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gerrit-public.fairphone.software / toolchain / llvm-project / 26b51b15edaddb7448f9f3342ca1c087a9c260b6 / . / 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">
8 <meta name="description"
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>
34 <li><a href="#linkage_linkonce">'<tt>linkonce_odr</tt>' Linkage</a></li>
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>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]46 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]47 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]48 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]49 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]50 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]51 </ol>
52 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]53 <li><a href="#typesystem">Type System</a>
54 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]55 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]56 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]57 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]58 <li><a href="#t_floating">Floating Point Types</a></li>
59 <li><a href="#t_void">Void Type</a></li>
60 <li><a href="#t_label">Label Type</a></li>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]61 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]62 </ol>
63 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]64 <li><a href="#t_derived">Derived Types</a>
65 <ol>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]66 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]67 <li><a href="#t_array">Array Type</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]68 <li><a href="#t_function">Function Type</a></li>
69 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]70 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]71 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]72 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]73 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]74 </ol>
75 </li>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]76 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]77 </ol>
78 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]79 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]80 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]81 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]82 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]83 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
84 <li><a href="#undefvalues">Undefined Values</a></li>
85 <li><a href="#constantexprs">Constant Expressions</a></li>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]86 <li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]87 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]88 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]89 <li><a href="#othervalues">Other Values</a>
90 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]91 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]92 </ol>
93 </li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]94 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
95 <ol>
96 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]97 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
98 Global Variable</a></li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]99 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
100 Global Variable</a></li>
101 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
102 Global Variable</a></li>
103 </ol>
104 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]105 <li><a href="#instref">Instruction Reference</a>
106 <ol>
107 <li><a href="#terminators">Terminator Instructions</a>
108 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]109 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
110 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]111 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
112 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]113 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]114 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]115 </ol>
116 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]117 <li><a href="#binaryops">Binary Operations</a>
118 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]119 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]120 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]121 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]122 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]123 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]124 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]125 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
126 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
127 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]128 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
129 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
130 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]131 </ol>
132 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]133 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
134 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]135 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
136 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
137 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]138 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]139 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]140 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]141 </ol>
142 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]143 <li><a href="#vectorops">Vector Operations</a>
144 <ol>
145 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
146 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
147 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]148 </ol>
149 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]150 <li><a href="#aggregateops">Aggregate Operations</a>
151 <ol>
152 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
153 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
154 </ol>
155 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]156 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]157 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]158 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
159 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
160 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]161 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
162 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
163 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]164 </ol>
165 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]166 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]167 <ol>
168 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
169 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
170 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
171 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
172 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]173 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
174 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
175 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
176 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]177 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
178 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]179 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]180 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]181 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]182 <li><a href="#otherops">Other Operations</a>
183 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]184 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
185 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]186 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]187 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]188 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]189 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]190 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]191 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]192 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]193 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]194 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]195 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]196 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
197 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]198 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
199 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
200 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]201 </ol>
202 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]203 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
204 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]205 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
206 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
207 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]208 </ol>
209 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]210 <li><a href="#int_codegen">Code Generator Intrinsics</a>
211 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]212 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
213 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
214 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
215 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
216 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
217 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
218 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]219 </ol>
220 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]221 <li><a href="#int_libc">Standard C Library Intrinsics</a>
222 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]223 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
224 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
225 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
226 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
227 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]228 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
229 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
230 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]231 </ol>
232 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]233 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]234 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]235 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]236 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
237 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
238 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]239 </ol>
240 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]241 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
242 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]243 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
244 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
245 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
246 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
247 <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]248 <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]249 </ol>
250 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]251 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]252 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]253 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]254 <ol>
255 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]256 </ol>
257 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]258 <li><a href="#int_atomics">Atomic intrinsics</a>
259 <ol>
260 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
261 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
262 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
263 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
264 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
265 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
266 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
267 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
268 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
269 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
270 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
271 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
272 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
273 </ol>
274 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]275 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]276 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]277 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]278 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]279 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]280 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]281 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]282 '<tt>llvm.trap</tt>' Intrinsic</a></li>
283 <li><a href="#int_stackprotector">
284 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]285 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]286 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]287 </ol>
288 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]289</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]290
291<div class="doc_author">
292 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
293 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]294</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]295
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]296<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]297<div class="doc_section"> <a name="abstract">Abstract </a></div>
298<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]299
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]300<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]301
302<p>This document is a reference manual for the LLVM assembly language. LLVM is
303 a Static Single Assignment (SSA) based representation that provides type
304 safety, low-level operations, flexibility, and the capability of representing
305 'all' high-level languages cleanly. It is the common code representation
306 used throughout all phases of the LLVM compilation strategy.</p>
307
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]308</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]309
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]310<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]311<div class="doc_section"> <a name="introduction">Introduction</a> </div>
312<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]313
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]314<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]315
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]316<p>The LLVM code representation is designed to be used in three different forms:
317 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
318 for fast loading by a Just-In-Time compiler), and as a human readable
319 assembly language representation. This allows LLVM to provide a powerful
320 intermediate representation for efficient compiler transformations and
321 analysis, while providing a natural means to debug and visualize the
322 transformations. The three different forms of LLVM are all equivalent. This
323 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]324
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]325<p>The LLVM representation aims to be light-weight and low-level while being
326 expressive, typed, and extensible at the same time. It aims to be a
327 "universal IR" of sorts, by being at a low enough level that high-level ideas
328 may be cleanly mapped to it (similar to how microprocessors are "universal
329 IR's", allowing many source languages to be mapped to them). By providing
330 type information, LLVM can be used as the target of optimizations: for
331 example, through pointer analysis, it can be proven that a C automatic
332 variable is never accessed outside of the current function... allowing it to
333 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]334
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]335</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]336
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]337<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]338<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]339
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]340<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]341
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]342<p>It is important to note that this document describes 'well formed' LLVM
343 assembly language. There is a difference between what the parser accepts and
344 what is considered 'well formed'. For example, the following instruction is
345 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]346
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]347<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]348<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]349%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]350</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]351</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]352
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]353<p>...because the definition of <tt>%x</tt> does not dominate all of its
354 uses. The LLVM infrastructure provides a verification pass that may be used
355 to verify that an LLVM module is well formed. This pass is automatically run
356 by the parser after parsing input assembly and by the optimizer before it
357 outputs bitcode. The violations pointed out by the verifier pass indicate
358 bugs in transformation passes or input to the parser.</p>
359
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]360</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]361
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]362<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]363
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]364<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]365<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]366<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]367
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]368<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]369
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]370<p>LLVM identifiers come in two basic types: global and local. Global
371 identifiers (functions, global variables) begin with the <tt>'@'</tt>
372 character. Local identifiers (register names, types) begin with
373 the <tt>'%'</tt> character. Additionally, there are three different formats
374 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]375
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]376<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]377 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]378 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
379 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
380 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
381 other characters in their names can be surrounded with quotes. Special
382 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
383 ASCII code for the character in hexadecimal. In this way, any character
384 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]385
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]386 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]387 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]388
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]389 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]390 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]391</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]392
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]393<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]394 don't need to worry about name clashes with reserved words, and the set of
395 reserved words may be expanded in the future without penalty. Additionally,
396 unnamed identifiers allow a compiler to quickly come up with a temporary
397 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]398
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]399<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]400 languages. There are keywords for different opcodes
401 ('<tt><a href="#i_add">add</a></tt>',
402 '<tt><a href="#i_bitcast">bitcast</a></tt>',
403 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
404 ('<tt><a href="#t_void">void</a></tt>',
405 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
406 reserved words cannot conflict with variable names, because none of them
407 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]408
409<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]410 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]411
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]412<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]413
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]414<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]415<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]416%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]417</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]418</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]419
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]420<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]421
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]422<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]423<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]424%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]425</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]426</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]427
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]428<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]429
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]430<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]431<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]432<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
433<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
434%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]435</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]436</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]437
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]438<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
439 lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]440
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]441<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]442 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]443 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]444
445 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]446 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]447
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]448 <li>Unnamed temporaries are numbered sequentially</li>
449</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]450
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]451<p>...and it also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]452 demonstrating instructions, we will follow an instruction with a comment that
453 defines the type and name of value produced. Comments are shown in italic
454 text.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]455
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]456</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]457
458<!-- *********************************************************************** -->
459<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
460<!-- *********************************************************************** -->
461
462<!-- ======================================================================= -->
463<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
464</div>
465
466<div class="doc_text">
467
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]468<p>LLVM programs are composed of "Module"s, each of which is a translation unit
469 of the input programs. Each module consists of functions, global variables,
470 and symbol table entries. Modules may be combined together with the LLVM
471 linker, which merges function (and global variable) definitions, resolves
472 forward declarations, and merges symbol table entries. Here is an example of
473 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]474
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]475<div class="doc_code">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]476<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]477<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
478 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]479
480<i>; External declaration of the puts function</i>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]481<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]482
483<i>; Definition of main function</i>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]484define i32 @main() { <i>; i32()* </i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]485 <i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]486 %cast210 = <a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]487 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]488
489 <i>; Call puts function to write out the string to stdout...</i>
490 <a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]491 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]492 <a
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]493 href="#i_ret">ret</a> i32 0<br>}<br>
494</pre>
495</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]496
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]497<p>This example is made up of a <a href="#globalvars">global variable</a> named
498 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function, and
499 a <a href="#functionstructure">function definition</a> for
500 "<tt>main</tt>".</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]501
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]502<p>In general, a module is made up of a list of global values, where both
503 functions and global variables are global values. Global values are
504 represented by a pointer to a memory location (in this case, a pointer to an
505 array of char, and a pointer to a function), and have one of the
506 following <a href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]507
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]508</div>
509
510<!-- ======================================================================= -->
511<div class="doc_subsection">
512 <a name="linkage">Linkage Types</a>
513</div>
514
515<div class="doc_text">
516
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]517<p>All Global Variables and Functions have one of the following types of
518 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]519
520<dl>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]521 <dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]522 <dd>Global values with private linkage are only directly accessible by objects
523 in the current module. In particular, linking code into a module with an
524 private global value may cause the private to be renamed as necessary to
525 avoid collisions. Because the symbol is private to the module, all
526 references can be updated. This doesn't show up in any symbol table in the
527 object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]528
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]529 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt>: </dt>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]530 <dd>Similar to private, but the symbol is passed through the assembler and
531 removed by the linker after evaluation.</dd>
532
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]533 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]534 <dd>Similar to private, but the value shows as a local symbol
535 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
536 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]537
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]538 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt>: </dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]539 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]540 into the object file corresponding to the LLVM module. They exist to
541 allow inlining and other optimizations to take place given knowledge of
542 the definition of the global, which is known to be somewhere outside the
543 module. Globals with <tt>available_externally</tt> linkage are allowed to
544 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
545 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]546
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]547 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]548 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]549 the same name when linkage occurs. This is typically used to implement
550 inline functions, templates, or other code which must be generated in each
551 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
552 allowed to be discarded.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]553
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]554 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]555 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
556 linkage, except that unreferenced <tt>common</tt> globals may not be
557 discarded. This is used for globals that may be emitted in multiple
558 translation units, but that are not guaranteed to be emitted into every
559 translation unit that uses them. One example of this is tentative
560 definitions in C, such as "<tt>int X;</tt>" at global scope.</dd>
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]561
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]562 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]563 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]564 that some targets may choose to emit different assembly sequences for them
565 for target-dependent reasons. This is used for globals that are declared
566 "weak" in C source code.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]567
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]568 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]569 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]570 pointer to array type. When two global variables with appending linkage
571 are linked together, the two global arrays are appended together. This is
572 the LLVM, typesafe, equivalent of having the system linker append together
573 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]574
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]575 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]576 <dd>The semantics of this linkage follow the ELF object file model: the symbol
577 is weak until linked, if not linked, the symbol becomes null instead of
578 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]579
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]580 <dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]581 <dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]582 <dd>Some languages allow differing globals to be merged, such as two functions
583 with different semantics. Other languages, such as <tt>C++</tt>, ensure
584 that only equivalent globals are ever merged (the "one definition rule" -
585 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
586 and <tt>weak_odr</tt> linkage types to indicate that the global will only
587 be merged with equivalent globals. These linkage types are otherwise the
588 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]589
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]590 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]591 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]592 visible, meaning that it participates in linkage and can be used to
593 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]594</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]595
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]596<p>The next two types of linkage are targeted for Microsoft Windows platform
597 only. They are designed to support importing (exporting) symbols from (to)
598 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]599
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]600<dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]601 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]602 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]603 or variable via a global pointer to a pointer that is set up by the DLL
604 exporting the symbol. On Microsoft Windows targets, the pointer name is
605 formed by combining <code>__imp_</code> and the function or variable
606 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]607
608 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]609 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]610 pointer to a pointer in a DLL, so that it can be referenced with the
611 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
612 name is formed by combining <code>__imp_</code> and the function or
613 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]614</dl>
615
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]616<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
617 another module defined a "<tt>.LC0</tt>" variable and was linked with this
618 one, one of the two would be renamed, preventing a collision. Since
619 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
620 declarations), they are accessible outside of the current module.</p>
621
622<p>It is illegal for a function <i>declaration</i> to have any linkage type
623 other than "externally visible", <tt>dllimport</tt>
624 or <tt>extern_weak</tt>.</p>
625
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]626<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]627 or <tt>weak_odr</tt> linkages.</p>
628
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]629</div>
630
631<!-- ======================================================================= -->
632<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]633 <a name="callingconv">Calling Conventions</a>
634</div>
635
636<div class="doc_text">
637
638<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]639 and <a href="#i_invoke">invokes</a> can all have an optional calling
640 convention specified for the call. The calling convention of any pair of
641 dynamic caller/callee must match, or the behavior of the program is
642 undefined. The following calling conventions are supported by LLVM, and more
643 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]644
645<dl>
646 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]647 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]648 specified) matches the target C calling conventions. This calling
649 convention supports varargs function calls and tolerates some mismatch in
650 the declared prototype and implemented declaration of the function (as
651 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]652
653 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]654 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]655 (e.g. by passing things in registers). This calling convention allows the
656 target to use whatever tricks it wants to produce fast code for the
657 target, without having to conform to an externally specified ABI
658 (Application Binary Interface). Implementations of this convention should
659 allow arbitrary <a href="CodeGenerator.html#tailcallopt">tail call
660 optimization</a> to be supported. This calling convention does not
661 support varargs and requires the prototype of all callees to exactly match
662 the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]663
664 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]665 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]666 as possible under the assumption that the call is not commonly executed.
667 As such, these calls often preserve all registers so that the call does
668 not break any live ranges in the caller side. This calling convention
669 does not support varargs and requires the prototype of all callees to
670 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]671
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]672 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]673 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]674 target-specific calling conventions to be used. Target specific calling
675 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]676</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]677
678<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]679 support Pascal conventions or any other well-known target-independent
680 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]681
682</div>
683
684<!-- ======================================================================= -->
685<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]686 <a name="visibility">Visibility Styles</a>
687</div>
688
689<div class="doc_text">
690
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]691<p>All Global Variables and Functions have one of the following visibility
692 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]693
694<dl>
695 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]696 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]697 that the declaration is visible to other modules and, in shared libraries,
698 means that the declared entity may be overridden. On Darwin, default
699 visibility means that the declaration is visible to other modules. Default
700 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]701
702 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]703 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]704 object if they are in the same shared object. Usually, hidden visibility
705 indicates that the symbol will not be placed into the dynamic symbol
706 table, so no other module (executable or shared library) can reference it
707 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]708
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]709 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]710 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]711 the dynamic symbol table, but that references within the defining module
712 will bind to the local symbol. That is, the symbol cannot be overridden by
713 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]714</dl>
715
716</div>
717
718<!-- ======================================================================= -->
719<div class="doc_subsection">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]720 <a name="namedtypes">Named Types</a>
721</div>
722
723<div class="doc_text">
724
725<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]726 it easier to read the IR and make the IR more condensed (particularly when
727 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]728
729<div class="doc_code">
730<pre>
731%mytype = type { %mytype*, i32 }
732</pre>
733</div>
734
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]735<p>You may give a name to any <a href="#typesystem">type</a> except
736 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
737 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]738
739<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]740 and that you can therefore specify multiple names for the same type. This
741 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
742 uses structural typing, the name is not part of the type. When printing out
743 LLVM IR, the printer will pick <em>one name</em> to render all types of a
744 particular shape. This means that if you have code where two different
745 source types end up having the same LLVM type, that the dumper will sometimes
746 print the "wrong" or unexpected type. This is an important design point and
747 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]748
749</div>
750
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]751<!-- ======================================================================= -->
752<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]753 <a name="globalvars">Global Variables</a>
754</div>
755
756<div class="doc_text">
757
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]758<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]759 instead of run-time. Global variables may optionally be initialized, may
760 have an explicit section to be placed in, and may have an optional explicit
761 alignment specified. A variable may be defined as "thread_local", which
762 means that it will not be shared by threads (each thread will have a
763 separated copy of the variable). A variable may be defined as a global
764 "constant," which indicates that the contents of the variable
765 will <b>never</b> be modified (enabling better optimization, allowing the
766 global data to be placed in the read-only section of an executable, etc).
