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gerrit-public.fairphone.software / toolchain / llvm-project / 9984bd6092e75b32e3f30bc486d5b0ee8af9e942 / . / llvm / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencercb84e432004-08-26 20:44:00 +0000[diff] [blame]6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
7 <meta name="author" content="Chris Lattner">
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]8 <meta name="description"
Reid Spencercb84e432004-08-26 20:44:00 +0000[diff] [blame]9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
27 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
28 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
29 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
30 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
31 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
32 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
33 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
Chris Lattner80d73c72009-10-10 18:26:06 +0000[diff] [blame]34 <li><a href="#linkage_linkonce_odr">'<tt>linkonce_odr</tt>' Linkage</a></li>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]35 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
36 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
37 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
38 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]39 </ol>
40 </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]41 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]42 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]43 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]44 <li><a href="#functionstructure">Functions</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]45 <li><a href="#aliasstructure">Aliases</a></li>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]46 <li><a href="#namedmetadatastructure">Named Metadata</a></li>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]47 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]48 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]49 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]50 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]51 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]52 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]53 </ol>
54 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]55 <li><a href="#typesystem">Type System</a>
56 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]57 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]58 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]59 <ol>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]60 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]61 <li><a href="#t_floating">Floating Point Types</a></li>
62 <li><a href="#t_void">Void Type</a></li>
63 <li><a href="#t_label">Label Type</a></li>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]64 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]65 </ol>
66 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]67 <li><a href="#t_derived">Derived Types</a>
68 <ol>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]69 <li><a href="#t_aggregate">Aggregate Types</a>
70 <ol>
71 <li><a href="#t_array">Array Type</a></li>
72 <li><a href="#t_struct">Structure Type</a></li>
73 <li><a href="#t_pstruct">Packed Structure Type</a></li>
74 <li><a href="#t_union">Union Type</a></li>
75 <li><a href="#t_vector">Vector Type</a></li>
76 </ol>
77 </li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]78 <li><a href="#t_function">Function Type</a></li>
79 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]80 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]81 </ol>
82 </li>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]83 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]84 </ol>
85 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]86 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]87 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]88 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]89 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]90 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
91 <li><a href="#undefvalues">Undefined Values</a></li>
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]92 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]93 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]94 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]95 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]96 <li><a href="#othervalues">Other Values</a>
97 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]98 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]99 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]100 </ol>
101 </li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]102 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
103 <ol>
104 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]105 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
106 Global Variable</a></li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]107 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
108 Global Variable</a></li>
109 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
110 Global Variable</a></li>
111 </ol>
112 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]113 <li><a href="#instref">Instruction Reference</a>
114 <ol>
115 <li><a href="#terminators">Terminator Instructions</a>
116 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]117 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
118 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]119 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]120 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]121 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]122 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]123 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]124 </ol>
125 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]126 <li><a href="#binaryops">Binary Operations</a>
127 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]128 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]129 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]130 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]131 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]132 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]133 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]134 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
135 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
136 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]137 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
138 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
139 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]140 </ol>
141 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]142 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
143 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]144 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
145 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
146 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]147 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]148 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]149 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]150 </ol>
151 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]152 <li><a href="#vectorops">Vector Operations</a>
153 <ol>
154 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
155 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
156 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]157 </ol>
158 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]159 <li><a href="#aggregateops">Aggregate Operations</a>
160 <ol>
161 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
162 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
163 </ol>
164 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]165 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]166 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]167 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]168 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
169 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
170 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]171 </ol>
172 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]173 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]174 <ol>
175 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
176 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
177 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
178 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
179 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]180 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
181 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
182 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
183 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]184 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
185 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]186 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]187 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]188 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]189 <li><a href="#otherops">Other Operations</a>
190 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]191 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
192 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]193 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]194 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]195 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]196 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]197 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]198 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]199 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]200 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]201 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]202 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]203 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
204 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]205 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
206 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
207 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]208 </ol>
209 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]210 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
211 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]212 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
213 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
214 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]215 </ol>
216 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]217 <li><a href="#int_codegen">Code Generator Intrinsics</a>
218 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]219 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
220 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
221 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
222 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
223 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
224 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
225 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]226 </ol>
227 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]228 <li><a href="#int_libc">Standard C Library Intrinsics</a>
229 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]230 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
231 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
232 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
233 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
234 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]235 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
236 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
237 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]238 </ol>
239 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]240 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]241 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]242 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]243 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
244 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
245 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]246 </ol>
247 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]248 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
249 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]250 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
251 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
252 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
253 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
254 <li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]255 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]256 </ol>
257 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]258 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]259 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]260 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]261 <ol>
262 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]263 </ol>
264 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]265 <li><a href="#int_atomics">Atomic intrinsics</a>
266 <ol>
267 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
268 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
269 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
270 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
271 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
272 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
273 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
274 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
275 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
276 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
277 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
278 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
279 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
280 </ol>
281 </li>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]282 <li><a href="#int_memorymarkers">Memory Use Markers</a>
283 <ol>
284 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
285 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
286 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
287 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
288 </ol>
289 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]290 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]291 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]292 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]293 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]294 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]295 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]296 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]297 '<tt>llvm.trap</tt>' Intrinsic</a></li>
298 <li><a href="#int_stackprotector">
299 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]300 <li><a href="#int_objectsize">
301 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]302 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]303 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]304 </ol>
305 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]306</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]307
308<div class="doc_author">
309 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
310 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]311</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]312
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]313<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]314<div class="doc_section"> <a name="abstract">Abstract </a></div>
315<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]316
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]317<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]318
319<p>This document is a reference manual for the LLVM assembly language. LLVM is
320 a Static Single Assignment (SSA) based representation that provides type
321 safety, low-level operations, flexibility, and the capability of representing
322 'all' high-level languages cleanly. It is the common code representation
323 used throughout all phases of the LLVM compilation strategy.</p>
324
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]325</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]326
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]327<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]328<div class="doc_section"> <a name="introduction">Introduction</a> </div>
329<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]330
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]331<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]332
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]333<p>The LLVM code representation is designed to be used in three different forms:
334 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
335 for fast loading by a Just-In-Time compiler), and as a human readable
336 assembly language representation. This allows LLVM to provide a powerful
337 intermediate representation for efficient compiler transformations and
338 analysis, while providing a natural means to debug and visualize the
339 transformations. The three different forms of LLVM are all equivalent. This
340 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]341
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]342<p>The LLVM representation aims to be light-weight and low-level while being
343 expressive, typed, and extensible at the same time. It aims to be a
344 "universal IR" of sorts, by being at a low enough level that high-level ideas
345 may be cleanly mapped to it (similar to how microprocessors are "universal
346 IR's", allowing many source languages to be mapped to them). By providing
347 type information, LLVM can be used as the target of optimizations: for
348 example, through pointer analysis, it can be proven that a C automatic
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]349 variable is never accessed outside of the current function, allowing it to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]350 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]351
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]352</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]353
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]354<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]355<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]356
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]357<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]358
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]359<p>It is important to note that this document describes 'well formed' LLVM
360 assembly language. There is a difference between what the parser accepts and
361 what is considered 'well formed'. For example, the following instruction is
362 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]363
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]364<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]365<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]366%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]367</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]368</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]369
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]370<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
371 LLVM infrastructure provides a verification pass that may be used to verify
372 that an LLVM module is well formed. This pass is automatically run by the
373 parser after parsing input assembly and by the optimizer before it outputs
374 bitcode. The violations pointed out by the verifier pass indicate bugs in
375 transformation passes or input to the parser.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]376
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]377</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]378
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]379<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]380
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]381<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]382<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]383<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]384
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]385<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]386
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]387<p>LLVM identifiers come in two basic types: global and local. Global
388 identifiers (functions, global variables) begin with the <tt>'@'</tt>
389 character. Local identifiers (register names, types) begin with
390 the <tt>'%'</tt> character. Additionally, there are three different formats
391 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]392
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]393<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]394 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]395 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
396 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
397 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
398 other characters in their names can be surrounded with quotes. Special
399 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
400 ASCII code for the character in hexadecimal. In this way, any character
401 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]402
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]403 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]404 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]405
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]406 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]407 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]408</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]409
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]410<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]411 don't need to worry about name clashes with reserved words, and the set of
412 reserved words may be expanded in the future without penalty. Additionally,
413 unnamed identifiers allow a compiler to quickly come up with a temporary
414 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]415
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]416<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]417 languages. There are keywords for different opcodes
418 ('<tt><a href="#i_add">add</a></tt>',
419 '<tt><a href="#i_bitcast">bitcast</a></tt>',
420 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
421 ('<tt><a href="#t_void">void</a></tt>',
422 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
423 reserved words cannot conflict with variable names, because none of them
424 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]425
426<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]427 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]428
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]429<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]430
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]431<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]432<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]433%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]434</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]435</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]436
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]437<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]438
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]439<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]440<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]441%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]442</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]443</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]444
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]445<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]446
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]447<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]448<pre>
Gabor Greifbd0328f2009-10-28 13:05:07 +0000[diff] [blame]449%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
450%1 = <a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]451%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]452</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]453</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]454
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]455<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
456 lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]457
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]458<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]459 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]460 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]461
462 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]463 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]464
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]465 <li>Unnamed temporaries are numbered sequentially</li>
466</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]467
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]468<p>It also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]469 demonstrating instructions, we will follow an instruction with a comment that
470 defines the type and name of value produced. Comments are shown in italic
471 text.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]472
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]473</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]474
475<!-- *********************************************************************** -->
476<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
477<!-- *********************************************************************** -->
478
479<!-- ======================================================================= -->
480<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
481</div>
482
483<div class="doc_text">
484
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]485<p>LLVM programs are composed of "Module"s, each of which is a translation unit
486 of the input programs. Each module consists of functions, global variables,
487 and symbol table entries. Modules may be combined together with the LLVM
488 linker, which merges function (and global variable) definitions, resolves
489 forward declarations, and merges symbol table entries. Here is an example of
490 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]491
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]492<div class="doc_code">
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]493<pre>
494<i>; Declare the string constant as a global constant.</i>
495<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]496
497<i>; External declaration of the puts function</i>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]498<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]499
500<i>; Definition of main function</i>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]501define i32 @main() { <i>; i32()* </i>
502 <i>; Convert [13 x i8]* to i8 *...</i>
503 %cast210 = <a href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]504
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]505 <i>; Call puts function to write out the string to stdout.</i>
506 <a href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]507 <a href="#i_ret">ret</a> i32 0<br>}
508
509<i>; Named metadata</i>
510!1 = metadata !{i32 41}
511!foo = !{!1, null}
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]512</pre>
513</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]514
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]515<p>This example is made up of a <a href="#globalvars">global variable</a> named
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]516 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]517 a <a href="#functionstructure">function definition</a> for
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]518 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
519 "<tt>foo"</tt>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]520
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]521<p>In general, a module is made up of a list of global values, where both
522 functions and global variables are global values. Global values are
523 represented by a pointer to a memory location (in this case, a pointer to an
524 array of char, and a pointer to a function), and have one of the
525 following <a href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]526
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]527</div>
528
529<!-- ======================================================================= -->
530<div class="doc_subsection">
531 <a name="linkage">Linkage Types</a>
532</div>
533
534<div class="doc_text">
535
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]536<p>All Global Variables and Functions have one of the following types of
537 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]538
539<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]540 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]541 <dd>Global values with private linkage are only directly accessible by objects
542 in the current module. In particular, linking code into a module with an
543 private global value may cause the private to be renamed as necessary to
544 avoid collisions. Because the symbol is private to the module, all
545 references can be updated. This doesn't show up in any symbol table in the
546 object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]547
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]548 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]549 <dd>Similar to private, but the symbol is passed through the assembler and
Chris Lattnere7f064e2009-08-24 04:32:16 +0000[diff] [blame]550 removed by the linker after evaluation. Note that (unlike private
551 symbols) linker_private symbols are subject to coalescing by the linker:
552 weak symbols get merged and redefinitions are rejected. However, unlike
553 normal strong symbols, they are removed by the linker from the final
554 linked image (executable or dynamic library).</dd>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]555
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]556 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]557 <dd>Similar to private, but the value shows as a local symbol
558 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
559 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]560
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]561 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]562 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]563 into the object file corresponding to the LLVM module. They exist to
564 allow inlining and other optimizations to take place given knowledge of
565 the definition of the global, which is known to be somewhere outside the
566 module. Globals with <tt>available_externally</tt> linkage are allowed to
567 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
568 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]569
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]570 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]571 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner0de4caa2010-01-09 19:15:14 +0000[diff] [blame]572 the same name when linkage occurs. This can be used to implement
573 some forms of inline functions, templates, or other code which must be
574 generated in each translation unit that uses it, but where the body may
575 be overridden with a more definitive definition later. Unreferenced
576 <tt>linkonce</tt> globals are allowed to be discarded. Note that
577 <tt>linkonce</tt> linkage does not actually allow the optimizer to
578 inline the body of this function into callers because it doesn't know if
579 this definition of the function is the definitive definition within the
580 program or whether it will be overridden by a stronger definition.
581 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
582 linkage.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]583
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]584 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]585 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
586 <tt>linkonce</tt> linkage, except that unreferenced globals with
587 <tt>weak</tt> linkage may not be discarded. This is used for globals that
588 are declared "weak" in C source code.</dd>
589
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]590 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]591 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
592 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
593 global scope.
594 Symbols with "<tt>common</tt>" linkage are merged in the same way as
595 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]596 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]597 must have a zero initializer, and may not be marked '<a
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]598 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
599 have common linkage.</dd>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]600
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]601
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]602 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]603 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]604 pointer to array type. When two global variables with appending linkage
605 are linked together, the two global arrays are appended together. This is
606 the LLVM, typesafe, equivalent of having the system linker append together
607 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]608
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]609 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]610 <dd>The semantics of this linkage follow the ELF object file model: the symbol
611 is weak until linked, if not linked, the symbol becomes null instead of
612 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]613
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]614 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
615 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]616 <dd>Some languages allow differing globals to be merged, such as two functions
617 with different semantics. Other languages, such as <tt>C++</tt>, ensure
618 that only equivalent globals are ever merged (the "one definition rule" -
619 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
620 and <tt>weak_odr</tt> linkage types to indicate that the global will only
621 be merged with equivalent globals. These linkage types are otherwise the
622 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]623
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]624 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]625 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]626 visible, meaning that it participates in linkage and can be used to
627 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]628</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]629
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]630<p>The next two types of linkage are targeted for Microsoft Windows platform
631 only. They are designed to support importing (exporting) symbols from (to)
632 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]633
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]634<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]635 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]636 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]637 or variable via a global pointer to a pointer that is set up by the DLL
638 exporting the symbol. On Microsoft Windows targets, the pointer name is
639 formed by combining <code>__imp_</code> and the function or variable
640 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]641
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]642 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]643 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]644 pointer to a pointer in a DLL, so that it can be referenced with the
645 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
646 name is formed by combining <code>__imp_</code> and the function or
647 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]648</dl>
649
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]650<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
651 another module defined a "<tt>.LC0</tt>" variable and was linked with this
652 one, one of the two would be renamed, preventing a collision. Since
653 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
654 declarations), they are accessible outside of the current module.</p>
655
656<p>It is illegal for a function <i>declaration</i> to have any linkage type
657 other than "externally visible", <tt>dllimport</tt>
658 or <tt>extern_weak</tt>.</p>
659
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]660<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]661 or <tt>weak_odr</tt> linkages.</p>
662
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]663</div>
664
665<!-- ======================================================================= -->
666<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]667 <a name="callingconv">Calling Conventions</a>
668</div>
669
670<div class="doc_text">
671
672<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]673 and <a href="#i_invoke">invokes</a> can all have an optional calling
674 convention specified for the call. The calling convention of any pair of
675 dynamic caller/callee must match, or the behavior of the program is
676 undefined. The following calling conventions are supported by LLVM, and more
677 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]678
679<dl>
680 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]681 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]682 specified) matches the target C calling conventions. This calling
683 convention supports varargs function calls and tolerates some mismatch in
684 the declared prototype and implemented declaration of the function (as
685 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]686
687 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]688 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]689 (e.g. by passing things in registers). This calling convention allows the
690 target to use whatever tricks it wants to produce fast code for the
691 target, without having to conform to an externally specified ABI
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]692 (Application Binary Interface).
693 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
694 when this convention is used.</a> This calling convention does not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]695 support varargs and requires the prototype of all callees to exactly match
696 the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]697
698 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]699 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]700 as possible under the assumption that the call is not commonly executed.
701 As such, these calls often preserve all registers so that the call does
702 not break any live ranges in the caller side. This calling convention
703 does not support varargs and requires the prototype of all callees to
704 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]705
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]706 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]707 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]708 target-specific calling conventions to be used. Target specific calling
709 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]710</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]711
712<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]713 support Pascal conventions or any other well-known target-independent
714 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]715
716</div>
717
718<!-- ======================================================================= -->
719<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]720 <a name="visibility">Visibility Styles</a>
721</div>
722
723<div class="doc_text">
724
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]725<p>All Global Variables and Functions have one of the following visibility
726 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]727
728<dl>
729 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]730 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]731 that the declaration is visible to other modules and, in shared libraries,
732 means that the declared entity may be overridden. On Darwin, default
733 visibility means that the declaration is visible to other modules. Default
734 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]735
736 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]737 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]738 object if they are in the same shared object. Usually, hidden visibility
739 indicates that the symbol will not be placed into the dynamic symbol
740 table, so no other module (executable or shared library) can reference it
741 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]742
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]743 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]744 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]745 the dynamic symbol table, but that references within the defining module
746 will bind to the local symbol. That is, the symbol cannot be overridden by
747 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]748</dl>
749
750</div>
751
752<!-- ======================================================================= -->
753<div class="doc_subsection">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]754 <a name="namedtypes">Named Types</a>
755</div>
756
757<div class="doc_text">
758
759<p>LLVM IR allows you to specify name aliases for certain types. This can make
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]760 it easier to read the IR and make the IR more condensed (particularly when
761 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]762
763<div class="doc_code">
764<pre>
765%mytype = type { %mytype*, i32 }
766</pre>
767</div>
768
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]769<p>You may give a name to any <a href="#typesystem">type</a> except
770 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
771 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]772
773<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]774 and that you can therefore specify multiple names for the same type. This
775 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
776 uses structural typing, the name is not part of the type. When printing out
777 LLVM IR, the printer will pick <em>one name</em> to render all types of a
778 particular shape. This means that if you have code where two different
779 source types end up having the same LLVM type, that the dumper will sometimes
780 print the "wrong" or unexpected type. This is an important design point and
781 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]782
783</div>
784
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]785<!-- ======================================================================= -->
786<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]787 <a name="globalvars">Global Variables</a>
788</div>
789
790<div class="doc_text">
791
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]792<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]793 instead of run-time. Global variables may optionally be initialized, may
794 have an explicit section to be placed in, and may have an optional explicit
795 alignment specified. A variable may be defined as "thread_local", which
796 means that it will not be shared by threads (each thread will have a
797 separated copy of the variable). A variable may be defined as a global
798 "constant," which indicates that the contents of the variable
799 will <b>never</b> be modified (enabling better optimization, allowing the
800 global data to be placed in the read-only section of an executable, etc).
