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gerrit-public.fairphone.software / toolchain / llvm-project / 08aa90643e8c14cb603a54e80d8e19f93fe7ef0d / . / 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>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a></li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]24 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]25 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]26 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]27 <li><a href="#functionstructure">Functions</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]28 <li><a href="#aliasstructure">Aliases</a></li>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]29 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]30 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]31 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]32 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]33 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]34 </ol>
35 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]36 <li><a href="#typesystem">Type System</a>
37 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]38 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]39 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]40 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]41 <li><a href="#t_floating">Floating Point Types</a></li>
42 <li><a href="#t_void">Void Type</a></li>
43 <li><a href="#t_label">Label Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]44 </ol>
45 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]46 <li><a href="#t_derived">Derived Types</a>
47 <ol>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]48 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]49 <li><a href="#t_array">Array Type</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]50 <li><a href="#t_function">Function Type</a></li>
51 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]52 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]53 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]54 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]55 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]56 </ol>
57 </li>
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]58 <li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]59 </ol>
60 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]61 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]62 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]63 <li><a href="#simpleconstants">Simple Constants</a></li>
64 <li><a href="#aggregateconstants">Aggregate Constants</a></li>
65 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
66 <li><a href="#undefvalues">Undefined Values</a></li>
67 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]68 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]69 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]70 <li><a href="#othervalues">Other Values</a>
71 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]72 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]73 </ol>
74 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]75 <li><a href="#instref">Instruction Reference</a>
76 <ol>
77 <li><a href="#terminators">Terminator Instructions</a>
78 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]79 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
80 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]81 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
82 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]83 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]84 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]85 </ol>
86 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]87 <li><a href="#binaryops">Binary Operations</a>
88 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]89 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
90 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
91 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]92 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
93 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
94 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]95 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
96 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
97 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]98 </ol>
99 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]100 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
101 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]102 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
103 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
104 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]105 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]106 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]107 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]108 </ol>
109 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]110 <li><a href="#vectorops">Vector Operations</a>
111 <ol>
112 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
113 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
114 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]115 </ol>
116 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]117 <li><a href="#aggregateops">Aggregate Operations</a>
118 <ol>
119 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
120 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
121 </ol>
122 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]123 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]124 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]125 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
126 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
127 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]128 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
129 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
130 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]131 </ol>
132 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]133 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]134 <ol>
135 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
136 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
137 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
138 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
139 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]140 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
141 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
142 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
143 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]144 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
145 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]146 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]147 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]148 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]149 <li><a href="#otherops">Other Operations</a>
150 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]151 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
152 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]153 <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
154 <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]155 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]156 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]157 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]158 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]159 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]160 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]161 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]162 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]163 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]164 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]165 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
166 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]167 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
168 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
169 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]170 </ol>
171 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]172 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
173 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]174 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
175 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
176 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]177 </ol>
178 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]179 <li><a href="#int_codegen">Code Generator Intrinsics</a>
180 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]181 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
182 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
183 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
184 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
185 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
186 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
187 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]188 </ol>
189 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]190 <li><a href="#int_libc">Standard C Library Intrinsics</a>
191 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]192 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
193 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
194 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
195 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
196 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]197 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
198 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
199 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]200 </ol>
201 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]202 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]203 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]204 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]205 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
206 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
207 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]208 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
209 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]210 </ol>
211 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]212 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]213 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]214 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]215 <ol>
216 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]217 </ol>
218 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]219 <li><a href="#int_atomics">Atomic intrinsics</a>
220 <ol>
221 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
222 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
223 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
224 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
225 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
226 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
227 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
228 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
229 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
230 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
231 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
232 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
233 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
234 </ol>
235 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]236 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]237 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]238 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]239 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]240 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]241 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]242 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]243 '<tt>llvm.trap</tt>' Intrinsic</a></li>
244 <li><a href="#int_stackprotector">
245 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]246 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]247 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]248 </ol>
249 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]250</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]251
252<div class="doc_author">
253 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
254 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]255</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]256
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]257<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]258<div class="doc_section"> <a name="abstract">Abstract </a></div>
259<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]260
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]261<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]262<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling6e03f9a2008-08-05 22:29:16 +0000[diff] [blame]263LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]264type safety, low-level operations, flexibility, and the capability of
265representing 'all' high-level languages cleanly. It is the common code
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]266representation used throughout all phases of the LLVM compilation
267strategy.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]268</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]269
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]270<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]271<div class="doc_section"> <a name="introduction">Introduction</a> </div>
272<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]273
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]274<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]275
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]276<p>The LLVM code representation is designed to be used in three
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]277different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]278representation (suitable for fast loading by a Just-In-Time compiler),
279and as a human readable assembly language representation. This allows
280LLVM to provide a powerful intermediate representation for efficient
281compiler transformations and analysis, while providing a natural means
282to debug and visualize the transformations. The three different forms
283of LLVM are all equivalent. This document describes the human readable
284representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]285
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]286<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]287while being expressive, typed, and extensible at the same time. It
288aims to be a "universal IR" of sorts, by being at a low enough level
289that high-level ideas may be cleanly mapped to it (similar to how
290microprocessors are "universal IR's", allowing many source languages to
291be mapped to them). By providing type information, LLVM can be used as
292the target of optimizations: for example, through pointer analysis, it
293can be proven that a C automatic variable is never accessed outside of
294the current function... allowing it to be promoted to a simple SSA
295value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]296
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]297</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]298
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]299<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]300<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]301
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]302<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]303
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]304<p>It is important to note that this document describes 'well formed'
305LLVM assembly language. There is a difference between what the parser
306accepts and what is considered 'well formed'. For example, the
307following instruction is syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]308
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]309<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]310<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]311%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]312</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]313</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]314
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]315<p>...because the definition of <tt>%x</tt> does not dominate all of
316its uses. The LLVM infrastructure provides a verification pass that may
317be used to verify that an LLVM module is well formed. This pass is
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]318automatically run by the parser after parsing input assembly and by
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]319the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]320by the verifier pass indicate bugs in transformation passes or input to
321the parser.</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]322</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]323
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]324<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]325
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]326<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]327<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]328<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]329
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]330<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]331
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]332 <p>LLVM identifiers come in two basic types: global and local. Global
333 identifiers (functions, global variables) begin with the @ character. Local
334 identifiers (register names, types) begin with the % character. Additionally,
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]335 there are three different formats for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]336
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]337<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]338 <li>Named values are represented as a string of characters with their prefix.
339 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
340 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]341 Identifiers which require other characters in their names can be surrounded
Daniel Dunbar0f8155a2008-10-14 23:51:43 +0000[diff] [blame]342 with quotes. Special characters may be escaped using "\xx" where xx is the
343 ASCII code for the character in hexadecimal. In this way, any character can
344 be used in a name value, even quotes themselves.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]345
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]346 <li>Unnamed values are represented as an unsigned numeric value with their
347 prefix. For example, %12, @2, %44.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]348
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]349 <li>Constants, which are described in a <a href="#constants">section about
350 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]351</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]352
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]353<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]354don't need to worry about name clashes with reserved words, and the set of
355reserved words may be expanded in the future without penalty. Additionally,
356unnamed identifiers allow a compiler to quickly come up with a temporary
357variable without having to avoid symbol table conflicts.</p>
358
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]359<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]360languages. There are keywords for different opcodes
361('<tt><a href="#i_add">add</a></tt>',
362 '<tt><a href="#i_bitcast">bitcast</a></tt>',
363 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]364href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]365and others. These reserved words cannot conflict with variable names, because
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]366none of them start with a prefix character ('%' or '@').</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]367
368<p>Here is an example of LLVM code to multiply the integer variable
369'<tt>%X</tt>' by 8:</p>
370
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]371<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]372
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]373<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]374<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]375%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]376</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]377</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]378
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]379<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]380
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]381<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]382<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]383%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]384</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]385</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]386
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]387<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]388
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]389<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]390<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]391<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
392<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
393%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]394</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]395</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]396
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]397<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
398important lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]399
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]400<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]401
402 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
403 line.</li>
404
405 <li>Unnamed temporaries are created when the result of a computation is not
406 assigned to a named value.</li>
407
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]408 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]409
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]410</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]411
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]412<p>...and it also shows a convention that we follow in this document. When
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]413demonstrating instructions, we will follow an instruction with a comment that
414defines the type and name of value produced. Comments are shown in italic
415text.</p>
416
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]417</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]418
419<!-- *********************************************************************** -->
420<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
421<!-- *********************************************************************** -->
422
423<!-- ======================================================================= -->
424<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
425</div>
426
427<div class="doc_text">
428
429<p>LLVM programs are composed of "Module"s, each of which is a
430translation unit of the input programs. Each module consists of
431functions, global variables, and symbol table entries. Modules may be
432combined together with the LLVM linker, which merges function (and
433global variable) definitions, resolves forward declarations, and merges
434symbol table entries. Here is an example of the "hello world" module:</p>
435
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]436<div class="doc_code">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]437<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]438<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
439 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]440
441<i>; External declaration of the puts function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]442<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]443
444<i>; Definition of main function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]445define i32 @main() { <i>; i32()* </i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]446 <i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]447 %cast210 = <a
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]448 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]449
450 <i>; Call puts function to write out the string to stdout...</i>
451 <a
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]452 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]453 <a
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]454 href="#i_ret">ret</a> i32 0<br>}<br>
455</pre>
456</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]457
458<p>This example is made up of a <a href="#globalvars">global variable</a>
459named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
460function, and a <a href="#functionstructure">function definition</a>
461for "<tt>main</tt>".</p>
462
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]463<p>In general, a module is made up of a list of global values,
464where both functions and global variables are global values. Global values are
465represented by a pointer to a memory location (in this case, a pointer to an
466array of char, and a pointer to a function), and have one of the following <a
467href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]468
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]469</div>
470
471<!-- ======================================================================= -->
472<div class="doc_subsection">
473 <a name="linkage">Linkage Types</a>
474</div>
475
476<div class="doc_text">
477
478<p>
479All Global Variables and Functions have one of the following types of linkage:
480</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]481
482<dl>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]483
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]484 <dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
485
486 <dd>Global values with private linkage are only directly accessible by
487 objects in the current module. In particular, linking code into a module with
488 an private global value may cause the private to be renamed as necessary to
489 avoid collisions. Because the symbol is private to the module, all
490 references can be updated. This doesn't show up in any symbol table in the
491 object file.
492 </dd>
493
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]494 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]495
Duncan Sands35e43c12009-01-16 09:29:46 +0000[diff] [blame]496 <dd> Similar to private, but the value shows as a local symbol (STB_LOCAL in
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]497 the case of ELF) in the object file. This corresponds to the notion of the
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]498 '<tt>static</tt>' keyword in C.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]499 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]500
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]501 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]502
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]503 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
504 the same name when linkage occurs. This is typically used to implement
505 inline functions, templates, or other code which must be generated in each
506 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
507 allowed to be discarded.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]508 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]509
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]510 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
511
512 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
513 linkage, except that unreferenced <tt>common</tt> globals may not be
514 discarded. This is used for globals that may be emitted in multiple
515 translation units, but that are not guaranteed to be emitted into every
516 translation unit that uses them. One example of this is tentative
517 definitions in C, such as "<tt>int X;</tt>" at global scope.
518 </dd>
519
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]520 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]521
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]522 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
523 that some targets may choose to emit different assembly sequences for them
524 for target-dependent reasons. This is used for globals that are declared
525 "weak" in C source code.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]526 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]527
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]528 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]529
530 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
531 pointer to array type. When two global variables with appending linkage are
532 linked together, the two global arrays are appended together. This is the
533 LLVM, typesafe, equivalent of having the system linker append together
534 "sections" with identical names when .o files are linked.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]535 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]536
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]537 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]538 <dd>The semantics of this linkage follow the ELF object file model: the
539 symbol is weak until linked, if not linked, the symbol becomes null instead
540 of being an undefined reference.