767 Note that variables that need runtime initialization cannot be marked
768 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]769
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]770<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
771 constant, even if the final definition of the global is not. This capability
772 can be used to enable slightly better optimization of the program, but
773 requires the language definition to guarantee that optimizations based on the
774 'constantness' are valid for the translation units that do not include the
775 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]776
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]777<p>As SSA values, global variables define pointer values that are in scope
778 (i.e. they dominate) all basic blocks in the program. Global variables
779 always define a pointer to their "content" type because they describe a
780 region of memory, and all memory objects in LLVM are accessed through
781 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]782
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]783<p>A global variable may be declared to reside in a target-specific numbered
784 address space. For targets that support them, address spaces may affect how
785 optimizations are performed and/or what target instructions are used to
786 access the variable. The default address space is zero. The address space
787 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]788
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]789<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]790 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]791
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]792<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]793 the alignment is set to zero, the alignment of the global is set by the
794 target to whatever it feels convenient. If an explicit alignment is
795 specified, the global is forced to have at least that much alignment. All
796 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]797
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]798<p>For example, the following defines a global in a numbered address space with
799 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]800
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]801<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]802<pre>
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]803@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]804</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]805</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]806
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]807</div>
808
809
810<!-- ======================================================================= -->
811<div class="doc_subsection">
812 <a name="functionstructure">Functions</a>
813</div>
814
815<div class="doc_text">
816
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]817<p>LLVM function definitions consist of the "<tt>define</tt>" keyord, an
818 optional <a href="#linkage">linkage type</a>, an optional
819 <a href="#visibility">visibility style</a>, an optional
820 <a href="#callingconv">calling convention</a>, a return type, an optional
821 <a href="#paramattrs">parameter attribute</a> for the return type, a function
822 name, a (possibly empty) argument list (each with optional
823 <a href="#paramattrs">parameter attributes</a>), optional
824 <a href="#fnattrs">function attributes</a>, an optional section, an optional
825 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
826 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]827
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]828<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
829 optional <a href="#linkage">linkage type</a>, an optional
830 <a href="#visibility">visibility style</a>, an optional
831 <a href="#callingconv">calling convention</a>, a return type, an optional
832 <a href="#paramattrs">parameter attribute</a> for the return type, a function
833 name, a possibly empty list of arguments, an optional alignment, and an
834 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]835
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]836<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]837 (Control Flow Graph) for the function. Each basic block may optionally start
838 with a label (giving the basic block a symbol table entry), contains a list
839 of instructions, and ends with a <a href="#terminators">terminator</a>
840 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]841
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]842<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]843 executed on entrance to the function, and it is not allowed to have
844 predecessor basic blocks (i.e. there can not be any branches to the entry
845 block of a function). Because the block can have no predecessors, it also
846 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]847
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]848<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]849 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]850
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]851<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]852 the alignment is set to zero, the alignment of the function is set by the
853 target to whatever it feels convenient. If an explicit alignment is
854 specified, the function is forced to have at least that much alignment. All
855 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]856
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]857<h5>Syntax:</h5>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]858<div class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]859<pre>
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]860define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]861 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
862 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
863 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
864 [<a href="#gc">gc</a>] { ... }
865</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]866</div>
867
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]868</div>
869
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]870<!-- ======================================================================= -->
871<div class="doc_subsection">
872 <a name="aliasstructure">Aliases</a>
873</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]874
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]875<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]876
877<p>Aliases act as "second name" for the aliasee value (which can be either
878 function, global variable, another alias or bitcast of global value). Aliases
879 may have an optional <a href="#linkage">linkage type</a>, and an
880 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]881
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]882<h5>Syntax:</h5>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]883<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]884<pre>
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]885@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]886</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]887</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]888
889</div>
890
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]891<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]892<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]893
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]894<div class="doc_text">
895
896<p>The return type and each parameter of a function type may have a set of
897 <i>parameter attributes</i> associated with them. Parameter attributes are
898 used to communicate additional information about the result or parameters of
899 a function. Parameter attributes are considered to be part of the function,
900 not of the function type, so functions with different parameter attributes
901 can have the same function type.</p>
902
903<p>Parameter attributes are simple keywords that follow the type specified. If
904 multiple parameter attributes are needed, they are space separated. For
905 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]906
907<div class="doc_code">
908<pre>
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]909declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]910declare i32 @atoi(i8 zeroext)
911declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]912</pre>
913</div>
914
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]915<p>Note that any attributes for the function result (<tt>nounwind</tt>,
916 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]917
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]918<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]919
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]920<dl>
921 <dt><tt>zeroext</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]922 <dd>This indicates to the code generator that the parameter or return value
923 should be zero-extended to a 32-bit value by the caller (for a parameter)
924 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]925
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]926 <dt><tt>signext</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]927 <dd>This indicates to the code generator that the parameter or return value
928 should be sign-extended to a 32-bit value by the caller (for a parameter)
929 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]930
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]931 <dt><tt>inreg</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]932 <dd>This indicates that this parameter or return value should be treated in a
933 special target-dependent fashion during while emitting code for a function
934 call or return (usually, by putting it in a register as opposed to memory,
935 though some targets use it to distinguish between two different kinds of
936 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]937
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]938 <dt><tt><a name="byval">byval</a></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]939 <dd>This indicates that the pointer parameter should really be passed by value
940 to the function. The attribute implies that a hidden copy of the pointee
941 is made between the caller and the callee, so the callee is unable to
942 modify the value in the callee. This attribute is only valid on LLVM
943 pointer arguments. It is generally used to pass structs and arrays by
944 value, but is also valid on pointers to scalars. The copy is considered
945 to belong to the caller not the callee (for example,
946 <tt><a href="#readonly">readonly</a></tt> functions should not write to
947 <tt>byval</tt> parameters). This is not a valid attribute for return
948 values. The byval attribute also supports specifying an alignment with
949 the align attribute. This has a target-specific effect on the code
950 generator that usually indicates a desired alignment for the synthesized
951 stack slot.</dd>
952
953 <dt><tt>sret</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]954 <dd>This indicates that the pointer parameter specifies the address of a
955 structure that is the return value of the function in the source program.
956 This pointer must be guaranteed by the caller to be valid: loads and
957 stores to the structure may be assumed by the callee to not to trap. This
958 may only be applied to the first parameter. This is not a valid attribute
959 for return values. </dd>
960
961 <dt><tt>noalias</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]962 <dd>This indicates that the pointer does not alias any global or any other
963 parameter. The caller is responsible for ensuring that this is the
964 case. On a function return value, <tt>noalias</tt> additionally indicates
965 that the pointer does not alias any other pointers visible to the
966 caller. For further details, please see the discussion of the NoAlias
967 response in
968 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
969 analysis</a>.</dd>
970
971 <dt><tt>nocapture</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]972 <dd>This indicates that the callee does not make any copies of the pointer
973 that outlive the callee itself. This is not a valid attribute for return
974 values.</dd>
975
976 <dt><tt>nest</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]977 <dd>This indicates that the pointer parameter can be excised using the
978 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
979 attribute for return values.</dd>
980</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]981
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]982</div>
983
984<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]985<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]986 <a name="gc">Garbage Collector Names</a>
987</div>
988
989<div class="doc_text">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]990
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]991<p>Each function may specify a garbage collector name, which is simply a
992 string:</p>
993
994<div class="doc_code">
995<pre>
996define void @f() gc "name" { ...
997</pre>
998</div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]999
1000<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1001 collector which will cause the compiler to alter its output in order to
1002 support the named garbage collection algorithm.</p>
1003
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1004</div>
1005
1006<!-- ======================================================================= -->
1007<div class="doc_subsection">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1008 <a name="fnattrs">Function Attributes</a>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1009</div>
1010
1011<div class="doc_text">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1012
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1013<p>Function attributes are set to communicate additional information about a
1014 function. Function attributes are considered to be part of the function, not
1015 of the function type, so functions with different parameter attributes can
1016 have the same function type.</p>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1017
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1018<p>Function attributes are simple keywords that follow the type specified. If
1019 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1020
1021<div class="doc_code">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1022<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1023define void @f() noinline { ... }
1024define void @f() alwaysinline { ... }
1025define void @f() alwaysinline optsize { ... }
1026define void @f() optsize
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1027</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1028</div>
1029
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1030<dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1031 <dt><tt>alwaysinline</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1032 <dd>This attribute indicates that the inliner should attempt to inline this
1033 function into callers whenever possible, ignoring any active inlining size
1034 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1035
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1036 <dt><tt>noinline</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1037 <dd>This attribute indicates that the inliner should never inline this
1038 function in any situation. This attribute may not be used together with
1039 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1040
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1041 <dt><tt>optsize</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1042 <dd>This attribute suggests that optimization passes and code generator passes
1043 make choices that keep the code size of this function low, and otherwise
1044 do optimizations specifically to reduce code size.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1045
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1046 <dt><tt>noreturn</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1047 <dd>This function attribute indicates that the function never returns
1048 normally. This produces undefined behavior at runtime if the function
1049 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1050
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1051 <dt><tt>nounwind</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1052 <dd>This function attribute indicates that the function never returns with an
1053 unwind or exceptional control flow. If the function does unwind, its
1054 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1055
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1056 <dt><tt>readnone</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1057 <dd>This attribute indicates that the function computes its result (or decides
1058 to unwind an exception) based strictly on its arguments, without
1059 dereferencing any pointer arguments or otherwise accessing any mutable
1060 state (e.g. memory, control registers, etc) visible to caller functions.
1061 It does not write through any pointer arguments
1062 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1063 changes any state visible to callers. This means that it cannot unwind
1064 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1065 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1066
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1067 <dt><tt><a name="readonly">readonly</a></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1068 <dd>This attribute indicates that the function does not write through any
1069 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1070 arguments) or otherwise modify any state (e.g. memory, control registers,
1071 etc) visible to caller functions. It may dereference pointer arguments
1072 and read state that may be set in the caller. A readonly function always
1073 returns the same value (or unwinds an exception identically) when called
1074 with the same set of arguments and global state. It cannot unwind an
1075 exception by calling the <tt>C++</tt> exception throwing methods, but may
1076 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1077
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1078 <dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1079 <dd>This attribute indicates that the function should emit a stack smashing
1080 protector. It is in the form of a "canary"&mdash;a random value placed on
1081 the stack before the local variables that's checked upon return from the
1082 function to see if it has been overwritten. A heuristic is used to
1083 determine if a function needs stack protectors or not.<br>
1084<br>
1085 If a function that has an <tt>ssp</tt> attribute is inlined into a
1086 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1087 function will have an <tt>ssp</tt> attribute.</dd>
1088
1089 <dt><tt>sspreq</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1090 <dd>This attribute indicates that the function should <em>always</em> emit a
1091 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1092 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1093<br>
1094 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1095 function that doesn't have an <tt>sspreq</tt> attribute or which has
1096 an <tt>ssp</tt> attribute, then the resulting function will have
1097 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1098
1099 <dt><tt>noredzone</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1100 <dd>This attribute indicates that the code generator should not use a red
1101 zone, even if the target-specific ABI normally permits it.</dd>
1102
1103 <dt><tt>noimplicitfloat</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1104 <dd>This attributes disables implicit floating point instructions.</dd>
1105
1106 <dt><tt>naked</tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1107 <dd>This attribute disables prologue / epilogue emission for the function.
1108 This can have very system-specific consequences.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1109</dl>
1110
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1111</div>
1112
1113<!-- ======================================================================= -->
1114<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1115 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1116</div>
1117
1118<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1119
1120<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1121 the GCC "file scope inline asm" blocks. These blocks are internally
1122 concatenated by LLVM and treated as a single unit, but may be separated in
1123 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1124
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1125<div class="doc_code">
1126<pre>
1127module asm "inline asm code goes here"
1128module asm "more can go here"
1129</pre>
1130</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1131
1132<p>The strings can contain any character by escaping non-printable characters.
1133 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]1134 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1135
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1136<p>The inline asm code is simply printed to the machine code .s file when
1137 assembly code is generated.</p>
1138
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1139</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1140
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1141<!-- ======================================================================= -->
1142<div class="doc_subsection">
1143 <a name="datalayout">Data Layout</a>
1144</div>
1145
1146<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1147
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1148<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1149 data is to be laid out in memory. The syntax for the data layout is
1150 simply:</p>
1151
1152<div class="doc_code">
1153<pre>
1154target datalayout = "<i>layout specification</i>"
1155</pre>
1156</div>
1157
1158<p>The <i>layout specification</i> consists of a list of specifications
1159 separated by the minus sign character ('-'). Each specification starts with
1160 a letter and may include other information after the letter to define some
1161 aspect of the data layout. The specifications accepted are as follows:</p>
1162
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1163<dl>
1164 <dt><tt>E</tt></dt>
1165 <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]1166 bits with the most significance have the lowest address location.</dd>
1167
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1168 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1169 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1170 the bits with the least significance have the lowest address
1171 location.</dd>
1172
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1173 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1174 <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]1175 <i>preferred</i> alignments. All sizes are in bits. Specifying
1176 the <i>pref</i> alignment is optional. If omitted, the
1177 preceding <tt>:</tt> should be omitted too.</dd>
1178
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1179 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1180 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1181 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1182
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1183 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1184 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1185 <i>size</i>.</dd>
1186
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1187 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1188 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1189 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1190 (double).</dd>
1191
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1192 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1193 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1194 <i>size</i>.</dd>
1195
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1196 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1197 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1198 <i>size</i>.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1199</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1200
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1201<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1202 default set of specifications which are then (possibly) overriden by the
1203 specifications in the <tt>datalayout</tt> keyword. The default specifications
1204 are given in this list:</p>
1205
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1206<ul>
1207 <li><tt>E</tt> - big endian</li>
1208 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1209 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1210 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1211 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1212 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1213 <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]1214 alignment of 64-bits</li>
1215 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1216 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1217 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1218 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1219 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1220 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1221</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1222
1223<p>When LLVM is determining the alignment for a given type, it uses the
1224 following rules:</p>
1225
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1226<ol>
1227 <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]1228 specification is used.</li>
1229
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1230 <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]1231 smallest integer type that is larger than the bitwidth of the sought type
1232 is used. If none of the specifications are larger than the bitwidth then
1233 the the largest integer type is used. For example, given the default
1234 specifications above, the i7 type will use the alignment of i8 (next
1235 largest) while both i65 and i256 will use the alignment of i64 (largest
1236 specified).</li>
1237
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1238 <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]1239 largest vector type that is smaller than the sought vector type will be
1240 used as a fall back. This happens because &lt;128 x double&gt; can be
1241 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1242</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1243
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1244</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1245
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1246<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1247<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1248<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1249
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1250<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1251
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1252<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1253 intermediate representation. Being typed enables a number of optimizations
1254 to be performed on the intermediate representation directly, without having
1255 to do extra analyses on the side before the transformation. A strong type
1256 system makes it easier to read the generated code and enables novel analyses
1257 and transformations that are not feasible to perform on normal three address
1258 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1259
1260</div>
1261
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1262<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1263<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1264Classifications</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1265
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1266<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1267
1268<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1269
1270<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1271 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1272 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1273 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1274 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1275 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1276 </tr>
1277 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1278 <td><a href="#t_floating">floating point</a></td>
1279 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1280 </tr>
1281 <tr>
1282 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1283 <td><a href="#t_integer">integer</a>,
1284 <a href="#t_floating">floating point</a>,
1285 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1286 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1287 <a href="#t_struct">structure</a>,
1288 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1289 <a href="#t_label">label</a>,
1290 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1291 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1292 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1293 <tr>
1294 <td><a href="#t_primitive">primitive</a></td>
1295 <td><a href="#t_label">label</a>,
1296 <a href="#t_void">void</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1297 <a href="#t_floating">floating point</a>,
1298 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1299 </tr>
1300 <tr>
1301 <td><a href="#t_derived">derived</a></td>
1302 <td><a href="#t_integer">integer</a>,
1303 <a href="#t_array">array</a>,
1304 <a href="#t_function">function</a>,
1305 <a href="#t_pointer">pointer</a>,
1306 <a href="#t_struct">structure</a>,
1307 <a href="#t_pstruct">packed structure</a>,
1308 <a href="#t_vector">vector</a>,
1309 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1310 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1311 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1312 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1313</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1314
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1315<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1316 important. Values of these types are the only ones which can be produced by
1317 instructions, passed as arguments, or used as operands to instructions.</p>
1318
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1319</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1320
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1321<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1322<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1323
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1324<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1325
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1326<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1327 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1328
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1329</div>
1330
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1331<!-- _______________________________________________________________________ -->
1332<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1333
1334<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1335
1336<table>
1337 <tbody>
1338 <tr><th>Type</th><th>Description</th></tr>
1339 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1340 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1341 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1342 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1343 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1344 </tbody>
1345</table>
1346
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1347</div>
1348
1349<!-- _______________________________________________________________________ -->
1350<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1351
1352<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1353
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1354<h5>Overview:</h5>
1355<p>The void type does not represent any value and has no size.</p>
1356
1357<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1358<pre>
1359 void
1360</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1361
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1362</div>
1363
1364<!-- _______________________________________________________________________ -->
1365<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1366
1367<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1368
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1369<h5>Overview:</h5>
1370<p>The label type represents code labels.</p>
1371
1372<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1373<pre>
1374 label
1375</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1376
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1377</div>
1378
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1379<!-- _______________________________________________________________________ -->
1380<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1381
1382<div class="doc_text">
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1383
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1384<h5>Overview:</h5>
1385<p>The metadata type represents embedded metadata. The only derived type that
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1386 may contain metadata is <tt>metadata*</tt> or a function type that returns or
1387 takes metadata typed parameters, but not pointer to metadata types.</p>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1388
1389<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1390<pre>
1391 metadata
1392</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1393
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1394</div>
1395
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1396
1397<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1398<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1399
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1400<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1401
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1402<p>The real power in LLVM comes from the derived types in the system. This is
1403 what allows a programmer to represent arrays, functions, pointers, and other
1404 useful types. Note that these derived types may be recursive: For example,
1405 it is possible to have a two dimensional array.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1406
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1407</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1408
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1409<!-- _______________________________________________________________________ -->
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1410<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1411
1412<div class="doc_text">
1413
1414<h5>Overview:</h5>
1415<p>The integer type is a very simple derived type that simply specifies an
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1416 arbitrary bit width for the integer type desired. Any bit width from 1 bit to
1417 2^23-1 (about 8 million) can be specified.</p>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1418
1419<h5>Syntax:</h5>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1420<pre>
1421 iN
1422</pre>
1423
1424<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1425 value.</p>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1426
1427<h5>Examples:</h5>
1428<table class="layout">
Nick Lewyckyaab930a2009-05-24 02:46:06 +0000[diff] [blame]1429 <tr class="layout">
1430 <td class="left"><tt>i1</tt></td>
1431 <td class="left">a single-bit integer.</td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1432 </tr>
Nick Lewyckyaab930a2009-05-24 02:46:06 +0000[diff] [blame]1433 <tr class="layout">
1434 <td class="left"><tt>i32</tt></td>
1435 <td class="left">a 32-bit integer.</td>
1436 </tr>
1437 <tr class="layout">
1438 <td class="left"><tt>i1942652</tt></td>
1439 <td class="left">a really big integer of over 1 million bits.</td>
1440 </tr>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1441</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1442
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1443<p>Note that the code generator does not yet support large integer types to be
1444 used as function return types. The specific limit on how large a return type
1445 the code generator can currently handle is target-dependent; currently it's
1446 often 64 bits for 32-bit targets and 128 bits for 64-bit targets.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1447
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1448</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1449
1450<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1451<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1452
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1453<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1454
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1455<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1456<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1457 sequentially in memory. The array type requires a size (number of elements)
1458 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1459
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1460<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1461<pre>
1462 [&lt;# elements&gt; x &lt;elementtype&gt;]
1463</pre>
1464
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1465<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1466 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1467
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1468<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1469<table class="layout">
1470 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1471 <td class="left"><tt>[40 x i32]</tt></td>
1472 <td class="left">Array of 40 32-bit integer values.</td>
1473 </tr>
1474 <tr class="layout">
1475 <td class="left"><tt>[41 x i32]</tt></td>
1476 <td class="left">Array of 41 32-bit integer values.</td>
1477 </tr>
1478 <tr class="layout">
1479 <td class="left"><tt>[4 x i8]</tt></td>
1480 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1481 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1482</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1483<p>Here are some examples of multidimensional arrays:</p>
1484<table class="layout">
1485 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1486 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1487 <td class="left">3x4 array of 32-bit integer values.</td>
1488 </tr>
1489 <tr class="layout">
1490 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1491 <td class="left">12x10 array of single precision floating point values.</td>
1492 </tr>
1493 <tr class="layout">
1494 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1495 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1496 </tr>
1497</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1498
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1499<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1500 length array. Normally, accesses past the end of an array are undefined in
1501 LLVM (e.g. it is illegal to access the 5th element of a 3 element array). As
1502 a special case, however, zero length arrays are recognized to be variable
1503 length. This allows implementation of 'pascal style arrays' with the LLVM
1504 type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1505
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1506<p>Note that the code generator does not yet support large aggregate types to be
1507 used as function return types. The specific limit on how large an aggregate
1508 return type the code generator can currently handle is target-dependent, and
1509 also dependent on the aggregate element types.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1510
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1511</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1512
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1513<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1514<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1515
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1516<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1517
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1518<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1519<p>The function type can be thought of as a function signature. It consists of
1520 a return type and a list of formal parameter types. The return type of a
1521 function type is a scalar type, a void type, or a struct type. If the return
1522 type is a struct type then all struct elements must be of first class types,
1523 and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1524
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1525<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1526<pre>
1527 &lt;returntype list&gt; (&lt;parameter list&gt;)
1528</pre>
1529
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1530<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]1531 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1532 which indicates that the function takes a variable number of arguments.