801 Note that variables that need runtime initialization cannot be marked
802 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]803
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]804<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
805 constant, even if the final definition of the global is not. This capability
806 can be used to enable slightly better optimization of the program, but
807 requires the language definition to guarantee that optimizations based on the
808 'constantness' are valid for the translation units that do not include the
809 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]810
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]811<p>As SSA values, global variables define pointer values that are in scope
812 (i.e. they dominate) all basic blocks in the program. Global variables
813 always define a pointer to their "content" type because they describe a
814 region of memory, and all memory objects in LLVM are accessed through
815 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]816
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]817<p>A global variable may be declared to reside in a target-specific numbered
818 address space. For targets that support them, address spaces may affect how
819 optimizations are performed and/or what target instructions are used to
820 access the variable. The default address space is zero. The address space
821 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]822
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]823<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]824 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]825
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]826<p>An explicit alignment may be specified for a global. If not present, or if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]827 the alignment is set to zero, the alignment of the global is set by the
828 target to whatever it feels convenient. If an explicit alignment is
829 specified, the global is forced to have at least that much alignment. All
830 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]831
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]832<p>For example, the following defines a global in a numbered address space with
833 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]834
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]835<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]836<pre>
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]837@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]838</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]839</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]840
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]841</div>
842
843
844<!-- ======================================================================= -->
845<div class="doc_subsection">
846 <a name="functionstructure">Functions</a>
847</div>
848
849<div class="doc_text">
850
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]851<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]852 optional <a href="#linkage">linkage type</a>, an optional
853 <a href="#visibility">visibility style</a>, an optional
854 <a href="#callingconv">calling convention</a>, a return type, an optional
855 <a href="#paramattrs">parameter attribute</a> for the return type, a function
856 name, a (possibly empty) argument list (each with optional
857 <a href="#paramattrs">parameter attributes</a>), optional
858 <a href="#fnattrs">function attributes</a>, an optional section, an optional
859 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
860 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]861
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]862<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
863 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]864 <a href="#visibility">visibility style</a>, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]865 <a href="#callingconv">calling convention</a>, a return type, an optional
866 <a href="#paramattrs">parameter attribute</a> for the return type, a function
867 name, a possibly empty list of arguments, an optional alignment, and an
868 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]869
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]870<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]871 (Control Flow Graph) for the function. Each basic block may optionally start
872 with a label (giving the basic block a symbol table entry), contains a list
873 of instructions, and ends with a <a href="#terminators">terminator</a>
874 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]875
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]876<p>The first basic block in a function is special in two ways: it is immediately
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]877 executed on entrance to the function, and it is not allowed to have
878 predecessor basic blocks (i.e. there can not be any branches to the entry
879 block of a function). Because the block can have no predecessors, it also
880 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]881
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]882<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]883 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]884
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]885<p>An explicit alignment may be specified for a function. If not present, or if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]886 the alignment is set to zero, the alignment of the function is set by the
887 target to whatever it feels convenient. If an explicit alignment is
888 specified, the function is forced to have at least that much alignment. All
889 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]890
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]891<h5>Syntax:</h5>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]892<div class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]893<pre>
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]894define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]895 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
896 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
897 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
898 [<a href="#gc">gc</a>] { ... }
899</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]900</div>
901
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]902</div>
903
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]904<!-- ======================================================================= -->
905<div class="doc_subsection">
906 <a name="aliasstructure">Aliases</a>
907</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]908
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]909<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]910
911<p>Aliases act as "second name" for the aliasee value (which can be either
912 function, global variable, another alias or bitcast of global value). Aliases
913 may have an optional <a href="#linkage">linkage type</a>, and an
914 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]915
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]916<h5>Syntax:</h5>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]917<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]918<pre>
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]919@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]920</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]921</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]922
923</div>
924
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]925<!-- ======================================================================= -->
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]926<div class="doc_subsection">
927 <a name="namedmetadatastructure">Named Metadata</a>
928</div>
929
930<div class="doc_text">
931
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]932<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
933 nodes</a> (but not metadata strings) and null are the only valid operands for
934 a named metadata.</p>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]935
936<h5>Syntax:</h5>
937<div class="doc_code">
938<pre>
939!1 = metadata !{metadata !"one"}
940!name = !{null, !1}
941</pre>
942</div>
943
944</div>
945
946<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]947<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]948
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]949<div class="doc_text">
950
951<p>The return type and each parameter of a function type may have a set of
952 <i>parameter attributes</i> associated with them. Parameter attributes are
953 used to communicate additional information about the result or parameters of
954 a function. Parameter attributes are considered to be part of the function,
955 not of the function type, so functions with different parameter attributes
956 can have the same function type.</p>
957
958<p>Parameter attributes are simple keywords that follow the type specified. If
959 multiple parameter attributes are needed, they are space separated. For
960 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]961
962<div class="doc_code">
963<pre>
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]964declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]965declare i32 @atoi(i8 zeroext)
966declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]967</pre>
968</div>
969
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]970<p>Note that any attributes for the function result (<tt>nounwind</tt>,
971 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]972
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]973<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]974
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]975<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]976 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]977 <dd>This indicates to the code generator that the parameter or return value
978 should be zero-extended to a 32-bit value by the caller (for a parameter)
979 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]980
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]981 <dt><tt><b>signext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]982 <dd>This indicates to the code generator that the parameter or return value
983 should be sign-extended to a 32-bit value by the caller (for a parameter)
984 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]985
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]986 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]987 <dd>This indicates that this parameter or return value should be treated in a
988 special target-dependent fashion during while emitting code for a function
989 call or return (usually, by putting it in a register as opposed to memory,
990 though some targets use it to distinguish between two different kinds of
991 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]992
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]993 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]994 <dd>This indicates that the pointer parameter should really be passed by value
995 to the function. The attribute implies that a hidden copy of the pointee
996 is made between the caller and the callee, so the callee is unable to
997 modify the value in the callee. This attribute is only valid on LLVM
998 pointer arguments. It is generally used to pass structs and arrays by
999 value, but is also valid on pointers to scalars. The copy is considered
1000 to belong to the caller not the callee (for example,
1001 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1002 <tt>byval</tt> parameters). This is not a valid attribute for return
1003 values. The byval attribute also supports specifying an alignment with
1004 the align attribute. This has a target-specific effect on the code
1005 generator that usually indicates a desired alignment for the synthesized
1006 stack slot.</dd>
1007
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1008 <dt><tt><b>sret</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1009 <dd>This indicates that the pointer parameter specifies the address of a
1010 structure that is the return value of the function in the source program.
1011 This pointer must be guaranteed by the caller to be valid: loads and
1012 stores to the structure may be assumed by the callee to not to trap. This
1013 may only be applied to the first parameter. This is not a valid attribute
1014 for return values. </dd>
1015
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1016 <dt><tt><b>noalias</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1017 <dd>This indicates that the pointer does not alias any global or any other
1018 parameter. The caller is responsible for ensuring that this is the
1019 case. On a function return value, <tt>noalias</tt> additionally indicates
1020 that the pointer does not alias any other pointers visible to the
1021 caller. For further details, please see the discussion of the NoAlias
1022 response in
1023 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
1024 analysis</a>.</dd>
1025
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1026 <dt><tt><b>nocapture</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1027 <dd>This indicates that the callee does not make any copies of the pointer
1028 that outlive the callee itself. This is not a valid attribute for return
1029 values.</dd>
1030
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1031 <dt><tt><b>nest</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1032 <dd>This indicates that the pointer parameter can be excised using the
1033 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1034 attribute for return values.</dd>
1035</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1036
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1037</div>
1038
1039<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1040<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1041 <a name="gc">Garbage Collector Names</a>
1042</div>
1043
1044<div class="doc_text">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1045
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1046<p>Each function may specify a garbage collector name, which is simply a
1047 string:</p>
1048
1049<div class="doc_code">
1050<pre>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1051define void @f() gc "name" { ... }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1052</pre>
1053</div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1054
1055<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1056 collector which will cause the compiler to alter its output in order to
1057 support the named garbage collection algorithm.</p>
1058
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1059</div>
1060
1061<!-- ======================================================================= -->
1062<div class="doc_subsection">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1063 <a name="fnattrs">Function Attributes</a>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1064</div>
1065
1066<div class="doc_text">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1067
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1068<p>Function attributes are set to communicate additional information about a
1069 function. Function attributes are considered to be part of the function, not
1070 of the function type, so functions with different parameter attributes can
1071 have the same function type.</p>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1072
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1073<p>Function attributes are simple keywords that follow the type specified. If
1074 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1075
1076<div class="doc_code">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1077<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1078define void @f() noinline { ... }
1079define void @f() alwaysinline { ... }
1080define void @f() alwaysinline optsize { ... }
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1081define void @f() optsize { ... }
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1082</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1083</div>
1084
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1085<dl>
Charles Davisbe5557e2010-02-12 00:31:15 +0000[diff] [blame]1086 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1087 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1088 the backend should forcibly align the stack pointer. Specify the
1089 desired alignment, which must be a power of two, in parentheses.
1090
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1091 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1092 <dd>This attribute indicates that the inliner should attempt to inline this
1093 function into callers whenever possible, ignoring any active inlining size
1094 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1095
Jakob Stoklund Olesen74bb06c2010-02-06 01:16:28 +0000[diff] [blame]1096 <dt><tt><b>inlinehint</b></tt></dt>
1097 <dd>This attribute indicates that the source code contained a hint that inlining
1098 this function is desirable (such as the "inline" keyword in C/C++). It
1099 is just a hint; it imposes no requirements on the inliner.</dd>
1100
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1101 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1102 <dd>This attribute indicates that the inliner should never inline this
1103 function in any situation. This attribute may not be used together with
1104 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1105
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1106 <dt><tt><b>optsize</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1107 <dd>This attribute suggests that optimization passes and code generator passes
1108 make choices that keep the code size of this function low, and otherwise
1109 do optimizations specifically to reduce code size.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1110
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1111 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1112 <dd>This function attribute indicates that the function never returns
1113 normally. This produces undefined behavior at runtime if the function
1114 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1115
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1116 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1117 <dd>This function attribute indicates that the function never returns with an
1118 unwind or exceptional control flow. If the function does unwind, its
1119 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1120
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1121 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1122 <dd>This attribute indicates that the function computes its result (or decides
1123 to unwind an exception) based strictly on its arguments, without
1124 dereferencing any pointer arguments or otherwise accessing any mutable
1125 state (e.g. memory, control registers, etc) visible to caller functions.
1126 It does not write through any pointer arguments
1127 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1128 changes any state visible to callers. This means that it cannot unwind
1129 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1130 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1131
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1132 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1133 <dd>This attribute indicates that the function does not write through any
1134 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1135 arguments) or otherwise modify any state (e.g. memory, control registers,
1136 etc) visible to caller functions. It may dereference pointer arguments
1137 and read state that may be set in the caller. A readonly function always
1138 returns the same value (or unwinds an exception identically) when called
1139 with the same set of arguments and global state. It cannot unwind an
1140 exception by calling the <tt>C++</tt> exception throwing methods, but may
1141 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1142
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1143 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1144 <dd>This attribute indicates that the function should emit a stack smashing
1145 protector. It is in the form of a "canary"&mdash;a random value placed on
1146 the stack before the local variables that's checked upon return from the
1147 function to see if it has been overwritten. A heuristic is used to
1148 determine if a function needs stack protectors or not.<br>
1149<br>
1150 If a function that has an <tt>ssp</tt> attribute is inlined into a
1151 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1152 function will have an <tt>ssp</tt> attribute.</dd>
1153
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1154 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1155 <dd>This attribute indicates that the function should <em>always</em> emit a
1156 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1157 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1158<br>
1159 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1160 function that doesn't have an <tt>sspreq</tt> attribute or which has
1161 an <tt>ssp</tt> attribute, then the resulting function will have
1162 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1163
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1164 <dt><tt><b>noredzone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1165 <dd>This attribute indicates that the code generator should not use a red
1166 zone, even if the target-specific ABI normally permits it.</dd>
1167
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1168 <dt><tt><b>noimplicitfloat</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1169 <dd>This attributes disables implicit floating point instructions.</dd>
1170
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1171 <dt><tt><b>naked</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1172 <dd>This attribute disables prologue / epilogue emission for the function.
1173 This can have very system-specific consequences.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1174</dl>
1175
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1176</div>
1177
1178<!-- ======================================================================= -->
1179<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1180 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1181</div>
1182
1183<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1184
1185<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1186 the GCC "file scope inline asm" blocks. These blocks are internally
1187 concatenated by LLVM and treated as a single unit, but may be separated in
1188 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1189
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1190<div class="doc_code">
1191<pre>
1192module asm "inline asm code goes here"
1193module asm "more can go here"
1194</pre>
1195</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1196
1197<p>The strings can contain any character by escaping non-printable characters.
1198 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1199 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1200
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1201<p>The inline asm code is simply printed to the machine code .s file when
1202 assembly code is generated.</p>
1203
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1204</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1205
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1206<!-- ======================================================================= -->
1207<div class="doc_subsection">
1208 <a name="datalayout">Data Layout</a>
1209</div>
1210
1211<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1212
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1213<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1214 data is to be laid out in memory. The syntax for the data layout is
1215 simply:</p>
1216
1217<div class="doc_code">
1218<pre>
1219target datalayout = "<i>layout specification</i>"
1220</pre>
1221</div>
1222
1223<p>The <i>layout specification</i> consists of a list of specifications
1224 separated by the minus sign character ('-'). Each specification starts with
1225 a letter and may include other information after the letter to define some
1226 aspect of the data layout. The specifications accepted are as follows:</p>
1227
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1228<dl>
1229 <dt><tt>E</tt></dt>
1230 <dd>Specifies that the target lays out data in big-endian form. That is, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1231 bits with the most significance have the lowest address location.</dd>
1232
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1233 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1234 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1235 the bits with the least significance have the lowest address
1236 location.</dd>
1237
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1238 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1239 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1240 <i>preferred</i> alignments. All sizes are in bits. Specifying
1241 the <i>pref</i> alignment is optional. If omitted, the
1242 preceding <tt>:</tt> should be omitted too.</dd>
1243
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1244 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1245 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1246 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1247
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1248 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1249 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1250 <i>size</i>.</dd>
1251
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1252 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1253 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1254 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1255 (double).</dd>
1256
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1257 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1258 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1259 <i>size</i>.</dd>
1260
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1261 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1262 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1263 <i>size</i>.</dd>
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1264
1265 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1266 <dd>This specifies a set of native integer widths for the target CPU
1267 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1268 "n32:64" for PowerPC 64, or "n8:16:32:64" for X86-64. Elements of
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1269 this set are considered to support most general arithmetic
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1270 operations efficiently.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1271</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1272
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1273<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1274 default set of specifications which are then (possibly) overriden by the
1275 specifications in the <tt>datalayout</tt> keyword. The default specifications
1276 are given in this list:</p>
1277
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1278<ul>
1279 <li><tt>E</tt> - big endian</li>
Dan Gohman8ad777d2010-02-23 02:44:03 +0000[diff] [blame]1280 <li><tt>p:64:64:64</tt> - 64-bit pointers with 64-bit alignment</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1281 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1282 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1283 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1284 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1285 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1286 alignment of 64-bits</li>
1287 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1288 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1289 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1290 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1291 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1292 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1293</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1294
1295<p>When LLVM is determining the alignment for a given type, it uses the
1296 following rules:</p>
1297
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1298<ol>
1299 <li>If the type sought is an exact match for one of the specifications, that
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1300 specification is used.</li>
1301
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1302 <li>If no match is found, and the type sought is an integer type, then the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1303 smallest integer type that is larger than the bitwidth of the sought type
1304 is used. If none of the specifications are larger than the bitwidth then
1305 the the largest integer type is used. For example, given the default
1306 specifications above, the i7 type will use the alignment of i8 (next
1307 largest) while both i65 and i256 will use the alignment of i64 (largest
1308 specified).</li>
1309
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1310 <li>If no match is found, and the type sought is a vector type, then the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1311 largest vector type that is smaller than the sought vector type will be
1312 used as a fall back. This happens because &lt;128 x double&gt; can be
1313 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1314</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1315
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1316</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1317
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1318<!-- ======================================================================= -->
1319<div class="doc_subsection">
1320 <a name="pointeraliasing">Pointer Aliasing Rules</a>
1321</div>
1322
1323<div class="doc_text">
1324
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1325<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1326with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1327is undefined. Pointer values are associated with address ranges
1328according to the following rules:</p>
1329
1330<ul>
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1331 <li>A pointer value formed from a
1332 <tt><a href="#i_getelementptr">getelementptr</a></tt> instruction
1333 is associated with the addresses associated with the first operand
1334 of the <tt>getelementptr</tt>.</li>
1335 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1336 range of the variable's storage.</li>
1337 <li>The result value of an allocation instruction is associated with
1338 the address range of the allocated storage.</li>
1339 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1340 no address.</li>
1341 <li>A pointer value formed by an
1342 <tt><a href="#i_inttoptr">inttoptr</a></tt> is associated with all
1343 address ranges of all pointer values that contribute (directly or
1344 indirectly) to the computation of the pointer's value.</li>
1345 <li>The result value of a
1346 <tt><a href="#i_bitcast">bitcast</a></tt> is associated with all
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1347 addresses associated with the operand of the <tt>bitcast</tt>.</li>
1348 <li>An integer constant other than zero or a pointer value returned
1349 from a function not defined within LLVM may be associated with address
1350 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1351 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1352 allocated by mechanisms provided by LLVM.</li>
1353 </ul>
1354
1355<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1356<tt><a href="#i_load">load</a></tt> merely indicates the size and
1357alignment of the memory from which to load, as well as the
1358interpretation of the value. The first operand of a
1359<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1360and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1361
1362<p>Consequently, type-based alias analysis, aka TBAA, aka
1363<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1364LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1365additional information which specialized optimization passes may use
1366to implement type-based alias analysis.</p>
1367
1368</div>
1369
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1370<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1371<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1372<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1373
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1374<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1375
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1376<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1377 intermediate representation. Being typed enables a number of optimizations
1378 to be performed on the intermediate representation directly, without having
1379 to do extra analyses on the side before the transformation. A strong type
1380 system makes it easier to read the generated code and enables novel analyses
1381 and transformations that are not feasible to perform on normal three address
1382 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1383
1384</div>
1385
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1386<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1387<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1388Classifications</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1389
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1390<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1391
1392<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1393
1394<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1395 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1396 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1397 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1398 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1399 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1400 </tr>
1401 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1402 <td><a href="#t_floating">floating point</a></td>
1403 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1404 </tr>
1405 <tr>
1406 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1407 <td><a href="#t_integer">integer</a>,
1408 <a href="#t_floating">floating point</a>,
1409 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1410 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1411 <a href="#t_struct">structure</a>,
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1412 <a href="#t_union">union</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1413 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1414 <a href="#t_label">label</a>,
1415 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1416 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1417 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1418 <tr>
1419 <td><a href="#t_primitive">primitive</a></td>
1420 <td><a href="#t_label">label</a>,
1421 <a href="#t_void">void</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1422 <a href="#t_floating">floating point</a>,
1423 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1424 </tr>
1425 <tr>
1426 <td><a href="#t_derived">derived</a></td>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1427 <td><a href="#t_array">array</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1428 <a href="#t_function">function</a>,
1429 <a href="#t_pointer">pointer</a>,
1430 <a href="#t_struct">structure</a>,
1431 <a href="#t_pstruct">packed structure</a>,
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1432 <a href="#t_union">union</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1433 <a href="#t_vector">vector</a>,
1434 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1435 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1436 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1437 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1438</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1439
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1440<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1441 important. Values of these types are the only ones which can be produced by
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1442 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1443
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1444</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1445
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1446<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1447<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1448
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1449<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1450
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1451<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1452 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1453
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1454</div>
1455
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1456<!-- _______________________________________________________________________ -->
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1457<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1458
1459<div class="doc_text">
1460
1461<h5>Overview:</h5>
1462<p>The integer type is a very simple type that simply specifies an arbitrary
1463 bit width for the integer type desired. Any bit width from 1 bit to
1464 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1465
1466<h5>Syntax:</h5>
1467<pre>
1468 iN
1469</pre>
1470
1471<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1472 value.</p>
1473
1474<h5>Examples:</h5>
1475<table class="layout">
1476 <tr class="layout">
1477 <td class="left"><tt>i1</tt></td>
1478 <td class="left">a single-bit integer.</td>
1479 </tr>
1480 <tr class="layout">
1481 <td class="left"><tt>i32</tt></td>
1482 <td class="left">a 32-bit integer.</td>
1483 </tr>
1484 <tr class="layout">
1485 <td class="left"><tt>i1942652</tt></td>
1486 <td class="left">a really big integer of over 1 million bits.</td>
1487 </tr>
1488</table>
1489
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1490</div>
1491
1492<!-- _______________________________________________________________________ -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1493<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1494
1495<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1496
1497<table>
1498 <tbody>
1499 <tr><th>Type</th><th>Description</th></tr>
1500 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1501 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1502 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1503 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1504 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1505 </tbody>
1506</table>
1507
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1508</div>
1509
1510<!-- _______________________________________________________________________ -->
1511<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1512
1513<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1514
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1515<h5>Overview:</h5>
1516<p>The void type does not represent any value and has no size.</p>
1517
1518<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1519<pre>
1520 void
1521</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1522
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1523</div>
1524
1525<!-- _______________________________________________________________________ -->
1526<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1527
1528<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1529
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1530<h5>Overview:</h5>
1531<p>The label type represents code labels.</p>
1532
1533<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1534<pre>
1535 label
1536</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1537
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1538</div>
1539
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1540<!-- _______________________________________________________________________ -->
1541<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1542
1543<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1544
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1545<h5>Overview:</h5>
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1546<p>The metadata type represents embedded metadata. No derived types may be
1547 created from metadata except for <a href="#t_function">function</a>
1548 arguments.
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1549
1550<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1551<pre>
1552 metadata
1553</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1554
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1555</div>
1556
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1557
1558<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1559<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1560
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1561<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1562
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1563<p>The real power in LLVM comes from the derived types in the system. This is
1564 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1565 useful types. Each of these types contain one or more element types which
1566 may be a primitive type, or another derived type. For example, it is
1567 possible to have a two dimensional array, using an array as the element type
1568 of another array.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1569
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1570
1571</div>
1572
1573<!-- _______________________________________________________________________ -->
1574<div class="doc_subsubsection"> <a name="t_aggregate">Aggregate Types</a> </div>
1575
1576<div class="doc_text">
1577
1578<p>Aggregate Types are a subset of derived types that can contain multiple
1579 member types. <a href="#t_array">Arrays</a>,
1580 <a href="#t_struct">structs</a>, <a href="#t_vector">vectors</a> and
1581 <a href="#t_union">unions</a> are aggregate types.</p>
1582
1583</div>
1584
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1585</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1586
1587<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1588<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1589
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1590<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1591
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1592<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1593<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1594 sequentially in memory. The array type requires a size (number of elements)
1595 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1596
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1597<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1598<pre>
1599 [&lt;# elements&gt; x &lt;elementtype&gt;]
1600</pre>
1601
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1602<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1603 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1604
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1605<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1606<table class="layout">
1607 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1608 <td class="left"><tt>[40 x i32]</tt></td>
1609 <td class="left">Array of 40 32-bit integer values.</td>
1610 </tr>
1611 <tr class="layout">
1612 <td class="left"><tt>[41 x i32]</tt></td>
1613 <td class="left">Array of 41 32-bit integer values.</td>
1614 </tr>
1615 <tr class="layout">
1616 <td class="left"><tt>[4 x i8]</tt></td>
1617 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1618 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1619</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1620<p>Here are some examples of multidimensional arrays:</p>
1621<table class="layout">
1622 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1623 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1624 <td class="left">3x4 array of 32-bit integer values.</td>
1625 </tr>
1626 <tr class="layout">
1627 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1628 <td class="left">12x10 array of single precision floating point values.</td>
1629 </tr>
1630 <tr class="layout">
1631 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1632 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1633 </tr>
1634</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1635
Dan Gohmanc74bc282009-11-09 19:01:53 +0000[diff] [blame]1636<p>There is no restriction on indexing beyond the end of the array implied by
1637 a static type (though there are restrictions on indexing beyond the bounds
1638 of an allocated object in some cases). This means that single-dimension
1639 'variable sized array' addressing can be implemented in LLVM with a zero
1640 length array type. An implementation of 'pascal style arrays' in LLVM could
1641 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1642
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1643</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1644
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1645<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1646<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1647
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1648<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1649
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1650<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1651<p>The function type can be thought of as a function signature. It consists of
1652 a return type and a list of formal parameter types. The return type of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1653 function type is a scalar type, a void type, a struct type, or a union
1654 type. If the return type is a struct type then all struct elements must be
1655 of first class types, and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1656
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1657<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1658<pre>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1659 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1660</pre>
1661
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1662<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1663 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1664 which indicates that the function takes a variable number of arguments.