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]541 </dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]542
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]543 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]544
545 <dd>If none of the above identifiers are used, the global is externally
546 visible, meaning that it participates in linkage and can be used to resolve
547 external symbol references.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]548 </dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]549</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]550
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]551 <p>
552 The next two types of linkage are targeted for Microsoft Windows platform
553 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]554 DLLs (Dynamic Link Libraries).
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]555 </p>
556
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]557 <dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]558 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
559
560 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
561 or variable via a global pointer to a pointer that is set up by the DLL
562 exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman33a9cef2009-01-12 21:35:55 +0000[diff] [blame]563 formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]564 </dd>
565
566 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
567
568 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
569 pointer to a pointer in a DLL, so that it can be referenced with the
570 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman33a9cef2009-01-12 21:35:55 +0000[diff] [blame]571 name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]572 name.
573 </dd>
574
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]575</dl>
576
Dan Gohman8ef44982008-11-24 17:18:39 +0000[diff] [blame]577<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]578variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
579variable and was linked with this one, one of the two would be renamed,
580preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
581external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer92c671e2007-01-05 00:59:10 +0000[diff] [blame]582outside of the current module.</p>
583<p>It is illegal for a function <i>declaration</i>
584to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]585or <tt>extern_weak</tt>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]586<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]587linkages.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]588</div>
589
590<!-- ======================================================================= -->
591<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]592 <a name="callingconv">Calling Conventions</a>
593</div>
594
595<div class="doc_text">
596
597<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
598and <a href="#i_invoke">invokes</a> can all have an optional calling convention
599specified for the call. The calling convention of any pair of dynamic
600caller/callee must match, or the behavior of the program is undefined. The
601following calling conventions are supported by LLVM, and more may be added in
602the future:</p>
603
604<dl>
605 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
606
607 <dd>This calling convention (the default if no other calling convention is
608 specified) matches the target C calling conventions. This calling convention
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]609 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer72ba4992006-12-31 21:30:18 +0000[diff] [blame]610 prototype and implemented declaration of the function (as does normal C).
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]611 </dd>
612
613 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
614
615 <dd>This calling convention attempts to make calls as fast as possible
616 (e.g. by passing things in registers). This calling convention allows the
617 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]618 without having to conform to an externally specified ABI (Application Binary
619 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer2c6b8882008-05-14 09:17:12 +0000[diff] [blame]620 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
621 supported. This calling convention does not support varargs and requires the
622 prototype of all callees to exactly match the prototype of the function
623 definition.
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]624 </dd>
625
626 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
627
628 <dd>This calling convention attempts to make code in the caller as efficient
629 as possible under the assumption that the call is not commonly executed. As
630 such, these calls often preserve all registers so that the call does not break
631 any live ranges in the caller side. This calling convention does not support
632 varargs and requires the prototype of all callees to exactly match the
633 prototype of the function definition.
634 </dd>
635
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]636 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]637
638 <dd>Any calling convention may be specified by number, allowing
639 target-specific calling conventions to be used. Target specific calling
640 conventions start at 64.
641 </dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]642</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]643
644<p>More calling conventions can be added/defined on an as-needed basis, to
645support pascal conventions or any other well-known target-independent
646convention.</p>
647
648</div>
649
650<!-- ======================================================================= -->
651<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]652 <a name="visibility">Visibility Styles</a>
653</div>
654
655<div class="doc_text">
656
657<p>
658All Global Variables and Functions have one of the following visibility styles:
659</p>
660
661<dl>
662 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
663
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]664 <dd>On targets that use the ELF object file format, default visibility means
665 that the declaration is visible to other
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]666 modules and, in shared libraries, means that the declared entity may be
667 overridden. On Darwin, default visibility means that the declaration is
668 visible to other modules. Default visibility corresponds to "external
669 linkage" in the language.
670 </dd>
671
672 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
673
674 <dd>Two declarations of an object with hidden visibility refer to the same
675 object if they are in the same shared object. Usually, hidden visibility
676 indicates that the symbol will not be placed into the dynamic symbol table,
677 so no other module (executable or shared library) can reference it
678 directly.
679 </dd>
680
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]681 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
682
683 <dd>On ELF, protected visibility indicates that the symbol will be placed in
684 the dynamic symbol table, but that references within the defining module will
685 bind to the local symbol. That is, the symbol cannot be overridden by another
686 module.
687 </dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]688</dl>
689
690</div>
691
692<!-- ======================================================================= -->
693<div class="doc_subsection">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]694 <a name="namedtypes">Named Types</a>
695</div>
696
697<div class="doc_text">
698
699<p>LLVM IR allows you to specify name aliases for certain types. This can make
700it easier to read the IR and make the IR more condensed (particularly when
701recursive types are involved). An example of a name specification is:
702</p>
703
704<div class="doc_code">
705<pre>
706%mytype = type { %mytype*, i32 }
707</pre>
708</div>
709
710<p>You may give a name to any <a href="#typesystem">type</a> except "<a
711href="t_void">void</a>". Type name aliases may be used anywhere a type is
712expected with the syntax "%mytype".</p>
713
714<p>Note that type names are aliases for the structural type that they indicate,
715and that you can therefore specify multiple names for the same type. This often
716leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
717structural typing, the name is not part of the type. When printing out LLVM IR,
718the printer will pick <em>one name</em> to render all types of a particular
719shape. This means that if you have code where two different source types end up
720having the same LLVM type, that the dumper will sometimes print the "wrong" or
721unexpected type. This is an important design point and isn't going to
722change.</p>
723
724</div>
725
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]726<!-- ======================================================================= -->
727<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]728 <a name="globalvars">Global Variables</a>
729</div>
730
731<div class="doc_text">
732
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]733<p>Global variables define regions of memory allocated at compilation time
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]734instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]735an explicit section to be placed in, and may have an optional explicit alignment
736specified. A variable may be defined as "thread_local", which means that it
737will not be shared by threads (each thread will have a separated copy of the
738variable). A variable may be defined as a global "constant," which indicates
739that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]740optimization, allowing the global data to be placed in the read-only section of
741an executable, etc). Note that variables that need runtime initialization
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]742cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]743
744<p>
745LLVM explicitly allows <em>declarations</em> of global variables to be marked
746constant, even if the final definition of the global is not. This capability
747can be used to enable slightly better optimization of the program, but requires
748the language definition to guarantee that optimizations based on the
749'constantness' are valid for the translation units that do not include the
750definition.
751</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]752
753<p>As SSA values, global variables define pointer values that are in
754scope (i.e. they dominate) all basic blocks in the program. Global
755variables always define a pointer to their "content" type because they
756describe a region of memory, and all memory objects in LLVM are
757accessed through pointers.</p>
758
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]759<p>A global variable may be declared to reside in a target-specifc numbered
760address space. For targets that support them, address spaces may affect how
761optimizations are performed and/or what target instructions are used to access
Christopher Lamb25f50762007-12-12 08:44:39 +0000[diff] [blame]762the variable. The default address space is zero. The address space qualifier
763must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]764
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]765<p>LLVM allows an explicit section to be specified for globals. If the target
766supports it, it will emit globals to the section specified.</p>
767
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]768<p>An explicit alignment may be specified for a global. If not present, or if
769the alignment is set to zero, the alignment of the global is set by the target
770to whatever it feels convenient. If an explicit alignment is specified, the
771global is forced to have at least that much alignment. All alignments must be
772a power of 2.</p>
773
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]774<p>For example, the following defines a global in a numbered address space with
775an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]776
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]777<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]778<pre>
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]779@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]780</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]781</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]782
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]783</div>
784
785
786<!-- ======================================================================= -->
787<div class="doc_subsection">
788 <a name="functionstructure">Functions</a>
789</div>
790
791<div class="doc_text">
792
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]793<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
794an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]795<a href="#visibility">visibility style</a>, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]796<a href="#callingconv">calling convention</a>, a return type, an optional
797<a href="#paramattrs">parameter attribute</a> for the return type, a function
798name, a (possibly empty) argument list (each with optional
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]799<a href="#paramattrs">parameter attributes</a>), optional
800<a href="#fnattrs">function attributes</a>, an optional section,
801an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattnercbc4d2a2008-10-04 18:10:21 +0000[diff] [blame]802an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]803
804LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
805optional <a href="#linkage">linkage type</a>, an optional
806<a href="#visibility">visibility style</a>, an optional
807<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]808<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]809name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksendc5cafb2007-12-10 03:30:21 +0000[diff] [blame]810<a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]811
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]812<p>A function definition contains a list of basic blocks, forming the CFG
813(Control Flow Graph) for
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]814the function. Each basic block may optionally start with a label (giving the
815basic block a symbol table entry), contains a list of instructions, and ends
816with a <a href="#terminators">terminator</a> instruction (such as a branch or
817function return).</p>
818
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]819<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]820executed on entrance to the function, and it is not allowed to have predecessor
821basic blocks (i.e. there can not be any branches to the entry block of a
822function). Because the block can have no predecessors, it also cannot have any
823<a href="#i_phi">PHI nodes</a>.</p>
824
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]825<p>LLVM allows an explicit section to be specified for functions. If the target
826supports it, it will emit functions to the section specified.</p>
827
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]828<p>An explicit alignment may be specified for a function. If not present, or if
829the alignment is set to zero, the alignment of the function is set by the target
830to whatever it feels convenient. If an explicit alignment is specified, the
831function is forced to have at least that much alignment. All alignments must be
832a power of 2.</p>
833
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]834 <h5>Syntax:</h5>
835
836<div class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]837<tt>
838define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
839 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
840 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
841 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
842 [<a href="#gc">gc</a>] { ... }
843</tt>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]844</div>
845
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]846</div>
847
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]848
849<!-- ======================================================================= -->
850<div class="doc_subsection">
851 <a name="aliasstructure">Aliases</a>
852</div>
853<div class="doc_text">
854 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov25b2e822008-03-22 08:36:14 +0000[diff] [blame]855 function, global variable, another alias or bitcast of global value). Aliases
856 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]857 optional <a href="#visibility">visibility style</a>.</p>
858
859 <h5>Syntax:</h5>
860
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]861<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]862<pre>
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]863@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]864</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]865</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]866
867</div>
868
869
870
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]871<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]872<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
873<div class="doc_text">
874 <p>The return type and each parameter of a function type may have a set of
875 <i>parameter attributes</i> associated with them. Parameter attributes are
876 used to communicate additional information about the result or parameters of
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]877 a function. Parameter attributes are considered to be part of the function,
878 not of the function type, so functions with different parameter attributes
879 can have the same function type.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]880
Reid Spencercf7ebf52007-01-15 18:27:39 +0000[diff] [blame]881 <p>Parameter attributes are simple keywords that follow the type specified. If
882 multiple parameter attributes are needed, they are space separated. For
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]883 example:</p>
884
885<div class="doc_code">
886<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]887declare i32 @printf(i8* noalias , ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]888declare i32 @atoi(i8 zeroext)
889declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]890</pre>
891</div>
892
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]893 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
894 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]895
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]896 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]897 <dl>
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]898 <dt><tt>zeroext</tt></dt>
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]899 <dd>This indicates to the code generator that the parameter or return value
900 should be zero-extended to a 32-bit value by the caller (for a parameter)
901 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]902
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]903 <dt><tt>signext</tt></dt>
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]904 <dd>This indicates to the code generator that the parameter or return value
905 should be sign-extended to a 32-bit value by the caller (for a parameter)
906 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]907
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]908 <dt><tt>inreg</tt></dt>
Dale Johannesenc50ada22008-09-25 20:47:45 +0000[diff] [blame]909 <dd>This indicates that this parameter or return value should be treated
910 in a special target-dependent fashion during while emitting code for a
911 function call or return (usually, by putting it in a register as opposed
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]912 to memory, though some targets use it to distinguish between two different
913 kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]914
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]915 <dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner352ab9b2008-01-15 04:34:22 +0000[diff] [blame]916 <dd>This indicates that the pointer parameter should really be passed by
917 value to the function. The attribute implies that a hidden copy of the
918 pointee is made between the caller and the callee, so the callee is unable
Chris Lattner1ca5c642008-08-05 18:21:08 +0000[diff] [blame]919 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner352ab9b2008-01-15 04:34:22 +0000[diff] [blame]920 pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]921 value, but is also valid on pointers to scalars. The copy is considered to
922 belong to the caller not the callee (for example,
923 <tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]924 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattner08aa9062009-02-05 05:42:28 +0000[diff] [blame^]925 values. The byval attribute also supports specifying an alignment with the
926 align attribute. This has a target-specific effect on the code generator
927 that usually indicates a desired alignment for the synthesized stack
928 slot.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]929
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]930 <dt><tt>sret</tt></dt>
Duncan Sandsfa4b6732008-02-18 04:19:38 +0000[diff] [blame]931 <dd>This indicates that the pointer parameter specifies the address of a
932 structure that is the return value of the function in the source program.