1533 Variable argument functions can access their arguments with
1534 the <a href="#int_varargs">variable argument handling intrinsic</a>
1535 functions. '<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1536 <a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1537
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1538<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1539<table class="layout">
1540 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1541 <td class="left"><tt>i32 (i32)</tt></td>
1542 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1543 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1544 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]1545 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1546 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1547 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1548 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1549 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1550 <tt>float</tt>.
1551 </td>
1552 </tr><tr class="layout">
1553 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1554 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1555 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1556 which returns an integer. This is the signature for <tt>printf</tt> in
1557 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1558 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1559 </tr><tr class="layout">
1560 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanc9813bd2008-11-27 06:41:20 +0000[diff] [blame]1561 <td class="left">A function taking an <tt>i32</tt>, returning two
1562 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1563 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1564 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1565</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1566
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1567</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1568
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1569<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1570<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1571
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1572<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1573
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1574<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1575<p>The structure type is used to represent a collection of data members together
1576 in memory. The packing of the field types is defined to match the ABI of the
1577 underlying processor. The elements of a structure may be any type that has a
1578 size.</p>
1579
1580<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1581 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1582 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1583
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1584<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1585<pre>
1586 { &lt;type list&gt; }
1587</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1588
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1589<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1590<table class="layout">
1591 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1592 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1593 <td class="left">A triple of three <tt>i32</tt> values</td>
1594 </tr><tr class="layout">
1595 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1596 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1597 second element is a <a href="#t_pointer">pointer</a> to a
1598 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1599 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1600 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1601</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1602
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1603<p>Note that the code generator does not yet support large aggregate types to be
1604 used as function return types. The specific limit on how large an aggregate
1605 return type the code generator can currently handle is target-dependent, and
1606 also dependent on the aggregate element types.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1607
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1608</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1609
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1610<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1611<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1612</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1613
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1614<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1615
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1616<h5>Overview:</h5>
1617<p>The packed structure type is used to represent a collection of data members
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1618 together in memory. There is no padding between fields. Further, the
1619 alignment of a packed structure is 1 byte. The elements of a packed
1620 structure may be any type that has a size.</p>
1621
1622<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1623 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1624 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1625
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1626<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1627<pre>
1628 &lt; { &lt;type list&gt; } &gt;
1629</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1630
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1631<h5>Examples:</h5>
1632<table class="layout">
1633 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1634 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1635 <td class="left">A triple of three <tt>i32</tt> values</td>
1636 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1637 <td class="left">
1638<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1639 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1640 second element is a <a href="#t_pointer">pointer</a> to a
1641 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1642 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1643 </tr>
1644</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1645
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1646</div>
1647
1648<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1649<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1650
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1651<div class="doc_text">
1652
1653<h5>Overview:</h5>
1654<p>As in many languages, the pointer type represents a pointer or reference to
1655 another object, which must live in memory. Pointer types may have an optional
1656 address space attribute defining the target-specific numbered address space
1657 where the pointed-to object resides. The default address space is zero.</p>
1658
1659<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1660 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1661
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1662<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1663<pre>
1664 &lt;type&gt; *
1665</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1666
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1667<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1668<table class="layout">
1669 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]1670 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1671 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1672 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1673 </tr>
1674 <tr class="layout">
1675 <td class="left"><tt>i32 (i32 *) *</tt></td>
1676 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1677 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1678 <tt>i32</tt>.</td>
1679 </tr>
1680 <tr class="layout">
1681 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1682 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1683 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1684 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1685</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1686
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1687</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1688
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1689<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1690<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1691
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1692<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1693
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1694<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1695<p>A vector type is a simple derived type that represents a vector of elements.
1696 Vector types are used when multiple primitive data are operated in parallel
1697 using a single instruction (SIMD). A vector type requires a size (number of
1698 elements) and an underlying primitive data type. Vectors must have a power
1699 of two length (1, 2, 4, 8, 16 ...). Vector types are considered
1700 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1701
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1702<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1703<pre>
1704 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1705</pre>
1706
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1707<p>The number of elements is a constant integer value; elementtype may be any
1708 integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1709
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1710<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1711<table class="layout">
1712 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1713 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1714 <td class="left">Vector of 4 32-bit integer values.</td>
1715 </tr>
1716 <tr class="layout">
1717 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1718 <td class="left">Vector of 8 32-bit floating-point values.</td>
1719 </tr>
1720 <tr class="layout">
1721 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1722 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1723 </tr>
1724</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1725
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1726<p>Note that the code generator does not yet support large vector types to be
1727 used as function return types. The specific limit on how large a vector
1728 return type codegen can currently handle is target-dependent; currently it's
1729 often a few times longer than a hardware vector register.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1730
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1731</div>
1732
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1733<!-- _______________________________________________________________________ -->
1734<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1735<div class="doc_text">
1736
1737<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1738<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1739 corresponds (for example) to the C notion of a forward declared structure
1740 type. In LLVM, opaque types can eventually be resolved to any type (not just
1741 a structure type).</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1742
1743<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1744<pre>
1745 opaque
1746</pre>
1747
1748<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1749<table class="layout">
1750 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1751 <td class="left"><tt>opaque</tt></td>
1752 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1753 </tr>
1754</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1755
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1756</div>
1757
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1758<!-- ======================================================================= -->
1759<div class="doc_subsection">
1760 <a name="t_uprefs">Type Up-references</a>
1761</div>
1762
1763<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1764
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1765<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1766<p>An "up reference" allows you to refer to a lexically enclosing type without
1767 requiring it to have a name. For instance, a structure declaration may
1768 contain a pointer to any of the types it is lexically a member of. Example
1769 of up references (with their equivalent as named type declarations)
1770 include:</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1771
1772<pre>
Chris Lattnerbf1d5452009-02-09 10:00:56 +0000[diff] [blame]1773 { \2 * } %x = type { %x* }
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1774 { \2 }* %y = type { %y }*
1775 \1* %z = type %z*
1776</pre>
1777
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1778<p>An up reference is needed by the asmprinter for printing out cyclic types
1779 when there is no declared name for a type in the cycle. Because the
1780 asmprinter does not want to print out an infinite type string, it needs a
1781 syntax to handle recursive types that have no names (all names are optional
1782 in llvm IR).</p>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1783
1784<h5>Syntax:</h5>
1785<pre>
1786 \&lt;level&gt;
1787</pre>
1788
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1789<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]1790
1791<h5>Examples:</h5>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1792<table class="layout">
1793 <tr class="layout">
1794 <td class="left"><tt>\1*</tt></td>
1795 <td class="left">Self-referential pointer.</td>
1796 </tr>
1797 <tr class="layout">
1798 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1799 <td class="left">Recursive structure where the upref refers to the out-most
1800 structure.</td>
1801 </tr>
1802</table>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1803
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1804</div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1805
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1806<!-- *********************************************************************** -->
1807<div class="doc_section"> <a name="constants">Constants</a> </div>
1808<!-- *********************************************************************** -->
1809
1810<div class="doc_text">
1811
1812<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1813 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1814
1815</div>
1816
1817<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1818<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1819
1820<div class="doc_text">
1821
1822<dl>
1823 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1824 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1825 constants of the <tt><a href="#t_primitive">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1826
1827 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1828 <dd>Standard integers (such as '4') are constants of
1829 the <a href="#t_integer">integer</a> type. Negative numbers may be used
1830 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1831
1832 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1833 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1834 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
1835 notation (see below). The assembler requires the exact decimal value of a
1836 floating-point constant. For example, the assembler accepts 1.25 but
1837 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1838 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1839
1840 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1841 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1842 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1843</dl>
1844
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1845<p>The one non-intuitive notation for constants is the hexadecimal form of
1846 floating point constants. For example, the form '<tt>double
1847 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
1848 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
1849 constants are required (and the only time that they are generated by the
1850 disassembler) is when a floating point constant must be emitted but it cannot
1851 be represented as a decimal floating point number in a reasonable number of
1852 digits. For example, NaN's, infinities, and other special values are
1853 represented in their IEEE hexadecimal format so that assembly and disassembly
1854 do not cause any bits to change in the constants.</p>
1855
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]1856<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1857 represented using the 16-digit form shown above (which matches the IEEE754
1858 representation for double); float values must, however, be exactly
1859 representable as IEE754 single precision. Hexadecimal format is always used
1860 for long double, and there are three forms of long double. The 80-bit format
1861 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
1862 The 128-bit format used by PowerPC (two adjacent doubles) is represented
1863 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
1864 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
1865 currently supported target uses this format. Long doubles will only work if
1866 they match the long double format on your target. All hexadecimal formats
1867 are big-endian (sign bit at the left).</p>
1868
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1869</div>
1870
1871<!-- ======================================================================= -->
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]1872<div class="doc_subsection">
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]1873<a name="aggregateconstants"></a> <!-- old anchor -->
1874<a name="complexconstants">Complex Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1875</div>
1876
1877<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1878
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]1879<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1880 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1881
1882<dl>
1883 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1884 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1885 type definitions (a comma separated list of elements, surrounded by braces
1886 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1887 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
1888 Structure constants must have <a href="#t_struct">structure type</a>, and
1889 the number and types of elements must match those specified by the
1890 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1891
1892 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1893 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1894 definitions (a comma separated list of elements, surrounded by square
1895 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
1896 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
1897 the number and types of elements must match those specified by the
1898 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1899
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1900 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1901 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1902 definitions (a comma separated list of elements, surrounded by
1903 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
1904 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
1905 have <a href="#t_vector">vector type</a>, and the number and types of
1906 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1907
1908 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1909 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1910 value to zero of <em>any</em> type, including scalar and aggregate types.
1911 This is often used to avoid having to print large zero initializers
1912 (e.g. for large arrays) and is always exactly equivalent to using explicit
1913 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]1914
1915 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]1916 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1917 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
1918 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
1919 be interpreted as part of the instruction stream, metadata is a place to
1920 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1921</dl>
1922
1923</div>
1924
1925<!-- ======================================================================= -->
1926<div class="doc_subsection">
1927 <a name="globalconstants">Global Variable and Function Addresses</a>
1928</div>
1929
1930<div class="doc_text">
1931
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1932<p>The addresses of <a href="#globalvars">global variables</a>
1933 and <a href="#functionstructure">functions</a> are always implicitly valid
1934 (link-time) constants. These constants are explicitly referenced when
1935 the <a href="#identifiers">identifier for the global</a> is used and always
1936 have <a href="#t_pointer">pointer</a> type. For example, the following is a
1937 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1938
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1939<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1940<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]1941@X = global i32 17
1942@Y = global i32 42
1943@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1944</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1945</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1946
1947</div>
1948
1949<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1950<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1951<div class="doc_text">
1952
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1953<p>The string '<tt>undef</tt>' is recognized as a type-less constant that has no
1954 specific value. Undefined values may be of any type and be used anywhere a
1955 constant is permitted.</p>
1956
1957<p>Undefined values indicate to the compiler that the program is well defined no
1958 matter what value is used, giving the compiler more freedom to optimize.</p>
1959
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1960</div>
1961
1962<!-- ======================================================================= -->
1963<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1964</div>
1965
1966<div class="doc_text">
1967
1968<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1969 to be used as constants. Constant expressions may be of
1970 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
1971 operation that does not have side effects (e.g. load and call are not
1972 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1973
1974<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1975 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1976 <dd>Truncate a constant to another type. The bit size of CST must be larger
1977 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1978
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1979 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1980 <dd>Zero extend a constant to another type. The bit size of CST must be
1981 smaller or equal to the bit size of TYPE. Both types must be
1982 integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1983
1984 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1985 <dd>Sign extend a constant to another type. The bit size of CST must be
1986 smaller or equal to the bit size of TYPE. Both types must be
1987 integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1988
1989 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1990 <dd>Truncate a floating point constant to another floating point type. The
1991 size of CST must be larger than the size of TYPE. Both types must be
1992 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1993
1994 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1995 <dd>Floating point extend a constant to another type. The size of CST must be
1996 smaller or equal to the size of TYPE. Both types must be floating
1997 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1998
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]1999 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2000 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2001 constant. TYPE must be a scalar or vector integer type. CST must be of
2002 scalar or vector floating point type. Both CST and TYPE must be scalars,
2003 or vectors of the same number of elements. If the value won't fit in the
2004 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2005
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2006 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2007 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2008 constant. TYPE must be a scalar or vector integer type. CST must be of
2009 scalar or vector floating point type. Both CST and TYPE must be scalars,
2010 or vectors of the same number of elements. If the value won't fit in the
2011 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2012
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2013 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2014 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2015 constant. TYPE must be a scalar or vector floating point type. CST must be
2016 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2017 vectors of the same number of elements. If the value won't fit in the
2018 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2019
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2020 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2021 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2022 constant. TYPE must be a scalar or vector floating point type. CST must be
2023 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2024 vectors of the same number of elements. If the value won't fit in the
2025 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2026
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2027 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2028 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2029 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2030 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2031 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2032
2033 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2034 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2035 type. CST must be of integer type. The CST value is zero extended,
2036 truncated, or unchanged to make it fit in a pointer size. This one is
2037 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2038
2039 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2040 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2041 are the same as those for the <a href="#i_bitcast">bitcast
2042 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2043
2044 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2045 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2046 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2047 instruction, the index list may have zero or more indexes, which are
2048 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2049
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2050 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2051 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2052
2053 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2054 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2055
2056 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2057 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2058
2059 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2060 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2061 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2062
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]2063 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2064 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2065 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2066
2067 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2068 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2069 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2070
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2071 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2072 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2073 be any of the <a href="#binaryops">binary</a>
2074 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2075 on operands are the same as those for the corresponding instruction
2076 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2077</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2078
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2079</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2080
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2081<!-- ======================================================================= -->
2082<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
2083</div>
2084
2085<div class="doc_text">
2086
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2087<p>Embedded metadata provides a way to attach arbitrary data to the instruction
2088 stream without affecting the behaviour of the program. There are two
2089 metadata primitives, strings and nodes. All metadata has the
2090 <tt>metadata</tt> type and is identified in syntax by a preceding exclamation
2091 point ('<tt>!</tt>').</p>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2092
2093<p>A metadata string is a string surrounded by double quotes. It can contain
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2094 any character by escaping non-printable characters with "\xx" where "xx" is
2095 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2096
2097<p>Metadata nodes are represented with notation similar to structure constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2098 (a comma separated list of elements, surrounded by braces and preceeded by an
2099 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2100 10}</tt>".</p>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2101
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2102<p>A metadata node will attempt to track changes to the values it holds. In the
2103 event that a value is deleted, it will be replaced with a typeless
2104 "<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewyckyb8f9b7a2009-05-10 20:57:05 +0000[diff] [blame]2105
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2106<p>Optimizations may rely on metadata to provide additional information about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2107 the program that isn't available in the instructions, or that isn't easily
2108 computable. Similarly, the code generator may expect a certain metadata
2109 format to be used to express debugging information.</p>
2110
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2111</div>
2112
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2113<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2114<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2115<!-- *********************************************************************** -->
2116
2117<!-- ======================================================================= -->
2118<div class="doc_subsection">
2119<a name="inlineasm">Inline Assembler Expressions</a>
2120</div>
2121
2122<div class="doc_text">
2123
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2124<p>LLVM supports inline assembler expressions (as opposed
2125 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2126 a special value. This value represents the inline assembler as a string
2127 (containing the instructions to emit), a list of operand constraints (stored
2128 as a string), and a flag that indicates whether or not the inline asm
2129 expression has side effects. An example inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2130
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2131<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2132<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2133i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2134</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2135</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2136
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2137<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2138 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2139 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2140
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2141<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2142<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2143%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]2144</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2145</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2146
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2147<p>Inline asms with side effects not visible in the constraint list must be
2148 marked as having side effects. This is done through the use of the
2149 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2150
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2151<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2152<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2153call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2154</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2155</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2156
2157<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2158 documented here. Constraints on what can be done (e.g. duplication, moving,
2159 etc need to be documented). This is probably best done by reference to
2160 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2161
2162</div>
2163
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2164
2165<!-- *********************************************************************** -->
2166<div class="doc_section">
2167 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2168</div>
2169<!-- *********************************************************************** -->
2170
2171<p>LLVM has a number of "magic" global variables that contain data that affect
2172code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2173of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2174section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2175by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2176
2177<!-- ======================================================================= -->
2178<div class="doc_subsection">
2179<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2180</div>
2181
2182<div class="doc_text">
2183
2184<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2185href="#linkage_appending">appending linkage</a>. This array contains a list of
2186pointers to global variables and functions which may optionally have a pointer
2187cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2188
2189<pre>
2190 @X = global i8 4
2191 @Y = global i32 123
2192
2193 @llvm.used = appending global [2 x i8*] [
2194 i8* @X,
2195 i8* bitcast (i32* @Y to i8*)
2196 ], section "llvm.metadata"
2197</pre>
2198
2199<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2200compiler, assembler, and linker are required to treat the symbol as if there is
2201a reference to the global that it cannot see. For example, if a variable has
2202internal linkage and no references other than that from the <tt>@llvm.used</tt>
2203list, it cannot be deleted. This is commonly used to represent references from
2204inline asms and other things the compiler cannot "see", and corresponds to
2205"attribute((used))" in GNU C.</p>
2206
2207<p>On some targets, the code generator must emit a directive to the assembler or
2208object file to prevent the assembler and linker from molesting the symbol.</p>
2209
2210</div>
2211
2212<!-- ======================================================================= -->
2213<div class="doc_subsection">
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2214<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2215</div>
2216
2217<div class="doc_text">
2218
2219<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2220<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2221touching the symbol. On targets that support it, this allows an intelligent
2222linker to optimize references to the symbol without being impeded as it would be
2223by <tt>@llvm.used</tt>.</p>
2224
2225<p>This is a rare construct that should only be used in rare circumstances, and
2226should not be exposed to source languages.</p>
2227
2228</div>
2229
2230<!-- ======================================================================= -->
2231<div class="doc_subsection">
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2232<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2233</div>
2234
2235<div class="doc_text">
2236
2237<p>TODO: Describe this.</p>
2238
2239</div>
2240
2241<!-- ======================================================================= -->
2242<div class="doc_subsection">
2243<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2244</div>
2245
2246<div class="doc_text">
2247
2248<p>TODO: Describe this.</p>
2249
2250</div>
2251
2252
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2253<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2254<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2255<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2256
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2257<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2258
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2259<p>The LLVM instruction set consists of several different classifications of
2260 instructions: <a href="#terminators">terminator
2261 instructions</a>, <a href="#binaryops">binary instructions</a>,
2262 <a href="#bitwiseops">bitwise binary instructions</a>,
2263 <a href="#memoryops">memory instructions</a>, and
2264 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2265
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2266</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2267
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2268<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2269<div class="doc_subsection"> <a name="terminators">Terminator
2270Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2271
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2272<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2273
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2274<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2275 in a program ends with a "Terminator" instruction, which indicates which
2276 block should be executed after the current block is finished. These
2277 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2278 control flow, not values (the one exception being the
2279 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2280
2281<p>There are six different terminator instructions: the
2282 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2283 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2284 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
2285 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2286 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2287 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2288
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2289</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2290
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2291<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2292<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2293Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2294
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2295<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2296
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2297<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2298<pre>
2299 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]2300 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2301</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2302
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2303<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2304<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2305 a value) from a function back to the caller.</p>
2306
2307<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2308 value and then causes control flow, and one that just causes control flow to
2309 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2310
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2311<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2312<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2313 return value. The type of the return value must be a
2314 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2315
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2316<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2317 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2318 value or a return value with a type that does not match its type, or if it
2319 has a void return type and contains a '<tt>ret</tt>' instruction with a
2320 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2321
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2322<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2323<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2324 the calling function's context. If the caller is a
2325 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2326 instruction after the call. If the caller was an
2327 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2328 the beginning of the "normal" destination block. If the instruction returns
2329 a value, that value shall set the call or invoke instruction's return
2330 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2331
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2332<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2333<pre>
2334 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2335 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]2336 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]2337</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2338
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2339<p>Note that the code generator does not yet fully support large
2340 return values. The specific sizes that are currently supported are
2341 dependent on the target. For integers, on 32-bit targets the limit
2342 is often 64 bits, and on 64-bit targets the limit is often 128 bits.