1665 Variable argument functions can access their arguments with
1666 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1667 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1668 <a href="#t_label">label</a>.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1669
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1670<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1671<table class="layout">
1672 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1673 <td class="left"><tt>i32 (i32)</tt></td>
1674 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1675 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1676 </tr><tr class="layout">
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1677 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1678 </tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1679 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1680 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1681 returning <tt>float</tt>.
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1682 </td>
1683 </tr><tr class="layout">
1684 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1685 <td class="left">A vararg function that takes at least one
1686 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1687 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1688 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1689 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1690 </tr><tr class="layout">
1691 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1692 <td class="left">A function taking an <tt>i32</tt>, returning a
1693 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1694 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1695 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1696</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1697
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1698</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1699
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1700<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1701<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1702
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1703<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1704
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1705<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1706<p>The structure type is used to represent a collection of data members together
1707 in memory. The packing of the field types is defined to match the ABI of the
1708 underlying processor. The elements of a structure may be any type that has a
1709 size.</p>
1710
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]1711<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1712 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1713 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1714 Structures in registers are accessed using the
1715 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1716 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1717<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1718<pre>
1719 { &lt;type list&gt; }
1720</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1721
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1722<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1723<table class="layout">
1724 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1725 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1726 <td class="left">A triple of three <tt>i32</tt> values</td>
1727 </tr><tr class="layout">
1728 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1729 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1730 second element is a <a href="#t_pointer">pointer</a> to a
1731 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1732 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1733 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1734</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1735
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1736</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1737
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1738<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1739<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1740</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1741
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1742<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1743
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1744<h5>Overview:</h5>
1745<p>The packed structure type is used to represent a collection of data members
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1746 together in memory. There is no padding between fields. Further, the
1747 alignment of a packed structure is 1 byte. The elements of a packed
1748 structure may be any type that has a size.</p>
1749
1750<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1751 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1752 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1753
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1754<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1755<pre>
1756 &lt; { &lt;type list&gt; } &gt;
1757</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1758
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1759<h5>Examples:</h5>
1760<table class="layout">
1761 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1762 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1763 <td class="left">A triple of three <tt>i32</tt> values</td>
1764 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1765 <td class="left">
1766<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1767 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1768 second element is a <a href="#t_pointer">pointer</a> to a
1769 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1770 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1771 </tr>
1772</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1773
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1774</div>
1775
1776<!-- _______________________________________________________________________ -->
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1777<div class="doc_subsubsection"> <a name="t_union">Union Type</a> </div>
1778
1779<div class="doc_text">
1780
1781<h5>Overview:</h5>
1782<p>A union type describes an object with size and alignment suitable for
1783 an object of any one of a given set of types (also known as an "untagged"
1784 union). It is similar in concept and usage to a
1785 <a href="#t_struct">struct</a>, except that all members of the union
1786 have an offset of zero. The elements of a union may be any type that has a
1787 size. Unions must have at least one member - empty unions are not allowed.
1788 </p>
1789
1790<p>The size of the union as a whole will be the size of its largest member,
1791 and the alignment requirements of the union as a whole will be the largest
1792 alignment requirement of any member.</p>
1793
Dan Gohman1ad14992010-02-25 16:51:31 +0000[diff] [blame]1794<p>Union members are accessed using '<tt><a href="#i_load">load</a></tt> and
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1795 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1796 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1797 Since all members are at offset zero, the getelementptr instruction does
1798 not affect the address, only the type of the resulting pointer.</p>
1799
1800<h5>Syntax:</h5>
1801<pre>
1802 union { &lt;type list&gt; }
1803</pre>
1804
1805<h5>Examples:</h5>
1806<table class="layout">
1807 <tr class="layout">
1808 <td class="left"><tt>union { i32, i32*, float }</tt></td>
1809 <td class="left">A union of three types: an <tt>i32</tt>, a pointer to
1810 an <tt>i32</tt>, and a <tt>float</tt>.</td>
1811 </tr><tr class="layout">
1812 <td class="left">
1813 <tt>union {&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1814 <td class="left">A union, where the first element is a <tt>float</tt> and the
1815 second element is a <a href="#t_pointer">pointer</a> to a
1816 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1817 an <tt>i32</tt>.</td>
1818 </tr>
1819</table>
1820
1821</div>
1822
1823<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1824<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1825
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1826<div class="doc_text">
1827
1828<h5>Overview:</h5>
Dan Gohman88481112010-02-25 16:50:07 +0000[diff] [blame]1829<p>The pointer type is used to specify memory locations.
1830 Pointers are commonly used to reference objects in memory.</p>
1831
1832<p>Pointer types may have an optional address space attribute defining the
1833 numbered address space where the pointed-to object resides. The default
1834 address space is number zero. The semantics of non-zero address
1835 spaces are target-specific.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1836
1837<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1838 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1839
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1840<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1841<pre>
1842 &lt;type&gt; *
1843</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1844
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1845<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1846<table class="layout">
1847 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]1848 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1849 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1850 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1851 </tr>
1852 <tr class="layout">
1853 <td class="left"><tt>i32 (i32 *) *</tt></td>
1854 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1855 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1856 <tt>i32</tt>.</td>
1857 </tr>
1858 <tr class="layout">
1859 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1860 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1861 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1862 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1863</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1864
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1865</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1866
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1867<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1868<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1869
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1870<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1871
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1872<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1873<p>A vector type is a simple derived type that represents a vector of elements.
1874 Vector types are used when multiple primitive data are operated in parallel
1875 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sands31c0e0e2009-11-27 13:38:03 +0000[diff] [blame]1876 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1877 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1878
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1879<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1880<pre>
1881 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1882</pre>
1883
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1884<p>The number of elements is a constant integer value; elementtype may be any
1885 integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1886
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1887<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1888<table class="layout">
1889 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1890 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1891 <td class="left">Vector of 4 32-bit integer values.</td>
1892 </tr>
1893 <tr class="layout">
1894 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1895 <td class="left">Vector of 8 32-bit floating-point values.</td>
1896 </tr>
1897 <tr class="layout">
1898 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1899 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1900 </tr>
1901</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1902
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1903</div>
1904
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1905<!-- _______________________________________________________________________ -->
1906<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1907<div class="doc_text">
1908
1909<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1910<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1911 corresponds (for example) to the C notion of a forward declared structure
1912 type. In LLVM, opaque types can eventually be resolved to any type (not just
1913 a structure type).</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1914
1915<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1916<pre>
1917 opaque
1918</pre>
1919
1920<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1921<table class="layout">
1922 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1923 <td class="left"><tt>opaque</tt></td>
1924 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1925 </tr>
1926</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1927
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1928</div>
1929
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1930<!-- ======================================================================= -->
1931<div class="doc_subsection">
1932 <a name="t_uprefs">Type Up-references</a>
1933</div>
1934
1935<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1936
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1937<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1938<p>An "up reference" allows you to refer to a lexically enclosing type without
1939 requiring it to have a name. For instance, a structure declaration may
1940 contain a pointer to any of the types it is lexically a member of. Example
1941 of up references (with their equivalent as named type declarations)
1942 include:</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1943
1944<pre>
Chris Lattnerbf1d5452009-02-09 10:00:56 +0000[diff] [blame]1945 { \2 * } %x = type { %x* }
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1946 { \2 }* %y = type { %y }*
1947 \1* %z = type %z*
1948</pre>
1949
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1950<p>An up reference is needed by the asmprinter for printing out cyclic types
1951 when there is no declared name for a type in the cycle. Because the
1952 asmprinter does not want to print out an infinite type string, it needs a
1953 syntax to handle recursive types that have no names (all names are optional
1954 in llvm IR).</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1955
1956<h5>Syntax:</h5>
1957<pre>
1958 \&lt;level&gt;
1959</pre>
1960
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1961<p>The level is the count of the lexical type that is being referred to.</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1962
1963<h5>Examples:</h5>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1964<table class="layout">
1965 <tr class="layout">
1966 <td class="left"><tt>\1*</tt></td>
1967 <td class="left">Self-referential pointer.</td>
1968 </tr>
1969 <tr class="layout">
1970 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1971 <td class="left">Recursive structure where the upref refers to the out-most
1972 structure.</td>
1973 </tr>
1974</table>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1975
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1976</div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1977
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1978<!-- *********************************************************************** -->
1979<div class="doc_section"> <a name="constants">Constants</a> </div>
1980<!-- *********************************************************************** -->
1981
1982<div class="doc_text">
1983
1984<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1985 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1986
1987</div>
1988
1989<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1990<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1991
1992<div class="doc_text">
1993
1994<dl>
1995 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1996 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1997 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1998
1999 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2000 <dd>Standard integers (such as '4') are constants of
2001 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2002 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2003
2004 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2005 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2006 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2007 notation (see below). The assembler requires the exact decimal value of a
2008 floating-point constant. For example, the assembler accepts 1.25 but
2009 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2010 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2011
2012 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2013 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2014 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2015</dl>
2016
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2017<p>The one non-intuitive notation for constants is the hexadecimal form of
2018 floating point constants. For example, the form '<tt>double
2019 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2020 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2021 constants are required (and the only time that they are generated by the
2022 disassembler) is when a floating point constant must be emitted but it cannot
2023 be represented as a decimal floating point number in a reasonable number of
2024 digits. For example, NaN's, infinities, and other special values are
2025 represented in their IEEE hexadecimal format so that assembly and disassembly
2026 do not cause any bits to change in the constants.</p>
2027
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]2028<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2029 represented using the 16-digit form shown above (which matches the IEEE754
2030 representation for double); float values must, however, be exactly
2031 representable as IEE754 single precision. Hexadecimal format is always used
2032 for long double, and there are three forms of long double. The 80-bit format
2033 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2034 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2035 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2036 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2037 currently supported target uses this format. Long doubles will only work if
2038 they match the long double format on your target. All hexadecimal formats
2039 are big-endian (sign bit at the left).</p>
2040
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2041</div>
2042
2043<!-- ======================================================================= -->
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2044<div class="doc_subsection">
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2045<a name="aggregateconstants"></a> <!-- old anchor -->
2046<a name="complexconstants">Complex Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2047</div>
2048
2049<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2050
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2051<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2052 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2053
2054<dl>
2055 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2056 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2057 type definitions (a comma separated list of elements, surrounded by braces
2058 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2059 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2060 Structure constants must have <a href="#t_struct">structure type</a>, and
2061 the number and types of elements must match those specified by the
2062 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2063
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2064 <dt><b>Union constants</b></dt>
2065 <dd>Union constants are represented with notation similar to a structure with
2066 a single element - that is, a single typed element surrounded
2067 by braces (<tt>{}</tt>)). For example: "<tt>{ i32 4 }</tt>". The
2068 <a href="#t_union">union type</a> can be initialized with a single-element
2069 struct as long as the type of the struct element matches the type of
2070 one of the union members.</dd>
2071
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2072 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2073 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2074 definitions (a comma separated list of elements, surrounded by square
2075 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2076 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2077 the number and types of elements must match those specified by the
2078 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2079
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2080 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2081 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2082 definitions (a comma separated list of elements, surrounded by
2083 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2084 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2085 have <a href="#t_vector">vector type</a>, and the number and types of
2086 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2087
2088 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2089 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2090 value to zero of <em>any</em> type, including scalar and
2091 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2092 This is often used to avoid having to print large zero initializers
2093 (e.g. for large arrays) and is always exactly equivalent to using explicit
2094 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2095
2096 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]2097 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2098 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2099 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2100 be interpreted as part of the instruction stream, metadata is a place to
2101 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2102</dl>
2103
2104</div>
2105
2106<!-- ======================================================================= -->
2107<div class="doc_subsection">
2108 <a name="globalconstants">Global Variable and Function Addresses</a>
2109</div>
2110
2111<div class="doc_text">
2112
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2113<p>The addresses of <a href="#globalvars">global variables</a>
2114 and <a href="#functionstructure">functions</a> are always implicitly valid
2115 (link-time) constants. These constants are explicitly referenced when
2116 the <a href="#identifiers">identifier for the global</a> is used and always
2117 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2118 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2119
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2120<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2121<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]2122@X = global i32 17
2123@Y = global i32 42
2124@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2125</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2126</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2127
2128</div>
2129
2130<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]2131<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2132<div class="doc_text">
2133
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2134<p>The string '<tt>undef</tt>' can be used anywhere a constant is expected, and
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]2135 indicates that the user of the value may receive an unspecified bit-pattern.
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2136 Undefined values may be of any type (other than label or void) and be used
2137 anywhere a constant is permitted.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2138
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2139<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2140 program is well defined no matter what value is used. This gives the
2141 compiler more freedom to optimize. Here are some examples of (potentially
2142 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2143
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2144
2145<div class="doc_code">
2146<pre>
2147 %A = add %X, undef
2148 %B = sub %X, undef
2149 %C = xor %X, undef
2150Safe:
2151 %A = undef
2152 %B = undef
2153 %C = undef
2154</pre>
2155</div>
2156
2157<p>This is safe because all of the output bits are affected by the undef bits.
2158Any output bit can have a zero or one depending on the input bits.</p>
2159
2160<div class="doc_code">
2161<pre>
2162 %A = or %X, undef
2163 %B = and %X, undef
2164Safe:
2165 %A = -1
2166 %B = 0
2167Unsafe:
2168 %A = undef
2169 %B = undef
2170</pre>
2171</div>
2172
2173<p>These logical operations have bits that are not always affected by the input.
2174For example, if "%X" has a zero bit, then the output of the 'and' operation will
2175always be a zero, no matter what the corresponding bit from the undef is. As
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2176such, it is unsafe to optimize or assume that the result of the and is undef.
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2177However, it is safe to assume that all bits of the undef could be 0, and
2178optimize the and to 0. Likewise, it is safe to assume that all the bits of
2179the undef operand to the or could be set, allowing the or to be folded to
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2180-1.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2181
2182<div class="doc_code">
2183<pre>
2184 %A = select undef, %X, %Y
2185 %B = select undef, 42, %Y
2186 %C = select %X, %Y, undef
2187Safe:
2188 %A = %X (or %Y)
2189 %B = 42 (or %Y)
2190 %C = %Y
2191Unsafe:
2192 %A = undef
2193 %B = undef
2194 %C = undef
2195</pre>
2196</div>
2197
2198<p>This set of examples show that undefined select (and conditional branch)
2199conditions can go "either way" but they have to come from one of the two
2200operands. In the %A example, if %X and %Y were both known to have a clear low
2201bit, then %A would have to have a cleared low bit. However, in the %C example,
2202the optimizer is allowed to assume that the undef operand could be the same as
2203%Y, allowing the whole select to be eliminated.</p>
2204
2205
2206<div class="doc_code">
2207<pre>
2208 %A = xor undef, undef
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2209
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2210 %B = undef
2211 %C = xor %B, %B
2212
2213 %D = undef
2214 %E = icmp lt %D, 4
2215 %F = icmp gte %D, 4
2216
2217Safe:
2218 %A = undef
2219 %B = undef
2220 %C = undef
2221 %D = undef
2222 %E = undef
2223 %F = undef
2224</pre>
2225</div>
2226
2227<p>This example points out that two undef operands are not necessarily the same.
2228This can be surprising to people (and also matches C semantics) where they
2229assume that "X^X" is always zero, even if X is undef. This isn't true for a
2230number of reasons, but the short answer is that an undef "variable" can
2231arbitrarily change its value over its "live range". This is true because the
2232"variable" doesn't actually <em>have a live range</em>. Instead, the value is
2233logically read from arbitrary registers that happen to be around when needed,
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]2234so the value is not necessarily consistent over time. In fact, %A and %C need
Chris Lattner6760e542009-09-08 15:13:16 +0000[diff] [blame]2235to have the same semantics or the core LLVM "replace all uses with" concept
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2236would not hold.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2237
2238<div class="doc_code">
2239<pre>
2240 %A = fdiv undef, %X
2241 %B = fdiv %X, undef
2242Safe:
2243 %A = undef
2244b: unreachable
2245</pre>
2246</div>
2247
2248<p>These examples show the crucial difference between an <em>undefined
2249value</em> and <em>undefined behavior</em>. An undefined value (like undef) is
2250allowed to have an arbitrary bit-pattern. This means that the %A operation
2251can be constant folded to undef because the undef could be an SNaN, and fdiv is
2252not (currently) defined on SNaN's. However, in the second example, we can make
2253a more aggressive assumption: because the undef is allowed to be an arbitrary
2254value, we are allowed to assume that it could be zero. Since a divide by zero
Chris Lattner10ff0c12009-09-08 19:45:34 +0000[diff] [blame]2255has <em>undefined behavior</em>, we are allowed to assume that the operation
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2256does not execute at all. This allows us to delete the divide and all code after
2257it: since the undefined operation "can't happen", the optimizer can assume that
2258it occurs in dead code.
2259</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2260
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2261<div class="doc_code">
2262<pre>
2263a: store undef -> %X
2264b: store %X -> undef
2265Safe:
2266a: &lt;deleted&gt;
2267b: unreachable
2268</pre>
2269</div>
2270
2271<p>These examples reiterate the fdiv example: a store "of" an undefined value
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2272can be assumed to not have any effect: we can assume that the value is
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2273overwritten with bits that happen to match what was already there. However, a
2274store "to" an undefined location could clobber arbitrary memory, therefore, it
2275has undefined behavior.</p>
2276
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2277</div>
2278
2279<!-- ======================================================================= -->
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]2280<div class="doc_subsection"><a name="blockaddress">Addresses of Basic
2281 Blocks</a></div>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2282<div class="doc_text">
2283
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2284<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2285
2286<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner5c5f0ac2009-10-27 21:49:40 +0000[diff] [blame]2287 basic block in the specified function, and always has an i8* type. Taking
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2288 the address of the entry block is illegal.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2289
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2290<p>This value only has defined behavior when used as an operand to the
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2291 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction or for comparisons
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2292 against null. Pointer equality tests between labels addresses is undefined
2293 behavior - though, again, comparison against null is ok, and no label is
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]2294 equal to the null pointer. This may also be passed around as an opaque
2295 pointer sized value as long as the bits are not inspected. This allows
Chris Lattnerda37b302009-10-27 21:44:20 +0000[diff] [blame]2296 <tt>ptrtoint</tt> and arithmetic to be performed on these values so long as
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2297 the original value is reconstituted before the <tt>indirectbr</tt>.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2298
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]2299<p>Finally, some targets may provide defined semantics when
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2300 using the value as the operand to an inline assembly, but that is target
2301 specific.
2302 </p>
2303
2304</div>
2305
2306
2307<!-- ======================================================================= -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2308<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
2309</div>
2310
2311<div class="doc_text">
2312
2313<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2314 to be used as constants. Constant expressions may be of
2315 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2316 operation that does not have side effects (e.g. load and call are not
2317 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2318
2319<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2320 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2321 <dd>Truncate a constant to another type. The bit size of CST must be larger
2322 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2323
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2324 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2325 <dd>Zero extend a constant to another type. The bit size of CST must be
2326 smaller or equal to the bit size of TYPE. Both types must be
2327 integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2328
2329 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2330 <dd>Sign extend a constant to another type. The bit size of CST must be
2331 smaller or equal to the bit size of TYPE. Both types must be
2332 integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2333
2334 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2335 <dd>Truncate a floating point constant to another floating point type. The
2336 size of CST must be larger than the size of TYPE. Both types must be
2337 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2338
2339 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2340 <dd>Floating point extend a constant to another type. The size of CST must be
2341 smaller or equal to the size of TYPE. Both types must be floating
2342 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2343
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]2344 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2345 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2346 constant. TYPE must be a scalar or vector integer type. CST must be of
2347 scalar or vector floating point type. Both CST and TYPE must be scalars,
2348 or vectors of the same number of elements. If the value won't fit in the
2349 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2350
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2351 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2352 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2353 constant. TYPE must be a scalar or vector integer type. CST must be of
2354 scalar or vector floating point type. Both CST and TYPE must be scalars,
2355 or vectors of the same number of elements. If the value won't fit in the
2356 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2357
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2358 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2359 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2360 constant. TYPE must be a scalar or vector floating point type. CST must be
2361 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2362 vectors of the same number of elements. If the value won't fit in the
2363 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2364
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2365 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2366 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2367 constant. TYPE must be a scalar or vector floating point type. CST must be
2368 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2369 vectors of the same number of elements. If the value won't fit in the
2370 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2371
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2372 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2373 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2374 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2375 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2376 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2377
2378 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2379 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2380 type. CST must be of integer type. The CST value is zero extended,
2381 truncated, or unchanged to make it fit in a pointer size. This one is
2382 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2383
2384 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2385 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2386 are the same as those for the <a href="#i_bitcast">bitcast
2387 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2388
2389 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]2390 <dt><b><tt>getelementptr inbounds ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2391 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2392 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2393 instruction, the index list may have zero or more indexes, which are
2394 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2395
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2396 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2397 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2398
2399 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2400 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2401
2402 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2403 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2404
2405 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2406 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2407 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2408
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]2409 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2410 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2411 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2412
2413 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2414 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2415 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2416
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2417 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2418 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2419 be any of the <a href="#binaryops">binary</a>
2420 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2421 on operands are the same as those for the corresponding instruction
2422 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2423</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2424
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2425</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2426
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2427<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2428<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2429<!-- *********************************************************************** -->
2430
2431<!-- ======================================================================= -->
2432<div class="doc_subsection">
2433<a name="inlineasm">Inline Assembler Expressions</a>
2434</div>
2435
2436<div class="doc_text">
2437
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2438<p>LLVM supports inline assembler expressions (as opposed
2439 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2440 a special value. This value represents the inline assembler as a string
2441 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2442 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2443 expression has side effects, and a flag indicating whether the function
2444 containing the asm needs to align its stack conservatively. An example
2445 inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2446
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2447<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2448<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2449i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2450</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2451</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2452
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2453<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2454 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2455 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2456
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2457<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2458<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2459%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2460</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2461</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2462
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2463<p>Inline asms with side effects not visible in the constraint list must be
2464 marked as having side effects. This is done through the use of the
2465 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2466
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2467<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2468<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2469call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2470</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2471</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2472
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2473<p>In some cases inline asms will contain code that will not work unless the
2474 stack is aligned in some way, such as calls or SSE instructions on x86,
2475 yet will not contain code that does that alignment within the asm.