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]933 This pointer must be guaranteed by the caller to be valid: loads and stores
934 to the structure may be assumed by the callee to not to trap. This may only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]935 be applied to the first parameter. This is not a valid attribute for
936 return values. </dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]937
Zhou Sheng2444a9a2007-06-05 05:28:26 +0000[diff] [blame]938 <dt><tt>noalias</tt></dt>
Nick Lewyckyf5ffcbc2008-11-24 03:41:24 +0000[diff] [blame]939 <dd>This indicates that the pointer does not alias any global or any other
940 parameter. The caller is responsible for ensuring that this is the
Nick Lewyckyd59572c2008-11-24 05:00:44 +0000[diff] [blame]941 case. On a function return value, <tt>noalias</tt> additionally indicates
942 that the pointer does not alias any other pointers visible to the
Nick Lewycky2abb1082008-12-19 06:39:12 +0000[diff] [blame]943 caller. For further details, please see the discussion of the NoAlias
944 response in
945 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
946 analysis</a>.</dd>
947
948 <dt><tt>nocapture</tt></dt>
949 <dd>This indicates that the callee does not make any copies of the pointer
950 that outlive the callee itself. This is not a valid attribute for return
951 values.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]952
Duncan Sands27e91592007-07-27 19:57:41 +0000[diff] [blame]953 <dt><tt>nest</tt></dt>
Duncan Sands825bde42008-07-08 09:27:25 +0000[diff] [blame]954 <dd>This indicates that the pointer parameter can be excised using the
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]955 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
956 attribute for return values.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]957 </dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]958
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]959</div>
960
961<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]962<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]963 <a name="gc">Garbage Collector Names</a>
964</div>
965
966<div class="doc_text">
967<p>Each function may specify a garbage collector name, which is simply a
968string.</p>
969
970<div class="doc_code"><pre
971>define void @f() gc "name" { ...</pre></div>
972
973<p>The compiler declares the supported values of <i>name</i>. Specifying a
974collector which will cause the compiler to alter its output in order to support
975the named garbage collection algorithm.</p>
976</div>
977
978<!-- ======================================================================= -->
979<div class="doc_subsection">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]980 <a name="fnattrs">Function Attributes</a>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]981</div>
982
983<div class="doc_text">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]984
985<p>Function attributes are set to communicate additional information about
986 a function. Function attributes are considered to be part of the function,
987 not of the function type, so functions with different parameter attributes
988 can have the same function type.</p>
989
990 <p>Function attributes are simple keywords that follow the type specified. If
991 multiple attributes are needed, they are space separated. For
992 example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]993
994<div class="doc_code">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]995<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]996define void @f() noinline { ... }
997define void @f() alwaysinline { ... }
998define void @f() alwaysinline optsize { ... }
999define void @f() optsize
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1000</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1001</div>
1002
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1003<dl>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1004<dt><tt>alwaysinline</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1005<dd>This attribute indicates that the inliner should attempt to inline this
1006function into callers whenever possible, ignoring any active inlining size
1007threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1008
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1009<dt><tt>noinline</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1010<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner0625c282008-10-05 17:14:59 +0000[diff] [blame]1011in any situation. This attribute may not be used together with the
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1012<tt>alwaysinline</tt> attribute.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1013
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1014<dt><tt>optsize</tt></dt>
Devang Patele9743902008-09-29 18:34:44 +0000[diff] [blame]1015<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1016make choices that keep the code size of this function low, and otherwise do
1017optimizations specifically to reduce code size.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1018
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1019<dt><tt>noreturn</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1020<dd>This function attribute indicates that the function never returns normally.
1021This produces undefined behavior at runtime if the function ever does
1022dynamically return.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1023
1024<dt><tt>nounwind</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1025<dd>This function attribute indicates that the function never returns with an
1026unwind or exceptional control flow. If the function does unwind, its runtime
1027behavior is undefined.</dd>
1028
1029<dt><tt>readnone</tt></dt>
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]1030<dd>This attribute indicates that the function computes its result (or the
1031exception it throws) based strictly on its arguments, without dereferencing any
1032pointer arguments or otherwise accessing any mutable state (e.g. memory, control
1033registers, etc) visible to caller functions. It does not write through any
1034pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
1035never changes any state visible to callers.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1036
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]1037<dt><tt><a name="readonly">readonly</a></tt></dt>
1038<dd>This attribute indicates that the function does not write through any
1039pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
1040or otherwise modify any state (e.g. memory, control registers, etc) visible to
1041caller functions. It may dereference pointer arguments and read state that may
1042be set in the caller. A readonly function always returns the same value (or
1043throws the same exception) when called with the same set of arguments and global
1044state.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1045
1046<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1047<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1048protector. It is in the form of a "canary"&mdash;a random value placed on the
1049stack before the local variables that's checked upon return from the function to
1050see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1051needs stack protectors or not.
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1052
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1053<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
1054that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
1055have an <tt>ssp</tt> attribute.</p></dd>
1056
1057<dt><tt>sspreq</tt></dt>
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1058<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1059stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1060function attribute.
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1061
1062<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
1063function that doesn't have an <tt>sspreq</tt> attribute or which has
1064an <tt>ssp</tt> attribute, then the resulting function will have
1065an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1066</dl>
1067
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1068</div>
1069
1070<!-- ======================================================================= -->
1071<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1072 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1073</div>
1074
1075<div class="doc_text">
1076<p>
1077Modules may contain "module-level inline asm" blocks, which corresponds to the
1078GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1079LLVM and treated as a single unit, but may be separated in the .ll file if
1080desired. The syntax is very simple:
1081</p>
1082
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1083<div class="doc_code">
1084<pre>
1085module asm "inline asm code goes here"
1086module asm "more can go here"
1087</pre>
1088</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1089
1090<p>The strings can contain any character by escaping non-printable characters.
1091 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1092 for the number.
1093</p>
1094
1095<p>
1096 The inline asm code is simply printed to the machine code .s file when
1097 assembly code is generated.
1098</p>
1099</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1100
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1101<!-- ======================================================================= -->
1102<div class="doc_subsection">
1103 <a name="datalayout">Data Layout</a>
1104</div>
1105
1106<div class="doc_text">
1107<p>A module may specify a target specific data layout string that specifies how
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]1108data is to be laid out in memory. The syntax for the data layout is simply:</p>
1109<pre> target datalayout = "<i>layout specification</i>"</pre>
1110<p>The <i>layout specification</i> consists of a list of specifications
1111separated by the minus sign character ('-'). Each specification starts with a
1112letter and may include other information after the letter to define some
1113aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1114<dl>
1115 <dt><tt>E</tt></dt>
1116 <dd>Specifies that the target lays out data in big-endian form. That is, the
1117 bits with the most significance have the lowest address location.</dd>
1118 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1119 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1120 the bits with the least significance have the lowest address location.</dd>
1121 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1122 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1123 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1124 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1125 too.</dd>
1126 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1127 <dd>This specifies the alignment for an integer type of a given bit
1128 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1129 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1130 <dd>This specifies the alignment for a vector type of a given bit
1131 <i>size</i>.</dd>
1132 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1133 <dd>This specifies the alignment for a floating point type of a given bit
1134 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1135 (double).</dd>
1136 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1137 <dd>This specifies the alignment for an aggregate type of a given bit
1138 <i>size</i>.</dd>
1139</dl>
1140<p>When constructing the data layout for a given target, LLVM starts with a
1141default set of specifications which are then (possibly) overriden by the
1142specifications in the <tt>datalayout</tt> keyword. The default specifications
1143are given in this list:</p>
1144<ul>
1145 <li><tt>E</tt> - big endian</li>
1146 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1147 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1148 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1149 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1150 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1151 <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]1152 alignment of 64-bits</li>
1153 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1154 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1155 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1156 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1157 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1158</ul>
Chris Lattner1ca5c642008-08-05 18:21:08 +0000[diff] [blame]1159<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1160following rules:</p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1161<ol>
1162 <li>If the type sought is an exact match for one of the specifications, that
1163 specification is used.</li>
1164 <li>If no match is found, and the type sought is an integer type, then the
1165 smallest integer type that is larger than the bitwidth of the sought type is
1166 used. If none of the specifications are larger than the bitwidth then the the
1167 largest integer type is used. For example, given the default specifications
1168 above, the i7 type will use the alignment of i8 (next largest) while both
1169 i65 and i256 will use the alignment of i64 (largest specified).</li>
1170 <li>If no match is found, and the type sought is a vector type, then the
1171 largest vector type that is smaller than the sought vector type will be used
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1172 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1173 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1174</ol>
1175</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1176
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1177<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1178<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1179<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1180
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1181<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1182
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1183<p>The LLVM type system is one of the most important features of the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1184intermediate representation. Being typed enables a number of
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1185optimizations to be performed on the intermediate representation directly,
1186without having to do
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1187extra analyses on the side before the transformation. A strong type
1188system makes it easier to read the generated code and enables novel
1189analyses and transformations that are not feasible to perform on normal
1190three address code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1191
1192</div>
1193
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1194<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1195<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1196Classifications</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1197<div class="doc_text">
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1198<p>The types fall into a few useful
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1199classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1200
1201<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1202 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1203 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1204 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1205 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1206 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1207 </tr>
1208 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1209 <td><a href="#t_floating">floating point</a></td>
1210 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1211 </tr>
1212 <tr>
1213 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1214 <td><a href="#t_integer">integer</a>,
1215 <a href="#t_floating">floating point</a>,
1216 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1217 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1218 <a href="#t_struct">structure</a>,
1219 <a href="#t_array">array</a>,
Dan Gohmanda52d212008-05-23 22:50:26 +0000[diff] [blame]1220 <a href="#t_label">label</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1221 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1222 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1223 <tr>
1224 <td><a href="#t_primitive">primitive</a></td>
1225 <td><a href="#t_label">label</a>,
1226 <a href="#t_void">void</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1227 <a href="#t_floating">floating point</a>.</td>
1228 </tr>
1229 <tr>
1230 <td><a href="#t_derived">derived</a></td>
1231 <td><a href="#t_integer">integer</a>,
1232 <a href="#t_array">array</a>,
1233 <a href="#t_function">function</a>,
1234 <a href="#t_pointer">pointer</a>,
1235 <a href="#t_struct">structure</a>,
1236 <a href="#t_pstruct">packed structure</a>,
1237 <a href="#t_vector">vector</a>,
1238 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1239 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1240 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1241 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1242</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1243
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1244<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1245most important. Values of these types are the only ones which can be
1246produced by instructions, passed as arguments, or used as operands to
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]1247instructions.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1248</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1249
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1250<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1251<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1252
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1253<div class="doc_text">
1254<p>The primitive types are the fundamental building blocks of the LLVM
1255system.</p>
1256
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1257</div>
1258
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1259<!-- _______________________________________________________________________ -->
1260<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1261
1262<div class="doc_text">
1263 <table>
1264 <tbody>
1265 <tr><th>Type</th><th>Description</th></tr>
1266 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1267 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1268 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1269 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1270 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1271 </tbody>
1272 </table>
1273</div>
1274
1275<!-- _______________________________________________________________________ -->
1276<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1277
1278<div class="doc_text">
1279<h5>Overview:</h5>
1280<p>The void type does not represent any value and has no size.</p>
1281
1282<h5>Syntax:</h5>
1283
1284<pre>
1285 void
1286</pre>
1287</div>
1288
1289<!-- _______________________________________________________________________ -->
1290<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1291
1292<div class="doc_text">
1293<h5>Overview:</h5>
1294<p>The label type represents code labels.</p>
1295
1296<h5>Syntax:</h5>
1297
1298<pre>
1299 label
1300</pre>
1301</div>
1302
1303
1304<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1305<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1306
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1307<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1308
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1309<p>The real power in LLVM comes from the derived types in the system.