2343 For aggregate types, the current limits are dependent on the element
2344 types; for example targets are often limited to 2 total integer
2345 elements and 2 total floating-point elements.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2346
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2347</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2348<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2349<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2350
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2351<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2352
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2353<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2354<pre>
2355 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]2356</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2357
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2358<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2359<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2360 different basic block in the current function. There are two forms of this
2361 instruction, corresponding to a conditional branch and an unconditional
2362 branch.</p>
2363
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2364<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2365<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2366 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2367 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2368 target.</p>
2369
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2370<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2371<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2372 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2373 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2374 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2375
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2376<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2377<pre>
2378Test:
2379 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2380 br i1 %cond, label %IfEqual, label %IfUnequal
2381IfEqual:
2382 <a href="#i_ret">ret</a> i32 1
2383IfUnequal:
2384 <a href="#i_ret">ret</a> i32 0
2385</pre>
2386
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2387</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2388
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2389<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2390<div class="doc_subsubsection">
2391 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2392</div>
2393
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2394<div class="doc_text">
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2395
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2396<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2397<pre>
2398 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2399</pre>
2400
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2401<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2402<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]2403 several different places. It is a generalization of the '<tt>br</tt>'
2404 instruction, allowing a branch to occur to one of many possible
2405 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2406
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2407<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2408<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2409 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2410 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2411 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2412
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2413<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2414<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2415 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2416 is searched for the given value. If the value is found, control flow is
2417 transfered to the corresponding destination; otherwise, control flow is
2418 transfered to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2419
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2420<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2421<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2422 <tt>switch</tt> instruction, this instruction may be code generated in
2423 different ways. For example, it could be generated as a series of chained
2424 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2425
2426<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2427<pre>
2428 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2429 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2430 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2431
2432 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2433 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2434
2435 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2436 switch i32 %val, label %otherwise [ i32 0, label %onzero
2437 i32 1, label %onone
2438 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2439</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2440
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2441</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2442
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2443<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2444<div class="doc_subsubsection">
2445 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2446</div>
2447
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2448<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2449
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2450<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2451<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2452 &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]2453 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2454</pre>
2455
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2456<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2457<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2458 function, with the possibility of control flow transfer to either the
2459 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2460 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2461 control flow will return to the "normal" label. If the callee (or any
2462 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2463 instruction, control is interrupted and continued at the dynamically nearest
2464 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2465
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2466<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2467<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2468
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2469<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2470 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2471 convention</a> the call should use. If none is specified, the call
2472 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2473
2474 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2475 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
2476 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2477
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2478 <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]2479 function value being invoked. In most cases, this is a direct function
2480 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
2481 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2482
2483 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2484 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2485
2486 <li>'<tt>function args</tt>': argument list whose types match the function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2487 signature argument types. If the function signature indicates the
2488 function accepts a variable number of arguments, the extra arguments can
2489 be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2490
2491 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2492 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2493
2494 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2495 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2496
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2497 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2498 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2499 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2500</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2501
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2502<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2503<p>This instruction is designed to operate as a standard
2504 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
2505 primary difference is that it establishes an association with a label, which
2506 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2507
2508<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2509 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2510 exception. Additionally, this is important for implementation of
2511 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2512
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2513<p>For the purposes of the SSA form, the definition of the value returned by the
2514 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
2515 block to the "normal" label. If the callee unwinds then no return value is
2516 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]2517
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2518<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2519<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2520 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2521 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2522 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2523 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2524</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2525
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2526</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2527
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2528<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2529
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2530<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2531Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2532
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2533<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2534
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2535<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2536<pre>
2537 unwind
2538</pre>
2539
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2540<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2541<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2542 at the first callee in the dynamic call stack which used
2543 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
2544 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2545
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2546<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2547<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2548 immediately halt. The dynamic call stack is then searched for the
2549 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
2550 Once found, execution continues at the "exceptional" destination block
2551 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
2552 instruction in the dynamic call chain, undefined behavior results.</p>
2553
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2554</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2555
2556<!-- _______________________________________________________________________ -->
2557
2558<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2559Instruction</a> </div>
2560
2561<div class="doc_text">
2562
2563<h5>Syntax:</h5>
2564<pre>
2565 unreachable
2566</pre>
2567
2568<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2569<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2570 instruction is used to inform the optimizer that a particular portion of the
2571 code is not reachable. This can be used to indicate that the code after a
2572 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2573
2574<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2575<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2576
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2577</div>
2578
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2579<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2580<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2581
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2582<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2583
2584<p>Binary operators are used to do most of the computation in a program. They
2585 require two operands of the same type, execute an operation on them, and
2586 produce a single value. The operands might represent multiple data, as is
2587 the case with the <a href="#t_vector">vector</a> data type. The result value
2588 has the same type as its operands.</p>
2589
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2590<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2591
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2592</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2593
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2594<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2595<div class="doc_subsubsection">
2596 <a name="i_add">'<tt>add</tt>' Instruction</a>
2597</div>
2598
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2599<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2600
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2601<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2602<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2603 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2604 &lt;result&gt; = nuw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2605 &lt;result&gt; = nsw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2606 &lt;result&gt; = nuw nsw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2607</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2608
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2609<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2610<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2611
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2612<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2613<p>The two arguments to the '<tt>add</tt>' instruction must
2614 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2615 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2616
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2617<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2618<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2619
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2620<p>If the sum has unsigned overflow, the result returned is the mathematical
2621 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]2622
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2623<p>Because LLVM integers use a two's complement representation, this instruction
2624 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2625
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2626<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2627 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2628 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
2629 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2630
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2631<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2632<pre>
2633 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2634</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2635
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2636</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2637
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2638<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2639<div class="doc_subsubsection">
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2640 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
2641</div>
2642
2643<div class="doc_text">
2644
2645<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2646<pre>
2647 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2648</pre>
2649
2650<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2651<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
2652
2653<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2654<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2655 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2656 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2657
2658<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2659<p>The value produced is the floating point sum of the two operands.</p>
2660
2661<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2662<pre>
2663 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
2664</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2665
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2666</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2667
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2668<!-- _______________________________________________________________________ -->
2669<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2670 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2671</div>
2672
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2673<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2674
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2675<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2676<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2677 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2678 &lt;result&gt; = nuw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2679 &lt;result&gt; = nsw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2680 &lt;result&gt; = nuw nsw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2681</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2682
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2683<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2684<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2685 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2686
2687<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2688 '<tt>neg</tt>' instruction present in most other intermediate
2689 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2690
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2691<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2692<p>The two arguments to the '<tt>sub</tt>' instruction must
2693 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2694 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2695
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2696<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2697<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2698
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2699<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2700 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
2701 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2702
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2703<p>Because LLVM integers use a two's complement representation, this instruction
2704 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2705
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2706<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2707 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2708 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
2709 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2710
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2711<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2712<pre>
2713 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2714 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2715</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2716
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2717</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2718
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2719<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2720<div class="doc_subsubsection">
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2721 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
2722</div>
2723
2724<div class="doc_text">
2725
2726<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2727<pre>
2728 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2729</pre>
2730
2731<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2732<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2733 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2734
2735<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2736 '<tt>fneg</tt>' instruction present in most other intermediate
2737 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2738
2739<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2740<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2741 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2742 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2743
2744<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2745<p>The value produced is the floating point difference of the two operands.</p>
2746
2747<h5>Example:</h5>
2748<pre>
2749 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
2750 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
2751</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2752
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2753</div>
2754
2755<!-- _______________________________________________________________________ -->
2756<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2757 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2758</div>
2759
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2760<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2761
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2762<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2763<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2764 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2765 &lt;result&gt; = nuw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2766 &lt;result&gt; = nsw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2767 &lt;result&gt; = nuw nsw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2768</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2769
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2770<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2771<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2772
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2773<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2774<p>The two arguments to the '<tt>mul</tt>' instruction must
2775 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2776 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2777
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2778<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2779<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2780
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2781<p>If the result of the multiplication has unsigned overflow, the result
2782 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
2783 width of the result.</p>
2784
2785<p>Because LLVM integers use a two's complement representation, and the result
2786 is the same width as the operands, this instruction returns the correct
2787 result for both signed and unsigned integers. If a full product
2788 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
2789 be sign-extended or zero-extended as appropriate to the width of the full
2790 product.</p>
2791
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]2792<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2793 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2794 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
2795 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2796
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2797<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2798<pre>
2799 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2800</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2801
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2802</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2803
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2804<!-- _______________________________________________________________________ -->
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2805<div class="doc_subsubsection">
2806 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
2807</div>
2808
2809<div class="doc_text">
2810
2811<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2812<pre>
2813 &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]2814</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2815
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2816<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2817<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2818
2819<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2820<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2821 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2822 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2823
2824<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2825<p>The value produced is the floating point product of the two operands.</p>
2826
2827<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2828<pre>
2829 &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]2830</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2831
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]2832</div>
2833
2834<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2835<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2836</a></div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2837
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2838<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2839
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2840<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2841<pre>
2842 &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]2843</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2844
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2845<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2846<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2847
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2848<h5>Arguments:</h5>
2849<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2850 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2851 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2852
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2853<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2854<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2855
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2856<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2857 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2858
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2859<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2860
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2861<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2862<pre>
2863 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2864</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2865
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2866</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2867
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2868<!-- _______________________________________________________________________ -->
2869<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2870</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2871
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2872<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2873
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2874<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2875<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2876 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2877 &lt;result&gt; = exact sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2878</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2879
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2880<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2881<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2882
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2883<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2884<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2885 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2886 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2887
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2888<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2889<p>The value produced is the signed integer quotient of the two operands rounded
2890 towards zero.</p>
2891
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2892<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2893 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2894
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2895<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2896 undefined behavior; this is a rare case, but can occur, for example, by doing
2897 a 32-bit division of -2147483648 by -1.</p>
2898
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]2899<p>If the <tt>exact</tt> keyword is present, the result value of the
2900 <tt>sdiv</tt> is undefined if the result would be rounded or if overflow
2901 would occur.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]2902
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2903<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2904<pre>
2905 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2906</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2907
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2908</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2909
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2910<!-- _______________________________________________________________________ -->
2911<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2912Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2913
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2914<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2915
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2916<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2917<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2918 &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]2919</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2920
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2921<h5>Overview:</h5>
2922<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2923
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2924<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2925<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2926 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2927 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2928
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2929<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2930<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2931
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2932<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2933<pre>
2934 &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]2935</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2936
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2937</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2938
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2939<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2940<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2941</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2942
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2943<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2944
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2945<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2946<pre>
2947 &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]2948</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2949
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2950<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2951<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
2952 division of its two arguments.</p>
2953
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2954<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2955<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2956 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2957 values. Both arguments must have identical types.</p>
2958
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2959<h5>Semantics:</h5>
2960<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2961 This instruction always performs an unsigned division to get the
2962 remainder.</p>
2963
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2964<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2965 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2966
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2967<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2968
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2969<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2970<pre>
2971 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2972</pre>
2973
2974</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2975
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2976<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2977<div class="doc_subsubsection">
2978 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2979</div>
2980
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2981<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2982
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2983<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2984<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2985 &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]2986</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2987
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2988<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2989<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
2990 division of its two operands. This instruction can also take
2991 <a href="#t_vector">vector</a> versions of the values in which case the
2992 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]2993
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2994<h5>Arguments:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2995<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2996 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2997 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2998
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2999<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3000<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3001 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3002 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3003 a value. For more information about the difference,
3004 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3005 Math Forum</a>. For a table of how this is implemented in various languages,
3006 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3007 Wikipedia: modulo operation</a>.</p>
3008
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3009<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3010 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3011
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3012<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3013 Overflow also leads to undefined behavior; this is a rare case, but can
3014 occur, for example, by taking the remainder of a 32-bit division of
3015 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3016 lets srem be implemented using instructions that return both the result of
3017 the division and the remainder.)</p>
3018
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3019<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3020<pre>
3021 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3022</pre>
3023
3024</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3025
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3026<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3027<div class="doc_subsubsection">
3028 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3029
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3030<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3031
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3032<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3033<pre>
3034 &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]3035</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3036
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3037<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3038<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3039 its two operands.</p>
3040
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3041<h5>Arguments:</h5>
3042<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3043 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3044 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3045
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3046<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3047<p>This instruction returns the <i>remainder</i> of a division. The remainder
3048 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3049
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3050<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3051<pre>
3052 &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]3053</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3054
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3055</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3056
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3057<!-- ======================================================================= -->
3058<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3059Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3060
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3061<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3062
3063<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3064 program. They are generally very efficient instructions and can commonly be
3065 strength reduced from other instructions. They require two operands of the
3066 same type, execute an operation on them, and produce a single value. The
3067 resulting value is the same type as its operands.</p>
3068
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3069</div>
3070
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3071<!-- _______________________________________________________________________ -->
3072<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3073Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3074
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3075<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3076
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3077<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3078<pre>
3079 &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]3080</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3081
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3082<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3083<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3084 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3085
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3086<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3087<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3088 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3089 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3090
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3091<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3092<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3093 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3094 is (statically or dynamically) negative or equal to or larger than the number
3095 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3096 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3097 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3098
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3099<h5>Example:</h5>
3100<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3101 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3102 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3103 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3104 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3105 &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]3106</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3107
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3108</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3109
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3110<!-- _______________________________________________________________________ -->
3111<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3112Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3113
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3114<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3115
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3116<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3117<pre>
3118 &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]3119</pre>
3120
3121<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3122<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3123 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3124
3125<h5>Arguments:</h5>
3126<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3127 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3128 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3129
3130<h5>Semantics:</h5>
3131<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3132 significant bits of the result will be filled with zero bits after the shift.
3133 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3134 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3135 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3136 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3137
3138<h5>Example:</h5>
3139<pre>
3140 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3141 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3142 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3143 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3144 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3145 &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]3146</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3147
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3148</div>
3149
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3150<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3151<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3152Instruction</a> </div>
3153<div class="doc_text">
3154
3155<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3156<pre>
3157 &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]3158</pre>
3159
3160<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3161<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3162 operand shifted to the right a specified number of bits with sign
3163 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3164
3165<h5>Arguments:</h5>
3166<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3167 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3168 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3169
3170<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3171<p>This instruction always performs an arithmetic shift right operation, The
3172 most significant bits of the result will be filled with the sign bit
3173 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3174 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3175 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3176 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3177
3178<h5>Example:</h5>
3179<pre>
3180 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3181 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3182 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3183 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3184 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3185 &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]3186</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3187
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3188</div>
3189
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3190<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3191<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3192Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3193
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3194<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3195
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3196<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3197<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3198 &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]3199</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3200
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3201<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3202<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3203 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3204
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3205<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3206<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3207 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3208 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3209
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3210<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3211<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3212
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3213<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3214 <tbody>
3215 <tr>
3216 <td>In0</td>
3217 <td>In1</td>
3218 <td>Out</td>
3219 </tr>
3220 <tr>
3221 <td>0</td>
3222 <td>0</td>
3223 <td>0</td>
3224 </tr>
3225 <tr>
3226 <td>0</td>
3227 <td>1</td>
3228 <td>0</td>
3229 </tr>
3230 <tr>
3231 <td>1</td>
3232 <td>0</td>
3233 <td>0</td>
3234 </tr>
3235 <tr>
3236 <td>1</td>
3237 <td>1</td>
3238 <td>1</td>
3239 </tr>
3240 </tbody>
3241</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3242
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3243<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3244<pre>
3245 &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]3246 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3247 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3248</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3249</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3250<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3251<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3252
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3253<div class="doc_text">
3254
3255<h5>Syntax:</h5>
3256<pre>
3257 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3258</pre>
3259
3260<h5>Overview:</h5>
3261<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3262 two operands.</p>
3263
3264<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3265<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3266 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3267 values. Both arguments must have identical types.</p>
3268
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3269<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3270<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3271
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3272<table border="1" cellspacing="0" cellpadding="4">
3273 <tbody>
3274 <tr>
3275 <td>In0</td>
3276 <td>In1</td>
3277 <td>Out</td>
3278 </tr>
3279 <tr>
3280 <td>0</td>
3281 <td>0</td>
3282 <td>0</td>
3283 </tr>
3284 <tr>
3285 <td>0</td>
3286 <td>1</td>
3287 <td>1</td>
3288 </tr>
3289 <tr>
3290 <td>1</td>
3291 <td>0</td>
3292 <td>1</td>
3293 </tr>
3294 <tr>
3295 <td>1</td>
3296 <td>1</td>
3297 <td>1</td>
3298 </tr>
3299 </tbody>
3300</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3301
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3302<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3303<pre>
3304 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3305 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3306 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3307</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3308
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3309</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3310
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3311<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3312<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3313Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3314
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3315<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3316
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3317<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3318<pre>
3319 &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]3320</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3321
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3322<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3323<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3324 its two operands. The <tt>xor</tt> is used to implement the "one's
3325 complement" operation, which is the "~" operator in C.</p>
3326
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3327<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3328<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3329 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3330 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3331
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3332<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3333<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3334
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3335<table border="1" cellspacing="0" cellpadding="4">
3336 <tbody>
3337 <tr>
3338 <td>In0</td>
3339 <td>In1</td>
3340 <td>Out</td>
3341 </tr>
3342 <tr>
3343 <td>0</td>
3344 <td>0</td>
3345 <td>0</td>
3346 </tr>
3347 <tr>
3348 <td>0</td>
3349 <td>1</td>
3350 <td>1</td>
3351 </tr>
3352 <tr>
3353 <td>1</td>
3354 <td>0</td>
3355 <td>1</td>
3356 </tr>
3357 <tr>
3358 <td>1</td>
3359 <td>1</td>
3360 <td>0</td>
3361 </tr>
3362 </tbody>
3363</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3364
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3365<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3366<pre>
3367 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3368 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3369 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3370 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3371</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3372
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3373</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3374
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3375<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3376<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3377 <a name="vectorops">Vector Operations</a>
3378</div>
3379
3380<div class="doc_text">
3381
3382<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3383 target-independent manner. These instructions cover the element-access and
3384 vector-specific operations needed to process vectors effectively. While LLVM
3385 does directly support these vector operations, many sophisticated algorithms
3386 will want to use target-specific intrinsics to take full advantage of a
3387 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3388
3389</div>
3390
3391<!-- _______________________________________________________________________ -->
3392<div class="doc_subsubsection">
3393 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3394</div>
3395
3396<div class="doc_text">
3397
3398<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3399<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3400 &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]3401</pre>
3402
3403<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3404<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3405 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3406
3407
3408<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3409<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3410 of <a href="#t_vector">vector</a> type. The second operand is an index
3411 indicating the position from which to extract the element. The index may be
3412 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3413
3414<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3415<p>The result is a scalar of the same type as the element type of
3416 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3417 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3418 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3419
3420<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3421<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3422 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3423</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3424
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3425</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3426
3427<!-- _______________________________________________________________________ -->
3428<div class="doc_subsubsection">
3429 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3430</div>
3431
3432<div class="doc_text">
3433
3434<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3435<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]3436 &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]3437</pre>
3438
3439<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3440<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3441 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3442
3443<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3444<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3445 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3446 whose type must equal the element type of the first operand. The third
3447 operand is an index indicating the position at which to insert the value.