2476 The compiler should make conservative assumptions about what the asm might
2477 contain and should generate its usual stack alignment code in the prologue
2478 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2479
2480<div class="doc_code">
2481<pre>
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2482call void asm alignstack "eieio", ""()
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2483</pre>
2484</div>
2485
2486<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2487 first.</p>
2488
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2489<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2490 documented here. Constraints on what can be done (e.g. duplication, moving,
2491 etc need to be documented). This is probably best done by reference to
2492 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2493
2494</div>
2495
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2496<!-- ======================================================================= -->
2497<div class="doc_subsection"><a name="metadata">Metadata Nodes and Metadata
2498 Strings</a>
2499</div>
2500
2501<div class="doc_text">
2502
2503<p>LLVM IR allows metadata to be attached to instructions in the program that
2504 can convey extra information about the code to the optimizers and code
2505 generator. One example application of metadata is source-level debug
2506 information. There are two metadata primitives: strings and nodes. All
2507 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2508 preceding exclamation point ('<tt>!</tt>').</p>
2509
2510<p>A metadata string is a string surrounded by double quotes. It can contain
2511 any character by escaping non-printable characters with "\xx" where "xx" is
2512 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2513
2514<p>Metadata nodes are represented with notation similar to structure constants
2515 (a comma separated list of elements, surrounded by braces and preceded by an
2516 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2517 10}</tt>". Metadata nodes can have any values as their operand.</p>
2518
2519<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2520 metadata nodes, which can be looked up in the module symbol table. For
2521 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2522
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame^]2523<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
2524 function is using two metadata arguments.
2525
2526 <div class="doc_code">
2527 <pre>
2528 call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2529 </pre>
2530 </div></p>
2531
2532<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
2533 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.
2534
2535 <div class="doc_code">
2536 <pre>
2537 %indvar.next = add i64 %indvar, 1, !dbg !21
2538 </pre>
2539 </div></p>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2540</div>
2541
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2542
2543<!-- *********************************************************************** -->
2544<div class="doc_section">
2545 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2546</div>
2547<!-- *********************************************************************** -->
2548
2549<p>LLVM has a number of "magic" global variables that contain data that affect
2550code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2551of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2552section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2553by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2554
2555<!-- ======================================================================= -->
2556<div class="doc_subsection">
2557<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2558</div>
2559
2560<div class="doc_text">
2561
2562<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2563href="#linkage_appending">appending linkage</a>. This array contains a list of
2564pointers to global variables and functions which may optionally have a pointer
2565cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2566
2567<pre>
2568 @X = global i8 4
2569 @Y = global i32 123
2570
2571 @llvm.used = appending global [2 x i8*] [
2572 i8* @X,
2573 i8* bitcast (i32* @Y to i8*)
2574 ], section "llvm.metadata"
2575</pre>
2576
2577<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2578compiler, assembler, and linker are required to treat the symbol as if there is
2579a reference to the global that it cannot see. For example, if a variable has
2580internal linkage and no references other than that from the <tt>@llvm.used</tt>
2581list, it cannot be deleted. This is commonly used to represent references from
2582inline asms and other things the compiler cannot "see", and corresponds to
2583"attribute((used))" in GNU C.</p>
2584
2585<p>On some targets, the code generator must emit a directive to the assembler or
2586object file to prevent the assembler and linker from molesting the symbol.</p>
2587
2588</div>
2589
2590<!-- ======================================================================= -->
2591<div class="doc_subsection">
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2592<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2593</div>
2594
2595<div class="doc_text">
2596
2597<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2598<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2599touching the symbol. On targets that support it, this allows an intelligent
2600linker to optimize references to the symbol without being impeded as it would be
2601by <tt>@llvm.used</tt>.</p>
2602
2603<p>This is a rare construct that should only be used in rare circumstances, and
2604should not be exposed to source languages.</p>
2605
2606</div>
2607
2608<!-- ======================================================================= -->
2609<div class="doc_subsection">
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2610<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2611</div>
2612
2613<div class="doc_text">
2614
2615<p>TODO: Describe this.</p>
2616
2617</div>
2618
2619<!-- ======================================================================= -->
2620<div class="doc_subsection">
2621<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2622</div>
2623
2624<div class="doc_text">
2625
2626<p>TODO: Describe this.</p>
2627
2628</div>
2629
2630
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2631<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2632<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2633<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2634
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2635<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2636
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2637<p>The LLVM instruction set consists of several different classifications of
2638 instructions: <a href="#terminators">terminator
2639 instructions</a>, <a href="#binaryops">binary instructions</a>,
2640 <a href="#bitwiseops">bitwise binary instructions</a>,
2641 <a href="#memoryops">memory instructions</a>, and
2642 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2643
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2644</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2645
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2646<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2647<div class="doc_subsection"> <a name="terminators">Terminator
2648Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2649
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2650<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2651
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2652<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2653 in a program ends with a "Terminator" instruction, which indicates which
2654 block should be executed after the current block is finished. These
2655 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2656 control flow, not values (the one exception being the
2657 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2658
2659<p>There are six different terminator instructions: the
2660 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2661 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2662 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling33fef7e2009-11-02 00:25:26 +0000[diff] [blame]2663 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2664 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2665 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2666 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2667
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2668</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2669
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2670<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2671<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2672Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2673
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2674<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2675
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2676<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2677<pre>
2678 ret &lt;type&gt; &lt;value&gt; <i>; Return a value from a non-void function</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2679 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2680</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2681
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2682<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2683<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2684 a value) from a function back to the caller.</p>
2685
2686<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2687 value and then causes control flow, and one that just causes control flow to
2688 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2689
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2690<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2691<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2692 return value. The type of the return value must be a
2693 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2694
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2695<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2696 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2697 value or a return value with a type that does not match its type, or if it
2698 has a void return type and contains a '<tt>ret</tt>' instruction with a
2699 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2700
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2701<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2702<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2703 the calling function's context. If the caller is a
2704 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2705 instruction after the call. If the caller was an
2706 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2707 the beginning of the "normal" destination block. If the instruction returns
2708 a value, that value shall set the call or invoke instruction's return
2709 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2710
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2711<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2712<pre>
2713 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2714 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]2715 ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2716</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2717
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2718</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2719<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2720<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2721
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2722<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2723
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2724<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2725<pre>
2726 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2727</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2728
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2729<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2730<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2731 different basic block in the current function. There are two forms of this
2732 instruction, corresponding to a conditional branch and an unconditional
2733 branch.</p>
2734
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2735<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2736<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2737 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2738 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2739 target.</p>
2740
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2741<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2742<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2743 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2744 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2745 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2746
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2747<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2748<pre>
2749Test:
2750 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2751 br i1 %cond, label %IfEqual, label %IfUnequal
2752IfEqual:
2753 <a href="#i_ret">ret</a> i32 1
2754IfUnequal:
2755 <a href="#i_ret">ret</a> i32 0
2756</pre>
2757
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2758</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2759
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2760<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2761<div class="doc_subsubsection">
2762 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2763</div>
2764
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2765<div class="doc_text">
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2766
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2767<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2768<pre>
2769 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2770</pre>
2771
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2772<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2773<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2774 several different places. It is a generalization of the '<tt>br</tt>'
2775 instruction, allowing a branch to occur to one of many possible
2776 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2777
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2778<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2779<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2780 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2781 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2782 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2783
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2784<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2785<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2786 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2787 is searched for the given value. If the value is found, control flow is
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]2788 transferred to the corresponding destination; otherwise, control flow is
2789 transferred to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2790
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2791<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2792<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2793 <tt>switch</tt> instruction, this instruction may be code generated in
2794 different ways. For example, it could be generated as a series of chained
2795 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2796
2797<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2798<pre>
2799 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2800 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2801 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2802
2803 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2804 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2805
2806 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2807 switch i32 %val, label %otherwise [ i32 0, label %onzero
2808 i32 1, label %onone
2809 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2810</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2811
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2812</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2813
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2814
2815<!-- _______________________________________________________________________ -->
2816<div class="doc_subsubsection">
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2817 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2818</div>
2819
2820<div class="doc_text">
2821
2822<h5>Syntax:</h5>
2823<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2824 indirectbr &lt;somety&gt;* &lt;address&gt;, [ label &lt;dest1&gt;, label &lt;dest2&gt;, ... ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2825</pre>
2826
2827<h5>Overview:</h5>
2828
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2829<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2830 within the current function, whose address is specified by
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2831 "<tt>address</tt>". Address must be derived from a <a
2832 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2833
2834<h5>Arguments:</h5>
2835
2836<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
2837 rest of the arguments indicate the full set of possible destinations that the
2838 address may point to. Blocks are allowed to occur multiple times in the
2839 destination list, though this isn't particularly useful.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2840
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2841<p>This destination list is required so that dataflow analysis has an accurate
2842 understanding of the CFG.</p>
2843
2844<h5>Semantics:</h5>
2845
2846<p>Control transfers to the block specified in the address argument. All
2847 possible destination blocks must be listed in the label list, otherwise this
2848 instruction has undefined behavior. This implies that jumps to labels
2849 defined in other functions have undefined behavior as well.</p>
2850
2851<h5>Implementation:</h5>
2852
2853<p>This is typically implemented with a jump through a register.</p>
2854
2855<h5>Example:</h5>
2856<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]2857 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]2858</pre>
2859
2860</div>
2861
2862
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2863<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2864<div class="doc_subsubsection">
2865 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2866</div>
2867
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2868<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2869
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2870<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2871<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2872 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ptr to function ty&gt; &lt;function ptr val&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner6b7a0082006-05-14 18:23:06 +0000[diff] [blame]2873 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2874</pre>
2875
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2876<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2877<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2878 function, with the possibility of control flow transfer to either the
2879 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2880 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2881 control flow will return to the "normal" label. If the callee (or any
2882 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2883 instruction, control is interrupted and continued at the dynamically nearest
2884 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2885
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2886<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2887<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2888
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2889<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2890 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2891 convention</a> the call should use. If none is specified, the call
2892 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2893
2894 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2895 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
2896 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2897
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2898 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2899 function value being invoked. In most cases, this is a direct function
2900 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
2901 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2902
2903 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2904 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2905
2906 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]2907 signature argument types and parameter attributes. All arguments must be
2908 of <a href="#t_firstclass">first class</a> type. If the function
2909 signature indicates the function accepts a variable number of arguments,
2910 the extra arguments can be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2911
2912 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2913 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2914
2915 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2916 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2917
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2918 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2919 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2920 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2921</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2922
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2923<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2924<p>This instruction is designed to operate as a standard
2925 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
2926 primary difference is that it establishes an association with a label, which
2927 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2928
2929<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2930 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2931 exception. Additionally, this is important for implementation of
2932 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2933
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2934<p>For the purposes of the SSA form, the definition of the value returned by the
2935 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
2936 block to the "normal" label. If the callee unwinds then no return value is
2937 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]2938
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]2939<p>Note that the code generator does not yet completely support unwind, and
2940that the invoke/unwind semantics are likely to change in future versions.</p>
2941
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2942<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2943<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2944 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2945 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2946 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2947 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2948</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2949
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2950</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2951
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2952<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2953
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2954<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2955Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2956
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2957<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2958
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2959<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2960<pre>
2961 unwind
2962</pre>
2963
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2964<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2965<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2966 at the first callee in the dynamic call stack which used
2967 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
2968 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2969
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2970<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2971<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2972 immediately halt. The dynamic call stack is then searched for the
2973 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
2974 Once found, execution continues at the "exceptional" destination block
2975 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
2976 instruction in the dynamic call chain, undefined behavior results.</p>
2977
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]2978<p>Note that the code generator does not yet completely support unwind, and
2979that the invoke/unwind semantics are likely to change in future versions.</p>
2980
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2981</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2982
2983<!-- _______________________________________________________________________ -->
2984
2985<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2986Instruction</a> </div>
2987
2988<div class="doc_text">
2989
2990<h5>Syntax:</h5>
2991<pre>
2992 unreachable
2993</pre>
2994
2995<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2996<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2997 instruction is used to inform the optimizer that a particular portion of the
2998 code is not reachable. This can be used to indicate that the code after a
2999 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3000
3001<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3002<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3003
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3004</div>
3005
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3006<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3007<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3008
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3009<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3010
3011<p>Binary operators are used to do most of the computation in a program. They
3012 require two operands of the same type, execute an operation on them, and
3013 produce a single value. The operands might represent multiple data, as is
3014 the case with the <a href="#t_vector">vector</a> data type. The result value
3015 has the same type as its operands.</p>
3016
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3017<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3018
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3019</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3020
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3021<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3022<div class="doc_subsubsection">
3023 <a name="i_add">'<tt>add</tt>' Instruction</a>
3024</div>
3025
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3026<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3027
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3028<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3029<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3030 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3031 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3032 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3033 &lt;result&gt; = add nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3034</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3035
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3036<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3037<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3038
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3039<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3040<p>The two arguments to the '<tt>add</tt>' instruction must
3041 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3042 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3043
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3044<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3045<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3046
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3047<p>If the sum has unsigned overflow, the result returned is the mathematical
3048 result modulo 2<sup>n</sup>, where n is the bit width of the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3049
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3050<p>Because LLVM integers use a two's complement representation, this instruction
3051 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3052
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3053<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3054 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3055 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
3056 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3057
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3058<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3059<pre>
3060 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3061</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3062
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3063</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3064
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3065<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3066<div class="doc_subsubsection">
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3067 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
3068</div>
3069
3070<div class="doc_text">
3071
3072<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3073<pre>
3074 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3075</pre>
3076
3077<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3078<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3079
3080<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3081<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3082 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3083 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3084
3085<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3086<p>The value produced is the floating point sum of the two operands.</p>
3087
3088<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3089<pre>
3090 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3091</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3092
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3093</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3094
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3095<!-- _______________________________________________________________________ -->
3096<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3097 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
3098</div>
3099
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3100<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3101
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3102<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3103<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3104 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3105 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3106 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3107 &lt;result&gt; = sub nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3108</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3109
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3110<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3111<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3112 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3113
3114<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3115 '<tt>neg</tt>' instruction present in most other intermediate
3116 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3117
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3118<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3119<p>The two arguments to the '<tt>sub</tt>' instruction must
3120 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3121 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3122
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3123<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3124<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3125
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3126<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3127 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3128 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3129
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3130<p>Because LLVM integers use a two's complement representation, this instruction
3131 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3132
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3133<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3134 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3135 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
3136 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3137
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3138<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3139<pre>
3140 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3141 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3142</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3143
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3144</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3145
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3146<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3147<div class="doc_subsubsection">
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3148 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
3149</div>
3150
3151<div class="doc_text">
3152
3153<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3154<pre>
3155 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3156</pre>
3157
3158<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3159<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3160 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3161
3162<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3163 '<tt>fneg</tt>' instruction present in most other intermediate
3164 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3165
3166<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]3167<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3168 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3169 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3170
3171<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3172<p>The value produced is the floating point difference of the two operands.</p>
3173
3174<h5>Example:</h5>
3175<pre>
3176 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3177 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3178</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3179
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3180</div>
3181
3182<!-- _______________________________________________________________________ -->
3183<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3184 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
3185</div>
3186
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3187<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3188
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3189<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3190<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3191 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3192 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3193 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3194 &lt;result&gt; = mul nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3195</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3196
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3197<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3198<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3199
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3200<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3201<p>The two arguments to the '<tt>mul</tt>' instruction must
3202 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3203 integer values. Both arguments must have identical types.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3204
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3205<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3206<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3207
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3208<p>If the result of the multiplication has unsigned overflow, the result
3209 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3210 width of the result.</p>
3211
3212<p>Because LLVM integers use a two's complement representation, and the result
3213 is the same width as the operands, this instruction returns the correct
3214 result for both signed and unsigned integers. If a full product
3215 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3216 be sign-extended or zero-extended as appropriate to the width of the full
3217 product.</p>
3218
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3219<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3220 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3221 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
3222 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3223
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3224<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3225<pre>
3226 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3227</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3228
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3229</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3230
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3231<!-- _______________________________________________________________________ -->
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3232<div class="doc_subsubsection">
3233 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
3234</div>
3235
3236<div class="doc_text">
3237
3238<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3239<pre>
3240 &lt;result&gt; = fmul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3241</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3242
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3243<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3244<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3245
3246<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3247<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3248 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3249 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3250
3251<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3252<p>The value produced is the floating point product of the two operands.</p>
3253
3254<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3255<pre>
3256 &lt;result&gt; = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3257</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3258
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3259</div>
3260
3261<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3262<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
3263</a></div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3264
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3265<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3266
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3267<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3268<pre>
3269 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3270</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3271
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3272<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3273<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3274
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3275<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3276<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3277 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3278 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3279
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3280<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3281<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3282
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3283<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3284 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3285
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3286<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3287
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3288<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3289<pre>
3290 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3291</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3292
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3293</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3294
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3295<!-- _______________________________________________________________________ -->
3296<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
3297</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3298
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3299<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3300
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3301<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3302<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3303 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3304 &lt;result&gt; = sdiv exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3305</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3306
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3307<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3308<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3309
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3310<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3311<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3312 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3313 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3314
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3315<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3316<p>The value produced is the signed integer quotient of the two operands rounded
3317 towards zero.</p>
3318
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3319<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3320 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3321
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3322<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3323 undefined behavior; this is a rare case, but can occur, for example, by doing
3324 a 32-bit division of -2147483648 by -1.</p>
3325
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]3326<p>If the <tt>exact</tt> keyword is present, the result value of the
3327 <tt>sdiv</tt> is undefined if the result would be rounded or if overflow
3328 would occur.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3329
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3330<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3331<pre>
3332 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3333</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3334
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3335</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3336
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3337<!-- _______________________________________________________________________ -->
3338<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3339Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3340
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3341<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3342
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3343<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3344<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3345 &lt;result&gt; = fdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3346</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3347
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3348<h5>Overview:</h5>
3349<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3350
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3351<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3352<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3353 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3354 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3355
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3356<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3357<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3358
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3359<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3360<pre>
3361 &lt;result&gt; = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3362</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3363
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3364</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3365
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3366<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3367<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3368</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3369
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3370<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3371
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3372<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3373<pre>
3374 &lt;result&gt; = urem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3375</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3376
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3377<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3378<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3379 division of its two arguments.</p>
3380
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3381<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3382<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3383 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3384 values. Both arguments must have identical types.</p>
3385
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3386<h5>Semantics:</h5>
3387<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3388 This instruction always performs an unsigned division to get the
3389 remainder.</p>
3390
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3391<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3392 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3393
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3394<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3395
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3396<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3397<pre>
3398 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3399</pre>
3400
3401</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3402
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3403<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3404<div class="doc_subsubsection">
3405 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
3406</div>
3407
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3408<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3409
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3410<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3411<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3412 &lt;result&gt; = srem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3413</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3414
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3415<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3416<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3417 division of its two operands. This instruction can also take
3418 <a href="#t_vector">vector</a> versions of the values in which case the
3419 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3420
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3421<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3422<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3423 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3424 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3425
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3426<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3427<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3428 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3429 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3430 a value. For more information about the difference,
3431 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3432 Math Forum</a>. For a table of how this is implemented in various languages,
3433 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3434 Wikipedia: modulo operation</a>.</p>
3435
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3436<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3437 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3438
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3439<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3440 Overflow also leads to undefined behavior; this is a rare case, but can
3441 occur, for example, by taking the remainder of a 32-bit division of
3442 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3443 lets srem be implemented using instructions that return both the result of
3444 the division and the remainder.)</p>
3445
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3446<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3447<pre>
3448 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3449</pre>
3450
3451</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3452
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3453<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3454<div class="doc_subsubsection">
3455 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3456
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3457<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3458
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3459<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3460<pre>
3461 &lt;result&gt; = frem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3462</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3463
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3464<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3465<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3466 its two operands.</p>
3467
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3468<h5>Arguments:</h5>
3469<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3470 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3471 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3472
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3473<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3474<p>This instruction returns the <i>remainder</i> of a division. The remainder
3475 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3476
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3477<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3478<pre>
3479 &lt;result&gt; = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3480</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3481
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3482</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3483
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3484<!-- ======================================================================= -->
3485<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3486Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3487
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3488<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3489
3490<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3491 program. They are generally very efficient instructions and can commonly be
3492 strength reduced from other instructions. They require two operands of the
3493 same type, execute an operation on them, and produce a single value. The
3494 resulting value is the same type as its operands.</p>
3495
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3496</div>
3497
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3498<!-- _______________________________________________________________________ -->
3499<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3500Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3501
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3502<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3503
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3504<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3505<pre>
3506 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3507</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3508
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3509<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3510<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3511 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3512
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3513<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3514<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3515 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3516 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3517
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3518<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3519<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3520 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3521 is (statically or dynamically) negative or equal to or larger than the number
3522 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3523 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3524 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3525
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3526<h5>Example:</h5>
3527<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3528 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3529 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3530 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3531 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3532 &lt;result&gt; = shl &lt;2 x i32&gt; &lt; i32 1, i32 1&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 2, i32 4&gt;</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3533</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3534
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3535</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3536
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3537<!-- _______________________________________________________________________ -->
3538<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3539Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3540
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3541<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3542
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3543<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3544<pre>
3545 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3546</pre>
3547
3548<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3549<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3550 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3551
3552<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3553<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3554 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3555 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3556
3557<h5>Semantics:</h5>
3558<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3559 significant bits of the result will be filled with zero bits after the shift.