1310This is what allows a programmer to represent arrays, functions,
1311pointers, and other useful types. Note that these derived types may be
1312recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1313
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1314</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1315
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1316<!-- _______________________________________________________________________ -->
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1317<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1318
1319<div class="doc_text">
1320
1321<h5>Overview:</h5>
1322<p>The integer type is a very simple derived type that simply specifies an
1323arbitrary bit width for the integer type desired. Any bit width from 1 bit to
13242^23-1 (about 8 million) can be specified.</p>
1325
1326<h5>Syntax:</h5>
1327
1328<pre>
1329 iN
1330</pre>
1331
1332<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1333value.</p>
1334
1335<h5>Examples:</h5>
1336<table class="layout">
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1337 <tbody>
1338 <tr>
1339 <td><tt>i1</tt></td>
1340 <td>a single-bit integer.</td>
1341 </tr><tr>
1342 <td><tt>i32</tt></td>
1343 <td>a 32-bit integer.</td>
1344 </tr><tr>
1345 <td><tt>i1942652</tt></td>
1346 <td>a really big integer of over 1 million bits.</td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1347 </tr>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1348 </tbody>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1349</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1350
1351<p>Note that the code generator does not yet support large integer types
1352to be used as function return types. The specific limit on how large a
1353return type the code generator can currently handle is target-dependent;
1354currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
1355targets.</p>
1356
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1357</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1358
1359<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1360<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1361
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1362<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1363
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1364<h5>Overview:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1365
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1366<p>The array type is a very simple derived type that arranges elements
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1367sequentially in memory. The array type requires a size (number of
1368elements) and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1369
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1370<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1371
1372<pre>
1373 [&lt;# elements&gt; x &lt;elementtype&gt;]
1374</pre>
1375
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1376<p>The number of elements is a constant integer value; elementtype may
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1377be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1378
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1379<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1380<table class="layout">
1381 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1382 <td class="left"><tt>[40 x i32]</tt></td>
1383 <td class="left">Array of 40 32-bit integer values.</td>
1384 </tr>
1385 <tr class="layout">
1386 <td class="left"><tt>[41 x i32]</tt></td>
1387 <td class="left">Array of 41 32-bit integer values.</td>
1388 </tr>
1389 <tr class="layout">
1390 <td class="left"><tt>[4 x i8]</tt></td>
1391 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1392 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1393</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1394<p>Here are some examples of multidimensional arrays:</p>
1395<table class="layout">
1396 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1397 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1398 <td class="left">3x4 array of 32-bit integer values.</td>
1399 </tr>
1400 <tr class="layout">
1401 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1402 <td class="left">12x10 array of single precision floating point values.</td>
1403 </tr>
1404 <tr class="layout">
1405 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1406 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1407 </tr>
1408</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1409
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1410<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1411length array. Normally, accesses past the end of an array are undefined in
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1412LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1413As a special case, however, zero length arrays are recognized to be variable
1414length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1415type "{ i32, [0 x float]}", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1416
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1417<p>Note that the code generator does not yet support large aggregate types
1418to be used as function return types. The specific limit on how large an
1419aggregate return type the code generator can currently handle is
1420target-dependent, and also dependent on the aggregate element types.</p>
1421
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1422</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1423
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1424<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1425<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1426<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1427
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1428<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1429
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1430<p>The function type can be thought of as a function signature. It
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1431consists of a return type and a list of formal parameter types. The
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1432return type of a function type is a scalar type, a void type, or a struct type.
Devang Patel9c1f8b12008-03-24 20:52:42 +0000[diff] [blame]1433If the return type is a struct type then all struct elements must be of first
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1434class types, and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1435
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1436<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1437
1438<pre>
1439 &lt;returntype list&gt; (&lt;parameter list&gt;)
1440</pre>
1441
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1442<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Misha Brukman20f9a622004-08-12 20:16:08 +0000[diff] [blame]1443specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1444which indicates that the function takes a variable number of arguments.
1445Variable argument functions can access their arguments with the <a
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1446 href="#int_varargs">variable argument handling intrinsic</a> functions.
1447'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1448<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1449
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1450<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1451<table class="layout">
1452 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1453 <td class="left"><tt>i32 (i32)</tt></td>
1454 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1455 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1456 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]1457 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1458 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1459 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1460 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1461 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1462 <tt>float</tt>.
1463 </td>
1464 </tr><tr class="layout">
1465 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1466 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1467 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1468 which returns an integer. This is the signature for <tt>printf</tt> in
1469 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1470 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1471 </tr><tr class="layout">
1472 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanc9813bd2008-11-27 06:41:20 +0000[diff] [blame]1473 <td class="left">A function taking an <tt>i32</tt>, returning two
1474 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1475 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1476 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1477</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1478
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1479</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1480<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1481<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1482<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1483<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1484<p>The structure type is used to represent a collection of data members
1485together in memory. The packing of the field types is defined to match
1486the ABI of the underlying processor. The elements of a structure may
1487be any type that has a size.</p>
1488<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1489and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1490field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1491instruction.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1492<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1493<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1494<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1495<table class="layout">
1496 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1497 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1498 <td class="left">A triple of three <tt>i32</tt> values</td>
1499 </tr><tr class="layout">
1500 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1501 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1502 second element is a <a href="#t_pointer">pointer</a> to a
1503 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1504 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1505 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1506</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1507
1508<p>Note that the code generator does not yet support large aggregate types
1509to be used as function return types. The specific limit on how large an
1510aggregate return type the code generator can currently handle is
1511target-dependent, and also dependent on the aggregate element types.</p>
1512
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1513</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1514
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1515<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1516<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1517</div>
1518<div class="doc_text">
1519<h5>Overview:</h5>
1520<p>The packed structure type is used to represent a collection of data members
1521together in memory. There is no padding between fields. Further, the alignment
1522of a packed structure is 1 byte. The elements of a packed structure may
1523be any type that has a size.</p>
1524<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1525and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1526field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1527instruction.</p>
1528<h5>Syntax:</h5>
1529<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1530<h5>Examples:</h5>
1531<table class="layout">
1532 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1533 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1534 <td class="left">A triple of three <tt>i32</tt> values</td>
1535 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1536 <td class="left">
1537<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1538 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1539 second element is a <a href="#t_pointer">pointer</a> to a
1540 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1541 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1542 </tr>
1543</table>
1544</div>
1545
1546<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1547<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1548<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1549<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1550<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]1551reference to another object, which must live in memory. Pointer types may have
1552an optional address space attribute defining the target-specific numbered
1553address space where the pointed-to object resides. The default address space is
1554zero.</p>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1555<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1556<pre> &lt;type&gt; *<br></pre>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1557<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1558<table class="layout">
1559 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]1560 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1561 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1562 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1563 </tr>
1564 <tr class="layout">
1565 <td class="left"><tt>i32 (i32 *) *</tt></td>
1566 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1567 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1568 <tt>i32</tt>.</td>
1569 </tr>
1570 <tr class="layout">
1571 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1572 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1573 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1574 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1575</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1576</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1577
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1578<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1579<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1580<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1581
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1582<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1583
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1584<p>A vector type is a simple derived type that represents a vector
1585of elements. Vector types are used when multiple primitive data
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1586are operated in parallel using a single instruction (SIMD).
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1587A vector type requires a size (number of
Chris Lattner330ce692005-11-10 01:44:22 +0000[diff] [blame]1588elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1589of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1590considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1591
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1592<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1593
1594<pre>
1595 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1596</pre>
1597
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1598<p>The number of elements is a constant integer value; elementtype may
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1599be any integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1600
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1601<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1602
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1603<table class="layout">
1604 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1605 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1606 <td class="left">Vector of 4 32-bit integer values.</td>
1607 </tr>
1608 <tr class="layout">
1609 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1610 <td class="left">Vector of 8 32-bit floating-point values.</td>
1611 </tr>
1612 <tr class="layout">
1613 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1614 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1615 </tr>
1616</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1617
1618<p>Note that the code generator does not yet support large vector types
1619to be used as function return types. The specific limit on how large a
1620vector return type codegen can currently handle is target-dependent;
1621currently it's often a few times longer than a hardware vector register.</p>
1622
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1623</div>
1624
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1625<!-- _______________________________________________________________________ -->
1626<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1627<div class="doc_text">
1628
1629<h5>Overview:</h5>
1630
1631<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksena699c4d2007-10-14 00:34:53 +0000[diff] [blame]1632corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1633In LLVM, opaque types can eventually be resolved to any type (not just a
1634structure type).</p>
1635
1636<h5>Syntax:</h5>
1637
1638<pre>
1639 opaque
1640</pre>
1641
1642<h5>Examples:</h5>
1643
1644<table class="layout">
1645 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1646 <td class="left"><tt>opaque</tt></td>
1647 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1648 </tr>
1649</table>
1650</div>
1651
Chris Lattnercf7a5842009-02-02 07:32:36 +0000[diff] [blame]1652<!-- ======================================================================= -->
1653<div class="doc_subsection">
1654 <a name="t_uprefs">Type Up-references</a>
1655</div>
1656
1657<div class="doc_text">
1658<h5>Overview:</h5>
1659<p>
1660An "up reference" allows you to refer to a lexically enclosing type without
1661requiring it to have a name. For instance, a structure declaration may contain a
1662pointer to any of the types it is lexically a member of. Example of up
1663references (with their equivalent as named type declarations) include:</p>
1664
1665<pre>
1666 { \2 * } %x = type { %t* }
1667 { \2 }* %y = type { %y }*
1668 \1* %z = type %z*
1669</pre>
1670
1671<p>
1672An up reference is needed by the asmprinter for printing out cyclic types when
1673there is no declared name for a type in the cycle. Because the asmprinter does
1674not want to print out an infinite type string, it needs a syntax to handle
1675recursive types that have no names (all names are optional in llvm IR).
1676</p>
1677
1678<h5>Syntax:</h5>
1679<pre>
1680 \&lt;level&gt;
1681</pre>
1682
1683<p>
1684The level is the count of the lexical type that is being referred to.
1685</p>
1686
1687<h5>Examples:</h5>
1688
1689<table class="layout">
1690 <tr class="layout">
1691 <td class="left"><tt>\1*</tt></td>
1692 <td class="left">Self-referential pointer.</td>
1693 </tr>
1694 <tr class="layout">
1695 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1696 <td class="left">Recursive structure where the upref refers to the out-most
1697 structure.</td>
1698 </tr>
1699</table>
1700</div>
1701
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1702
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1703<!-- *********************************************************************** -->
1704<div class="doc_section"> <a name="constants">Constants</a> </div>
1705<!-- *********************************************************************** -->
1706
1707<div class="doc_text">
1708
1709<p>LLVM has several different basic types of constants. This section describes
1710them all and their syntax.</p>
1711
1712</div>
1713
1714<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1715<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1716
1717<div class="doc_text">
1718
1719<dl>
1720 <dt><b>Boolean constants</b></dt>
1721
1722 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1723 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1724 </dd>
1725
1726 <dt><b>Integer constants</b></dt>
1727
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1728 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1729 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1730 integer types.