3448 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3449
3450<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3451<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3452 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3453 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3454 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3455
3456<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3457<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3458 %result = 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]3459</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3460
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3461</div>
3462
3463<!-- _______________________________________________________________________ -->
3464<div class="doc_subsubsection">
3465 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3466</div>
3467
3468<div class="doc_text">
3469
3470<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3471<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3472 &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]3473</pre>
3474
3475<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3476<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
3477 from two input vectors, returning a vector with the same element type as the
3478 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3479
3480<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3481<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3482 with types that match each other. The third argument is a shuffle mask whose
3483 element type is always 'i32'. The result of the instruction is a vector
3484 whose length is the same as the shuffle mask and whose element type is the
3485 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3486
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3487<p>The shuffle mask operand is required to be a constant vector with either
3488 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3489
3490<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3491<p>The elements of the two input vectors are numbered from left to right across
3492 both of the vectors. The shuffle mask operand specifies, for each element of
3493 the result vector, which element of the two input vectors the result element
3494 gets. The element selector may be undef (meaning "don't care") and the
3495 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3496
3497<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3498<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3499 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3500 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3501 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3502 &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.
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3503 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3504 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3505 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3506 &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]3507</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3508
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3509</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]3510
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3511<!-- ======================================================================= -->
3512<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3513 <a name="aggregateops">Aggregate Operations</a>
3514</div>
3515
3516<div class="doc_text">
3517
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3518<p>LLVM supports several instructions for working with aggregate values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3519
3520</div>
3521
3522<!-- _______________________________________________________________________ -->
3523<div class="doc_subsubsection">
3524 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3525</div>
3526
3527<div class="doc_text">
3528
3529<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3530<pre>
3531 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3532</pre>
3533
3534<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3535<p>The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3536 or array element from an aggregate value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3537
3538<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3539<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
3540 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3541 operands are constant indices to specify which value to extract in a similar
3542 manner as indices in a
3543 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3544
3545<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3546<p>The result is the value at the position in the aggregate specified by the
3547 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3548
3549<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3550<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3551 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3552</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3553
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3554</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3555
3556<!-- _______________________________________________________________________ -->
3557<div class="doc_subsubsection">
3558 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3559</div>
3560
3561<div class="doc_text">
3562
3563<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3564<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3565 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;val&gt;, &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3566</pre>
3567
3568<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3569<p>The '<tt>insertvalue</tt>' instruction inserts a value into a struct field or
3570 array element in an aggregate.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3571
3572
3573<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3574<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
3575 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3576 second operand is a first-class value to insert. The following operands are
3577 constant indices indicating the position at which to insert the value in a
3578 similar manner as indices in a
3579 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
3580 value to insert must have the same type as the value identified by the
3581 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3582
3583<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3584<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
3585 that of <tt>val</tt> except that the value at the position specified by the
3586 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3587
3588<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3589<pre>
Dan Gohman88ce1a52008-06-23 15:26:37 +0000[diff] [blame]3590 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3591</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3592
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3593</div>
3594
3595
3596<!-- ======================================================================= -->
3597<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3598 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3599</div>
3600
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3601<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3602
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3603<p>A key design point of an SSA-based representation is how it represents
3604 memory. In LLVM, no memory locations are in SSA form, which makes things
3605 very simple. This section describes how to read, write, allocate, and free
3606 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3607
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3608</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3609
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3610<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3611<div class="doc_subsubsection">
3612 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3613</div>
3614
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3615<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3616
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3617<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3618<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3619 &lt;result&gt; = malloc &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]3620</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3621
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3622<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3623<p>The '<tt>malloc</tt>' instruction allocates memory from the system heap and
3624 returns a pointer to it. The object is always allocated in the generic
3625 address space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3626
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3627<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3628<p>The '<tt>malloc</tt>' instruction allocates
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3629 <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory from the operating
3630 system and returns a pointer of the appropriate type to the program. If
3631 "NumElements" is specified, it is the number of elements allocated, otherwise
3632 "NumElements" is defaulted to be one. If a constant alignment is specified,
3633 the value result of the allocation is guaranteed to be aligned to at least
3634 that boundary. If not specified, or if zero, the target can choose to align
3635 the allocation on any convenient boundary compatible with the type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3636
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3637<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3638
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3639<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3640<p>Memory is allocated using the system "<tt>malloc</tt>" function, and a
3641 pointer is returned. The result of a zero byte allocation is undefined. The
3642 result is null if there is insufficient memory available.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3643
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3644<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3645<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3646 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3647
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3648 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3649 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3650 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3651 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3652 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3653</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]3654
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3655<p>Note that the code generator does not yet respect the alignment value.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]3656
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3657</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3658
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3659<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3660<div class="doc_subsubsection">
3661 <a name="i_free">'<tt>free</tt>' Instruction</a>
3662</div>
3663
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3664<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3665
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3666<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3667<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3668 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3669</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3670
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3671<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3672<p>The '<tt>free</tt>' instruction returns memory back to the unused memory heap
3673 to be reallocated in the future.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3674
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3675<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3676<p>'<tt>value</tt>' shall be a pointer value that points to a value that was
3677 allocated with the '<tt><a href="#i_malloc">malloc</a></tt>' instruction.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3678
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3679<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3680<p>Access to the memory pointed to by the pointer is no longer defined after
3681 this instruction executes. If the pointer is null, the operation is a
3682 noop.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3683
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3684<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3685<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3686 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3687 free [4 x i8]* %array
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3688</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3689
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3690</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3691
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3692<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3693<div class="doc_subsubsection">
3694 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3695</div>
3696
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3697<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3698
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3699<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3700<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3701 &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]3702</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3703
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3704<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3705<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3706 currently executing function, to be automatically released when this function
3707 returns to its caller. The object is always allocated in the generic address
3708 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3709
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3710<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3711<p>The '<tt>alloca</tt>' instruction
3712 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
3713 runtime stack, returning a pointer of the appropriate type to the program.
3714 If "NumElements" is specified, it is the number of elements allocated,
3715 otherwise "NumElements" is defaulted to be one. If a constant alignment is
3716 specified, the value result of the allocation is guaranteed to be aligned to
3717 at least that boundary. If not specified, or if zero, the target can choose
3718 to align the allocation on any convenient boundary compatible with the
3719 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3720
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3721<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3722
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3723<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]3724<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3725 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
3726 memory is automatically released when the function returns. The
3727 '<tt>alloca</tt>' instruction is commonly used to represent automatic
3728 variables that must have an address available. When the function returns
3729 (either with the <tt><a href="#i_ret">ret</a></tt>
3730 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
3731 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3732
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3733<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3734<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3735 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3736 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3737 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3738 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3739</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3740
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3741</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3742
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3743<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3744<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3745Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3746
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3747<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3748
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3749<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3750<pre>
3751 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3752 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3753</pre>
3754
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3755<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3756<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3757
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3758<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3759<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
3760 from which to load. The pointer must point to
3761 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
3762 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
3763 number or order of execution of this <tt>load</tt> with other
3764 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3765 instructions. </p>
3766
3767<p>The optional constant "align" argument specifies the alignment of the
3768 operation (that is, the alignment of the memory address). A value of 0 or an
3769 omitted "align" argument means that the operation has the preferential
3770 alignment for the target. It is the responsibility of the code emitter to
3771 ensure that the alignment information is correct. Overestimating the
3772 alignment results in an undefined behavior. Underestimating the alignment may
3773 produce less efficient code. An alignment of 1 is always safe.</p>
3774
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3775<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3776<p>The location of memory pointed to is loaded. If the value being loaded is of
3777 scalar type then the number of bytes read does not exceed the minimum number
3778 of bytes needed to hold all bits of the type. For example, loading an
3779 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
3780 <tt>i20</tt> with a size that is not an integral number of bytes, the result
3781 is undefined if the value was not originally written using a store of the
3782 same type.</p>
3783
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3784<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3785<pre>
3786 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
3787 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3788 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3789</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3790
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3791</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3792
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3793<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3794<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3795Instruction</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3796
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]3797<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3798
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3799<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3800<pre>
3801 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3802 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3803</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3804
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3805<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3806<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3807
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3808<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3809<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
3810 and an address at which to store it. The type of the
3811 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
3812 the <a href="#t_firstclass">first class</a> type of the
3813 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked
3814 as <tt>volatile</tt>, then the optimizer is not allowed to modify the number
3815 or order of execution of this <tt>store</tt> with other
3816 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3817 instructions.</p>
3818
3819<p>The optional constant "align" argument specifies the alignment of the
3820 operation (that is, the alignment of the memory address). A value of 0 or an
3821 omitted "align" argument means that the operation has the preferential
3822 alignment for the target. It is the responsibility of the code emitter to
3823 ensure that the alignment information is correct. Overestimating the
3824 alignment results in an undefined behavior. Underestimating the alignment may
3825 produce less efficient code. An alignment of 1 is always safe.</p>
3826
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3827<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3828<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
3829 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
3830 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
3831 does not exceed the minimum number of bytes needed to hold all bits of the
3832 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
3833 writing a value of a type like <tt>i20</tt> with a size that is not an
3834 integral number of bytes, it is unspecified what happens to the extra bits
3835 that do not belong to the type, but they will typically be overwritten.</p>
3836
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3837<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3838<pre>
3839 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]3840 store i32 3, i32* %ptr <i>; yields {void}</i>
3841 %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]3842</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3843
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3844</div>
3845
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3846<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3847<div class="doc_subsubsection">
3848 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3849</div>
3850
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3851<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3852
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3853<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3854<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3855 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3856</pre>
3857
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3858<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3859<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
3860 subelement of an aggregate data structure. It performs address calculation
3861 only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3862
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3863<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3864<p>The first argument is always a pointer, and forms the basis of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3865 calculation. The remaining arguments are indices, that indicate which of the
3866 elements of the aggregate object are indexed. The interpretation of each
3867 index is dependent on the type being indexed into. The first index always
3868 indexes the pointer value given as the first argument, the second index
3869 indexes a value of the type pointed to (not necessarily the value directly
3870 pointed to, since the first index can be non-zero), etc. The first type
3871 indexed into must be a pointer value, subsequent types can be arrays, vectors
3872 and structs. Note that subsequent types being indexed into can never be
3873 pointers, since that would require loading the pointer before continuing
3874 calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3875
3876<p>The type of each index argument depends on the type it is indexing into.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3877 When indexing into a (packed) structure, only <tt>i32</tt> integer
3878 <b>constants</b> are allowed. When indexing into an array, pointer or
3879 vector, integers of any width are allowed (also non-constants).</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3880
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3881<p>For example, let's consider a C code fragment and how it gets compiled to
3882 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3883
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3884<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3885<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3886struct RT {
3887 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3888 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3889 char C;
3890};
3891struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3892 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3893 double Y;
3894 struct RT Z;
3895};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3896
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3897int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3898 return &amp;s[1].Z.B[5][13];
3899}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3900</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3901</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3902
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3903<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3904
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3905<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3906<pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]3907%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3908%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3909
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]3910define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3911entry:
3912 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3913 ret i32* %reg
3914}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3915</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3916</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3917
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3918<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3919<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]3920 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
3921 }</tt>' type, a structure. The second index indexes into the third element
3922 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3923 i8 }</tt>' type, another structure. The third index indexes into the second
3924 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
3925 array. The two dimensions of the array are subscripted into, yielding an
3926 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
3927 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3928
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3929<p>Note that it is perfectly legal to index partially through a structure,
3930 returning a pointer to an inner element. Because of this, the LLVM code for
3931 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3932
3933<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]3934 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3935 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3936 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3937 %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]3938 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3939 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3940 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3941 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3942</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3943
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3944<p>The getelementptr instruction is often confusing. For some more insight into
3945 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3946
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3947<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3948<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3949 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3950 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3951 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3952 %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]3953 <i>; yields i8*:eptr</i>
3954 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]3955 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]3956 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3957</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3958
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3959</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3960
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3961<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3962<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3963</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3964
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3965<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3966
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3967<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3968 which all take a single operand and a type. They perform various bit
3969 conversions on the operand.</p>
3970
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3971</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3972
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3973<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3974<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3975 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3976</div>
3977<div class="doc_text">
3978
3979<h5>Syntax:</h5>
3980<pre>
3981 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3982</pre>
3983
3984<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3985<p>The '<tt>trunc</tt>' instruction truncates its operand to the
3986 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3987
3988<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3989<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3990 be an <a href="#t_integer">integer</a> type, and a type that specifies the
3991 size and type of the result, which must be
3992 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
3993 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
3994 allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3995
3996<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3997<p>The '<tt>trunc</tt>' instruction truncates the high order bits
3998 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
3999 source size must be larger than the destination size, <tt>trunc</tt> cannot
4000 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4001
4002<h5>Example:</h5>
4003<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4004 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4005 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4006 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4007</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4008
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4009</div>
4010
4011<!-- _______________________________________________________________________ -->
4012<div class="doc_subsubsection">
4013 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4014</div>
4015<div class="doc_text">
4016
4017<h5>Syntax:</h5>
4018<pre>
4019 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4020</pre>
4021
4022<h5>Overview:</h5>
4023<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4024 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4025
4026
4027<h5>Arguments:</h5>
4028<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]4029 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4030 also be of <a href="#t_integer">integer</a> type. The bit size of the
4031 <tt>value</tt> must be smaller than the bit size of the destination type,
4032 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4033
4034<h5>Semantics:</h5>
4035<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]4036 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4037
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]4038<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]4039
4040<h5>Example:</h5>
4041<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4042 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4043 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4044</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4045
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4046</div>
4047
4048<!-- _______________________________________________________________________ -->
4049<div class="doc_subsubsection">
4050 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4051</div>
4052<div class="doc_text">
4053
4054<h5>Syntax:</h5>
4055<pre>
4056 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4057</pre>
4058
4059<h5>Overview:</h5>
4060<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4061
4062<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4063<p>The '<tt>sext</tt>' instruction takes a value to cast, which must be of
4064 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4065 also be of <a href="#t_integer">integer</a> type. The bit size of the
4066 <tt>value</tt> must be smaller than the bit size of the destination type,
4067 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4068
4069<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4070<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4071 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4072 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4073
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4074<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]4075
4076<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4077<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4078 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4079 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4080</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4081
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4082</div>
4083
4084<!-- _______________________________________________________________________ -->
4085<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4086 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4087</div>
4088
4089<div class="doc_text">
4090
4091<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4092<pre>
4093 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4094</pre>
4095
4096<h5>Overview:</h5>
4097<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4098 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4099
4100<h5>Arguments:</h5>
4101<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4102 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4103 to cast it to. The size of <tt>value</tt> must be larger than the size of
4104 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
4105 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4106
4107<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4108<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
4109 <a href="#t_floating">floating point</a> type to a smaller
4110 <a href="#t_floating">floating point</a> type. If the value cannot fit
4111 within the destination type, <tt>ty2</tt>, then the results are
4112 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4113
4114<h5>Example:</h5>
4115<pre>
4116 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4117 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4118</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4119
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4120</div>
4121
4122<!-- _______________________________________________________________________ -->
4123<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4124 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4125</div>
4126<div class="doc_text">
4127
4128<h5>Syntax:</h5>
4129<pre>
4130 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4131</pre>
4132
4133<h5>Overview:</h5>
4134<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]4135 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4136
4137<h5>Arguments:</h5>
4138<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4139 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4140 a <a href="#t_floating">floating point</a> type to cast it to. The source
4141 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4142
4143<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4144<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4145 <a href="#t_floating">floating point</a> type to a larger
4146 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4147 used to make a <i>no-op cast</i> because it always changes bits. Use
4148 <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]4149
4150<h5>Example:</h5>
4151<pre>
4152 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4153 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4154</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4155
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4156</div>
4157
4158<!-- _______________________________________________________________________ -->
4159<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]4160 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4161</div>
4162<div class="doc_text">
4163
4164<h5>Syntax:</h5>
4165<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4166 &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]4167</pre>
4168
4169<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4170<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4171 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4172
4173<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4174<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4175 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4176 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4177 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4178 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4179
4180<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4181<p>The '<tt>fptoui</tt>' instruction converts its
4182 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4183 towards zero) unsigned integer value. If the value cannot fit
4184 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4185
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4186<h5>Example:</h5>
4187<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4188 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4189 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4190 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4191</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4192
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4193</div>
4194
4195<!-- _______________________________________________________________________ -->
4196<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4197 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4198</div>
4199<div class="doc_text">
4200
4201<h5>Syntax:</h5>
4202<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4203 &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]4204</pre>
4205
4206<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4207<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4208 <a href="#t_floating">floating point</a> <tt>value</tt> to
4209 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4210
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4211<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4212<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4213 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4214 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4215 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4216 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4217
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4218<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4219<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4220 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4221 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4222 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4223
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4224<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4225<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4226 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4227 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4228 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4229</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4230
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4231</div>
4232
4233<!-- _______________________________________________________________________ -->
4234<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4235 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4236</div>
4237<div class="doc_text">
4238
4239<h5>Syntax:</h5>
4240<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4241 &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]4242</pre>
4243
4244<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4245<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4246 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4247
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4248<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4249<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]4250 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4251 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4252 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4253 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4254
4255<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4256<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4257 integer quantity and converts it to the corresponding floating point
4258 value. If the value cannot fit in the floating point value, the results are
4259 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4260
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4261<h5>Example:</h5>
4262<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4263 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4264 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4265</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4266
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4267</div>
4268
4269<!-- _______________________________________________________________________ -->
4270<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4271 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4272</div>
4273<div class="doc_text">
4274
4275<h5>Syntax:</h5>
4276<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4277 &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]4278</pre>
4279
4280<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4281<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4282 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4283
4284<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4285<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]4286 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4287 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4288 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4289 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4290
4291<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4292<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4293 quantity and converts it to the corresponding floating point value. If the
4294 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4295
4296<h5>Example:</h5>
4297<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4298 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4299 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4300</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4301
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4302</div>
4303
4304<!-- _______________________________________________________________________ -->
4305<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4306 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4307</div>
4308<div class="doc_text">
4309
4310<h5>Syntax:</h5>
4311<pre>
4312 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4313</pre>
4314
4315<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4316<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4317 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4318
4319<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4320<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4321 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4322 <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]4323
4324<h5>Semantics:</h5>
4325<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4326 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4327 truncating or zero extending that value to the size of the integer type. If
4328 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4329 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4330 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4331 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4332
4333<h5>Example:</h5>
4334<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4335 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4336 %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]4337</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4338
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4339</div>
4340
4341<!-- _______________________________________________________________________ -->
4342<div class="doc_subsubsection">