3560 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3561 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3562 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3563 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3564
3565<h5>Example:</h5>
3566<pre>
3567 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3568 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3569 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3570 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3571 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3572 &lt;result&gt; = lshr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0x7FFFFFFF, i32 1&gt;</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3573</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3574
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3575</div>
3576
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3577<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3578<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3579Instruction</a> </div>
3580<div class="doc_text">
3581
3582<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3583<pre>
3584 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3585</pre>
3586
3587<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3588<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3589 operand shifted to the right a specified number of bits with sign
3590 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3591
3592<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3593<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3594 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3595 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3596
3597<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3598<p>This instruction always performs an arithmetic shift right operation, The
3599 most significant bits of the result will be filled with the sign bit
3600 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3601 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3602 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3603 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3604
3605<h5>Example:</h5>
3606<pre>
3607 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3608 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3609 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3610 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3611 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3612 &lt;result&gt; = ashr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 3&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 -1, i32 0&gt;</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3613</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3614
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3615</div>
3616
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3617<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3618<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3619Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3620
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3621<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3622
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3623<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3624<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3625 &lt;result&gt; = and &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3626</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3627
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3628<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3629<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3630 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3631
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3632<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3633<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3634 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3635 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3636
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3637<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3638<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3639
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3640<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3641 <tbody>
3642 <tr>
3643 <td>In0</td>
3644 <td>In1</td>
3645 <td>Out</td>
3646 </tr>
3647 <tr>
3648 <td>0</td>
3649 <td>0</td>
3650 <td>0</td>
3651 </tr>
3652 <tr>
3653 <td>0</td>
3654 <td>1</td>
3655 <td>0</td>
3656 </tr>
3657 <tr>
3658 <td>1</td>
3659 <td>0</td>
3660 <td>0</td>
3661 </tr>
3662 <tr>
3663 <td>1</td>
3664 <td>1</td>
3665 <td>1</td>
3666 </tr>
3667 </tbody>
3668</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3669
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3670<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3671<pre>
3672 &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3673 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3674 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3675</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3676</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3677<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3678<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3679
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3680<div class="doc_text">
3681
3682<h5>Syntax:</h5>
3683<pre>
3684 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3685</pre>
3686
3687<h5>Overview:</h5>
3688<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3689 two operands.</p>
3690
3691<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3692<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3693 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3694 values. Both arguments must have identical types.</p>
3695
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3696<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3697<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3698
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3699<table border="1" cellspacing="0" cellpadding="4">
3700 <tbody>
3701 <tr>
3702 <td>In0</td>
3703 <td>In1</td>
3704 <td>Out</td>
3705 </tr>
3706 <tr>
3707 <td>0</td>
3708 <td>0</td>
3709 <td>0</td>
3710 </tr>
3711 <tr>
3712 <td>0</td>
3713 <td>1</td>
3714 <td>1</td>
3715 </tr>
3716 <tr>
3717 <td>1</td>
3718 <td>0</td>
3719 <td>1</td>
3720 </tr>
3721 <tr>
3722 <td>1</td>
3723 <td>1</td>
3724 <td>1</td>
3725 </tr>
3726 </tbody>
3727</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3728
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3729<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3730<pre>
3731 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3732 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3733 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3734</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3735
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3736</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3737
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3738<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3739<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3740Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3741
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3742<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3743
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3744<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3745<pre>
3746 &lt;result&gt; = xor &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3747</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3748
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3749<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3750<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3751 its two operands. The <tt>xor</tt> is used to implement the "one's
3752 complement" operation, which is the "~" operator in C.</p>
3753
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3754<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3755<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3756 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3757 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3758
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3759<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3760<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3761
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3762<table border="1" cellspacing="0" cellpadding="4">
3763 <tbody>
3764 <tr>
3765 <td>In0</td>
3766 <td>In1</td>
3767 <td>Out</td>
3768 </tr>
3769 <tr>
3770 <td>0</td>
3771 <td>0</td>
3772 <td>0</td>
3773 </tr>
3774 <tr>
3775 <td>0</td>
3776 <td>1</td>
3777 <td>1</td>
3778 </tr>
3779 <tr>
3780 <td>1</td>
3781 <td>0</td>
3782 <td>1</td>
3783 </tr>
3784 <tr>
3785 <td>1</td>
3786 <td>1</td>
3787 <td>0</td>
3788 </tr>
3789 </tbody>
3790</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3791
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3792<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3793<pre>
3794 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3795 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3796 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3797 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3798</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3799
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3800</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3801
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3802<!-- ======================================================================= -->
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3803<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3804 <a name="vectorops">Vector Operations</a>
3805</div>
3806
3807<div class="doc_text">
3808
3809<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3810 target-independent manner. These instructions cover the element-access and
3811 vector-specific operations needed to process vectors effectively. While LLVM
3812 does directly support these vector operations, many sophisticated algorithms
3813 will want to use target-specific intrinsics to take full advantage of a
3814 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3815
3816</div>
3817
3818<!-- _______________________________________________________________________ -->
3819<div class="doc_subsubsection">
3820 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3821</div>
3822
3823<div class="doc_text">
3824
3825<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3826<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3827 &lt;result&gt; = extractelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, i32 &lt;idx&gt; <i>; yields &lt;ty&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3828</pre>
3829
3830<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3831<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3832 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3833
3834
3835<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3836<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3837 of <a href="#t_vector">vector</a> type. The second operand is an index
3838 indicating the position from which to extract the element. The index may be
3839 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3840
3841<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3842<p>The result is a scalar of the same type as the element type of
3843 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3844 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3845 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3846
3847<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3848<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]3849 &lt;result&gt; = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3850</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3851
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3852</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3853
3854<!-- _______________________________________________________________________ -->
3855<div class="doc_subsubsection">
3856 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3857</div>
3858
3859<div class="doc_text">
3860
3861<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3862<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]3863 &lt;result&gt; = insertelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, i32 &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3864</pre>
3865
3866<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3867<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3868 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3869
3870<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3871<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3872 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3873 whose type must equal the element type of the first operand. The third
3874 operand is an index indicating the position at which to insert the value.
3875 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3876
3877<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3878<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3879 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3880 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3881 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3882
3883<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3884<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]3885 &lt;result&gt; = insertelement &lt;4 x i32&gt; %vec, i32 1, i32 0 <i>; yields &lt;4 x i32&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3886</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3887
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3888</div>
3889
3890<!-- _______________________________________________________________________ -->
3891<div class="doc_subsubsection">
3892 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3893</div>
3894
3895<div class="doc_text">
3896
3897<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3898<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3899 &lt;result&gt; = shufflevector &lt;n x &lt;ty&gt;&gt; &lt;v1&gt;, &lt;n x &lt;ty&gt;&gt; &lt;v2&gt;, &lt;m x i32&gt; &lt;mask&gt; <i>; yields &lt;m x &lt;ty&gt;&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3900</pre>
3901
3902<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3903<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
3904 from two input vectors, returning a vector with the same element type as the
3905 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3906
3907<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3908<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3909 with types that match each other. The third argument is a shuffle mask whose
3910 element type is always 'i32'. The result of the instruction is a vector
3911 whose length is the same as the shuffle mask and whose element type is the
3912 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3913
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3914<p>The shuffle mask operand is required to be a constant vector with either
3915 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3916
3917<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3918<p>The elements of the two input vectors are numbered from left to right across
3919 both of the vectors. The shuffle mask operand specifies, for each element of
3920 the result vector, which element of the two input vectors the result element
3921 gets. The element selector may be undef (meaning "don't care") and the
3922 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3923
3924<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3925<pre>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3926 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3927 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3928 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3929 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i> - Identity shuffle.
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3930 &lt;result&gt; = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3931 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3932 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3933 &lt;8 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 &gt; <i>; yields &lt;8 x i32&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3934</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3935
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3936</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]3937
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3938<!-- ======================================================================= -->
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3939<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3940 <a name="aggregateops">Aggregate Operations</a>
3941</div>
3942
3943<div class="doc_text">
3944
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]3945<p>LLVM supports several instructions for working with
3946 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3947
3948</div>
3949
3950<!-- _______________________________________________________________________ -->
3951<div class="doc_subsubsection">
3952 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3953</div>
3954
3955<div class="doc_text">
3956
3957<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3958<pre>
3959 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3960</pre>
3961
3962<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]3963<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
3964 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3965
3966<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3967<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]3968 of <a href="#t_struct">struct</a>, <a href="#t_union">union</a> or
3969 <a href="#t_array">array</a> type. The operands are constant indices to
3970 specify which value to extract in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3971 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3972
3973<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3974<p>The result is the value at the position in the aggregate specified by the
3975 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3976
3977<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3978<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]3979 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3980</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3981
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3982</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3983
3984<!-- _______________________________________________________________________ -->
3985<div class="doc_subsubsection">
3986 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3987</div>
3988
3989<div class="doc_text">
3990
3991<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3992<pre>
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]3993 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt; <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3994</pre>
3995
3996<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]3997<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
3998 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3999
4000<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4001<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4002 of <a href="#t_struct">struct</a>, <a href="#t_union">union</a> or
4003 <a href="#t_array">array</a> type. The second operand is a first-class
4004 value to insert. The following operands are constant indices indicating
4005 the position at which to insert the value in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4006 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
4007 value to insert must have the same type as the value identified by the
4008 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4009
4010<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4011<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4012 that of <tt>val</tt> except that the value at the position specified by the
4013 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4014
4015<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4016<pre>
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]4017 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4018 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4019</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4020
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4021</div>
4022
4023
4024<!-- ======================================================================= -->
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4025<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4026 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4027</div>
4028
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4029<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4030
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4031<p>A key design point of an SSA-based representation is how it represents
4032 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]4033 very simple. This section describes how to read, write, and allocate
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4034 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4035
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4036</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4037
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4038<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4039<div class="doc_subsubsection">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4040 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
4041</div>
4042
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4043<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4044
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4045<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4046<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4047 &lt;result&gt; = alloca &lt;type&gt;[, i32 &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4048</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4049
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4050<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4051<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4052 currently executing function, to be automatically released when this function
4053 returns to its caller. The object is always allocated in the generic address
4054 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4055
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4056<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4057<p>The '<tt>alloca</tt>' instruction
4058 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4059 runtime stack, returning a pointer of the appropriate type to the program.
4060 If "NumElements" is specified, it is the number of elements allocated,
4061 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4062 specified, the value result of the allocation is guaranteed to be aligned to
4063 at least that boundary. If not specified, or if zero, the target can choose
4064 to align the allocation on any convenient boundary compatible with the
4065 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4066
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4067<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4068
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4069<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]4070<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4071 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4072 memory is automatically released when the function returns. The
4073 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4074 variables that must have an address available. When the function returns
4075 (either with the <tt><a href="#i_ret">ret</a></tt>
4076 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4077 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4078
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4079<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4080<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]4081 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4082 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4083 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4084 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4085</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4086
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4087</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4088
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4089<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4090<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
4091Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4092
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4093<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4094
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4095<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4096<pre>
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4097 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4098 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4099 !&lt;index&gt; = !{ i32 1 }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4100</pre>
4101
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4102<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4103<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4104
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4105<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4106<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4107 from which to load. The pointer must point to
4108 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4109 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
4110 number or order of execution of this <tt>load</tt> with other
4111 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4112 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4113
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4114<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4115 operation (that is, the alignment of the memory address). A value of 0 or an
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4116 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4117 alignment for the target. It is the responsibility of the code emitter to
4118 ensure that the alignment information is correct. Overestimating the
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4119 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4120 produce less efficient code. An alignment of 1 is always safe.</p>
4121
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4122<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4123 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4124 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4125 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4126 and code generator that this load is not expected to be reused in the cache.
4127 The code generator may select special instructions to save cache bandwidth,
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4128 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4129
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4130<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4131<p>The location of memory pointed to is loaded. If the value being loaded is of
4132 scalar type then the number of bytes read does not exceed the minimum number
4133 of bytes needed to hold all bits of the type. For example, loading an
4134 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4135 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4136 is undefined if the value was not originally written using a store of the
4137 same type.</p>
4138
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4139<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4140<pre>
4141 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4142 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4143 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4144</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4145
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4146</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4147
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4148<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4149<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
4150Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4151
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]4152<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4153
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4154<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4155<pre>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4156 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !<index>] <i>; yields {void}</i>
4157 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !<index>] <i>; yields {void}</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4158</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4159
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4160<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4161<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4162
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4163<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4164<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4165 and an address at which to store it. The type of the
4166 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4167 the <a href="#t_firstclass">first class</a> type of the
4168 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked
4169 as <tt>volatile</tt>, then the optimizer is not allowed to modify the number
4170 or order of execution of this <tt>store</tt> with other
4171 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
4172 instructions.</p>
4173
4174<p>The optional constant "align" argument specifies the alignment of the
4175 operation (that is, the alignment of the memory address). A value of 0 or an
4176 omitted "align" argument means that the operation has the preferential
4177 alignment for the target. It is the responsibility of the code emitter to
4178 ensure that the alignment information is correct. Overestimating the
4179 alignment results in an undefined behavior. Underestimating the alignment may
4180 produce less efficient code. An alignment of 1 is always safe.</p>
4181
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4182<p>The optional !nontemporal metadata must reference a single metatadata
4183 name <index> corresponding to a metadata node with one i32 entry of
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4184 value 1. The existence of the !nontemporal metatadata on the
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4185 instruction tells the optimizer and code generator that this load is
4186 not expected to be reused in the cache. The code generator may
4187 select special instructions to save cache bandwidth, such as the
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4188 MOVNT instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4189
4190
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4191<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4192<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4193 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4194 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4195 does not exceed the minimum number of bytes needed to hold all bits of the
4196 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4197 writing a value of a type like <tt>i20</tt> with a size that is not an
4198 integral number of bytes, it is unspecified what happens to the extra bits
4199 that do not belong to the type, but they will typically be overwritten.</p>
4200
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4201<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4202<pre>
4203 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]4204 store i32 3, i32* %ptr <i>; yields {void}</i>
4205 %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4206</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4207
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4208</div>
4209
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4210<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4211<div class="doc_subsubsection">
4212 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
4213</div>
4214
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4215<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4216
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4217<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4218<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4219 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4220 &lt;result&gt; = getelementptr inbounds &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4221</pre>
4222
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4223<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4224<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4225 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4226 It performs address calculation only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4227
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4228<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4229<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4230 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4231 elements of the aggregate object are indexed. The interpretation of each
4232 index is dependent on the type being indexed into. The first index always
4233 indexes the pointer value given as the first argument, the second index
4234 indexes a value of the type pointed to (not necessarily the value directly
4235 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4236 indexed into must be a pointer value, subsequent types can be arrays,
4237 vectors, structs and unions. Note that subsequent types being indexed into
4238 can never be pointers, since that would require loading the pointer before
4239 continuing calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4240
4241<p>The type of each index argument depends on the type it is indexing into.
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4242 When indexing into a (optionally packed) structure or union, only <tt>i32</tt>
4243 integer <b>constants</b> are allowed. When indexing into an array, pointer
4244 or vector, integers of any width are allowed, and they are not required to be
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4245 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4246
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4247<p>For example, let's consider a C code fragment and how it gets compiled to
4248 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4249
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4250<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4251<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4252struct RT {
4253 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4254 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4255 char C;
4256};
4257struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4258 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4259 double Y;
4260 struct RT Z;
4261};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4262
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4263int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4264 return &amp;s[1].Z.B[5][13];
4265}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4266</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4267</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4268
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4269<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4270
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4271<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4272<pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]4273%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4274%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4275
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4276define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4277entry:
4278 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4279 ret i32* %reg
4280}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4281</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4282</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4283
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4284<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4285<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4286 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4287 }</tt>' type, a structure. The second index indexes into the third element
4288 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4289 i8 }</tt>' type, another structure. The third index indexes into the second
4290 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4291 array. The two dimensions of the array are subscripted into, yielding an
4292 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4293 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4294
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4295<p>Note that it is perfectly legal to index partially through a structure,
4296 returning a pointer to an inner element. Because of this, the LLVM code for
4297 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4298
4299<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4300 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4301 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4302 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4303 %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4304 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4305 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4306 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4307 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4308</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]4309
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4310<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman61acaaa2009-07-29 16:00:30 +0000[diff] [blame]4311 <tt>getelementptr</tt> is undefined if the base pointer is not an
4312 <i>in bounds</i> address of an allocated object, or if any of the addresses
Dan Gohman2de532c2009-08-20 17:08:17 +0000[diff] [blame]4313 that would be formed by successive addition of the offsets implied by the
4314 indices to the base address with infinitely precise arithmetic are not an
4315 <i>in bounds</i> address of that allocated object.