1731 </dd>
1732
1733 <dt><b>Floating point constants</b></dt>
1734
1735 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1736 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]1737 notation (see below). The assembler requires the exact decimal value of
1738 a floating-point constant. For example, the assembler accepts 1.25 but
1739 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1740 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1741
1742 <dt><b>Null pointer constants</b></dt>
1743
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1744 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1745 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1746
1747</dl>
1748
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1749<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1750of floating point constants. For example, the form '<tt>double
17510x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
17524.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1753(and the only time that they are generated by the disassembler) is when a
1754floating point constant must be emitted but it cannot be represented as a
1755decimal floating point number. For example, NaN's, infinities, and other
1756special values are represented in their IEEE hexadecimal format so that
1757assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1758
1759</div>
1760
1761<!-- ======================================================================= -->
1762<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1763</div>
1764
1765<div class="doc_text">
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]1766<p>Aggregate constants arise from aggregation of simple constants
1767and smaller aggregate constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1768
1769<dl>
1770 <dt><b>Structure constants</b></dt>
1771
1772 <dd>Structure constants are represented with notation similar to structure
1773 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattnerbea11172007-12-25 20:34:52 +0000[diff] [blame]1774 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1775 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]1776 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1777 types of elements must match those specified by the type.
1778 </dd>
1779
1780 <dt><b>Array constants</b></dt>
1781
1782 <dd>Array constants are represented with notation similar to array type
1783 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1784 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1785 constants must have <a href="#t_array">array type</a>, and the number and
1786 types of elements must match those specified by the type.
1787 </dd>
1788
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1789 <dt><b>Vector constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1790
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1791 <dd>Vector constants are represented with notation similar to vector type
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1792 definitions (a comma separated list of elements, surrounded by
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1793 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32 42,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1794 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1795 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1796 match those specified by the type.
1797 </dd>
1798
1799 <dt><b>Zero initialization</b></dt>
1800
1801 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1802 value to zero of <em>any</em> type, including scalar and aggregate types.
1803 This is often used to avoid having to print large zero initializers (e.g. for
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1804 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1805 initializers.
1806 </dd>
1807</dl>
1808
1809</div>
1810
1811<!-- ======================================================================= -->
1812<div class="doc_subsection">
1813 <a name="globalconstants">Global Variable and Function Addresses</a>
1814</div>
1815
1816<div class="doc_text">
1817
1818<p>The addresses of <a href="#globalvars">global variables</a> and <a
1819href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1820constants. These constants are explicitly referenced when the <a
1821href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1822href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1823file:</p>
1824
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1825<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1826<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]1827@X = global i32 17
1828@Y = global i32 42
1829@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1830</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1831</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1832
1833</div>
1834
1835<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1836<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1837<div class="doc_text">
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1838 <p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1839 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1840 a constant is permitted.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1841
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1842 <p>Undefined values indicate to the compiler that the program is well defined
1843 no matter what value is used, giving the compiler more freedom to optimize.
1844 </p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1845</div>
1846
1847<!-- ======================================================================= -->
1848<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1849</div>
1850
1851<div class="doc_text">
1852
1853<p>Constant expressions are used to allow expressions involving other constants
1854to be used as constants. Constant expressions may be of any <a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1855href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1856that does not have side effects (e.g. load and call are not supported). The
1857following is the syntax for constant expressions:</p>
1858
1859<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1860 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1861 <dd>Truncate a constant to another type. The bit size of CST must be larger
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1862 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1863
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1864 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1865 <dd>Zero extend a constant to another type. The bit size of CST must be
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1866 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1867
1868 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1869 <dd>Sign extend a constant to another type. The bit size of CST must be
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1870 smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1871
1872 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1873 <dd>Truncate a floating point constant to another floating point type. The
1874 size of CST must be larger than the size of TYPE. Both types must be
1875 floating point.</dd>
1876
1877 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1878 <dd>Floating point extend a constant to another type. The size of CST must be
1879 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1880
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]1881 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1882 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1883 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1884 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1885 of the same number of elements. If the value won't fit in the integer type,
1886 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1887
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1888 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1889 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1890 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1891 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1892 of the same number of elements. If the value won't fit in the integer type,
1893 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1894
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1895 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1896 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1897 constant. TYPE must be a scalar or vector floating point type. CST must be of
1898 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1899 of the same number of elements. If the value won't fit in the floating point
1900 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1901
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1902 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1903 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1904 constant. TYPE must be a scalar or vector floating point type. CST must be of
1905 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1906 of the same number of elements. If the value won't fit in the floating point
1907 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1908
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1909 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1910 <dd>Convert a pointer typed constant to the corresponding integer constant
1911 TYPE must be an integer type. CST must be of pointer type. The CST value is
1912 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1913
1914 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1915 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1916 pointer type. CST must be of integer type. The CST value is zero extended,
1917 truncated, or unchanged to make it fit in a pointer size. This one is
1918 <i>really</i> dangerous!</dd>
1919
1920 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1921 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1922 identical (same number of bits). The conversion is done as if the CST value
1923 was stored to memory and read back as TYPE. In other words, no bits change
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1924 with this operator, just the type. This can be used for conversion of
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1925 vector types to any other type, as long as they have the same bit width. For
Dan Gohmanc05dca92008-09-08 16:45:59 +0000[diff] [blame]1926 pointers it is only valid to cast to another pointer type. It is not valid
1927 to bitcast to or from an aggregate type.
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1928 </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1929
1930 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1931
1932 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1933 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1934 instruction, the index list may have zero or more indexes, which are required
1935 to make sense for the type of "CSTPTR".</dd>
1936
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1937 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1938
1939 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1940 constants.</dd>
1941
1942 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1943 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1944
1945 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1946 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1947
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]1948 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1949 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1950
1951 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1952 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1953
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1954 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1955
1956 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1957 operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1958
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1959 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1960
1961 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1962 operation</a> on constants.</dd>
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1963
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1964
1965 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1966
1967 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1968 operation</a> on constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1969
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1970 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1971
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1972 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1973 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1974 binary</a> operations. The constraints on operands are the same as those for
1975 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1976 values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1977</dl>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1978</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]1979
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1980<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1981<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1982<!-- *********************************************************************** -->
1983
1984<!-- ======================================================================= -->
1985<div class="doc_subsection">
1986<a name="inlineasm">Inline Assembler Expressions</a>
1987</div>
1988
1989<div class="doc_text">
1990
1991<p>
1992LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1993Module-Level Inline Assembly</a>) through the use of a special value. This
1994value represents the inline assembler as a string (containing the instructions
1995to emit), a list of operand constraints (stored as a string), and a flag that
1996indicates whether or not the inline asm expression has side effects. An example
1997inline assembler expression is:
1998</p>
1999
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2000<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2001<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2002i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2003</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2004</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2005
2006<p>
2007Inline assembler expressions may <b>only</b> be used as the callee operand of
2008a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
2009</p>
2010
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2011<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2012<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2013%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]2014</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2015</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2016
2017<p>
2018Inline asms with side effects not visible in the constraint list must be marked
2019as having side effects. This is done through the use of the
2020'<tt>sideeffect</tt>' keyword, like so:
2021</p>
2022
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2023<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2024<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2025call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2026</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2027</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2028
2029<p>TODO: The format of the asm and constraints string still need to be
2030documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattnerd5528262008-10-04 18:36:02 +0000[diff] [blame]2031need to be documented). This is probably best done by reference to another
2032document that covers inline asm from a holistic perspective.
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2033</p>
2034
2035</div>
2036
2037<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2038<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2039<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2040
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2041<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2042
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2043<p>The LLVM instruction set consists of several different
2044classifications of instructions: <a href="#terminators">terminator
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2045instructions</a>, <a href="#binaryops">binary instructions</a>,
2046<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2047 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
2048instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2049
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2050</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2051
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2052<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2053<div class="doc_subsection"> <a name="terminators">Terminator
2054Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2055
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2056<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2057
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2058<p>As mentioned <a href="#functionstructure">previously</a>, every
2059basic block in a program ends with a "Terminator" instruction, which
2060indicates which block should be executed after the current block is
2061finished. These terminator instructions typically yield a '<tt>void</tt>'
2062value: they produce control flow, not values (the one exception being
2063the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2064<p>There are six different terminator instructions: the '<a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2065 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
2066instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2067the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
2068 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
2069 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2070
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2071</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2072
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2073<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2074<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2075Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2076<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2077<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2078<pre>
2079 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]2080 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2081</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2082
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2083<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2084
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2085<p>The '<tt>ret</tt>' instruction is used to return control flow (and
2086optionally a value) from a function back to the caller.</p>
John Criswell417228d2004-04-09 16:48:45 +0000[diff] [blame]2087<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2088returns a value and then causes control flow, and one that just causes
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2089control flow to occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2090
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2091<h5>Arguments:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2092
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2093<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
2094the return value. The type of the return value must be a
2095'<a href="#t_firstclass">first class</a>' type.</p>
2096
2097<p>A function is not <a href="#wellformed">well formed</a> if
2098it it has a non-void return type and contains a '<tt>ret</tt>'
2099instruction with no return value or a return value with a type that
2100does not match its type, or if it has a void return type and contains
2101a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2102
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2103<h5>Semantics:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2104
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2105<p>When the '<tt>ret</tt>' instruction is executed, control flow
2106returns back to the calling function's context. If the caller is a "<a
John Criswell40db33f2004-06-25 15:16:57 +0000[diff] [blame]2107 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2108the instruction after the call. If the caller was an "<a
2109 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2110at the beginning of the "normal" destination block. If the instruction
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2111returns a value, that value shall set the call or invoke instruction's
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]2112return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2113
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2114<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2115
2116<pre>
2117 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2118 ret void <i>; Return from a void function</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2119 ret { i32, i8 } { i32 4, i8 2 } <i>; Return an aggregate of values 4 and 2</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2120</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2121
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2122<p>Note that the code generator does not yet fully support large
2123 return values. The specific sizes that are currently supported are
2124 dependent on the target. For integers, on 32-bit targets the limit
2125 is often 64 bits, and on 64-bit targets the limit is often 128 bits.
