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7717
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7718<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7719
7720<h5>Syntax:</h5>
7721<pre>
Nick Lewycky29b6cb42010-11-30 04:13:41 +0000[diff] [blame]7722 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7723</pre>
7724
7725<h5>Overview:</h5>
7726<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7727 a memory object will not change.</p>
7728
7729<h5>Arguments:</h5>
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7730<p>The first argument is a constant integer representing the size of the
7731 object, or -1 if it is variable sized. The second argument is a pointer to
7732 the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7733
7734<h5>Semantics:</h5>
7735<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7736 the return value, the referenced memory location is constant and
7737 unchanging.</p>
7738
7739</div>
7740
7741<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7742<h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7743 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7744</h4>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7745
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7746<div>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7747
7748<h5>Syntax:</h5>
7749<pre>
7750 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7751</pre>
7752
7753<h5>Overview:</h5>
7754<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7755 a memory object are mutable.</p>
7756
7757<h5>Arguments:</h5>
7758<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky321333e2009-10-13 07:57:33 +0000[diff] [blame]7759 The second argument is a constant integer representing the size of the
7760 object, or -1 if it is variable sized and the third argument is a pointer
7761 to the object.</p>
Nick Lewyckycc271862009-10-13 07:03:23 +0000[diff] [blame]7762
7763<h5>Semantics:</h5>
7764<p>This intrinsic indicates that the memory is mutable again.</p>
7765
7766</div>
7767
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7768</div>
7769
Andrew Lenharth22c5c1b2008-02-16 01:24:58 +0000[diff] [blame]7770<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7771<h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7772 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7773</h3>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7774
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7775<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7776
7777<p>This class of intrinsics is designed to be generic and has no specific
7778 purpose.</p>
7779
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7780<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7781<h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7782 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7783</h4>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7784
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7785<div>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7786
7787<h5>Syntax:</h5>
7788<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7789 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]7790</pre>
7791
7792<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7793<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7794
7795<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7796<p>The first argument is a pointer to a value, the second is a pointer to a
7797 global string, the third is a pointer to a global string which is the source
7798 file name, and the last argument is the line number.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7799
7800<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7801<p>This intrinsic allows annotation of local variables with arbitrary strings.
7802 This can be useful for special purpose optimizations that want to look for
7803 these annotations. These have no other defined use, they are ignored by code
7804 generation and optimization.</p>
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7805
Tanya Lattner6d806e92007-06-15 20:50:54 +0000[diff] [blame]7806</div>
7807
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7808<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7809<h4>
Tanya Lattnere1a8da02007-09-21 23:57:59 +0000[diff] [blame]7810 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7811</h4>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7812
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7813<div>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7814
7815<h5>Syntax:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7816<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7817 any integer bit width.</p>
7818
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7819<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7820 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7821 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7822 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7823 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7824 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]7825</pre>
7826
7827<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7828<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7829
7830<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7831<p>The first argument is an integer value (result of some expression), the
7832 second is a pointer to a global string, the third is a pointer to a global
7833 string which is the source file name, and the last argument is the line
7834 number. It returns the value of the first argument.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7835
7836<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7837<p>This intrinsic allows annotations to be put on arbitrary expressions with
7838 arbitrary strings. This can be useful for special purpose optimizations that
7839 want to look for these annotations. These have no other defined use, they
7840 are ignored by code generation and optimization.</p>
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7841
Tanya Lattnerb6367882007-09-21 22:59:12 +0000[diff] [blame]7842</div>
Jim Laskeydd4ef1b2007-03-14 19:31:19 +0000[diff] [blame]7843
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7844<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7845<h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7846 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7847</h4>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7848
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7849<div>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7850
7851<h5>Syntax:</h5>
7852<pre>
7853 declare void @llvm.trap()
7854</pre>
7855
7856<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7857<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7858
7859<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7860<p>None.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7861
7862<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7863<p>This intrinsics is lowered to the target dependent trap instruction. If the
7864 target does not have a trap instruction, this intrinsic will be lowered to
7865 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7866
Anton Korobeynikov4cb86182008-01-15 22:31:34 +0000[diff] [blame]7867</div>
7868
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7869<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7870<h4>
Misha Brukmandccb0252008-11-22 23:55:29 +0000[diff] [blame]7871 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7872</h4>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7873
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7874<div>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7875
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7876<h5>Syntax:</h5>
7877<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7878 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7879</pre>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7880
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7881<h5>Overview:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7882<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
7883 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
7884 ensure that it is placed on the stack before local variables.</p>
7885
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7886<h5>Arguments:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7887<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
7888 arguments. The first argument is the value loaded from the stack
7889 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
7890 that has enough space to hold the value of the guard.</p>
7891
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7892<h5>Semantics:</h5>
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7893<p>This intrinsic causes the prologue/epilogue inserter to force the position of
7894 the <tt>AllocaInst</tt> stack slot to be before local variables on the
7895 stack. This is to ensure that if a local variable on the stack is
7896 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]7897 the guard on the stack is checked against the original guard. If they are
Bill Wendlinge910b4c2009-07-20 02:29:24 +0000[diff] [blame]7898 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
7899 function.</p>
7900
Bill Wendling69e4adb2008-11-19 05:56:17 +0000[diff] [blame]7901</div>
7902
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7903<!-- _______________________________________________________________________ -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7904<h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7905 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]7906</h4>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7907
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7908<div>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7909
7910<h5>Syntax:</h5>
7911<pre>
Dan Gohman3dfb3cf2010-05-28 17:07:41 +0000[diff] [blame]7912 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
7913 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7914</pre>
7915
7916<h5>Overview:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]7917<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
7918 the optimizers to determine at compile time whether a) an operation (like
7919 memcpy) will overflow a buffer that corresponds to an object, or b) that a
7920 runtime check for overflow isn't necessary. An object in this context means
7921 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7922
7923<h5>Arguments:</h5>
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]7924<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher8295a0a2009-12-23 00:29:49 +0000[diff] [blame]7925 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]7926 is a boolean 0 or 1. This argument determines whether you want the
7927 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]7928 1, variables are not allowed.</p>
7929
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7930<h5>Semantics:</h5>
7931<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling1b383ba2010-10-27 01:07:41 +0000[diff] [blame]7932 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
7933 depending on the <tt>type</tt> argument, if the size cannot be determined at
7934 compile time.</p>
Eric Christopher0e671492009-11-30 08:03:53 +0000[diff] [blame]7935
7936</div>
7937
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]7938</div>
7939
7940</div>
7941
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]7942<!-- *********************************************************************** -->
Chris Lattner00950542001-06-06 20:29:01 +0000[diff] [blame]7943<hr>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7944<address>
7945 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]7946 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7947 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman44408702008-12-11 17:34:48 +0000[diff] [blame]7948 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]7949
7950 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]7951 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmandaa4cb02004-03-01 17:47:27 +0000[diff] [blame]7952 Last modified: $Date$
7953</address>
Chris Lattnerc7d3ab32008-01-04 04:33:49 +0000[diff] [blame]7954
Misha Brukman9d0919f2003-11-08 01:05:38 +0000[diff] [blame]7955</body>
7956</html>