Dan Gohman61acaaa2009-07-29 16:00:30 +0000[diff] [blame]4316 The <i>in bounds</i> addresses for an allocated object are all the addresses
Dan Gohman2de532c2009-08-20 17:08:17 +0000[diff] [blame]4317 that point into the object, plus the address one byte past the end.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4318
4319<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4320 the base address with silently-wrapping two's complement arithmetic, and
4321 the result value of the <tt>getelementptr</tt> may be outside the object
4322 pointed to by the base pointer. The result value may not necessarily be
4323 used to access memory though, even if it happens to point into allocated
4324 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4325 section for more information.</p>
4326
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4327<p>The getelementptr instruction is often confusing. For some more insight into
4328 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4329
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4330<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4331<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4332 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4333 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4334 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4335 %vptr = getelementptr {i32, &lt;2 x i8&gt;}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4336 <i>; yields i8*:eptr</i>
4337 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]4338 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]4339 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4340</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4341
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4342</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4343
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4344<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4345<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4346</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4347
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4348<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4349
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4350<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4351 which all take a single operand and a type. They perform various bit
4352 conversions on the operand.</p>
4353
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4354</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4355
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4356<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4357<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4358 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
4359</div>
4360<div class="doc_text">
4361
4362<h5>Syntax:</h5>
4363<pre>
4364 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4365</pre>
4366
4367<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4368<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4369 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4370
4371<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4372<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
4373 be an <a href="#t_integer">integer</a> type, and a type that specifies the
4374 size and type of the result, which must be
4375 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
4376 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
4377 allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4378
4379<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4380<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4381 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4382 source size must be larger than the destination size, <tt>trunc</tt> cannot
4383 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4384
4385<h5>Example:</h5>
4386<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4387 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4388 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4389 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4390</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4391
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4392</div>
4393
4394<!-- _______________________________________________________________________ -->
4395<div class="doc_subsubsection">
4396 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4397</div>
4398<div class="doc_text">
4399
4400<h5>Syntax:</h5>
4401<pre>
4402 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4403</pre>
4404
4405<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4406<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4407 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4408
4409
4410<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4411<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4412 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4413 also be of <a href="#t_integer">integer</a> type. The bit size of the
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4414 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4415 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4416
4417<h5>Semantics:</h5>
4418<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4419 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4420
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]4421<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4422
4423<h5>Example:</h5>
4424<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4425 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4426 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4427</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4428
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4429</div>
4430
4431<!-- _______________________________________________________________________ -->
4432<div class="doc_subsubsection">
4433 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4434</div>
4435<div class="doc_text">
4436
4437<h5>Syntax:</h5>
4438<pre>
4439 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4440</pre>
4441
4442<h5>Overview:</h5>
4443<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4444
4445<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4446<p>The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4447 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4448 also be of <a href="#t_integer">integer</a> type. The bit size of the
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4449 <tt>value</tt> must be smaller than the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4450 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4451
4452<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4453<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4454 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4455 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4456
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4457<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4458
4459<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4460<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4461 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4462 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4463</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4464
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4465</div>
4466
4467<!-- _______________________________________________________________________ -->
4468<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4469 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4470</div>
4471
4472<div class="doc_text">
4473
4474<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4475<pre>
4476 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4477</pre>
4478
4479<h5>Overview:</h5>
4480<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4481 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4482
4483<h5>Arguments:</h5>
4484<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4485 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4486 to cast it to. The size of <tt>value</tt> must be larger than the size of
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4487 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4488 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4489
4490<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4491<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4492 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4493 <a href="#t_floating">floating point</a> type. If the value cannot fit
4494 within the destination type, <tt>ty2</tt>, then the results are
4495 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4496
4497<h5>Example:</h5>
4498<pre>
4499 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4500 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4501</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4502
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4503</div>
4504
4505<!-- _______________________________________________________________________ -->
4506<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4507 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4508</div>
4509<div class="doc_text">
4510
4511<h5>Syntax:</h5>
4512<pre>
4513 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4514</pre>
4515
4516<h5>Overview:</h5>
4517<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4518 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4519
4520<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4521<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4522 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4523 a <a href="#t_floating">floating point</a> type to cast it to. The source
4524 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4525
4526<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4527<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4528 <a href="#t_floating">floating point</a> type to a larger
4529 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4530 used to make a <i>no-op cast</i> because it always changes bits. Use
4531 <tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4532
4533<h5>Example:</h5>
4534<pre>
4535 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4536 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4537</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4538
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4539</div>
4540
4541<!-- _______________________________________________________________________ -->
4542<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]4543 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4544</div>
4545<div class="doc_text">
4546
4547<h5>Syntax:</h5>
4548<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4549 &lt;result&gt; = fptoui &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4550</pre>
4551
4552<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4553<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4554 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4555
4556<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4557<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4558 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4559 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4560 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4561 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4562
4563<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4564<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4565 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4566 towards zero) unsigned integer value. If the value cannot fit
4567 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4568
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4569<h5>Example:</h5>
4570<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4571 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4572 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4573 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4574</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4575
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4576</div>
4577
4578<!-- _______________________________________________________________________ -->
4579<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4580 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4581</div>
4582<div class="doc_text">
4583
4584<h5>Syntax:</h5>
4585<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4586 &lt;result&gt; = fptosi &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4587</pre>
4588
4589<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4590<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4591 <a href="#t_floating">floating point</a> <tt>value</tt> to
4592 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4593
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4594<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4595<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4596 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4597 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4598 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4599 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4600
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4601<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4602<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4603 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4604 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4605 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4606
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4607<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4608<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4609 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4610 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4611 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4612</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4613
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4614</div>
4615
4616<!-- _______________________________________________________________________ -->
4617<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4618 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4619</div>
4620<div class="doc_text">
4621
4622<h5>Syntax:</h5>
4623<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4624 &lt;result&gt; = uitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4625</pre>
4626
4627<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4628<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4629 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4630
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4631<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4632<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4633 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4634 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4635 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4636 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4637
4638<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4639<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4640 integer quantity and converts it to the corresponding floating point
4641 value. If the value cannot fit in the floating point value, the results are
4642 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4643
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4644<h5>Example:</h5>
4645<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4646 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4647 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4648</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4649
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4650</div>
4651
4652<!-- _______________________________________________________________________ -->
4653<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4654 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4655</div>
4656<div class="doc_text">
4657
4658<h5>Syntax:</h5>
4659<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4660 &lt;result&gt; = sitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4661</pre>
4662
4663<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4664<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4665 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4666
4667<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4668<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4669 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4670 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4671 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4672 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4673
4674<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4675<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4676 quantity and converts it to the corresponding floating point value. If the
4677 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4678
4679<h5>Example:</h5>
4680<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4681 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4682 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4683</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4684
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4685</div>
4686
4687<!-- _______________________________________________________________________ -->
4688<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4689 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4690</div>
4691<div class="doc_text">
4692
4693<h5>Syntax:</h5>
4694<pre>
4695 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4696</pre>
4697
4698<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4699<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4700 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4701
4702<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4703<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4704 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4705 <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4706
4707<h5>Semantics:</h5>
4708<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4709 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4710 truncating or zero extending that value to the size of the integer type. If
4711 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4712 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4713 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4714 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4715
4716<h5>Example:</h5>
4717<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4718 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4719 %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4720</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4721
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4722</div>
4723
4724<!-- _______________________________________________________________________ -->
4725<div class="doc_subsubsection">
4726 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4727</div>
4728<div class="doc_text">
4729
4730<h5>Syntax:</h5>
4731<pre>
4732 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4733</pre>
4734
4735<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4736<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4737 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4738
4739<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4740<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4741 value to cast, and a type to cast it to, which must be a
4742 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4743
4744<h5>Semantics:</h5>
4745<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4746 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4747 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4748 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4749 than the size of a pointer then a zero extension is done. If they are the
4750 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4751
4752<h5>Example:</h5>
4753<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4754 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4755 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4756 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4757</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4758
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4759</div>
4760
4761<!-- _______________________________________________________________________ -->
4762<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4763 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4764</div>
4765<div class="doc_text">
4766
4767<h5>Syntax:</h5>
4768<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4769 &lt;result&gt; = bitcast &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4770</pre>
4771
4772<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4773<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4774 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4775
4776<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4777<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4778 non-aggregate first class value, and a type to cast it to, which must also be
4779 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4780 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4781 identical. If the source type is a pointer, the destination type must also be
4782 a pointer. This instruction supports bitwise conversion of vectors to
4783 integers and to vectors of other types (as long as they have the same
4784 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4785
4786<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4787<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4788 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4789 this conversion. The conversion is done as if the <tt>value</tt> had been
4790 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4791 be converted to other pointer types with this instruction. To convert
4792 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4793 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4794
4795<h5>Example:</h5>
4796<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4797 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4798 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4799 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4800</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4801
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4802</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4803
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4804<!-- ======================================================================= -->
4805<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4806
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4807<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4808
4809<p>The instructions in this category are the "miscellaneous" instructions, which
4810 defy better classification.</p>
4811
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4812</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4813
4814<!-- _______________________________________________________________________ -->
4815<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4816</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4817
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4818<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4819
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4820<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4821<pre>
4822 &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4823</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4824
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4825<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4826<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4827 boolean values based on comparison of its two integer, integer vector, or
4828 pointer operands.</p>
4829
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4830<h5>Arguments:</h5>
4831<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4832 the condition code indicating the kind of comparison to perform. It is not a
4833 value, just a keyword. The possible condition code are:</p>
4834
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4835<ol>
4836 <li><tt>eq</tt>: equal</li>
4837 <li><tt>ne</tt>: not equal </li>
4838 <li><tt>ugt</tt>: unsigned greater than</li>
4839 <li><tt>uge</tt>: unsigned greater or equal</li>
4840 <li><tt>ult</tt>: unsigned less than</li>
4841 <li><tt>ule</tt>: unsigned less or equal</li>
4842 <li><tt>sgt</tt>: signed greater than</li>
4843 <li><tt>sge</tt>: signed greater or equal</li>
4844 <li><tt>slt</tt>: signed less than</li>
4845 <li><tt>sle</tt>: signed less or equal</li>
4846</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4847
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]4848<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4849 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4850 typed. They must also be identical types.</p>
4851
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4852<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4853<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4854 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]4855 either an <a href="#t_integer"><tt>i1</tt></a> or vector of <tt>i1</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4856 result, as follows:</p>
4857
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4858<ol>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4859 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4860 <tt>false</tt> otherwise. No sign interpretation is necessary or
4861 performed.</li>
4862
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4863 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4864 <tt>false</tt> otherwise. No sign interpretation is necessary or
4865 performed.</li>
4866
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4867 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4868 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4869
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4870 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4871 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4872 to <tt>op2</tt>.</li>
4873
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4874 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4875 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4876
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4877 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4878 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4879
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4880 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4881 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4882
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4883 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4884 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4885 to <tt>op2</tt>.</li>
4886
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4887 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4888 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4889
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4890 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4891 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4892</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4893
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4894<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4895 values are compared as if they were integers.</p>
4896
4897<p>If the operands are integer vectors, then they are compared element by
4898 element. The result is an <tt>i1</tt> vector with the same number of elements
4899 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4900
4901<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4902<pre>
4903 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4904 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4905 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4906 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4907 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4908 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4909</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4910
4911<p>Note that the code generator does not yet support vector types with
4912 the <tt>icmp</tt> instruction.</p>
4913
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4914</div>
4915
4916<!-- _______________________________________________________________________ -->
4917<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4918</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4919
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4920<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4921
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4922<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4923<pre>
4924 &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4925</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4926
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4927<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4928<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
4929 values based on comparison of its operands.</p>
4930
4931<p>If the operands are floating point scalars, then the result type is a boolean
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]4932(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4933
4934<p>If the operands are floating point vectors, then the result type is a vector
4935 of boolean with the same number of elements as the operands being
4936 compared.</p>
4937
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4938<h5>Arguments:</h5>
4939<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4940 the condition code indicating the kind of comparison to perform. It is not a
4941 value, just a keyword. The possible condition code are:</p>
4942
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4943<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4944 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4945 <li><tt>oeq</tt>: ordered and equal</li>
4946 <li><tt>ogt</tt>: ordered and greater than </li>
4947 <li><tt>oge</tt>: ordered and greater than or equal</li>
4948 <li><tt>olt</tt>: ordered and less than </li>
4949 <li><tt>ole</tt>: ordered and less than or equal</li>
4950 <li><tt>one</tt>: ordered and not equal</li>
4951 <li><tt>ord</tt>: ordered (no nans)</li>
4952 <li><tt>ueq</tt>: unordered or equal</li>
4953 <li><tt>ugt</tt>: unordered or greater than </li>
4954 <li><tt>uge</tt>: unordered or greater than or equal</li>
4955 <li><tt>ult</tt>: unordered or less than </li>
4956 <li><tt>ule</tt>: unordered or less than or equal</li>
4957 <li><tt>une</tt>: unordered or not equal</li>
4958 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4959 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4960</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4961
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4962<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4963 <i>unordered</i> means that either operand may be a QNAN.</p>
4964
4965<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
4966 a <a href="#t_floating">floating point</a> type or
4967 a <a href="#t_vector">vector</a> of floating point type. They must have
4968 identical types.</p>
4969
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4970<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4971<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4972 according to the condition code given as <tt>cond</tt>. If the operands are
4973 vectors, then the vectors are compared element by element. Each comparison
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]4974 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4975 follows:</p>
4976
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4977<ol>
4978 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4979
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4980 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4981 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4982
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4983 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4984 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4985
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4986 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4987 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4988
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4989 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4990 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4991
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4992 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4993 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4994
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4995 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4996 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4997
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4998 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4999
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5000 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5001 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5002
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5003 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5004 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5005
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5006 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5007 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5008
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5009 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5010 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5011
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5012 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5013 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5014
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5015 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5016 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5017
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5018 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5019
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5020 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5021</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5022
5023<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5024<pre>
5025 &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]5026 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5027 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5028 &lt;result&gt; = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5029</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5030
5031<p>Note that the code generator does not yet support vector types with
5032 the <tt>fcmp</tt> instruction.</p>
5033
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5034</div>
5035
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5036<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]5037<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5038 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
5039</div>
5040
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5041<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5042
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5043<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5044<pre>
5045 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5046</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5047
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5048<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5049<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5050 SSA graph representing the function.</p>
5051
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5052<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5053<p>The type of the incoming values is specified with the first type field. After
5054 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5055 one pair for each predecessor basic block of the current block. Only values
5056 of <a href="#t_firstclass">first class</a> type may be used as the value
5057 arguments to the PHI node. Only labels may be used as the label
5058 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5059
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5060<p>There must be no non-phi instructions between the start of a basic block and
5061 the PHI instructions: i.e. PHI instructions must be first in a basic
5062 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5063
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5064<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5065 occur on the edge from the corresponding predecessor block to the current
5066 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5067 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]5068
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5069<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5070<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5071 specified by the pair corresponding to the predecessor basic block that
5072 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5073
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5074<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5075<pre>
5076Loop: ; Infinite loop that counts from 0 on up...
5077 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5078 %nextindvar = add i32 %indvar, 1
5079 br label %Loop
5080</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5081
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5082</div>
5083
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5084<!-- _______________________________________________________________________ -->
5085<div class="doc_subsubsection">
5086 <a name="i_select">'<tt>select</tt>' Instruction</a>
5087</div>
5088
5089<div class="doc_text">
5090
5091<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5092<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]5093 &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>
5094
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5095 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5096</pre>
5097
5098<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5099<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5100 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5101
5102
5103<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5104<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5105 values indicating the condition, and two values of the
5106 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5107 vectors and the condition is a scalar, then entire vectors are selected, not
5108 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5109
5110<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5111<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5112 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5113
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5114<p>If the condition is a vector of i1, then the value arguments must be vectors
5115 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5116
5117<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5118<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5119 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5120</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5121
5122<p>Note that the code generator does not yet support conditions
5123 with vector type.</p>
5124
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5125</div>
5126
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]5127<!-- _______________________________________________________________________ -->
5128<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5129 <a name="i_call">'<tt>call</tt>' Instruction</a>
5130</div>
5131
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5132<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5133
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5134<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5135<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]5136 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5137</pre>
5138
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5139<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5140<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5141
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5142<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5143<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5144
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5145<ol>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5146 <li>The optional "tail" marker indicates that the callee function does not
5147 access any allocas or varargs in the caller. Note that calls may be
5148 marked "tail" even if they do not occur before
5149 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5150 present, the function call is eligible for tail call optimization,
5151 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
5152 optimized into a jump</a>. As of this writing, the extra requirements for
5153 a call to actually be optimized are:
5154 <ul>
5155 <li>Caller and callee both have the calling
5156 convention <tt>fastcc</tt>.</li>
5157 <li>The call is in tail position (ret immediately follows call and ret
5158 uses value of call or is void).</li>
5159 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohman6232f732010-03-02 01:08:11 +0000[diff] [blame]5160 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5161 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5162 constraints are met.</a></li>
5163 </ul>
5164 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5165
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5166 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5167 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5168 defaults to using C calling conventions. The calling convention of the
5169 call must match the calling convention of the target function, or else the
5170 behavior is undefined.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5171
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5172 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5173 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5174 '<tt>inreg</tt>' attributes are valid here.</li>
5175
5176 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5177 type of the return value. Functions that return no value are marked
5178 <tt><a href="#t_void">void</a></tt>.</li>
5179
5180 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5181 being invoked. The argument types must match the types implied by this
5182 signature. This type can be omitted if the function is not varargs and if
5183 the function type does not return a pointer to a function.</li>
5184
5185 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5186 be invoked. In most cases, this is a direct function invocation, but
5187 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5188 to function value.</li>
5189
5190 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]5191 signature argument types and parameter attributes. All arguments must be
5192 of <a href="#t_firstclass">first class</a> type. If the function
5193 signature indicates the function accepts a variable number of arguments,
5194 the extra arguments can be specified.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5195
5196 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5197 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5198 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5199</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5200
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5201<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5202<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5203 a specified function, with its incoming arguments bound to the specified
5204 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5205 function, control flow continues with the instruction after the function
5206 call, and the return value of the function is bound to the result
5207 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5208
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5209<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5210<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]5211 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]5212 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
5213 %X = tail call i32 @foo() <i>; yields i32</i>
5214 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5215 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]5216
5217 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5218 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]5219 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5220 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]5221 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]5222 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5223</pre>
5224
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5225<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen722212d2009-09-25 17:04:42 +0000[diff] [blame]5226standard C99 library as being the C99 library functions, and may perform
5227optimizations or generate code for them under that assumption. This is
5228something we'd like to change in the future to provide better support for
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5229freestanding environments and non-C-based languages.</p>
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5230
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5231</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5232
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5233<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5234<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]5235 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5236</div>
5237
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5238<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5239
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5240<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5241<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5242 &lt;resultval&gt; = va_arg &lt;va_list*&gt; &lt;arglist&gt;, &lt;argty&gt;
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5243</pre>
5244
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5245<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5246<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5247 the "variable argument" area of a function call. It is used to implement the
5248 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5249
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5250<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5251<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5252 argument. It returns a value of the specified argument type and increments
5253 the <tt>va_list</tt> to point to the next argument. The actual type
5254 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5255
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5256<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5257<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5258 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5259 to the next argument. For more information, see the variable argument
5260 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5261
5262<p>It is legal for this instruction to be called in a function which does not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5263 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5264 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5265
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5266<p><tt>va_arg</tt> is an LLVM instruction instead of
5267 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5268 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5269
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5270<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5271<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5272
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5273<p>Note that the code generator does not yet fully support va_arg on many
5274 targets. Also, it does not currently support va_arg with aggregate types on
5275 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]5276
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5277</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5278
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5279<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]5280<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
5281<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5282
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5283<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5284
5285<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5286 well known names and semantics and are required to follow certain
5287 restrictions. Overall, these intrinsics represent an extension mechanism for
5288 the LLVM language that does not require changing all of the transformations
5289 in LLVM when adding to the language (or the bitcode reader/writer, the
5290 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5291
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5292<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5293 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5294 begin with this prefix. Intrinsic functions must always be external
5295 functions: you cannot define the body of intrinsic functions. Intrinsic
5296 functions may only be used in call or invoke instructions: it is illegal to
5297 take the address of an intrinsic function. Additionally, because intrinsic
5298 functions are part of the LLVM language, it is required if any are added that
5299 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5300
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5301<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5302 family of functions that perform the same operation but on different data
5303 types. Because LLVM can represent over 8 million different integer types,
5304 overloading is used commonly to allow an intrinsic function to operate on any
5305 integer type. One or more of the argument types or the result type can be
5306 overloaded to accept any integer type. Argument types may also be defined as
5307 exactly matching a previous argument's type or the result type. This allows
5308 an intrinsic function which accepts multiple arguments, but needs all of them
5309 to be of the same type, to only be overloaded with respect to a single
5310 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5311
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5312<p>Overloaded intrinsics will have the names of its overloaded argument types
5313 encoded into its function name, each preceded by a period. Only those types
5314 which are overloaded result in a name suffix. Arguments whose type is matched
5315 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5316 can take an integer of any width and returns an integer of exactly the same
5317 integer width. This leads to a family of functions such as
5318 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5319 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5320 suffix is required. Because the argument's type is matched against the return
5321 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5322
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5323<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5324 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5325
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5326</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5327
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5328<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5329<div class="doc_subsection">
5330 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
5331</div>
5332
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5333<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5334
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5335<p>Variable argument support is defined in LLVM with
5336 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5337 intrinsic functions. These functions are related to the similarly named
5338 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5339
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5340<p>All of these functions operate on arguments that use a target-specific value
5341 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5342 not define what this type is, so all transformations should be prepared to
5343 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5344
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]5345<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5346 instruction and the variable argument handling intrinsic functions are
5347 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5348
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5349<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5350<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5351define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5352 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5353 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5354 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5355 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5356
5357 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5358 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5359
5360 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5361 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5362 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5363 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5364 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5365
5366 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5367 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5368 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5369}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5370
5371declare void @llvm.va_start(i8*)
5372declare void @llvm.va_copy(i8*, i8*)
5373declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5374</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5375</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5376
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]5377</div>
5378
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5379<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5380<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5381 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5382</div>
5383
5384
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5385<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5386
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5387<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5388<pre>
5389 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5390</pre>
5391
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5392<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5393<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5394 for subsequent use by <tt><a href="#i_va_arg">va_arg</a></tt>.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5395
5396<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5397<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5398
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5399<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5400<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5401 macro available in C. In a target-dependent way, it initializes
5402 the <tt>va_list</tt> element to which the argument points, so that the next
5403 call to <tt>va_arg</tt> will produce the first variable argument passed to
5404 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5405 need to know the last argument of the function as the compiler can figure
5406 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5407
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5408</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5409
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5410<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5411<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5412 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5413</div>
5414
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5415<div class="doc_text">
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5416
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5417<h5>Syntax:</h5>
5418<pre>
5419 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5420</pre>
5421
5422<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5423<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5424 which has been initialized previously
5425 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5426 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5427
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5428<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5429<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5430
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5431<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5432<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5433 macro available in C. In a target-dependent way, it destroys
5434 the <tt>va_list</tt> element to which the argument points. Calls
5435 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5436 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5437 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5438
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5439</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5440
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5441<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5442<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5443 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5444</div>
5445
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5446<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5447
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5448<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5449<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5450 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5451</pre>
5452
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5453<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5454<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5455 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5456
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5457<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5458<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5459 The second argument is a pointer to a <tt>va_list</tt> element to copy
5460 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5461
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5462<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5463<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5464 macro available in C. In a target-dependent way, it copies the
5465 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5466 element. This intrinsic is necessary because
5467 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5468 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5469
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5470</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5471
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5472<!-- ======================================================================= -->
5473<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5474 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5475</div>
5476
5477<div class="doc_text">
5478
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5479<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5480Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5481intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5482roots on the stack</a>, as well as garbage collector implementations that
5483require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5484barriers. Front-ends for type-safe garbage collected languages should generate
5485these intrinsics to make use of the LLVM garbage collectors. For more details,
5486see <a href="GarbageCollection.html">Accurate Garbage Collection with
5487LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5488
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5489<p>The garbage collection intrinsics only operate on objects in the generic
5490 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5491
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5492</div>
5493
5494<!-- _______________________________________________________________________ -->
5495<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5496 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5497</div>
5498
5499<div class="doc_text">
5500
5501<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5502<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5503 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5504</pre>
5505
5506<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]5507<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5508 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5509
5510<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5511<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5512 root pointer. The second pointer (which must be either a constant or a
5513 global value address) contains the meta-data to be associated with the
5514 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5515
5516<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]5517<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5518 location. At compile-time, the code generator generates information to allow
5519 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5520 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5521 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5522
5523</div>
5524
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5525<!-- _______________________________________________________________________ -->
5526<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5527 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5528</div>
5529
5530<div class="doc_text">
5531
5532<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5533<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5534 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5535</pre>
5536
5537<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5538<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5539 locations, allowing garbage collector implementations that require read
5540 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5541
5542<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5543<p>The second argument is the address to read from, which should be an address
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5544 allocated from the garbage collector. The first object is a pointer to the
5545 start of the referenced object, if needed by the language runtime (otherwise
5546 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5547
5548<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5549<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5550 instruction, but may be replaced with substantially more complex code by the
5551 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5552 may only be used in a function which <a href="#gc">specifies a GC
5553 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5554
5555</div>
5556
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5557<!-- _______________________________________________________________________ -->
5558<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5559 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5560</div>
5561
5562<div class="doc_text">
5563
5564<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5565<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5566 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5567</pre>
5568
5569<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5570<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5571 locations, allowing garbage collector implementations that require write
5572 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5573
5574<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5575<p>The first argument is the reference to store, the second is the start of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5576 object to store it to, and the third is the address of the field of Obj to
5577 store to. If the runtime does not require a pointer to the object, Obj may
5578 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5579
5580<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5581<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5582 instruction, but may be replaced with substantially more complex code by the
5583 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5584 may only be used in a function which <a href="#gc">specifies a GC
5585 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5586
5587</div>
5588
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5589<!-- ======================================================================= -->
5590<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5591 <a name="int_codegen">Code Generator Intrinsics</a>
5592</div>
5593
5594<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5595
5596<p>These intrinsics are provided by LLVM to expose special features that may
5597 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5598
5599</div>
5600
5601<!-- _______________________________________________________________________ -->
5602<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5603 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5604</div>
5605
5606<div class="doc_text">
5607
5608<h5>Syntax:</h5>
5609<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5610 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5611</pre>
5612
5613<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5614<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5615 target-specific value indicating the return address of the current function
5616 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5617
5618<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5619<p>The argument to this intrinsic indicates which function to return the address
5620 for. Zero indicates the calling function, one indicates its caller, etc.