2126 For aggregate types, the current limits are dependent on the element
2127 types; for example targets are often limited to 2 total integer
2128 elements and 2 total floating-point elements.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2129
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2130</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2131<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2132<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2133<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2134<h5>Syntax:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2135<pre> 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]2136</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2137<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2138<p>The '<tt>br</tt>' instruction is used to cause control flow to
2139transfer to a different basic block in the current function. There are
2140two forms of this instruction, corresponding to a conditional branch
2141and an unconditional branch.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2142<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2143<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2144single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]2145unconditional form of the '<tt>br</tt>' instruction takes a single
2146'<tt>label</tt>' value as a target.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2147<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2148<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2149argument is evaluated. If the value is <tt>true</tt>, control flows
2150to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2151control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2152<h5>Example:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2153<pre>Test:<br> %cond = <a href="#i_icmp">icmp</a> eq, i32 %a, %b<br> br i1 %cond, label %IfEqual, label %IfUnequal<br>IfEqual:<br> <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2154 href="#i_ret">ret</a> i32 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> i32 0<br></pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2155</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2156<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2157<div class="doc_subsubsection">
2158 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2159</div>
2160
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2161<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2162<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2163
2164<pre>
2165 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2166</pre>
2167
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2168<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2169
2170<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2171several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2172instruction, allowing a branch to occur to one of many possible
2173destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2174
2175
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2176<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2177
2178<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2179comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2180an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2181table is not allowed to contain duplicate constant entries.</p>
2182
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2183<h5>Semantics:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2184
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2185<p>The <tt>switch</tt> instruction specifies a table of values and
2186destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]2187table is searched for the given value. If the value is found, control flow is
2188transfered to the corresponding destination; otherwise, control flow is
2189transfered to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2190
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2191<h5>Implementation:</h5>
2192
2193<p>Depending on properties of the target machine and the particular
2194<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]2195ways. For example, it could be generated as a series of chained conditional
2196branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2197
2198<h5>Example:</h5>
2199
2200<pre>
2201 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2202 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2203 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2204
2205 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2206 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2207
2208 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2209 switch i32 %val, label %otherwise [ i32 0, label %onzero
2210 i32 1, label %onone
2211 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2212</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2213</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2214
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2215<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2216<div class="doc_subsubsection">
2217 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2218</div>
2219
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2220<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2221
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2222<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2223
2224<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2225 &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]2226 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2227</pre>
2228
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2229<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2230
2231<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2232function, with the possibility of control flow transfer to either the
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2233'<tt>normal</tt>' label or the
2234'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2235"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2236"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2237href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]2238continued at the dynamically nearest "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2239
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2240<h5>Arguments:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2241
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2242<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2243
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2244<ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2245 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]2246 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2247 convention</a> the call should use. If none is specified, the call defaults
2248 to using C calling conventions.
2249 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2250
2251 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2252 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2253 and '<tt>inreg</tt>' attributes are valid here.</li>
2254
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2255 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2256 function value being invoked. In most cases, this is a direct function
2257 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2258 an arbitrary pointer to function value.
2259 </li>
2260
2261 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2262 function to be invoked. </li>
2263
2264 <li>'<tt>function args</tt>': argument list whose types match the function
2265 signature argument types. If the function signature indicates the function
2266 accepts a variable number of arguments, the extra arguments can be
2267 specified. </li>
2268
2269 <li>'<tt>normal label</tt>': the label reached when the called function
2270 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2271
2272 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2273 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2274
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2275 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2276 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2277 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2278</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2279
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2280<h5>Semantics:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2281
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2282<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2283href="#i_call">call</a></tt>' instruction in most regards. The primary
2284difference is that it establishes an association with a label, which is used by
2285the runtime library to unwind the stack.</p>
2286
2287<p>This instruction is used in languages with destructors to ensure that proper
2288cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2289exception. Additionally, this is important for implementation of
2290'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2291
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2292<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2293<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2294 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2295 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2296 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2297 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2298</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2299</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2300
2301
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2302<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2303
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2304<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2305Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2306
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2307<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2308
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2309<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2310<pre>
2311 unwind
2312</pre>
2313
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2314<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2315
2316<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2317at the first callee in the dynamic call stack which used an <a
2318href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2319primarily used to implement exception handling.</p>
2320
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2321<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2322
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2323<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2324immediately halt. The dynamic call stack is then searched for the first <a
2325href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2326execution continues at the "exceptional" destination block specified by the
2327<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2328dynamic call chain, undefined behavior results.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2329</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2330
2331<!-- _______________________________________________________________________ -->
2332
2333<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2334Instruction</a> </div>
2335
2336<div class="doc_text">
2337
2338<h5>Syntax:</h5>
2339<pre>
2340 unreachable
2341</pre>
2342
2343<h5>Overview:</h5>
2344
2345<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2346instruction is used to inform the optimizer that a particular portion of the
2347code is not reachable. This can be used to indicate that the code after a
2348no-return function cannot be reached, and other facts.</p>
2349
2350<h5>Semantics:</h5>
2351
2352<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2353</div>
2354
2355
2356
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2357<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2358<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2359<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2360<p>Binary operators are used to do most of the computation in a
Chris Lattner81f92972008-04-01 18:47:32 +0000[diff] [blame]2361program. They require two operands of the same type, execute an operation on them, and
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2362produce a single value. The operands might represent
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2363multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattner81f92972008-04-01 18:47:32 +0000[diff] [blame]2364The result value has the same type as its operands.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2365<p>There are several different binary operators:</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2366</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2367<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2368<div class="doc_subsubsection">
2369 <a name="i_add">'<tt>add</tt>' Instruction</a>
2370</div>
2371
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2372<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2373
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2374<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2375
2376<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2377 &lt;result&gt; = 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]2378</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2379
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2380<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2381
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2382<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2383
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2384<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2385
2386<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2387 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2388 <a href="#t_vector">vector</a> values. Both arguments must have identical
2389 types.</p>
2390
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2391<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2392
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2393<p>The value produced is the integer or floating point sum of the two
2394operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2395
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2396<p>If an integer sum has unsigned overflow, the result returned is the
2397mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2398the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2399
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2400<p>Because LLVM integers use a two's complement representation, this
2401instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2402
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2403<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2404
2405<pre>
2406 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2407</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2408</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2409<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2410<div class="doc_subsubsection">
2411 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2412</div>
2413
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2414<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2415
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2416<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2417
2418<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2419 &lt;result&gt; = 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]2420</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2421
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2422<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2423
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2424<p>The '<tt>sub</tt>' instruction returns the difference of its two
2425operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2426
2427<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2428'<tt>neg</tt>' instruction present in most other intermediate
2429representations.</p>
2430
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2431<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2432
2433<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2434 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2435 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2436 types.</p>
2437
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2438<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2439
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2440<p>The value produced is the integer or floating point difference of
2441the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2442
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2443<p>If an integer difference has unsigned overflow, the result returned is the
2444mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2445the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2446
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2447<p>Because LLVM integers use a two's complement representation, this
2448instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2449
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2450<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2451<pre>
2452 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2453 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2454</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2455</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2456
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2457<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2458<div class="doc_subsubsection">
2459 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2460</div>
2461
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2462<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2463
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2464<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2465<pre> &lt;result&gt; = 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]2466</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2467<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2468<p>The '<tt>mul</tt>' instruction returns the product of its two
2469operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2470
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2471<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2472
2473<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2474href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2475or <a href="#t_vector">vector</a> values. Both arguments must have identical
2476types.</p>
2477
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2478<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2479
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2480<p>The value produced is the integer or floating point product of the
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2481two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2482
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2483<p>If the result of an integer multiplication has unsigned overflow,
2484the result returned is the mathematical result modulo
24852<sup>n</sup>, where n is the bit width of the result.</p>
2486<p>Because LLVM integers use a two's complement representation, and the
2487result is the same width as the operands, this instruction returns the
2488correct result for both signed and unsigned integers. If a full product
2489(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2490should be sign-extended or zero-extended as appropriate to the
2491width of the full product.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2492<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2493<pre> &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2494</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2495</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2496
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2497<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2498<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2499</a></div>
2500<div class="doc_text">
2501<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2502<pre> &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]2503</pre>
2504<h5>Overview:</h5>
2505<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2506operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2507
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2508<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2509
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2510<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2511<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2512values. Both arguments must have identical types.</p>
2513
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2514<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2515
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2516<p>The value produced is the unsigned integer quotient of the two operands.</p>
2517<p>Note that unsigned integer division and signed integer division are distinct
2518operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2519<p>Division by zero leads to undefined behavior.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2520<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2521<pre> &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2522</pre>
2523</div>
2524<!-- _______________________________________________________________________ -->
2525<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2526</a> </div>
2527<div class="doc_text">
2528<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2529<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2530 &lt;result&gt; = 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]2531</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2532
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2533<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2534
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2535<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2536operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2537
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2538<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2539
2540<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2541<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2542values. Both arguments must have identical types.</p>
2543
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2544<h5>Semantics:</h5>
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2545<p>The value produced is the signed integer quotient of the two operands rounded towards zero.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2546<p>Note that signed integer division and unsigned integer division are distinct
2547operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2548<p>Division by zero leads to undefined behavior. Overflow also leads to
2549undefined behavior; this is a rare case, but can occur, for example,
2550by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2551<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2552<pre> &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2553</pre>
2554</div>
2555<!-- _______________________________________________________________________ -->
2556<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2557Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2558<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2559<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2560<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2561 &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]2562</pre>
2563<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2564
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2565<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2566operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2567
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2568<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2569
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2570<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2571<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2572of floating point values. Both arguments must have identical types.</p>
2573
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2574<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2575
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2576<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2577
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2578<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2579
2580<pre>
2581 &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]2582</pre>
2583</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2584
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2585<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2586<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2587</div>
2588<div class="doc_text">
2589<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2590<pre> &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]2591</pre>
2592<h5>Overview:</h5>
2593<p>The '<tt>urem</tt>' instruction returns the remainder from the
2594unsigned division of its two arguments.</p>
2595<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2596<p>The two arguments to the '<tt>urem</tt>' instruction must be
2597<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2598values. Both arguments must have identical types.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2599<h5>Semantics:</h5>
2600<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2601This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2602<p>Note that unsigned integer remainder and signed integer remainder are
2603distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2604<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2605<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2606<pre> &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2607</pre>
2608
2609</div>
2610<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2611<div class="doc_subsubsection">
2612 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2613</div>
2614
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2615<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2616
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2617<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2618
2619<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2620 &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]2621</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2622
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2623<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2624
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2625<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame]2626signed division of its two operands. This instruction can also take
2627<a href="#t_vector">vector</a> versions of the values in which case
2628the elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]2629
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2630<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2631
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2632<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2633<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2634values. Both arguments must have identical types.</p>
2635
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2636<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2637
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2638<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2639has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2640operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2641a value. For more information about the difference, see <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2642 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2643Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencerdb3b93b2007-03-24 22:40:44 +0000[diff] [blame]2644please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2645Wikipedia: modulo operation</a>.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2646<p>Note that signed integer remainder and unsigned integer remainder are
2647distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2648<p>Taking the remainder of a division by zero leads to undefined behavior.
2649Overflow also leads to undefined behavior; this is a rare case, but can occur,
2650for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2651(The remainder doesn't actually overflow, but this rule lets srem be
2652implemented using instructions that return both the result of the division
2653and the remainder.)</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2654<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2655<pre> &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2656</pre>
2657
2658</div>
2659<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2660<div class="doc_subsubsection">
2661 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2662
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2663<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2664
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2665<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2666<pre> &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]2667</pre>
2668<h5>Overview:</h5>
2669<p>The '<tt>frem</tt>' instruction returns the remainder from the
2670division of its two operands.</p>
2671<h5>Arguments:</h5>
2672<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2673<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2674of floating point values. Both arguments must have identical types.</p>
2675
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2676<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2677
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2678<p>This instruction returns the <i>remainder</i> of a division.