4343 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4344</div>
4345<div class="doc_text">
4346
4347<h5>Syntax:</h5>
4348<pre>
4349 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4350</pre>
4351
4352<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4353<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4354 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4355
4356<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4357<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4358 value to cast, and a type to cast it to, which must be a
4359 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4360
4361<h5>Semantics:</h5>
4362<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4363 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4364 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4365 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4366 than the size of a pointer then a zero extension is done. If they are the
4367 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4368
4369<h5>Example:</h5>
4370<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4371 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
4372 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4373 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4374</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4375
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4376</div>
4377
4378<!-- _______________________________________________________________________ -->
4379<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4380 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4381</div>
4382<div class="doc_text">
4383
4384<h5>Syntax:</h5>
4385<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4386 &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]4387</pre>
4388
4389<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4390<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4391 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4392
4393<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4394<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4395 non-aggregate first class value, and a type to cast it to, which must also be
4396 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4397 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4398 identical. If the source type is a pointer, the destination type must also be
4399 a pointer. This instruction supports bitwise conversion of vectors to
4400 integers and to vectors of other types (as long as they have the same
4401 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4402
4403<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4404<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4405 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4406 this conversion. The conversion is done as if the <tt>value</tt> had been
4407 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4408 be converted to other pointer types with this instruction. To convert
4409 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4410 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4411
4412<h5>Example:</h5>
4413<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4414 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4415 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4416 %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]4417</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4418
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4419</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4420
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4421<!-- ======================================================================= -->
4422<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4423
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4424<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4425
4426<p>The instructions in this category are the "miscellaneous" instructions, which
4427 defy better classification.</p>
4428
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4429</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4430
4431<!-- _______________________________________________________________________ -->
4432<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4433</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4434
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4435<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4436
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4437<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4438<pre>
4439 &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]4440</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4441
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4442<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4443<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4444 boolean values based on comparison of its two integer, integer vector, or
4445 pointer operands.</p>
4446
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4447<h5>Arguments:</h5>
4448<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4449 the condition code indicating the kind of comparison to perform. It is not a
4450 value, just a keyword. The possible condition code are:</p>
4451
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4452<ol>
4453 <li><tt>eq</tt>: equal</li>
4454 <li><tt>ne</tt>: not equal </li>
4455 <li><tt>ugt</tt>: unsigned greater than</li>
4456 <li><tt>uge</tt>: unsigned greater or equal</li>
4457 <li><tt>ult</tt>: unsigned less than</li>
4458 <li><tt>ule</tt>: unsigned less or equal</li>
4459 <li><tt>sgt</tt>: signed greater than</li>
4460 <li><tt>sge</tt>: signed greater or equal</li>
4461 <li><tt>slt</tt>: signed less than</li>
4462 <li><tt>sle</tt>: signed less or equal</li>
4463</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4464
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]4465<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4466 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4467 typed. They must also be identical types.</p>
4468
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4469<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4470<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4471 condition code given as <tt>cond</tt>. The comparison performed always yields
4472 either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt>
4473 result, as follows:</p>
4474
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4475<ol>
4476 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4477 <tt>false</tt> otherwise. No sign interpretation is necessary or
4478 performed.</li>
4479
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4480 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4481 <tt>false</tt> otherwise. No sign interpretation is necessary or
4482 performed.</li>
4483
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4484 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4485 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4486
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4487 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4488 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4489 to <tt>op2</tt>.</li>
4490
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4491 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4492 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4493
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4494 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4495 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4496
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4497 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4498 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4499
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4500 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4501 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4502 to <tt>op2</tt>.</li>
4503
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4504 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4505 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4506
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4507 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4508 <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]4509</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4510
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4511<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4512 values are compared as if they were integers.</p>
4513
4514<p>If the operands are integer vectors, then they are compared element by
4515 element. The result is an <tt>i1</tt> vector with the same number of elements
4516 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4517
4518<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4519<pre>
4520 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4521 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4522 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4523 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4524 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4525 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4526</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4527
4528<p>Note that the code generator does not yet support vector types with
4529 the <tt>icmp</tt> instruction.</p>
4530
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4531</div>
4532
4533<!-- _______________________________________________________________________ -->
4534<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4535</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4536
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4537<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4538
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4539<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4540<pre>
4541 &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]4542</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4543
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4544<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4545<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
4546 values based on comparison of its operands.</p>
4547
4548<p>If the operands are floating point scalars, then the result type is a boolean
4549(<a href="#t_primitive"><tt>i1</tt></a>).</p>
4550
4551<p>If the operands are floating point vectors, then the result type is a vector
4552 of boolean with the same number of elements as the operands being
4553 compared.</p>
4554
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4555<h5>Arguments:</h5>
4556<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4557 the condition code indicating the kind of comparison to perform. It is not a
4558 value, just a keyword. The possible condition code are:</p>
4559
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4560<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4561 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4562 <li><tt>oeq</tt>: ordered and equal</li>
4563 <li><tt>ogt</tt>: ordered and greater than </li>
4564 <li><tt>oge</tt>: ordered and greater than or equal</li>
4565 <li><tt>olt</tt>: ordered and less than </li>
4566 <li><tt>ole</tt>: ordered and less than or equal</li>
4567 <li><tt>one</tt>: ordered and not equal</li>
4568 <li><tt>ord</tt>: ordered (no nans)</li>
4569 <li><tt>ueq</tt>: unordered or equal</li>
4570 <li><tt>ugt</tt>: unordered or greater than </li>
4571 <li><tt>uge</tt>: unordered or greater than or equal</li>
4572 <li><tt>ult</tt>: unordered or less than </li>
4573 <li><tt>ule</tt>: unordered or less than or equal</li>
4574 <li><tt>une</tt>: unordered or not equal</li>
4575 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4576 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4577</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4578
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4579<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4580 <i>unordered</i> means that either operand may be a QNAN.</p>
4581
4582<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
4583 a <a href="#t_floating">floating point</a> type or
4584 a <a href="#t_vector">vector</a> of floating point type. They must have
4585 identical types.</p>
4586
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4587<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4588<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4589 according to the condition code given as <tt>cond</tt>. If the operands are
4590 vectors, then the vectors are compared element by element. Each comparison
4591 performed always yields an <a href="#t_primitive">i1</a> result, as
4592 follows:</p>
4593
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4594<ol>
4595 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4596
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4597 <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]4598 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4599
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4600 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4601 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
4602
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4603 <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]4604 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4605
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4606 <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]4607 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4608
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4609 <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]4610 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4611
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4612 <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]4613 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4614
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4615 <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]4616
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4617 <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]4618 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4619
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4620 <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]4621 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4622
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4623 <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]4624 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4625
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4626 <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]4627 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4628
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4629 <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]4630 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4631
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4632 <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]4633 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4634
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4635 <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]4636
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4637 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4638</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4639
4640<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4641<pre>
4642 &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]4643 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4644 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4645 &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]4646</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4647
4648<p>Note that the code generator does not yet support vector types with
4649 the <tt>fcmp</tt> instruction.</p>
4650
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4651</div>
4652
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4653<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4654<div class="doc_subsubsection">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4655 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4656</div>
4657
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4658<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4659
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4660<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4661<pre>
4662 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
4663</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4664
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4665<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4666<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
4667 SSA graph representing the function.</p>
4668
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4669<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4670<p>The type of the incoming values is specified with the first type field. After
4671 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
4672 one pair for each predecessor basic block of the current block. Only values
4673 of <a href="#t_firstclass">first class</a> type may be used as the value
4674 arguments to the PHI node. Only labels may be used as the label
4675 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4676
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4677<p>There must be no non-phi instructions between the start of a basic block and
4678 the PHI instructions: i.e. PHI instructions must be first in a basic
4679 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4680
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4681<p>For the purposes of the SSA form, the use of each incoming value is deemed to
4682 occur on the edge from the corresponding predecessor block to the current
4683 block (but after any definition of an '<tt>invoke</tt>' instruction's return
4684 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]4685
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4686<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4687<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4688 specified by the pair corresponding to the predecessor basic block that
4689 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4690
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4691<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4692<pre>
4693Loop: ; Infinite loop that counts from 0 on up...
4694 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4695 %nextindvar = add i32 %indvar, 1
4696 br label %Loop
4697</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4698
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4699</div>
4700
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4701<!-- _______________________________________________________________________ -->
4702<div class="doc_subsubsection">
4703 <a name="i_select">'<tt>select</tt>' Instruction</a>
4704</div>
4705
4706<div class="doc_text">
4707
4708<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4709<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4710 &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>
4711
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4712 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4713</pre>
4714
4715<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4716<p>The '<tt>select</tt>' instruction is used to choose one value based on a
4717 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4718
4719
4720<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4721<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
4722 values indicating the condition, and two values of the
4723 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
4724 vectors and the condition is a scalar, then entire vectors are selected, not
4725 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4726
4727<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4728<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
4729 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4730
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4731<p>If the condition is a vector of i1, then the value arguments must be vectors
4732 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4733
4734<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4735<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4736 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4737</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4738
4739<p>Note that the code generator does not yet support conditions
4740 with vector type.</p>
4741
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4742</div>
4743
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]4744<!-- _______________________________________________________________________ -->
4745<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4746 <a name="i_call">'<tt>call</tt>' Instruction</a>
4747</div>
4748
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4749<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4750
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4751<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4752<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4753 &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]4754</pre>
4755
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4756<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4757<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4758
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4759<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4760<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4761
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4762<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4763 <li>The optional "tail" marker indicates whether the callee function accesses
4764 any allocas or varargs in the caller. If the "tail" marker is present,
4765 the function call is eligible for tail call optimization. Note that calls
4766 may be marked "tail" even if they do not occur before
4767 a <a href="#i_ret"><tt>ret</tt></a> instruction.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4768
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4769 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
4770 convention</a> the call should use. If none is specified, the call
4771 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4772
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4773 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4774 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
4775 '<tt>inreg</tt>' attributes are valid here.</li>
4776
4777 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
4778 type of the return value. Functions that return no value are marked
4779 <tt><a href="#t_void">void</a></tt>.</li>
4780
4781 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
4782 being invoked. The argument types must match the types implied by this
4783 signature. This type can be omitted if the function is not varargs and if
4784 the function type does not return a pointer to a function.</li>
4785
4786 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4787 be invoked. In most cases, this is a direct function invocation, but
4788 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
4789 to function value.</li>
4790
4791 <li>'<tt>function args</tt>': argument list whose types match the function
4792 signature argument types. All arguments must be of
4793 <a href="#t_firstclass">first class</a> type. If the function signature
4794 indicates the function accepts a variable number of arguments, the extra
4795 arguments can be specified.</li>
4796
4797 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
4798 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4799 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4800</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4801
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4802<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4803<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
4804 a specified function, with its incoming arguments bound to the specified
4805 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
4806 function, control flow continues with the instruction after the function
4807 call, and the return value of the function is bound to the result
4808 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4809
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4810<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4811<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4812 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]4813 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4814 %X = tail call i32 @foo() <i>; yields i32</i>
4815 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4816 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4817
4818 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4819 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]4820 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4821 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]4822 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]4823 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4824</pre>
4825
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4826</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4827
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4828<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4829<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4830 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4831</div>
4832
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4833<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4834
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4835<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4836<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4837 &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]4838</pre>
4839
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4840<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4841<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4842 the "variable argument" area of a function call. It is used to implement the
4843 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4844
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4845<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4846<p>This instruction takes a <tt>va_list*</tt> value and the type of the
4847 argument. It returns a value of the specified argument type and increments
4848 the <tt>va_list</tt> to point to the next argument. The actual type
4849 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4850
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4851<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4852<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
4853 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
4854 to the next argument. For more information, see the variable argument
4855 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4856
4857<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]4858 take a variable number of arguments, for example, the <tt>vfprintf</tt>
4859 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4860
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4861<p><tt>va_arg</tt> is an LLVM instruction instead of
4862 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
4863 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4864
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4865<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4866<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4867
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4868<p>Note that the code generator does not yet fully support va_arg on many
4869 targets. Also, it does not currently support va_arg with aggregate types on
4870 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]4871
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4872</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4873
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4874<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4875<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4876<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4877
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4878<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4879
4880<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4881 well known names and semantics and are required to follow certain
4882 restrictions. Overall, these intrinsics represent an extension mechanism for
4883 the LLVM language that does not require changing all of the transformations
4884 in LLVM when adding to the language (or the bitcode reader/writer, the
4885 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4886
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4887<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4888 prefix is reserved in LLVM for intrinsic names; thus, function names may not
4889 begin with this prefix. Intrinsic functions must always be external
4890 functions: you cannot define the body of intrinsic functions. Intrinsic
4891 functions may only be used in call or invoke instructions: it is illegal to
4892 take the address of an intrinsic function. Additionally, because intrinsic
4893 functions are part of the LLVM language, it is required if any are added that
4894 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4895
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4896<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
4897 family of functions that perform the same operation but on different data
4898 types. Because LLVM can represent over 8 million different integer types,
4899 overloading is used commonly to allow an intrinsic function to operate on any
4900 integer type. One or more of the argument types or the result type can be
4901 overloaded to accept any integer type. Argument types may also be defined as
4902 exactly matching a previous argument's type or the result type. This allows
4903 an intrinsic function which accepts multiple arguments, but needs all of them
4904 to be of the same type, to only be overloaded with respect to a single
4905 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4906
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4907<p>Overloaded intrinsics will have the names of its overloaded argument types
4908 encoded into its function name, each preceded by a period. Only those types
4909 which are overloaded result in a name suffix. Arguments whose type is matched
4910 against another type do not. For example, the <tt>llvm.ctpop</tt> function
4911 can take an integer of any width and returns an integer of exactly the same
4912 integer width. This leads to a family of functions such as
4913 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
4914 %val)</tt>. Only one type, the return type, is overloaded, and only one type
4915 suffix is required. Because the argument's type is matched against the return
4916 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4917
4918<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4919 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4920
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4921</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4922
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4923<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4924<div class="doc_subsection">
4925 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4926</div>
4927
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4928<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4929
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4930<p>Variable argument support is defined in LLVM with
4931 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
4932 intrinsic functions. These functions are related to the similarly named
4933 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4934
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4935<p>All of these functions operate on arguments that use a target-specific value
4936 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
4937 not define what this type is, so all transformations should be prepared to
4938 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4939
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]4940<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]4941 instruction and the variable argument handling intrinsic functions are
4942 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4943
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4944<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4945<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4946define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4947 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4948 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4949 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4950 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4951
4952 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4953 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4954
4955 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4956 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4957 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4958 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4959 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4960
4961 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4962 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4963 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4964}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4965
4966declare void @llvm.va_start(i8*)
4967declare void @llvm.va_copy(i8*, i8*)
4968declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4969</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4970</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4971
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4972</div>
4973
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4974<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4975<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4976 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4977</div>
4978
4979
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4980<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4981
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4982<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4983<pre>
4984 declare void %llvm.va_start(i8* &lt;arglist&gt;)
4985</pre>
4986
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4987<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4988<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
4989 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]4990
4991<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4992<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]4993
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4994<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4995<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]4996 macro available in C. In a target-dependent way, it initializes
4997 the <tt>va_list</tt> element to which the argument points, so that the next
4998 call to <tt>va_arg</tt> will produce the first variable argument passed to
4999 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5000 need to know the last argument of the function as the compiler can figure
5001 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5002
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5003</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5004
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5005<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5006<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5007 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5008</div>
5009
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5010<div class="doc_text">
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5011
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5012<h5>Syntax:</h5>
5013<pre>
5014 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5015</pre>
5016
5017<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5018<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5019 which has been initialized previously
5020 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5021 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5022
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5023<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5024<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]5025
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5026<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5027<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]5028 macro available in C. In a target-dependent way, it destroys
5029 the <tt>va_list</tt> element to which the argument points. Calls
5030 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5031 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5032 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5033
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5034</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5035
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5036<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5037<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5038 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5039</div>
5040
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5041<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5042
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5043<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5044<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5045 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5046</pre>
5047
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5048<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5049<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5050 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5051
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5052<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5053<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]5054 The second argument is a pointer to a <tt>va_list</tt> element to copy
5055 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5056
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5057<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5058<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]5059 macro available in C. In a target-dependent way, it copies the
5060 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5061 element. This intrinsic is necessary because
5062 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5063 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5064
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5065</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5066
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5067<!-- ======================================================================= -->
5068<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5069 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5070</div>
5071
5072<div class="doc_text">
5073
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5074<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5075Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5076intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5077roots on the stack</a>, as well as garbage collector implementations that
5078require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5079barriers. Front-ends for type-safe garbage collected languages should generate
5080these intrinsics to make use of the LLVM garbage collectors. For more details,
5081see <a href="GarbageCollection.html">Accurate Garbage Collection with
5082LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5083
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5084<p>The garbage collection intrinsics only operate on objects in the generic
5085 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5086
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5087</div>
5088
5089<!-- _______________________________________________________________________ -->
5090<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5091 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5092</div>
5093
5094<div class="doc_text">
5095
5096<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5097<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5098 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5099</pre>
5100
5101<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]5102<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]5103 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5104
5105<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5106<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5107 root pointer. The second pointer (which must be either a constant or a
5108 global value address) contains the meta-data to be associated with the
5109 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5110
5111<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]5112<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]5113 location. At compile-time, the code generator generates information to allow
5114 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5115 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5116 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5117
5118</div>
5119
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5120<!-- _______________________________________________________________________ -->
5121<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5122 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5123</div>
5124
5125<div class="doc_text">
5126
5127<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5128<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5129 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5130</pre>
5131
5132<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5133<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5134 locations, allowing garbage collector implementations that require read
5135 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5136
5137<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5138<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]5139 allocated from the garbage collector. The first object is a pointer to the
5140 start of the referenced object, if needed by the language runtime (otherwise
5141 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5142
5143<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5144<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5145 instruction, but may be replaced with substantially more complex code by the
5146 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5147 may only be used in a function which <a href="#gc">specifies a GC
5148 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5149
5150</div>
5151
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5152<!-- _______________________________________________________________________ -->
5153<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5154 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5155</div>
5156
5157<div class="doc_text">
5158
5159<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5160<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5161 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5162</pre>
5163
5164<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5165<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5166 locations, allowing garbage collector implementations that require write
5167 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5168
5169<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5170<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]5171 object to store it to, and the third is the address of the field of Obj to
5172 store to. If the runtime does not require a pointer to the object, Obj may
5173 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5174
5175<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5176<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5177 instruction, but may be replaced with substantially more complex code by the
5178 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5179 may only be used in a function which <a href="#gc">specifies a GC
5180 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5181
5182</div>
5183
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5184<!-- ======================================================================= -->
5185<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5186 <a name="int_codegen">Code Generator Intrinsics</a>
5187</div>
5188
5189<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5190
5191<p>These intrinsics are provided by LLVM to expose special features that may
5192 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5193
5194</div>
5195
5196<!-- _______________________________________________________________________ -->
5197<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5198 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5199</div>
5200
5201<div class="doc_text">
5202
5203<h5>Syntax:</h5>
5204<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5205 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5206</pre>
5207
5208<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5209<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5210 target-specific value indicating the return address of the current function
5211 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5212
5213<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5214<p>The argument to this intrinsic indicates which function to return the address
5215 for. Zero indicates the calling function, one indicates its caller, etc.