5621 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5622
5623<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5624<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5625 indicating the return address of the specified call frame, or zero if it
5626 cannot be identified. The value returned by this intrinsic is likely to be
5627 incorrect or 0 for arguments other than zero, so it should only be used for
5628 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5629
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5630<p>Note that calling this intrinsic does not prevent function inlining or other
5631 aggressive transformations, so the value returned may not be that of the
5632 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5633
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5634</div>
5635
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5636<!-- _______________________________________________________________________ -->
5637<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5638 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5639</div>
5640
5641<div class="doc_text">
5642
5643<h5>Syntax:</h5>
5644<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5645 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5646</pre>
5647
5648<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5649<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5650 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5651
5652<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5653<p>The argument to this intrinsic indicates which function to return the frame
5654 pointer for. Zero indicates the calling function, one indicates its caller,
5655 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5656
5657<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5658<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5659 indicating the frame address of the specified call frame, or zero if it
5660 cannot be identified. The value returned by this intrinsic is likely to be
5661 incorrect or 0 for arguments other than zero, so it should only be used for
5662 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5663
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5664<p>Note that calling this intrinsic does not prevent function inlining or other
5665 aggressive transformations, so the value returned may not be that of the
5666 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5667
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5668</div>
5669
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5670<!-- _______________________________________________________________________ -->
5671<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5672 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5673</div>
5674
5675<div class="doc_text">
5676
5677<h5>Syntax:</h5>
5678<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5679 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5680</pre>
5681
5682<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5683<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5684 of the function stack, for use
5685 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5686 useful for implementing language features like scoped automatic variable
5687 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5688
5689<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5690<p>This intrinsic returns a opaque pointer value that can be passed
5691 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5692 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5693 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5694 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5695 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5696 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5697
5698</div>
5699
5700<!-- _______________________________________________________________________ -->
5701<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5702 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5703</div>
5704
5705<div class="doc_text">
5706
5707<h5>Syntax:</h5>
5708<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5709 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5710</pre>
5711
5712<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5713<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5714 the function stack to the state it was in when the
5715 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5716 executed. This is useful for implementing language features like scoped
5717 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5718
5719<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5720<p>See the description
5721 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5722
5723</div>
5724
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5725<!-- _______________________________________________________________________ -->
5726<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5727 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5728</div>
5729
5730<div class="doc_text">
5731
5732<h5>Syntax:</h5>
5733<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5734 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5735</pre>
5736
5737<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5738<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5739 insert a prefetch instruction if supported; otherwise, it is a noop.
5740 Prefetches have no effect on the behavior of the program but can change its
5741 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5742
5743<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5744<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5745 specifier determining if the fetch should be for a read (0) or write (1),
5746 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5747 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5748 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5749
5750<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5751<p>This intrinsic does not modify the behavior of the program. In particular,
5752 prefetches cannot trap and do not produce a value. On targets that support
5753 this intrinsic, the prefetch can provide hints to the processor cache for
5754 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5755
5756</div>
5757
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5758<!-- _______________________________________________________________________ -->
5759<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5760 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5761</div>
5762
5763<div class="doc_text">
5764
5765<h5>Syntax:</h5>
5766<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5767 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5768</pre>
5769
5770<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5771<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5772 Counter (PC) in a region of code to simulators and other tools. The method
5773 is target specific, but it is expected that the marker will use exported
5774 symbols to transmit the PC of the marker. The marker makes no guarantees
5775 that it will remain with any specific instruction after optimizations. It is
5776 possible that the presence of a marker will inhibit optimizations. The
5777 intended use is to be inserted after optimizations to allow correlations of
5778 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5779
5780<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5781<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5782
5783<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5784<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5785 not support this intrinsic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5786
5787</div>
5788
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5789<!-- _______________________________________________________________________ -->
5790<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5791 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5792</div>
5793
5794<div class="doc_text">
5795
5796<h5>Syntax:</h5>
5797<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5798 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5799</pre>
5800
5801<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5802<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5803 counter register (or similar low latency, high accuracy clocks) on those
5804 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5805 should map to RPCC. As the backing counters overflow quickly (on the order
5806 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5807
5808<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5809<p>When directly supported, reading the cycle counter should not modify any
5810 memory. Implementations are allowed to either return a application specific
5811 value or a system wide value. On backends without support, this is lowered
5812 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5813
5814</div>
5815
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5816<!-- ======================================================================= -->
5817<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5818 <a name="int_libc">Standard C Library Intrinsics</a>
5819</div>
5820
5821<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5822
5823<p>LLVM provides intrinsics for a few important standard C library functions.
5824 These intrinsics allow source-language front-ends to pass information about
5825 the alignment of the pointer arguments to the code generator, providing
5826 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5827
5828</div>
5829
5830<!-- _______________________________________________________________________ -->
5831<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5832 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5833</div>
5834
5835<div class="doc_text">
5836
5837<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5838<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
5839 integer bit width. Not all targets support all bit widths however.</p>
5840
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5841<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5842 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5843 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5844 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5845 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5846 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5847 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5848 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5849 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5850</pre>
5851
5852<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5853<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5854 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5855
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5856<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5857 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5858
5859<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5860<p>The first argument is a pointer to the destination, the second is a pointer
5861 to the source. The third argument is an integer argument specifying the
5862 number of bytes to copy, and the fourth argument is the alignment of the
5863 source and destination locations.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5864
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5865<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5866 then the caller guarantees that both the source and destination pointers are
5867 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5868
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5869<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5870<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5871 source location to the destination location, which are not allowed to
5872 overlap. It copies "len" bytes of memory over. If the argument is known to
5873 be aligned to some boundary, this can be specified as the fourth argument,
5874 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5875
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5876</div>
5877
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5878<!-- _______________________________________________________________________ -->
5879<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5880 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5881</div>
5882
5883<div class="doc_text">
5884
5885<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5886<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5887 width. Not all targets support all bit widths however.</p>
5888
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5889<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5890 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5891 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5892 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5893 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5894 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5895 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5896 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5897 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5898</pre>
5899
5900<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5901<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
5902 source location to the destination location. It is similar to the
5903 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
5904 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5905
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5906<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5907 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5908
5909<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5910<p>The first argument is a pointer to the destination, the second is a pointer
5911 to the source. The third argument is an integer argument specifying the
5912 number of bytes to copy, and the fourth argument is the alignment of the
5913 source and destination locations.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5914
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5915<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5916 then the caller guarantees that the source and destination pointers are
5917 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5918
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5919<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5920<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
5921 source location to the destination location, which may overlap. It copies
5922 "len" bytes of memory over. If the argument is known to be aligned to some
5923 boundary, this can be specified as the fourth argument, otherwise it should
5924 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5925
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5926</div>
5927
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5928<!-- _______________________________________________________________________ -->
5929<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5930 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5931</div>
5932
5933<div class="doc_text">
5934
5935<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5936<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5937 width. Not all targets support all bit widths however.</p>
5938
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5939<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5940 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5941 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5942 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5943 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5944 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5945 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5946 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5947 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5948</pre>
5949
5950<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5951<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
5952 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5953
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5954<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
5955 intrinsic does not return a value, and takes an extra alignment argument.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5956
5957<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5958<p>The first argument is a pointer to the destination to fill, the second is the
5959 byte value to fill it with, the third argument is an integer argument
5960 specifying the number of bytes to fill, and the fourth argument is the known
5961 alignment of destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5962
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5963<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5964 then the caller guarantees that the destination pointer is aligned to that
5965 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5966
5967<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5968<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
5969 at the destination location. If the argument is known to be aligned to some
5970 boundary, this can be specified as the fourth argument, otherwise it should
5971 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5972
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5973</div>
5974
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5975<!-- _______________________________________________________________________ -->
5976<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5977 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5978</div>
5979
5980<div class="doc_text">
5981
5982<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5983<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
5984 floating point or vector of floating point type. Not all targets support all
5985 types however.</p>
5986
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5987<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5988 declare float @llvm.sqrt.f32(float %Val)
5989 declare double @llvm.sqrt.f64(double %Val)
5990 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5991 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5992 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5993</pre>
5994
5995<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5996<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
5997 returning the same value as the libm '<tt>sqrt</tt>' functions would.
5998 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
5999 behavior for negative numbers other than -0.0 (which allows for better
6000 optimization, because there is no need to worry about errno being
6001 set). <tt>llvm.sqrt(-0.0)</tt> is defined to return -0.0 like IEEE sqrt.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6002
6003<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6004<p>The argument and return value are floating point numbers of the same
6005 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6006
6007<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6008<p>This function returns the sqrt of the specified operand if it is a
6009 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6010
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6011</div>
6012
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6013<!-- _______________________________________________________________________ -->
6014<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6015 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6016</div>
6017
6018<div class="doc_text">
6019
6020<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6021<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6022 floating point or vector of floating point type. Not all targets support all
6023 types however.</p>
6024
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6025<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6026 declare float @llvm.powi.f32(float %Val, i32 %power)
6027 declare double @llvm.powi.f64(double %Val, i32 %power)
6028 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6029 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6030 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6031</pre>
6032
6033<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6034<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6035 specified (positive or negative) power. The order of evaluation of
6036 multiplications is not defined. When a vector of floating point type is
6037 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6038
6039<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6040<p>The second argument is an integer power, and the first is a value to raise to
6041 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6042
6043<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6044<p>This function returns the first value raised to the second power with an
6045 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6046
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6047</div>
6048
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6049<!-- _______________________________________________________________________ -->
6050<div class="doc_subsubsection">
6051 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
6052</div>
6053
6054<div class="doc_text">
6055
6056<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6057<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6058 floating point or vector of floating point type. Not all targets support all
6059 types however.</p>
6060
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6061<pre>
6062 declare float @llvm.sin.f32(float %Val)
6063 declare double @llvm.sin.f64(double %Val)
6064 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6065 declare fp128 @llvm.sin.f128(fp128 %Val)
6066 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6067</pre>
6068
6069<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6070<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6071
6072<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6073<p>The argument and return value are floating point numbers of the same
6074 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6075
6076<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6077<p>This function returns the sine of the specified operand, returning the same
6078 values as the libm <tt>sin</tt> functions would, and handles error conditions
6079 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6080
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6081</div>
6082
6083<!-- _______________________________________________________________________ -->
6084<div class="doc_subsubsection">
6085 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
6086</div>
6087
6088<div class="doc_text">
6089
6090<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6091<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6092 floating point or vector of floating point type. Not all targets support all
6093 types however.</p>
6094
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6095<pre>
6096 declare float @llvm.cos.f32(float %Val)
6097 declare double @llvm.cos.f64(double %Val)
6098 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6099 declare fp128 @llvm.cos.f128(fp128 %Val)
6100 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6101</pre>
6102
6103<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6104<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6105
6106<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6107<p>The argument and return value are floating point numbers of the same
6108 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6109
6110<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6111<p>This function returns the cosine of the specified operand, returning the same
6112 values as the libm <tt>cos</tt> functions would, and handles error conditions
6113 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6114
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6115</div>
6116
6117<!-- _______________________________________________________________________ -->
6118<div class="doc_subsubsection">
6119 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
6120</div>
6121
6122<div class="doc_text">
6123
6124<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6125<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6126 floating point or vector of floating point type. Not all targets support all
6127 types however.</p>
6128
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6129<pre>
6130 declare float @llvm.pow.f32(float %Val, float %Power)
6131 declare double @llvm.pow.f64(double %Val, double %Power)
6132 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6133 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6134 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6135</pre>
6136
6137<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6138<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6139 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6140
6141<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6142<p>The second argument is a floating point power, and the first is a value to
6143 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6144
6145<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6146<p>This function returns the first value raised to the second power, returning
6147 the same values as the libm <tt>pow</tt> functions would, and handles error
6148 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6149
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6150</div>
6151
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6152<!-- ======================================================================= -->
6153<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6154 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6155</div>
6156
6157<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6158
6159<p>LLVM provides intrinsics for a few important bit manipulation operations.
6160 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6161
6162</div>
6163
6164<!-- _______________________________________________________________________ -->
6165<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6166 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6167</div>
6168
6169<div class="doc_text">
6170
6171<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6172<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6173 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6174
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6175<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6176 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6177 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6178 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6179</pre>
6180
6181<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6182<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6183 values with an even number of bytes (positive multiple of 16 bits). These
6184 are useful for performing operations on data that is not in the target's
6185 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6186
6187<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6188<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6189 and low byte of the input i16 swapped. Similarly,
6190 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6191 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6192 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6193 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6194 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6195 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6196
6197</div>
6198
6199<!-- _______________________________________________________________________ -->
6200<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]6201 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6202</div>
6203
6204<div class="doc_text">
6205
6206<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6207<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6208 width. Not all targets support all bit widths however.</p>
6209
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6210<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6211 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6212 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6213 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6214 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6215 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6216</pre>
6217
6218<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6219<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6220 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6221
6222<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6223<p>The only argument is the value to be counted. The argument may be of any
6224 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6225
6226<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6227<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6228
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6229</div>
6230
6231<!-- _______________________________________________________________________ -->
6232<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6233 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6234</div>
6235
6236<div class="doc_text">
6237
6238<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6239<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
6240 integer bit width. Not all targets support all bit widths however.</p>
6241
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6242<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6243 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6244 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6245 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6246 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6247 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6248</pre>
6249
6250<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6251<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6252 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6253
6254<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6255<p>The only argument is the value to be counted. The argument may be of any
6256 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6257
6258<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6259<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
6260 zeros in a variable. If the src == 0 then the result is the size in bits of
6261 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6262
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6263</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6264
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6265<!-- _______________________________________________________________________ -->
6266<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6267 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6268</div>
6269
6270<div class="doc_text">
6271
6272<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6273<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
6274 integer bit width. Not all targets support all bit widths however.</p>
6275
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6276<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6277 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6278 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6279 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6280 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6281 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6282</pre>
6283
6284<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6285<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6286 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6287
6288<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6289<p>The only argument is the value to be counted. The argument may be of any
6290 integer type. The return type must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6291
6292<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6293<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
6294 zeros in a variable. If the src == 0 then the result is the size in bits of
6295 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6296
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6297</div>
6298
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6299<!-- ======================================================================= -->
6300<div class="doc_subsection">
6301 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
6302</div>
6303
6304<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6305
6306<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6307
6308</div>
6309
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6310<!-- _______________________________________________________________________ -->
6311<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6312 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6313</div>
6314
6315<div class="doc_text">
6316
6317<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6318<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6319 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6320
6321<pre>
6322 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6323 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6324 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6325</pre>
6326
6327<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6328<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6329 a signed addition of the two arguments, and indicate whether an overflow
6330 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6331
6332<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6333<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6334 be of integer types of any bit width, but they must have the same bit
6335 width. The second element of the result structure must be of
6336 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6337 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6338
6339<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6340<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6341 a signed addition of the two variables. They return a structure &mdash; the
6342 first element of which is the signed summation, and the second element of
6343 which is a bit specifying if the signed summation resulted in an
6344 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6345
6346<h5>Examples:</h5>
6347<pre>
6348 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6349 %sum = extractvalue {i32, i1} %res, 0
6350 %obit = extractvalue {i32, i1} %res, 1
6351 br i1 %obit, label %overflow, label %normal
6352</pre>
6353
6354</div>
6355
6356<!-- _______________________________________________________________________ -->
6357<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6358 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6359</div>
6360
6361<div class="doc_text">
6362
6363<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6364<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6365 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6366
6367<pre>
6368 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6369 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6370 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6371</pre>
6372
6373<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6374<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6375 an unsigned addition of the two arguments, and indicate whether a carry
6376 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6377
6378<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6379<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6380 be of integer types of any bit width, but they must have the same bit
6381 width. The second element of the result structure must be of
6382 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6383 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6384
6385<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6386<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6387 an unsigned addition of the two arguments. They return a structure &mdash;
6388 the first element of which is the sum, and the second element of which is a
6389 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6390
6391<h5>Examples:</h5>
6392<pre>
6393 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6394 %sum = extractvalue {i32, i1} %res, 0
6395 %obit = extractvalue {i32, i1} %res, 1
6396 br i1 %obit, label %carry, label %normal
6397</pre>
6398
6399</div>
6400
6401<!-- _______________________________________________________________________ -->
6402<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6403 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6404</div>
6405
6406<div class="doc_text">
6407
6408<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6409<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6410 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6411
6412<pre>
6413 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6414 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6415 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6416</pre>
6417
6418<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6419<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6420 a signed subtraction of the two arguments, and indicate whether an overflow
6421 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6422
6423<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6424<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6425 be of integer types of any bit width, but they must have the same bit
6426 width. The second element of the result structure must be of
6427 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6428 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6429
6430<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6431<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6432 a signed subtraction of the two arguments. They return a structure &mdash;
6433 the first element of which is the subtraction, and the second element of
6434 which is a bit specifying if the signed subtraction resulted in an
6435 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6436
6437<h5>Examples:</h5>
6438<pre>
6439 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6440 %sum = extractvalue {i32, i1} %res, 0
6441 %obit = extractvalue {i32, i1} %res, 1
6442 br i1 %obit, label %overflow, label %normal
6443</pre>
6444
6445</div>
6446
6447<!-- _______________________________________________________________________ -->
6448<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6449 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6450</div>
6451
6452<div class="doc_text">
6453
6454<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6455<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6456 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6457
6458<pre>
6459 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6460 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6461 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6462</pre>
6463
6464<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6465<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6466 an unsigned subtraction of the two arguments, and indicate whether an
6467 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6468
6469<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6470<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6471 be of integer types of any bit width, but they must have the same bit
6472 width. The second element of the result structure must be of
6473 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6474 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6475
6476<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6477<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6478 an unsigned subtraction of the two arguments. They return a structure &mdash;
6479 the first element of which is the subtraction, and the second element of
6480 which is a bit specifying if the unsigned subtraction resulted in an
6481 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6482
6483<h5>Examples:</h5>
6484<pre>
6485 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6486 %sum = extractvalue {i32, i1} %res, 0
6487 %obit = extractvalue {i32, i1} %res, 1
6488 br i1 %obit, label %overflow, label %normal
6489</pre>
6490
6491</div>
6492
6493<!-- _______________________________________________________________________ -->
6494<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6495 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6496</div>
6497
6498<div class="doc_text">
6499
6500<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6501<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6502 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6503
6504<pre>
6505 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6506 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6507 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6508</pre>
6509
6510<h5>Overview:</h5>
6511
6512<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6513 a signed multiplication of the two arguments, and indicate whether an
6514 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6515
6516<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6517<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6518 be of integer types of any bit width, but they must have the same bit
6519 width. The second element of the result structure must be of
6520 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6521 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6522
6523<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6524<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6525 a signed multiplication of the two arguments. They return a structure &mdash;
6526 the first element of which is the multiplication, and the second element of
6527 which is a bit specifying if the signed multiplication resulted in an
6528 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6529
6530<h5>Examples:</h5>
6531<pre>
6532 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6533 %sum = extractvalue {i32, i1} %res, 0
6534 %obit = extractvalue {i32, i1} %res, 1
6535 br i1 %obit, label %overflow, label %normal
6536</pre>
6537
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]6538</div>
6539
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6540<!-- _______________________________________________________________________ -->
6541<div class="doc_subsubsection">
6542 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6543</div>
6544
6545<div class="doc_text">
6546
6547<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6548<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6549 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6550
6551<pre>
6552 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6553 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6554 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6555</pre>
6556
6557<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6558<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6559 a unsigned multiplication of the two arguments, and indicate whether an
6560 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6561
6562<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6563<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6564 be of integer types of any bit width, but they must have the same bit
6565 width. The second element of the result structure must be of
6566 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6567 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6568
6569<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6570<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6571 an unsigned multiplication of the two arguments. They return a structure
6572 &mdash; the first element of which is the multiplication, and the second
6573 element of which is a bit specifying if the unsigned multiplication resulted
6574 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6575
6576<h5>Examples:</h5>
6577<pre>
6578 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6579 %sum = extractvalue {i32, i1} %res, 0
6580 %obit = extractvalue {i32, i1} %res, 1
6581 br i1 %obit, label %overflow, label %normal
6582</pre>
6583
6584</div>
6585
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6586<!-- ======================================================================= -->
6587<div class="doc_subsection">
6588 <a name="int_debugger">Debugger Intrinsics</a>
6589</div>
6590
6591<div class="doc_text">
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6592
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6593<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6594 prefix), are described in
6595 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6596 Level Debugging</a> document.</p>
6597
6598</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6599
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6600<!-- ======================================================================= -->
6601<div class="doc_subsection">
6602 <a name="int_eh">Exception Handling Intrinsics</a>
6603</div>
6604
6605<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6606
6607<p>The LLVM exception handling intrinsics (which all start with
6608 <tt>llvm.eh.</tt> prefix), are described in
6609 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6610 Handling</a> document.</p>
6611
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6612</div>
6613
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6614<!-- ======================================================================= -->
6615<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6616 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6617</div>
6618
6619<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6620
6621<p>This intrinsic makes it possible to excise one parameter, marked with
6622 the <tt>nest</tt> attribute, from a function. The result is a callable
6623 function pointer lacking the nest parameter - the caller does not need to
6624 provide a value for it. Instead, the value to use is stored in advance in a
6625 "trampoline", a block of memory usually allocated on the stack, which also
6626 contains code to splice the nest value into the argument list. This is used
6627 to implement the GCC nested function address extension.</p>
6628
6629<p>For example, if the function is
6630 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6631 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6632 follows:</p>
6633
6634<div class="doc_code">
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6635<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6636 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6637 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6638 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6639 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6640</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6641</div>
6642
6643<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6644 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6645
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6646</div>
6647
6648<!-- _______________________________________________________________________ -->
6649<div class="doc_subsubsection">
6650 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6651</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6652
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6653<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6654
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6655<h5>Syntax:</h5>
6656<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6657 declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6658</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6659
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6660<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6661<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6662 function pointer suitable for executing it.</p>
6663
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6664<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6665<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6666 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6667 sufficiently aligned block of memory; this memory is written to by the
6668 intrinsic. Note that the size and the alignment are target-specific - LLVM
6669 currently provides no portable way of determining them, so a front-end that
6670 generates this intrinsic needs to have some target-specific knowledge.