2679The remainder has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2680
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2681<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2682
2683<pre>
2684 &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]2685</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2686</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]2687
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2688<!-- ======================================================================= -->
2689<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2690Operations</a> </div>
2691<div class="doc_text">
2692<p>Bitwise binary operators are used to do various forms of
2693bit-twiddling in a program. They are generally very efficient
2694instructions and can commonly be strength reduced from other
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2695instructions. They require two operands of the same type, execute an operation on them,
2696and produce a single value. The resulting value is the same type as its operands.</p>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2697</div>
2698
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2699<!-- _______________________________________________________________________ -->
2700<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2701Instruction</a> </div>
2702<div class="doc_text">
2703<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2704<pre> &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]2705</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2706
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2707<h5>Overview:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2708
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2709<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2710the left a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2711
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2712<h5>Arguments:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2713
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2714<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2715 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2716type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2717
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2718<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2719
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2720<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2721where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
Mon P Wang68d4eee2008-12-10 08:55:09 +0000[diff] [blame]2722equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
2723If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2724corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2725
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2726<h5>Example:</h5><pre>
2727 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2728 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2729 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2730 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]2731 &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]2732</pre>
2733</div>
2734<!-- _______________________________________________________________________ -->
2735<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2736Instruction</a> </div>
2737<div class="doc_text">
2738<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2739<pre> &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]2740</pre>
2741
2742<h5>Overview:</h5>
2743<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2744operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2745
2746<h5>Arguments:</h5>
2747<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2748<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2749type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2750
2751<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2752
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2753<p>This instruction always performs a logical shift right operation. The most
2754significant bits of the result will be filled with zero bits after the
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2755shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang68d4eee2008-12-10 08:55:09 +0000[diff] [blame]2756the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
2757vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
2758amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2759
2760<h5>Example:</h5>
2761<pre>
2762 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2763 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2764 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2765 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2766 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]2767 &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]2768</pre>
2769</div>
2770
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2771<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2772<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2773Instruction</a> </div>
2774<div class="doc_text">
2775
2776<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2777<pre> &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]2778</pre>
2779
2780<h5>Overview:</h5>
2781<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2782operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2783
2784<h5>Arguments:</h5>
2785<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2786<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2787type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2788
2789<h5>Semantics:</h5>
2790<p>This instruction always performs an arithmetic shift right operation,
2791The most significant bits of the result will be filled with the sign bit
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2792of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
Mon P Wang68d4eee2008-12-10 08:55:09 +0000[diff] [blame]2793larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
2794arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2795corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2796
2797<h5>Example:</h5>
2798<pre>
2799 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2800 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2801 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2802 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2803 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]2804 &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]2805</pre>
2806</div>
2807
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2808<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2809<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2810Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2811
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2812<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2813
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2814<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2815
2816<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2817 &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]2818</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2819
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2820<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2821
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2822<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2823its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2824
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2825<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2826
2827<p>The two arguments to the '<tt>and</tt>' instruction must be
2828<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2829values. Both arguments must have identical types.</p>
2830
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2831<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2832<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2833<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2834<div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2835<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2836 <tbody>
2837 <tr>
2838 <td>In0</td>
2839 <td>In1</td>
2840 <td>Out</td>
2841 </tr>
2842 <tr>
2843 <td>0</td>
2844 <td>0</td>
2845 <td>0</td>
2846 </tr>
2847 <tr>
2848 <td>0</td>
2849 <td>1</td>
2850 <td>0</td>
2851 </tr>
2852 <tr>
2853 <td>1</td>
2854 <td>0</td>
2855 <td>0</td>
2856 </tr>
2857 <tr>
2858 <td>1</td>
2859 <td>1</td>
2860 <td>1</td>
2861 </tr>
2862 </tbody>
2863</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2864</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2865<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2866<pre>
2867 &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]2868 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2869 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2870</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2871</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2872<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2873<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2874<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2875<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2876<pre> &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2877</pre>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2878<h5>Overview:</h5>
2879<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2880or of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2881<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2882
2883<p>The two arguments to the '<tt>or</tt>' instruction must be
2884<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2885values. Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2886<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2887<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2888<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2889<div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2890<table border="1" cellspacing="0" cellpadding="4">
2891 <tbody>
2892 <tr>
2893 <td>In0</td>
2894 <td>In1</td>
2895 <td>Out</td>
2896 </tr>
2897 <tr>
2898 <td>0</td>
2899 <td>0</td>
2900 <td>0</td>
2901 </tr>
2902 <tr>
2903 <td>0</td>
2904 <td>1</td>
2905 <td>1</td>
2906 </tr>
2907 <tr>
2908 <td>1</td>
2909 <td>0</td>
2910 <td>1</td>
2911 </tr>
2912 <tr>
2913 <td>1</td>
2914 <td>1</td>
2915 <td>1</td>
2916 </tr>
2917 </tbody>
2918</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2919</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2920<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2921<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2922 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2923 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2924</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2925</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2926<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2927<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2928Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2929<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2930<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2931<pre> &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]2932</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2933<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2934<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2935or of its two operands. The <tt>xor</tt> is used to implement the
2936"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2937<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2938<p>The two arguments to the '<tt>xor</tt>' instruction must be
2939<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2940values. Both arguments must have identical types.</p>
2941
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2942<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2943
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2944<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2945<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2946<div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2947<table border="1" cellspacing="0" cellpadding="4">
2948 <tbody>
2949 <tr>
2950 <td>In0</td>
2951 <td>In1</td>
2952 <td>Out</td>
2953 </tr>
2954 <tr>
2955 <td>0</td>
2956 <td>0</td>
2957 <td>0</td>
2958 </tr>
2959 <tr>
2960 <td>0</td>
2961 <td>1</td>
2962 <td>1</td>
2963 </tr>
2964 <tr>
2965 <td>1</td>
2966 <td>0</td>
2967 <td>1</td>
2968 </tr>
2969 <tr>
2970 <td>1</td>
2971 <td>1</td>
2972 <td>0</td>
2973 </tr>
2974 </tbody>
2975</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2976</div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2977<p> </p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2978<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2979<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2980 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2981 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2982 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2983</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2984</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2985
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2986<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2987<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2988 <a name="vectorops">Vector Operations</a>
2989</div>
2990
2991<div class="doc_text">
2992
2993<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2994target-independent manner. These instructions cover the element-access and
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2995vector-specific operations needed to process vectors effectively. While LLVM
2996does directly support these vector operations, many sophisticated algorithms
2997will want to use target-specific intrinsics to take full advantage of a specific
2998target.</p>
2999
3000</div>
3001
3002<!-- _______________________________________________________________________ -->
3003<div class="doc_subsubsection">
3004 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3005</div>
3006
3007<div class="doc_text">
3008
3009<h5>Syntax:</h5>
3010
3011<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3012 &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]3013</pre>
3014
3015<h5>Overview:</h5>
3016
3017<p>
3018The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]3019element from a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3020</p>
3021
3022
3023<h5>Arguments:</h5>
3024
3025<p>
3026The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]3027value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3028an index indicating the position from which to extract the element.
3029The index may be a variable.</p>
3030
3031<h5>Semantics:</h5>
3032
3033<p>
3034The result is a scalar of the same type as the element type of
3035<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3036<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3037results are undefined.
3038</p>
3039
3040<h5>Example:</h5>
3041
3042<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3043 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3044</pre>
3045</div>
3046
3047
3048<!-- _______________________________________________________________________ -->
3049<div class="doc_subsubsection">
3050 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3051</div>
3052
3053<div class="doc_text">
3054
3055<h5>Syntax:</h5>
3056
3057<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]3058 &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]3059</pre>
3060
3061<h5>Overview:</h5>
3062
3063<p>
3064The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]3065element into a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3066</p>
3067
3068
3069<h5>Arguments:</h5>
3070
3071<p>
3072The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]3073value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3074scalar value whose type must equal the element type of the first
3075operand. The third operand is an index indicating the position at
3076which to insert the value. The index may be a variable.</p>
3077
3078<h5>Semantics:</h5>
3079
3080<p>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]3081The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3082element values are those of <tt>val</tt> except at position
3083<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
3084exceeds the length of <tt>val</tt>, the results are undefined.
3085</p>
3086
3087<h5>Example:</h5>
3088
3089<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3090 %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]3091</pre>
3092</div>
3093
3094<!-- _______________________________________________________________________ -->
3095<div class="doc_subsubsection">
3096 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3097</div>
3098
3099<div class="doc_text">
3100
3101<h5>Syntax:</h5>
3102
3103<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3104 &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]3105</pre>
3106
3107<h5>Overview:</h5>
3108
3109<p>
3110The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3111from two input vectors, returning a vector with the same element type as
3112the input and length that is the same as the shuffle mask.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3113</p>
3114
3115<h5>Arguments:</h5>
3116
3117<p>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3118The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3119with types that match each other. The third argument is a shuffle mask whose
3120element type is always 'i32'. The result of the instruction is a vector whose
3121length is the same as the shuffle mask and whose element type is the same as
3122the element type of the first two operands.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3123</p>
3124
3125<p>
3126The shuffle mask operand is required to be a constant vector with either
3127constant integer or undef values.
3128</p>
3129
3130<h5>Semantics:</h5>
3131
3132<p>
3133The elements of the two input vectors are numbered from left to right across
3134both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3135the result vector, which element of the two input vectors the result element
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3136gets. The element selector may be undef (meaning "don't care") and the second
3137operand may be undef if performing a shuffle from only one vector.
3138</p>
3139
3140<h5>Example:</h5>
3141
3142<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3143 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3144 &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]3145 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3146 &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]3147 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3148 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3149 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3150 &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]3151</pre>
3152</div>
3153
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]3154
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3155<!-- ======================================================================= -->
3156<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3157 <a name="aggregateops">Aggregate Operations</a>
3158</div>
3159
3160<div class="doc_text">
3161
3162<p>LLVM supports several instructions for working with aggregate values.
3163</p>
3164
3165</div>
3166
3167<!-- _______________________________________________________________________ -->
3168<div class="doc_subsubsection">
3169 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3170</div>
3171
3172<div class="doc_text">
3173
3174<h5>Syntax:</h5>
3175
3176<pre>
3177 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3178</pre>
3179
3180<h5>Overview:</h5>
3181
3182<p>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3183The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3184or array element from an aggregate value.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3185</p>
3186
3187
3188<h5>Arguments:</h5>
3189
3190<p>
3191The first operand of an '<tt>extractvalue</tt>' instruction is a
3192value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3193type. The operands are constant indices to specify which value to extract
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3194in a similar manner as indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3195'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3196</p>
3197
3198<h5>Semantics:</h5>
3199
3200<p>
3201The result is the value at the position in the aggregate specified by
3202the index operands.
3203</p>
3204
3205<h5>Example:</h5>
3206
3207<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3208 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3209</pre>
3210</div>
3211
3212
3213<!-- _______________________________________________________________________ -->
3214<div class="doc_subsubsection">
3215 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3216</div>
3217
3218<div class="doc_text">
3219
3220<h5>Syntax:</h5>
3221
3222<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3223 &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]3224</pre>
3225
3226<h5>Overview:</h5>
3227
3228<p>
3229The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3230into a struct field or array element in an aggregate.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3231</p>
3232
3233
3234<h5>Arguments:</h5>
3235
3236<p>
3237The first operand of an '<tt>insertvalue</tt>' instruction is a
3238value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3239The second operand is a first-class value to insert.
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]3240The following operands are constant indices
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3241indicating the position at which to insert the value in a similar manner as
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3242indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3243'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3244The value to insert must have the same type as the value identified
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3245by the indices.