5216 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5217
5218<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5219<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5220 indicating the return address of the specified call frame, or zero if it
5221 cannot be identified. The value returned by this intrinsic is likely to be
5222 incorrect or 0 for arguments other than zero, so it should only be used for
5223 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5224
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5225<p>Note that calling this intrinsic does not prevent function inlining or other
5226 aggressive transformations, so the value returned may not be that of the
5227 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5228
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5229</div>
5230
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5231<!-- _______________________________________________________________________ -->
5232<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5233 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5234</div>
5235
5236<div class="doc_text">
5237
5238<h5>Syntax:</h5>
5239<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5240 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5241</pre>
5242
5243<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5244<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5245 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5246
5247<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5248<p>The argument to this intrinsic indicates which function to return the frame
5249 pointer for. Zero indicates the calling function, one indicates its caller,
5250 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5251
5252<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5253<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5254 indicating the frame address of the specified call frame, or zero if it
5255 cannot be identified. The value returned by this intrinsic is likely to be
5256 incorrect or 0 for arguments other than zero, so it should only be used for
5257 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5258
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5259<p>Note that calling this intrinsic does not prevent function inlining or other
5260 aggressive transformations, so the value returned may not be that of the
5261 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5262
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5263</div>
5264
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5265<!-- _______________________________________________________________________ -->
5266<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5267 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5268</div>
5269
5270<div class="doc_text">
5271
5272<h5>Syntax:</h5>
5273<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5274 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5275</pre>
5276
5277<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5278<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5279 of the function stack, for use
5280 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5281 useful for implementing language features like scoped automatic variable
5282 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5283
5284<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5285<p>This intrinsic returns a opaque pointer value that can be passed
5286 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5287 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5288 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5289 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5290 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5291 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5292
5293</div>
5294
5295<!-- _______________________________________________________________________ -->
5296<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5297 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5298</div>
5299
5300<div class="doc_text">
5301
5302<h5>Syntax:</h5>
5303<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5304 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5305</pre>
5306
5307<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5308<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5309 the function stack to the state it was in when the
5310 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5311 executed. This is useful for implementing language features like scoped
5312 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5313
5314<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5315<p>See the description
5316 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5317
5318</div>
5319
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5320<!-- _______________________________________________________________________ -->
5321<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5322 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5323</div>
5324
5325<div class="doc_text">
5326
5327<h5>Syntax:</h5>
5328<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5329 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]5330</pre>
5331
5332<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5333<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5334 insert a prefetch instruction if supported; otherwise, it is a noop.
5335 Prefetches have no effect on the behavior of the program but can change its
5336 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5337
5338<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5339<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5340 specifier determining if the fetch should be for a read (0) or write (1),
5341 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5342 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5343 and <tt>locality</tt> arguments must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5344
5345<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5346<p>This intrinsic does not modify the behavior of the program. In particular,
5347 prefetches cannot trap and do not produce a value. On targets that support
5348 this intrinsic, the prefetch can provide hints to the processor cache for
5349 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5350
5351</div>
5352
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5353<!-- _______________________________________________________________________ -->
5354<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5355 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5356</div>
5357
5358<div class="doc_text">
5359
5360<h5>Syntax:</h5>
5361<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5362 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5363</pre>
5364
5365<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5366<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5367 Counter (PC) in a region of code to simulators and other tools. The method
5368 is target specific, but it is expected that the marker will use exported
5369 symbols to transmit the PC of the marker. The marker makes no guarantees
5370 that it will remain with any specific instruction after optimizations. It is
5371 possible that the presence of a marker will inhibit optimizations. The
5372 intended use is to be inserted after optimizations to allow correlations of
5373 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5374
5375<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5376<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5377
5378<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5379<p>This intrinsic does not modify the behavior of the program. Backends that do
5380 not support this intrinisic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5381
5382</div>
5383
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5384<!-- _______________________________________________________________________ -->
5385<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5386 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5387</div>
5388
5389<div class="doc_text">
5390
5391<h5>Syntax:</h5>
5392<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5393 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5394</pre>
5395
5396<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5397<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5398 counter register (or similar low latency, high accuracy clocks) on those
5399 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5400 should map to RPCC. As the backing counters overflow quickly (on the order
5401 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5402
5403<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5404<p>When directly supported, reading the cycle counter should not modify any
5405 memory. Implementations are allowed to either return a application specific
5406 value or a system wide value. On backends without support, this is lowered
5407 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5408
5409</div>
5410
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5411<!-- ======================================================================= -->
5412<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5413 <a name="int_libc">Standard C Library Intrinsics</a>
5414</div>
5415
5416<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5417
5418<p>LLVM provides intrinsics for a few important standard C library functions.
5419 These intrinsics allow source-language front-ends to pass information about
5420 the alignment of the pointer arguments to the code generator, providing
5421 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5422
5423</div>
5424
5425<!-- _______________________________________________________________________ -->
5426<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5427 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5428</div>
5429
5430<div class="doc_text">
5431
5432<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5433<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
5434 integer bit width. Not all targets support all bit widths however.</p>
5435
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5436<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5437 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5438 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5439 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5440 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5441 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5442 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5443 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5444 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5445</pre>
5446
5447<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5448<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5449 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5450
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5451<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5452 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5453
5454<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5455<p>The first argument is a pointer to the destination, the second is a pointer
5456 to the source. The third argument is an integer argument specifying the
5457 number of bytes to copy, and the fourth argument is the alignment of the
5458 source and destination locations.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5459
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5460<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5461 then the caller guarantees that both the source and destination pointers are
5462 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5463
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5464<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5465<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5466 source location to the destination location, which are not allowed to
5467 overlap. It copies "len" bytes of memory over. If the argument is known to
5468 be aligned to some boundary, this can be specified as the fourth argument,
5469 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5470
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5471</div>
5472
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5473<!-- _______________________________________________________________________ -->
5474<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5475 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5476</div>
5477
5478<div class="doc_text">
5479
5480<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5481<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]5482 width. Not all targets support all bit widths however.</p>
5483
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5484<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5485 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5486 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5487 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5488 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5489 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5490 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5491 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5492 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5493</pre>
5494
5495<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5496<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
5497 source location to the destination location. It is similar to the
5498 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
5499 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5500
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5501<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5502 intrinsics do not return a value, and takes an extra alignment argument.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5503
5504<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5505<p>The first argument is a pointer to the destination, the second is a pointer
5506 to the source. The third argument is an integer argument specifying the
5507 number of bytes to copy, and the fourth argument is the alignment of the
5508 source and destination locations.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5509
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5510<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5511 then the caller guarantees that the source and destination pointers are
5512 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5513
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5514<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5515<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
5516 source location to the destination location, which may overlap. It copies
5517 "len" bytes of memory over. If the argument is known to be aligned to some
5518 boundary, this can be specified as the fourth argument, otherwise it should
5519 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5520
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5521</div>
5522
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5523<!-- _______________________________________________________________________ -->
5524<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5525 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5526</div>
5527
5528<div class="doc_text">
5529
5530<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5531<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]5532 width. Not all targets support all bit widths however.</p>
5533
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5534<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5535 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5536 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5537 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5538 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5539 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5540 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5541 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5542 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5543</pre>
5544
5545<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5546<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
5547 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5548
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5549<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
5550 intrinsic does not return a value, and takes an extra alignment argument.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5551
5552<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5553<p>The first argument is a pointer to the destination to fill, the second is the
5554 byte value to fill it with, the third argument is an integer argument
5555 specifying the number of bytes to fill, and the fourth argument is the known
5556 alignment of destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5557
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5558<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5559 then the caller guarantees that the destination pointer is aligned to that
5560 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5561
5562<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5563<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
5564 at the destination location. If the argument is known to be aligned to some
5565 boundary, this can be specified as the fourth argument, otherwise it should
5566 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5567
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5568</div>
5569
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5570<!-- _______________________________________________________________________ -->
5571<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5572 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5573</div>
5574
5575<div class="doc_text">
5576
5577<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5578<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
5579 floating point or vector of floating point type. Not all targets support all
5580 types however.</p>
5581
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5582<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5583 declare float @llvm.sqrt.f32(float %Val)
5584 declare double @llvm.sqrt.f64(double %Val)
5585 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5586 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5587 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5588</pre>
5589
5590<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5591<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
5592 returning the same value as the libm '<tt>sqrt</tt>' functions would.
5593 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
5594 behavior for negative numbers other than -0.0 (which allows for better
5595 optimization, because there is no need to worry about errno being
5596 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]5597
5598<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5599<p>The argument and return value are floating point numbers of the same
5600 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5601
5602<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5603<p>This function returns the sqrt of the specified operand if it is a
5604 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5605
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5606</div>
5607
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5608<!-- _______________________________________________________________________ -->
5609<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5610 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5611</div>
5612
5613<div class="doc_text">
5614
5615<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5616<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
5617 floating point or vector of floating point type. Not all targets support all
5618 types however.</p>
5619
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5620<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5621 declare float @llvm.powi.f32(float %Val, i32 %power)
5622 declare double @llvm.powi.f64(double %Val, i32 %power)
5623 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5624 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5625 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5626</pre>
5627
5628<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5629<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5630 specified (positive or negative) power. The order of evaluation of
5631 multiplications is not defined. When a vector of floating point type is
5632 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5633
5634<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5635<p>The second argument is an integer power, and the first is a value to raise to
5636 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5637
5638<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5639<p>This function returns the first value raised to the second power with an
5640 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5641
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5642</div>
5643
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5644<!-- _______________________________________________________________________ -->
5645<div class="doc_subsubsection">
5646 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5647</div>
5648
5649<div class="doc_text">
5650
5651<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5652<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5653 floating point or vector of floating point type. Not all targets support all
5654 types however.</p>
5655
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5656<pre>
5657 declare float @llvm.sin.f32(float %Val)
5658 declare double @llvm.sin.f64(double %Val)
5659 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5660 declare fp128 @llvm.sin.f128(fp128 %Val)
5661 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5662</pre>
5663
5664<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5665<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5666
5667<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5668<p>The argument and return value are floating point numbers of the same
5669 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5670
5671<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5672<p>This function returns the sine of the specified operand, returning the same
5673 values as the libm <tt>sin</tt> functions would, and handles error conditions
5674 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5675
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5676</div>
5677
5678<!-- _______________________________________________________________________ -->
5679<div class="doc_subsubsection">
5680 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5681</div>
5682
5683<div class="doc_text">
5684
5685<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5686<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5687 floating point or vector of floating point type. Not all targets support all
5688 types however.</p>
5689
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5690<pre>
5691 declare float @llvm.cos.f32(float %Val)
5692 declare double @llvm.cos.f64(double %Val)
5693 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5694 declare fp128 @llvm.cos.f128(fp128 %Val)
5695 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5696</pre>
5697
5698<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5699<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5700
5701<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5702<p>The argument and return value are floating point numbers of the same
5703 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5704
5705<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5706<p>This function returns the cosine of the specified operand, returning the same
5707 values as the libm <tt>cos</tt> functions would, and handles error conditions
5708 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5709
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5710</div>
5711
5712<!-- _______________________________________________________________________ -->
5713<div class="doc_subsubsection">
5714 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5715</div>
5716
5717<div class="doc_text">
5718
5719<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5720<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5721 floating point or vector of floating point type. Not all targets support all
5722 types however.</p>
5723
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5724<pre>
5725 declare float @llvm.pow.f32(float %Val, float %Power)
5726 declare double @llvm.pow.f64(double %Val, double %Power)
5727 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5728 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5729 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5730</pre>
5731
5732<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5733<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5734 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5735
5736<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5737<p>The second argument is a floating point power, and the first is a value to
5738 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5739
5740<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5741<p>This function returns the first value raised to the second power, returning
5742 the same values as the libm <tt>pow</tt> functions would, and handles error
5743 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5744
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5745</div>
5746
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5747<!-- ======================================================================= -->
5748<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5749 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5750</div>
5751
5752<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5753
5754<p>LLVM provides intrinsics for a few important bit manipulation operations.
5755 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5756
5757</div>
5758
5759<!-- _______________________________________________________________________ -->
5760<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5761 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5762</div>
5763
5764<div class="doc_text">
5765
5766<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5767<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5768 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
5769
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5770<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5771 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5772 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5773 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5774</pre>
5775
5776<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5777<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
5778 values with an even number of bytes (positive multiple of 16 bits). These
5779 are useful for performing operations on data that is not in the target's
5780 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5781
5782<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5783<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
5784 and low byte of the input i16 swapped. Similarly,
5785 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
5786 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
5787 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
5788 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
5789 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
5790 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5791
5792</div>
5793
5794<!-- _______________________________________________________________________ -->
5795<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5796 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5797</div>
5798
5799<div class="doc_text">
5800
5801<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5802<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]5803 width. Not all targets support all bit widths however.</p>
5804
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5805<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5806 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5807 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5808 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5809 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5810 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5811</pre>
5812
5813<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5814<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
5815 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5816
5817<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5818<p>The only argument is the value to be counted. The argument may be of any
5819 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5820
5821<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5822<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]5823
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5824</div>
5825
5826<!-- _______________________________________________________________________ -->
5827<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5828 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5829</div>
5830
5831<div class="doc_text">
5832
5833<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5834<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
5835 integer bit width. Not all targets support all bit widths however.</p>
5836
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5837<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5838 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5839 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5840 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5841 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5842 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5843</pre>
5844
5845<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5846<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5847 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5848
5849<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5850<p>The only argument is the value to be counted. The argument may be of any
5851 integer type. The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5852
5853<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5854<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
5855 zeros in a variable. If the src == 0 then the result is the size in bits of
5856 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5857
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5858</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5859
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5860<!-- _______________________________________________________________________ -->
5861<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5862 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5863</div>
5864
5865<div class="doc_text">
5866
5867<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5868<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
5869 integer bit width. Not all targets support all bit widths however.</p>
5870
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5871<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5872 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5873 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5874 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5875 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5876 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5877</pre>
5878
5879<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5880<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5881 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5882
5883<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5884<p>The only argument is the value to be counted. The argument may be of any
5885 integer type. The return type must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5886
5887<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5888<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
5889 zeros in a variable. If the src == 0 then the result is the size in bits of
5890 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5891
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5892</div>
5893
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]5894<!-- ======================================================================= -->
5895<div class="doc_subsection">
5896 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
5897</div>
5898
5899<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5900
5901<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]5902
5903</div>
5904
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5905<!-- _______________________________________________________________________ -->
5906<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]5907 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5908</div>
5909
5910<div class="doc_text">
5911
5912<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5913<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]5914 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5915
5916<pre>
5917 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
5918 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5919 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
5920</pre>
5921
5922<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5923<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5924 a signed addition of the two arguments, and indicate whether an overflow
5925 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5926
5927<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5928<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]5929 be of integer types of any bit width, but they must have the same bit
5930 width. The second element of the result structure must be of
5931 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
5932 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5933
5934<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5935<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5936 a signed addition of the two variables. They return a structure &mdash; the
5937 first element of which is the signed summation, and the second element of
5938 which is a bit specifying if the signed summation resulted in an
5939 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5940
5941<h5>Examples:</h5>
5942<pre>
5943 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
5944 %sum = extractvalue {i32, i1} %res, 0
5945 %obit = extractvalue {i32, i1} %res, 1
5946 br i1 %obit, label %overflow, label %normal
5947</pre>
5948
5949</div>
5950
5951<!-- _______________________________________________________________________ -->
5952<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]5953 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5954</div>
5955
5956<div class="doc_text">
5957
5958<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5959<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]5960 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5961
5962<pre>
5963 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
5964 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
5965 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
5966</pre>
5967
5968<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5969<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5970 an unsigned addition of the two arguments, and indicate whether a carry
5971 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5972
5973<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5974<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]5975 be of integer types of any bit width, but they must have the same bit
5976 width. The second element of the result structure must be of
5977 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
5978 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5979
5980<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5981<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5982 an unsigned addition of the two arguments. They return a structure &mdash;
5983 the first element of which is the sum, and the second element of which is a
5984 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5985
5986<h5>Examples:</h5>
5987<pre>
5988 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
5989 %sum = extractvalue {i32, i1} %res, 0
5990 %obit = extractvalue {i32, i1} %res, 1
5991 br i1 %obit, label %carry, label %normal
5992</pre>
5993
5994</div>
5995
5996<!-- _______________________________________________________________________ -->
5997<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]5998 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]5999</div>
6000
6001<div class="doc_text">
6002
6003<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6004<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]6005 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6006
6007<pre>
6008 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6009 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6010 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6011</pre>
6012
6013<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6014<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6015 a signed subtraction of the two arguments, and indicate whether an overflow
6016 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6017
6018<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6019<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]6020 be of integer types of any bit width, but they must have the same bit
6021 width. The second element of the result structure must be of
6022 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6023 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6024
6025<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6026<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6027 a signed subtraction of the two arguments. They return a structure &mdash;
6028 the first element of which is the subtraction, and the second element of
6029 which is a bit specifying if the signed subtraction resulted in an
6030 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6031
6032<h5>Examples:</h5>
6033<pre>
6034 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6035 %sum = extractvalue {i32, i1} %res, 0
6036 %obit = extractvalue {i32, i1} %res, 1
6037 br i1 %obit, label %overflow, label %normal
6038</pre>
6039
6040</div>
6041
6042<!-- _______________________________________________________________________ -->
6043<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6044 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6045</div>
6046
6047<div class="doc_text">
6048
6049<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6050<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]6051 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6052
6053<pre>
6054 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6055 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6056 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6057</pre>
6058
6059<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6060<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6061 an unsigned subtraction of the two arguments, and indicate whether an
6062 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6063
6064<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6065<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]6066 be of integer types of any bit width, but they must have the same bit
6067 width. The second element of the result structure must be of
6068 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6069 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6070
6071<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6072<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6073 an unsigned subtraction of the two arguments. They return a structure &mdash;
6074 the first element of which is the subtraction, and the second element of
6075 which is a bit specifying if the unsigned subtraction resulted in an
6076 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6077
6078<h5>Examples:</h5>
6079<pre>
6080 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6081 %sum = extractvalue {i32, i1} %res, 0
6082 %obit = extractvalue {i32, i1} %res, 1
6083 br i1 %obit, label %overflow, label %normal
6084</pre>
6085
6086</div>
6087
6088<!-- _______________________________________________________________________ -->
6089<div class="doc_subsubsection">
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6090 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6091</div>
6092
6093<div class="doc_text">
6094
6095<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6096<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]6097 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6098
6099<pre>
6100 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6101 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6102 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6103</pre>
6104
6105<h5>Overview:</h5>
6106
6107<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6108 a signed multiplication of the two arguments, and indicate whether an
6109 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6110
6111<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6112<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]6113 be of integer types of any bit width, but they must have the same bit
6114 width. The second element of the result structure must be of
6115 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6116 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6117
6118<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6119<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6120 a signed multiplication of the two arguments. They return a structure &mdash;
6121 the first element of which is the multiplication, and the second element of
6122 which is a bit specifying if the signed multiplication resulted in an
6123 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6124
6125<h5>Examples:</h5>
6126<pre>
6127 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6128 %sum = extractvalue {i32, i1} %res, 0
6129 %obit = extractvalue {i32, i1} %res, 1
6130 br i1 %obit, label %overflow, label %normal
6131</pre>
6132
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]6133</div>
6134
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6135<!-- _______________________________________________________________________ -->
6136<div class="doc_subsubsection">
6137 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6138</div>
6139
6140<div class="doc_text">
6141
6142<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6143<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]6144 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6145
6146<pre>
6147 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6148 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6149 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6150</pre>
6151
6152<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6153<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6154 a unsigned multiplication of the two arguments, and indicate whether an
6155 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6156
6157<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6158<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]6159 be of integer types of any bit width, but they must have the same bit
6160 width. The second element of the result structure must be of
6161 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6162 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6163
6164<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6165<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6166 an unsigned multiplication of the two arguments. They return a structure
6167 &mdash; the first element of which is the multiplication, and the second
6168 element of which is a bit specifying if the unsigned multiplication resulted
6169 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6170
6171<h5>Examples:</h5>
6172<pre>
6173 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6174 %sum = extractvalue {i32, i1} %res, 0
6175 %obit = extractvalue {i32, i1} %res, 1
6176 br i1 %obit, label %overflow, label %normal
6177</pre>
6178
6179</div>
6180
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6181<!-- ======================================================================= -->
6182<div class="doc_subsection">
6183 <a name="int_debugger">Debugger Intrinsics</a>
6184</div>
6185
6186<div class="doc_text">
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6187
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6188<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6189 prefix), are described in
6190 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6191 Level Debugging</a> document.</p>
6192
6193</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6194
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6195<!-- ======================================================================= -->
6196<div class="doc_subsection">
6197 <a name="int_eh">Exception Handling Intrinsics</a>
6198</div>
6199
6200<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6201
6202<p>The LLVM exception handling intrinsics (which all start with
6203 <tt>llvm.eh.</tt> prefix), are described in
6204 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6205 Handling</a> document.</p>
6206
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6207</div>
6208
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6209<!-- ======================================================================= -->
6210<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6211 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6212</div>
6213
6214<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6215
6216<p>This intrinsic makes it possible to excise one parameter, marked with
6217 the <tt>nest</tt> attribute, from a function. The result is a callable
6218 function pointer lacking the nest parameter - the caller does not need to
6219 provide a value for it. Instead, the value to use is stored in advance in a
6220 "trampoline", a block of memory usually allocated on the stack, which also
6221 contains code to splice the nest value into the argument list. This is used
6222 to implement the GCC nested function address extension.</p>
6223
6224<p>For example, if the function is
6225 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6226 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6227 follows:</p>
6228
6229<div class="doc_code">
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6230<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]6231 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6232 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6233 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6234 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6235</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6236</div>
6237
6238<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6239 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6240
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6241</div>
6242
6243<!-- _______________________________________________________________________ -->
6244<div class="doc_subsubsection">
6245 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6246</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6247
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6248<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6249
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6250<h5>Syntax:</h5>
6251<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6252 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]6253</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6254
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6255<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6256<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6257 function pointer suitable for executing it.</p>
6258
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6259<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6260<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6261 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6262 sufficiently aligned block of memory; this memory is written to by the
6263 intrinsic. Note that the size and the alignment are target-specific - LLVM
6264 currently provides no portable way of determining them, so a front-end that
6265 generates this intrinsic needs to have some target-specific knowledge.