6671 The <tt>func</tt> argument must hold a function bitcast to
6672 an <tt>i8*</tt>.</p>
6673
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6674<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6675<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6676 dependent code, turning it into a function. A pointer to this function is
6677 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6678 function pointer type</a> before being called. The new function's signature
6679 is the same as that of <tt>func</tt> with any arguments marked with
6680 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6681 is allowed, and it must be of pointer type. Calling the new function is
6682 equivalent to calling <tt>func</tt> with the same argument list, but
6683 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6684 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6685 by <tt>tramp</tt> is modified, then the effect of any later call to the
6686 returned function pointer is undefined.</p>
6687
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6688</div>
6689
6690<!-- ======================================================================= -->
6691<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6692 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6693</div>
6694
6695<div class="doc_text">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6696
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6697<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6698 hardware constructs for atomic operations and memory synchronization. This
6699 provides an interface to the hardware, not an interface to the programmer. It
6700 is aimed at a low enough level to allow any programming models or APIs
6701 (Application Programming Interfaces) which need atomic behaviors to map
6702 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6703 hardware provides a "universal IR" for source languages, it also provides a
6704 starting point for developing a "universal" atomic operation and
6705 synchronization IR.</p>
6706
6707<p>These do <em>not</em> form an API such as high-level threading libraries,
6708 software transaction memory systems, atomic primitives, and intrinsic
6709 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6710 application libraries. The hardware interface provided by LLVM should allow
6711 a clean implementation of all of these APIs and parallel programming models.
6712 No one model or paradigm should be selected above others unless the hardware
6713 itself ubiquitously does so.</p>
6714
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6715</div>
6716
6717<!-- _______________________________________________________________________ -->
6718<div class="doc_subsubsection">
6719 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6720</div>
6721<div class="doc_text">
6722<h5>Syntax:</h5>
6723<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6724 declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;, i1 &lt;device&gt; )
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6725</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6726
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6727<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6728<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6729 specific pairs of memory access types.</p>
6730
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6731<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6732<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6733 The first four arguments enables a specific barrier as listed below. The
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6734 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6735 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6736
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6737<ul>
6738 <li><tt>ll</tt>: load-load barrier</li>
6739 <li><tt>ls</tt>: load-store barrier</li>
6740 <li><tt>sl</tt>: store-load barrier</li>
6741 <li><tt>ss</tt>: store-store barrier</li>
6742 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6743</ul>
6744
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6745<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6746<p>This intrinsic causes the system to enforce some ordering constraints upon
6747 the loads and stores of the program. This barrier does not
6748 indicate <em>when</em> any events will occur, it only enforces
6749 an <em>order</em> in which they occur. For any of the specified pairs of load
6750 and store operations (f.ex. load-load, or store-load), all of the first
6751 operations preceding the barrier will complete before any of the second
6752 operations succeeding the barrier begin. Specifically the semantics for each
6753 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6754
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6755<ul>
6756 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6757 after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6758 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6759 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6760 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6761 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6762 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6763 load after the barrier begins.</li>
6764</ul>
6765
6766<p>These semantics are applied with a logical "and" behavior when more than one
6767 is enabled in a single memory barrier intrinsic.</p>
6768
6769<p>Backends may implement stronger barriers than those requested when they do
6770 not support as fine grained a barrier as requested. Some architectures do
6771 not need all types of barriers and on such architectures, these become
6772 noops.</p>
6773
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6774<h5>Example:</h5>
6775<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6776%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6777%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6778 store i32 4, %ptr
6779
6780%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6781 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6782 <i>; guarantee the above finishes</i>
6783 store i32 8, %ptr <i>; before this begins</i>
6784</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6785
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6786</div>
6787
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6788<!-- _______________________________________________________________________ -->
6789<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6790 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6791</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6792
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6793<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6794
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6795<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6796<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6797 any integer bit width and for different address spaces. Not all targets
6798 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6799
6800<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6801 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6802 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6803 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6804 declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6805</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6806
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6807<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6808<p>This loads a value in memory and compares it to a given value. If they are
6809 equal, it stores a new value into the memory.</p>
6810
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6811<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6812<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
6813 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6814 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6815 this integer type. While any bit width integer may be used, targets may only
6816 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6817
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6818<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6819<p>This entire intrinsic must be executed atomically. It first loads the value
6820 in memory pointed to by <tt>ptr</tt> and compares it with the
6821 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
6822 memory. The loaded value is yielded in all cases. This provides the
6823 equivalent of an atomic compare-and-swap operation within the SSA
6824 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6825
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6826<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6827<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6828%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6829%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6830 store i32 4, %ptr
6831
6832%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6833%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6834 <i>; yields {i32}:result1 = 4</i>
6835%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6836%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6837
6838%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6839%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6840 <i>; yields {i32}:result2 = 8</i>
6841%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6842
6843%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6844</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6845
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6846</div>
6847
6848<!-- _______________________________________________________________________ -->
6849<div class="doc_subsubsection">
6850 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6851</div>
6852<div class="doc_text">
6853<h5>Syntax:</h5>
6854
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6855<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6856 integer bit width. Not all targets support all bit widths however.</p>
6857
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6858<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6859 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6860 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6861 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6862 declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6863</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6864
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6865<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6866<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6867 the value from memory. It then stores the value in <tt>val</tt> in the memory
6868 at <tt>ptr</tt>.</p>
6869
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6870<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6871<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
6872 the <tt>val</tt> argument and the result must be integers of the same bit
6873 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6874 integer type. The targets may only lower integer representations they
6875 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6876
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6877<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6878<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6879 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6880 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6881
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6882<h5>Examples:</h5>
6883<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6884%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6885%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6886 store i32 4, %ptr
6887
6888%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6889%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6890 <i>; yields {i32}:result1 = 4</i>
6891%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6892%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6893
6894%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6895%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6896 <i>; yields {i32}:result2 = 8</i>
6897
6898%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6899%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6900</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6901
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6902</div>
6903
6904<!-- _______________________________________________________________________ -->
6905<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6906 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6907
6908</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6909
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6910<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6911
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6912<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6913<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
6914 any integer bit width. Not all targets support all bit widths however.</p>
6915
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6916<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6917 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6918 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6919 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6920 declare i64 @llvm.atomic.load.add.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6921</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6922
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6923<h5>Overview:</h5>
6924<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
6925 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6926
6927<h5>Arguments:</h5>
6928<p>The intrinsic takes two arguments, the first a pointer to an integer value
6929 and the second an integer value. The result is also an integer value. These
6930 integer types can have any bit width, but they must all have the same bit
6931 width. The targets may only lower integer representations they support.</p>
6932
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6933<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6934<p>This intrinsic does a series of operations atomically. It first loads the
6935 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6936 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6937
6938<h5>Examples:</h5>
6939<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6940%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6941%ptr = bitcast i8* %mallocP to i32*
6942 store i32 4, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6943%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6944 <i>; yields {i32}:result1 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6945%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6946 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6947%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6948 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6949%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6950</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6951
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6952</div>
6953
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6954<!-- _______________________________________________________________________ -->
6955<div class="doc_subsubsection">
6956 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6957
6958</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6959
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6960<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6961
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6962<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6963<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
6964 any integer bit width and for different address spaces. Not all targets
6965 support all bit widths however.</p>
6966
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6967<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6968 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6969 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6970 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6971 declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6972</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6973
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6974<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]6975<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6976 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6977
6978<h5>Arguments:</h5>
6979<p>The intrinsic takes two arguments, the first a pointer to an integer value
6980 and the second an integer value. The result is also an integer value. These
6981 integer types can have any bit width, but they must all have the same bit
6982 width. The targets may only lower integer representations they support.</p>
6983
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6984<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6985<p>This intrinsic does a series of operations atomically. It first loads the
6986 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6987 result to <tt>ptr</tt>. It yields the original value stored
6988 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6989
6990<h5>Examples:</h5>
6991<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]6992%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
6993%ptr = bitcast i8* %mallocP to i32*
6994 store i32 8, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6995%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6996 <i>; yields {i32}:result1 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6997%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6998 <i>; yields {i32}:result2 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6999%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7000 <i>; yields {i32}:result3 = 2</i>
7001%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7002</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7003
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7004</div>
7005
7006<!-- _______________________________________________________________________ -->
7007<div class="doc_subsubsection">
7008 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
7009 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
7010 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
7011 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7012</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7013
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7014<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7015
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7016<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7017<p>These are overloaded intrinsics. You can
7018 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7019 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7020 bit width and for different address spaces. Not all targets support all bit
7021 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7022
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7023<pre>
7024 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7025 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7026 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7027 declare i64 @llvm.atomic.load.and.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7028</pre>
7029
7030<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7031 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7032 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7033 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7034 declare i64 @llvm.atomic.load.or.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7035</pre>
7036
7037<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7038 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7039 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7040 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7041 declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7042</pre>
7043
7044<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7045 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7046 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7047 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7048 declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7049</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7050
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7051<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7052<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7053 the value stored in memory at <tt>ptr</tt>. It yields the original value
7054 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7055
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7056<h5>Arguments:</h5>
7057<p>These intrinsics take two arguments, the first a pointer to an integer value
7058 and the second an integer value. The result is also an integer value. These
7059 integer types can have any bit width, but they must all have the same bit
7060 width. The targets may only lower integer representations they support.</p>
7061
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7062<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7063<p>These intrinsics does a series of operations atomically. They first load the
7064 value stored at <tt>ptr</tt>. They then do the bitwise
7065 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7066 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7067
7068<h5>Examples:</h5>
7069<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7070%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7071%ptr = bitcast i8* %mallocP to i32*
7072 store i32 0x0F0F, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7073%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7074 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7075%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7076 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7077%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7078 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7079%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7080 <i>; yields {i32}:result3 = FF</i>
7081%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7082</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7083
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7084</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7085
7086<!-- _______________________________________________________________________ -->
7087<div class="doc_subsubsection">
7088 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
7089 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
7090 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
7091 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7092</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7093
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7094<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7095
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7096<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7097<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7098 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7099 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7100 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7101
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7102<pre>
7103 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7104 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7105 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7106 declare i64 @llvm.atomic.load.max.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7107</pre>
7108
7109<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7110 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7111 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7112 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7113 declare i64 @llvm.atomic.load.min.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7114</pre>
7115
7116<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7117 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7118 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7119 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7120 declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7121</pre>
7122
7123<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7124 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
7125 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
7126 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
7127 declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7128</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7129
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7130<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7131<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7132 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7133 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7134
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7135<h5>Arguments:</h5>
7136<p>These intrinsics take two arguments, the first a pointer to an integer value
7137 and the second an integer value. The result is also an integer value. These
7138 integer types can have any bit width, but they must all have the same bit
7139 width. The targets may only lower integer representations they support.</p>
7140
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7141<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7142<p>These intrinsics does a series of operations atomically. They first load the
7143 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7144 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7145 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7146
7147<h5>Examples:</h5>
7148<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7149%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7150%ptr = bitcast i8* %mallocP to i32*
7151 store i32 7, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7152%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7153 <i>; yields {i32}:result0 = 7</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7154%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7155 <i>; yields {i32}:result1 = -2</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7156%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7157 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]7158%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7159 <i>; yields {i32}:result3 = 8</i>
7160%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7161</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7162
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7163</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7164
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7165
7166<!-- ======================================================================= -->
7167<div class="doc_subsection">
7168 <a name="int_memorymarkers">Memory Use Markers</a>
7169</div>
7170
7171<div class="doc_text">
7172
7173<p>This class of intrinsics exists to information about the lifetime of memory
7174 objects and ranges where variables are immutable.</p>
7175
7176</div>
7177
7178<!-- _______________________________________________________________________ -->
7179<div class="doc_subsubsection">
7180 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
7181</div>
7182
7183<div class="doc_text">
7184
7185<h5>Syntax:</h5>
7186<pre>
7187 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7188</pre>
7189
7190<h5>Overview:</h5>
7191<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7192 object's lifetime.</p>
7193
7194<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7195<p>The first argument is a constant integer representing the size of the
7196 object, or -1 if it is variable sized. The second argument is a pointer to
7197 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7198
7199<h5>Semantics:</h5>
7200<p>This intrinsic indicates that before this point in the code, the value of the
7201 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
Nick Lewyckyd20fd592009-10-27 16:56:58 +0000[diff] [blame]7202 never be used and has an undefined value. A load from the pointer that
7203 precedes this intrinsic can be replaced with
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7204 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7205
7206</div>
7207
7208<!-- _______________________________________________________________________ -->
7209<div class="doc_subsubsection">
7210 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
7211</div>
7212
7213<div class="doc_text">
7214
7215<h5>Syntax:</h5>
7216<pre>
7217 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7218</pre>
7219
7220<h5>Overview:</h5>
7221<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7222 object's lifetime.</p>
7223
7224<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7225<p>The first argument is a constant integer representing the size of the
7226 object, or -1 if it is variable sized. The second argument is a pointer to
7227 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7228
7229<h5>Semantics:</h5>
7230<p>This intrinsic indicates that after this point in the code, the value of the
7231 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7232 never be used and has an undefined value. Any stores into the memory object
7233 following this intrinsic may be removed as dead.
7234
7235</div>
7236
7237<!-- _______________________________________________________________________ -->
7238<div class="doc_subsubsection">
7239 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
7240</div>
7241
7242<div class="doc_text">
7243
7244<h5>Syntax:</h5>
7245<pre>
7246 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;) readonly
7247</pre>
7248
7249<h5>Overview:</h5>
7250<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7251 a memory object will not change.</p>
7252
7253<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7254<p>The first argument is a constant integer representing the size of the
7255 object, or -1 if it is variable sized. The second argument is a pointer to
7256 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7257
7258<h5>Semantics:</h5>
7259<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7260 the return value, the referenced memory location is constant and
7261 unchanging.</p>
7262
7263</div>
7264
7265<!-- _______________________________________________________________________ -->
7266<div class="doc_subsubsection">
7267 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
7268</div>
7269
7270<div class="doc_text">
7271
7272<h5>Syntax:</h5>
7273<pre>
7274 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7275</pre>
7276
7277<h5>Overview:</h5>
7278<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7279 a memory object are mutable.</p>
7280
7281<h5>Arguments:</h5>
7282<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7283 The second argument is a constant integer representing the size of the
7284 object, or -1 if it is variable sized and the third argument is a pointer
7285 to the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7286
7287<h5>Semantics:</h5>
7288<p>This intrinsic indicates that the memory is mutable again.</p>
7289
7290</div>
7291
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7292<!-- ======================================================================= -->
7293<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7294 <a name="int_general">General Intrinsics</a>
7295</div>
7296
7297<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7298
7299<p>This class of intrinsics is designed to be generic and has no specific
7300 purpose.</p>
7301
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7302</div>
7303
7304<!-- _______________________________________________________________________ -->
7305<div class="doc_subsubsection">
7306 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
7307</div>
7308
7309<div class="doc_text">
7310
7311<h5>Syntax:</h5>
7312<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]7313 declare void @llvm.var.annotation(i8* &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7314</pre>
7315
7316<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7317<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7318
7319<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7320<p>The first argument is a pointer to a value, the second is a pointer to a
7321 global string, the third is a pointer to a global string which is the source
7322 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7323
7324<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7325<p>This intrinsic allows annotation of local variables with arbitrary strings.
7326 This can be useful for special purpose optimizations that want to look for
7327 these annotations. These have no other defined use, they are ignored by code
7328 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7329
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7330</div>
7331
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7332<!-- _______________________________________________________________________ -->
7333<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]7334 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7335</div>
7336
7337<div class="doc_text">
7338
7339<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7340<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7341 any integer bit width.</p>
7342
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7343<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]7344 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7345 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7346 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7347 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
7348 declare i256 @llvm.annotation.i256(i256 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7349</pre>
7350
7351<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7352<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7353
7354<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7355<p>The first argument is an integer value (result of some expression), the
7356 second is a pointer to a global string, the third is a pointer to a global
7357 string which is the source file name, and the last argument is the line
7358 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7359
7360<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7361<p>This intrinsic allows annotations to be put on arbitrary expressions with
7362 arbitrary strings. This can be useful for special purpose optimizations that
7363 want to look for these annotations. These have no other defined use, they
7364 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7365
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7366</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7367
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7368<!-- _______________________________________________________________________ -->
7369<div class="doc_subsubsection">
7370 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
7371</div>
7372
7373<div class="doc_text">
7374
7375<h5>Syntax:</h5>
7376<pre>
7377 declare void @llvm.trap()
7378</pre>
7379
7380<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7381<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7382
7383<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7384<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7385
7386<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7387<p>This intrinsics is lowered to the target dependent trap instruction. If the
7388 target does not have a trap instruction, this intrinsic will be lowered to
7389 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7390
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7391</div>
7392
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7393<!-- _______________________________________________________________________ -->
7394<div class="doc_subsubsection">
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]7395 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7396</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7397
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7398<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7399
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7400<h5>Syntax:</h5>
7401<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7402 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7403</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7404
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7405<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7406<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
7407 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
7408 ensure that it is placed on the stack before local variables.</p>
7409
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7410<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7411<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
7412 arguments. The first argument is the value loaded from the stack
7413 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
7414 that has enough space to hold the value of the guard.</p>
7415
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7416<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7417<p>This intrinsic causes the prologue/epilogue inserter to force the position of
7418 the <tt>AllocaInst</tt> stack slot to be before local variables on the
7419 stack. This is to ensure that if a local variable on the stack is
7420 overwritten, it will destroy the value of the guard. When the function exits,
7421 the guard on the stack is checked against the original guard. If they're
7422 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
7423 function.</p>
7424
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7425</div>
7426
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7427<!-- _______________________________________________________________________ -->
7428<div class="doc_subsubsection">
7429 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
7430</div>
7431
7432<div class="doc_text">
7433
7434<h5>Syntax:</h5>
7435<pre>
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]7436 declare i32 @llvm.objectsize.i32( i8* &lt;object&gt;, i1 &lt;type&gt; )
7437 declare i64 @llvm.objectsize.i64( i8* &lt;object&gt;, i1 &lt;type&gt; )
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7438</pre>
7439
7440<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7441<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information
Eric Christopher3070e162010-01-08 21:42:39 +0000[diff] [blame]7442 to the optimizers to discover at compile time either a) when an
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7443 operation like memcpy will either overflow a buffer that corresponds to
7444 an object, or b) to determine that a runtime check for overflow isn't
7445 necessary. An object in this context means an allocation of a
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]7446 specific class, structure, array, or other object.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7447
7448<h5>Arguments:</h5>
7449<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]7450 argument is a pointer to or into the <tt>object</tt>. The second argument
7451 is a boolean 0 or 1. This argument determines whether you want the
7452 maximum (0) or minimum (1) bytes remaining. This needs to be a literal 0 or
7453 1, variables are not allowed.</p>
7454
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7455<h5>Semantics:</h5>
7456<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7457 representing the size of the object concerned or <tt>i32/i64 -1 or 0</tt>
7458 (depending on the <tt>type</tt> argument if the size cannot be determined
7459 at compile time.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7460
7461</div>
7462
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]7463<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]7464<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7465<address>
7466 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7470
7471 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]7472 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7473 Last modified: $Date$
7474</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]7475
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]7476</body>
7477</html>