6266 The <tt>func</tt> argument must hold a function bitcast to
6267 an <tt>i8*</tt>.</p>
6268
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6269<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6270<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6271 dependent code, turning it into a function. A pointer to this function is
6272 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6273 function pointer type</a> before being called. The new function's signature
6274 is the same as that of <tt>func</tt> with any arguments marked with
6275 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6276 is allowed, and it must be of pointer type. Calling the new function is
6277 equivalent to calling <tt>func</tt> with the same argument list, but
6278 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6279 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6280 by <tt>tramp</tt> is modified, then the effect of any later call to the
6281 returned function pointer is undefined.</p>
6282
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]6283</div>
6284
6285<!-- ======================================================================= -->
6286<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6287 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6288</div>
6289
6290<div class="doc_text">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6291
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6292<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6293 hardware constructs for atomic operations and memory synchronization. This
6294 provides an interface to the hardware, not an interface to the programmer. It
6295 is aimed at a low enough level to allow any programming models or APIs
6296 (Application Programming Interfaces) which need atomic behaviors to map
6297 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6298 hardware provides a "universal IR" for source languages, it also provides a
6299 starting point for developing a "universal" atomic operation and
6300 synchronization IR.</p>
6301
6302<p>These do <em>not</em> form an API such as high-level threading libraries,
6303 software transaction memory systems, atomic primitives, and intrinsic
6304 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6305 application libraries. The hardware interface provided by LLVM should allow
6306 a clean implementation of all of these APIs and parallel programming models.
6307 No one model or paradigm should be selected above others unless the hardware
6308 itself ubiquitously does so.</p>
6309
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6310</div>
6311
6312<!-- _______________________________________________________________________ -->
6313<div class="doc_subsubsection">
6314 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6315</div>
6316<div class="doc_text">
6317<h5>Syntax:</h5>
6318<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6319 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]6320</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6321
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6322<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6323<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6324 specific pairs of memory access types.</p>
6325
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6326<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6327<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6328 The first four arguments enables a specific barrier as listed below. The
6329 fith argument specifies that the barrier applies to io or device or uncached
6330 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6331
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6332<ul>
6333 <li><tt>ll</tt>: load-load barrier</li>
6334 <li><tt>ls</tt>: load-store barrier</li>
6335 <li><tt>sl</tt>: store-load barrier</li>
6336 <li><tt>ss</tt>: store-store barrier</li>
6337 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6338</ul>
6339
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6340<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6341<p>This intrinsic causes the system to enforce some ordering constraints upon
6342 the loads and stores of the program. This barrier does not
6343 indicate <em>when</em> any events will occur, it only enforces
6344 an <em>order</em> in which they occur. For any of the specified pairs of load
6345 and store operations (f.ex. load-load, or store-load), all of the first
6346 operations preceding the barrier will complete before any of the second
6347 operations succeeding the barrier begin. Specifically the semantics for each
6348 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6349
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6350<ul>
6351 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6352 after the barrier begins.</li>
6353 <li><tt>ls</tt>: All loads before the barrier must complete before any
6354 store after the barrier begins.</li>
6355 <li><tt>ss</tt>: All stores before the barrier must complete before any
6356 store after the barrier begins.</li>
6357 <li><tt>sl</tt>: All stores before the barrier must complete before any
6358 load after the barrier begins.</li>
6359</ul>
6360
6361<p>These semantics are applied with a logical "and" behavior when more than one
6362 is enabled in a single memory barrier intrinsic.</p>
6363
6364<p>Backends may implement stronger barriers than those requested when they do
6365 not support as fine grained a barrier as requested. Some architectures do
6366 not need all types of barriers and on such architectures, these become
6367 noops.</p>
6368
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6369<h5>Example:</h5>
6370<pre>
6371%ptr = malloc i32
6372 store i32 4, %ptr
6373
6374%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6375 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6376 <i>; guarantee the above finishes</i>
6377 store i32 8, %ptr <i>; before this begins</i>
6378</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6379
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6380</div>
6381
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6382<!-- _______________________________________________________________________ -->
6383<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6384 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6385</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6386
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6387<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6388
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6389<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6390<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6391 any integer bit width and for different address spaces. Not all targets
6392 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6393
6394<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6395 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6396 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6397 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6398 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]6399</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6400
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6401<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6402<p>This loads a value in memory and compares it to a given value. If they are
6403 equal, it stores a new value into the memory.</p>
6404
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6405<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6406<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
6407 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6408 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6409 this integer type. While any bit width integer may be used, targets may only
6410 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6411
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6412<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6413<p>This entire intrinsic must be executed atomically. It first loads the value
6414 in memory pointed to by <tt>ptr</tt> and compares it with the
6415 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
6416 memory. The loaded value is yielded in all cases. This provides the
6417 equivalent of an atomic compare-and-swap operation within the SSA
6418 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6419
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6420<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6421<pre>
6422%ptr = malloc i32
6423 store i32 4, %ptr
6424
6425%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6426%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6427 <i>; yields {i32}:result1 = 4</i>
6428%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6429%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6430
6431%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6432%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6433 <i>; yields {i32}:result2 = 8</i>
6434%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6435
6436%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6437</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6438
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6439</div>
6440
6441<!-- _______________________________________________________________________ -->
6442<div class="doc_subsubsection">
6443 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6444</div>
6445<div class="doc_text">
6446<h5>Syntax:</h5>
6447
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6448<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6449 integer bit width. Not all targets support all bit widths however.</p>
6450
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6451<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6452 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6453 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6454 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6455 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]6456</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6457
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6458<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6459<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6460 the value from memory. It then stores the value in <tt>val</tt> in the memory
6461 at <tt>ptr</tt>.</p>
6462
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6463<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6464<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
6465 the <tt>val</tt> argument and the result must be integers of the same bit
6466 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6467 integer type. The targets may only lower integer representations they
6468 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6469
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6470<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6471<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6472 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6473 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6474
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6475<h5>Examples:</h5>
6476<pre>
6477%ptr = malloc i32
6478 store i32 4, %ptr
6479
6480%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6481%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6482 <i>; yields {i32}:result1 = 4</i>
6483%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6484%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6485
6486%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6487%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6488 <i>; yields {i32}:result2 = 8</i>
6489
6490%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6491%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6492</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6493
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6494</div>
6495
6496<!-- _______________________________________________________________________ -->
6497<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6498 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6499
6500</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6501
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6502<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6503
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6504<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6505<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
6506 any integer bit width. Not all targets support all bit widths however.</p>
6507
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6508<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6509 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6510 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6511 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6512 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]6513</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6514
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6515<h5>Overview:</h5>
6516<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
6517 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6518
6519<h5>Arguments:</h5>
6520<p>The intrinsic takes two arguments, the first a pointer to an integer value
6521 and the second an integer value. The result is also an integer value. These
6522 integer types can have any bit width, but they must all have the same bit
6523 width. The targets may only lower integer representations they support.</p>
6524
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6525<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6526<p>This intrinsic does a series of operations atomically. It first loads the
6527 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6528 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]6529
6530<h5>Examples:</h5>
6531<pre>
6532%ptr = malloc i32
6533 store i32 4, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6534%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6535 <i>; yields {i32}:result1 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6536%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6537 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6538%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6539 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6540%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6541</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6542
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6543</div>
6544
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6545<!-- _______________________________________________________________________ -->
6546<div class="doc_subsubsection">
6547 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6548
6549</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6550
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6551<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6552
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6553<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6554<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
6555 any integer bit width and for different address spaces. Not all targets
6556 support all bit widths however.</p>
6557
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6558<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6559 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6560 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6561 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6562 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]6563</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6564
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6565<h5>Overview:</h5>
6566<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6567 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6568
6569<h5>Arguments:</h5>
6570<p>The intrinsic takes two arguments, the first a pointer to an integer value
6571 and the second an integer value. The result is also an integer value. These
6572 integer types can have any bit width, but they must all have the same bit
6573 width. The targets may only lower integer representations they support.</p>
6574
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6575<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6576<p>This intrinsic does a series of operations atomically. It first loads the
6577 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6578 result to <tt>ptr</tt>. It yields the original value stored
6579 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6580
6581<h5>Examples:</h5>
6582<pre>
6583%ptr = malloc i32
6584 store i32 8, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6585%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6586 <i>; yields {i32}:result1 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6587%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6588 <i>; yields {i32}:result2 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6589%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6590 <i>; yields {i32}:result3 = 2</i>
6591%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6592</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6593
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6594</div>
6595
6596<!-- _______________________________________________________________________ -->
6597<div class="doc_subsubsection">
6598 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6599 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6600 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6601 <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]6602</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6603
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6604<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6605
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6606<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6607<p>These are overloaded intrinsics. You can
6608 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
6609 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
6610 bit width and for different address spaces. Not all targets support all bit
6611 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6612
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6613<pre>
6614 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6615 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6616 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6617 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]6618</pre>
6619
6620<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6621 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6622 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6623 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6624 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]6625</pre>
6626
6627<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6628 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6629 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6630 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6631 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]6632</pre>
6633
6634<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6635 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6636 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6637 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6638 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]6639</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6640
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6641<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6642<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6643 the value stored in memory at <tt>ptr</tt>. It yields the original value
6644 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6645
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6646<h5>Arguments:</h5>
6647<p>These intrinsics take two arguments, the first a pointer to an integer value
6648 and the second an integer value. The result is also an integer value. These
6649 integer types can have any bit width, but they must all have the same bit
6650 width. The targets may only lower integer representations they support.</p>
6651
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6652<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6653<p>These intrinsics does a series of operations atomically. They first load the
6654 value stored at <tt>ptr</tt>. They then do the bitwise
6655 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
6656 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6657
6658<h5>Examples:</h5>
6659<pre>
6660%ptr = malloc i32
6661 store i32 0x0F0F, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6662%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6663 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6664%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6665 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6666%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6667 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6668%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6669 <i>; yields {i32}:result3 = FF</i>
6670%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6671</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6672
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6673</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6674
6675<!-- _______________________________________________________________________ -->
6676<div class="doc_subsubsection">
6677 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6678 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6679 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6680 <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]6681</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6682
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6683<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6684
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6685<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6686<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6687 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
6688 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6689 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6690
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6691<pre>
6692 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6693 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6694 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6695 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]6696</pre>
6697
6698<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6699 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6700 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6701 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6702 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]6703</pre>
6704
6705<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6706 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6707 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6708 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6709 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]6710</pre>
6711
6712<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6713 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6714 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6715 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6716 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]6717</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6718
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6719<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6720<p>These intrinsics takes the signed or unsigned minimum or maximum of
6721 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6722 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6723
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6724<h5>Arguments:</h5>
6725<p>These intrinsics take two arguments, the first a pointer to an integer value
6726 and the second an integer value. The result is also an integer value. These
6727 integer types can have any bit width, but they must all have the same bit
6728 width. The targets may only lower integer representations they support.</p>
6729
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6730<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6731<p>These intrinsics does a series of operations atomically. They first load the
6732 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
6733 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
6734 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6735
6736<h5>Examples:</h5>
6737<pre>
6738%ptr = malloc i32
6739 store i32 7, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6740%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6741 <i>; yields {i32}:result0 = 7</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6742%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6743 <i>; yields {i32}:result1 = -2</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6744%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6745 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6746%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6747 <i>; yields {i32}:result3 = 8</i>
6748%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6749</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6750
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6751</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6752
6753<!-- ======================================================================= -->
6754<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6755 <a name="int_general">General Intrinsics</a>
6756</div>
6757
6758<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6759
6760<p>This class of intrinsics is designed to be generic and has no specific
6761 purpose.</p>
6762
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6763</div>
6764
6765<!-- _______________________________________________________________________ -->
6766<div class="doc_subsubsection">
6767 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6768</div>
6769
6770<div class="doc_text">
6771
6772<h5>Syntax:</h5>
6773<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6774 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]6775</pre>
6776
6777<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6778<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6779
6780<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6781<p>The first argument is a pointer to a value, the second is a pointer to a
6782 global string, the third is a pointer to a global string which is the source
6783 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6784
6785<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6786<p>This intrinsic allows annotation of local variables with arbitrary strings.
6787 This can be useful for special purpose optimizations that want to look for
6788 these annotations. These have no other defined use, they are ignored by code
6789 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6790
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6791</div>
6792
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6793<!-- _______________________________________________________________________ -->
6794<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]6795 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6796</div>
6797
6798<div class="doc_text">
6799
6800<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6801<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6802 any integer bit width.</p>
6803
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6804<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]6805 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6806 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6807 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6808 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6809 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]6810</pre>
6811
6812<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6813<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6814
6815<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6816<p>The first argument is an integer value (result of some expression), the
6817 second is a pointer to a global string, the third is a pointer to a global
6818 string which is the source file name, and the last argument is the line
6819 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6820
6821<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6822<p>This intrinsic allows annotations to be put on arbitrary expressions with
6823 arbitrary strings. This can be useful for special purpose optimizations that
6824 want to look for these annotations. These have no other defined use, they
6825 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6826
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6827</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6828
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6829<!-- _______________________________________________________________________ -->
6830<div class="doc_subsubsection">
6831 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6832</div>
6833
6834<div class="doc_text">
6835
6836<h5>Syntax:</h5>
6837<pre>
6838 declare void @llvm.trap()
6839</pre>
6840
6841<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6842<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6843
6844<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6845<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6846
6847<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6848<p>This intrinsics is lowered to the target dependent trap instruction. If the
6849 target does not have a trap instruction, this intrinsic will be lowered to
6850 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6851
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6852</div>
6853
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6854<!-- _______________________________________________________________________ -->
6855<div class="doc_subsubsection">
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]6856 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6857</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6858
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6859<div class="doc_text">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6860
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6861<h5>Syntax:</h5>
6862<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6863 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6864</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6865
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6866<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6867<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
6868 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
6869 ensure that it is placed on the stack before local variables.</p>
6870
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6871<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6872<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
6873 arguments. The first argument is the value loaded from the stack
6874 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
6875 that has enough space to hold the value of the guard.</p>
6876
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6877<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6878<p>This intrinsic causes the prologue/epilogue inserter to force the position of
6879 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6880 stack. This is to ensure that if a local variable on the stack is
6881 overwritten, it will destroy the value of the guard. When the function exits,
6882 the guard on the stack is checked against the original guard. If they're
6883 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
6884 function.</p>
6885
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6886</div>
6887
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6888<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6889<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6890<address>
6891 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]6892 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6893 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]6894 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6895
6896 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]6897 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6898 Last modified: $Date$
6899</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]6900
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6901</body>
6902</html>