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3246</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3247
3248<h5>Semantics:</h5>
3249
3250<p>
3251The result is an aggregate of the same type as <tt>val</tt>. Its
3252value is that of <tt>val</tt> except that the value at the position
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3253specified by the indices is that of <tt>elt</tt>.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3254</p>
3255
3256<h5>Example:</h5>
3257
3258<pre>
Dan Gohman88ce1a52008-06-23 15:26:37 +0000[diff] [blame]3259 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3260</pre>
3261</div>
3262
3263
3264<!-- ======================================================================= -->
3265<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3266 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3267</div>
3268
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3269<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3270
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3271<p>A key design point of an SSA-based representation is how it
3272represents memory. In LLVM, no memory locations are in SSA form, which
3273makes things very simple. This section describes how to read, write,
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3274allocate, and free memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3275
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3276</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3277
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3278<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3279<div class="doc_subsubsection">
3280 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3281</div>
3282
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3283<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3284
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3285<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3286
3287<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3288 &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]3289</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3290
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3291<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3292
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3293<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3294heap and returns a pointer to it. The object is always allocated in the generic
3295address space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3296
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3297<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3298
3299<p>The '<tt>malloc</tt>' instruction allocates
3300<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswella92e5862004-02-24 16:13:56 +0000[diff] [blame]3301bytes of memory from the operating system and returns a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3302appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3303number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3304If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3305be aligned to at least that boundary. If not specified, or if zero, the target can
3306choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3307
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3308<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3309
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3310<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3311
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3312<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewyckyf5ffcbc2008-11-24 03:41:24 +0000[diff] [blame]3313a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3314result is null if there is insufficient memory available.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3315
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3316<h5>Example:</h5>
3317
3318<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3319 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3320
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3321 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3322 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3323 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3324 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3325 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3326</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]3327
3328<p>Note that the code generator does not yet respect the
3329 alignment value.</p>
3330
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3331</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3332
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3333<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3334<div class="doc_subsubsection">
3335 <a name="i_free">'<tt>free</tt>' Instruction</a>
3336</div>
3337
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3338<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3339
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3340<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3341
3342<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3343 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3344</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3345
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3346<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3347
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3348<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3349memory heap to be reallocated in the future.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3350
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3351<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3352
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3353<p>'<tt>value</tt>' shall be a pointer value that points to a value
3354that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3355instruction.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3356
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3357<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3358
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3359<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner0f103e12008-04-19 22:41:32 +0000[diff] [blame]3360after this instruction executes. If the pointer is null, the operation
3361is a noop.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3362
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3363<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3364
3365<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3366 %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]3367 free [4 x i8]* %array
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3368</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3369</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3370
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3371<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3372<div class="doc_subsubsection">
3373 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3374</div>
3375
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3376<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3377
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3378<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3379
3380<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3381 &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]3382</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3383
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3384<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3385
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3386<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3387currently executing function, to be automatically released when this function
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3388returns to its caller. The object is always allocated in the generic address
3389space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3390
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3391<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3392
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3393<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3394bytes of memory on the runtime stack, returning a pointer of the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3395appropriate type to the program. If "NumElements" is specified, it is the
3396number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3397If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3398to be aligned to at least that boundary. If not specified, or if zero, the target
3399can choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3400
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3401<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3402
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3403<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3404
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3405<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3406there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3407memory is automatically released when the function returns. The '<tt>alloca</tt>'
3408instruction is commonly used to represent automatic variables that must
3409have an address available. When the function returns (either with the <tt><a
John Criswellc932bef2005-05-12 16:55:34 +0000[diff] [blame]3410 href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3411instructions), the memory is reclaimed. Allocating zero bytes
3412is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3413
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3414<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3415
3416<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3417 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3418 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3419 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3420 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3421</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3422</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3423
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3424<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3425<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3426Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3427<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3428<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3429<pre> &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]<br> &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]<br></pre>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3430<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3431<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3432<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3433<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3434address from which to load. The pointer must point to a <a
Chris Lattner10ee9652004-06-03 22:57:15 +0000[diff] [blame]3435 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3436marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3437the number or order of execution of this <tt>load</tt> with other
3438volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3439instructions. </p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3440<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3441The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3442(that is, the alignment of the memory address). A value of 0 or an
3443omitted "align" argument means that the operation has the preferential
3444alignment for the target. It is the responsibility of the code emitter
3445to ensure that the alignment information is correct. Overestimating
3446the alignment results in an undefined behavior. Underestimating the
3447alignment may produce less efficient code. An alignment of 1 is always
3448safe.
3449</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3450<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3451<p>The location of memory pointed to is loaded.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3452<h5>Examples:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3453<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3454 <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3455 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3456 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3457</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3458</div>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3459<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3460<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3461Instruction</a> </div>
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]3462<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3463<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3464<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3465 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]3466</pre>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3467<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3468<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3469<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3470<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3471to store and an address at which to store it. The type of the '<tt>&lt;pointer&gt;</tt>'
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3472operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3473of the '<tt>&lt;value&gt;</tt>'
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3474operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3475optimizer is not allowed to modify the number or order of execution of
3476this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3477 href="#i_store">store</a></tt> instructions.</p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3478<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3479The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3480(that is, the alignment of the memory address). A value of 0 or an
3481omitted "align" argument means that the operation has the preferential
3482alignment for the target. It is the responsibility of the code emitter
3483to ensure that the alignment information is correct. Overestimating
3484the alignment results in an undefined behavior. Underestimating the
3485alignment may produce less efficient code. An alignment of 1 is always
3486safe.
3487</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3488<h5>Semantics:</h5>
3489<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3490at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3491<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3492<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]3493 store i32 3, i32* %ptr <i>; yields {void}</i>
3494 %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]3495</pre>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3496</div>
3497
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3498<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3499<div class="doc_subsubsection">
3500 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3501</div>
3502
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3503<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3504<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3505<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3506 &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]3507</pre>
3508
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3509<h5>Overview:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3510
3511<p>
3512The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3513subelement of an aggregate data structure. It performs address calculation only
3514and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3515
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3516<h5>Arguments:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3517
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3518<p>The first argument is always a pointer, and forms the basis of the
3519calculation. The remaining arguments are indices, that indicate which of the
3520elements of the aggregate object are indexed. The interpretation of each index
3521is dependent on the type being indexed into. The first index always indexes the
3522pointer value given as the first argument, the second index indexes a value of
3523the type pointed to (not necessarily the value directly pointed to, since the
3524first index can be non-zero), etc. The first type indexed into must be a pointer
3525value, subsequent types can be arrays, vectors and structs. Note that subsequent
3526types being indexed into can never be pointers, since that would require loading
3527the pointer before continuing calculation.</p>
3528
3529<p>The type of each index argument depends on the type it is indexing into.
3530When indexing into a (packed) structure, only <tt>i32</tt> integer
3531<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3532only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3533will be sign extended to 64-bits if required.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3534
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3535<p>For example, let's consider a C code fragment and how it gets
3536compiled to LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3537
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3538<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3539<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3540struct RT {
3541 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3542 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3543 char C;
3544};
3545struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3546 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3547 double Y;
3548 struct RT Z;
3549};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3550
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3551int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3552 return &amp;s[1].Z.B[5][13];
3553}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3554</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3555</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3556
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3557<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3558
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3559<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3560<pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]3561%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3562%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3563
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3564define i32* %foo(%ST* %s) {
3565entry:
3566 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3567 ret i32* %reg
3568}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3569</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3570</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3571
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3572<h5>Semantics:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3573
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3574<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3575type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3576}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3577the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3578i8 }</tt>' type, another structure. The third index indexes into the second
3579element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3580array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3581'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3582to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3583
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3584<p>Note that it is perfectly legal to index partially through a
3585structure, returning a pointer to an inner element. Because of this,
3586the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3587
3588<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3589 define i32* %foo(%ST* %s) {
3590 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3591 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3592 %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]3593 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3594 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3595 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3596 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3597</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3598
3599<p>Note that it is undefined to access an array out of bounds: array and
3600pointer indexes must always be within the defined bounds of the array type.
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]3601The one exception for this rule is zero length arrays. These arrays are
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3602defined to be accessible as variable length arrays, which requires access
3603beyond the zero'th element.</p>
3604
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3605<p>The getelementptr instruction is often confusing. For some more insight
3606into how it works, see <a href="GetElementPtr.html">the getelementptr
3607FAQ</a>.</p>
3608
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3609<h5>Example:</h5>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3610
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3611<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3612 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3613 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3614 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3615 %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]3616 <i>; yields i8*:eptr</i>
3617 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3618</pre>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3619</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3620
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3621<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3622<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3623</div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3624<div class="doc_text">
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3625<p>The instructions in this category are the conversion instructions (casting)
3626which all take a single operand and a type. They perform various bit conversions
3627on the operand.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3628</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3629
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3630<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3631<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3632 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3633</div>
3634<div class="doc_text">
3635
3636<h5>Syntax:</h5>
3637<pre>
3638 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3639</pre>
3640
3641<h5>Overview:</h5>
3642<p>
3643The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3644</p>
3645
3646<h5>Arguments:</h5>
3647<p>
3648The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3649be an <a href="#t_integer">integer</a> type, and a type that specifies the size
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3650and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3651type. The bit size of <tt>value</tt> must be larger than the bit size of
3652<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3653
3654<h5>Semantics:</h5>
3655<p>
3656The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3657and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3658larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3659It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3660
3661<h5>Example:</h5>
3662<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3663 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3664 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3665 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3666</pre>
3667</div>
3668
3669<!-- _______________________________________________________________________ -->
3670<div class="doc_subsubsection">
3671 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3672</div>
3673<div class="doc_text">
3674
3675<h5>Syntax:</h5>
3676<pre>
3677 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3678</pre>
3679
3680<h5>Overview:</h5>
3681<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3682<tt>ty2</tt>.</p>
3683
3684
3685<h5>Arguments:</h5>
3686<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3687<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3688also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3689<tt>value</tt> must be smaller than the bit size of the destination type,
3690<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3691
3692<h5>Semantics:</h5>
3693<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Chris Lattnerc87f3df2007-05-24 19:13:27 +0000[diff] [blame]3694bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3695
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]3696<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]3697
3698<h5>Example:</h5>
3699<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3700 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3701 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3702</pre>
3703</div>
3704
3705<!-- _______________________________________________________________________ -->
3706<div class="doc_subsubsection">
3707 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3708</div>
3709<div class="doc_text">
3710
3711<h5>Syntax:</h5>
3712<pre>
3713 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3714</pre>
3715
3716<h5>Overview:</h5>
3717<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3718
3719<h5>Arguments:</h5>
3720<p>
3721The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3722<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3723also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3724<tt>value</tt> must be smaller than the bit size of the destination type,
3725<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3726
3727<h5>Semantics:</h5>
3728<p>
3729The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3730bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
Chris Lattnerc87f3df2007-05-24 19:13:27 +0000[diff] [blame]3731the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3732
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3733<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]3734
3735<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3736<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3737 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3738 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3739</pre>
3740</div>
3741
3742<!-- _______________________________________________________________________ -->
3743<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3744 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3745</div>
3746
3747<div class="doc_text">
3748
3749<h5>Syntax:</h5>
3750
3751<pre>
3752 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3753</pre>
3754
3755<h5>Overview:</h5>
3756<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3757<tt>ty2</tt>.</p>
3758
3759
3760<h5>Arguments:</h5>
3761<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3762 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3763cast it to. The size of <tt>value</tt> must be larger than the size of
3764<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3765<i>no-op cast</i>.</p>
3766
3767<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3768<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3769<a href="#t_floating">floating point</a> type to a smaller
3770<a href="#t_floating">floating point</a> type. If the value cannot fit within
3771the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3772
3773<h5>Example:</h5>
3774<pre>
3775 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3776 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3777</pre>
3778</div>
3779
3780<!-- _______________________________________________________________________ -->
3781<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3782 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3783</div>
3784<div class="doc_text">
3785
3786<h5>Syntax:</h5>
3787<pre>
3788 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3789</pre>
3790
3791<h5>Overview:</h5>
3792<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3793floating point value.</p>
3794
3795<h5>Arguments:</h5>
3796<p>The '<tt>fpext</tt>' instruction takes a
3797<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3798and a <a href="#t_floating">floating point</a> type to cast it to. The source
3799type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3800
3801<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3802<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3803<a href="#t_floating">floating point</a> type to a larger
3804<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3805used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3806<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]3807
3808<h5>Example:</h5>
3809<pre>
3810 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3811 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3812</pre>
3813</div>
3814
3815<!-- _______________________________________________________________________ -->
3816<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]3817 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3818</div>
3819<div class="doc_text">
3820
3821<h5>Syntax:</h5>
3822<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3823 &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]3824</pre>
3825
3826<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3827<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3828unsigned integer equivalent of type <tt>ty2</tt>.
3829</p>
3830
3831<h5>Arguments:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3832<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3833scalar or vector <a href="#t_floating">floating point</a> value, and a type
3834to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3835type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3836vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3837
3838<h5>Semantics:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3839<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3840<a href="#t_floating">floating point</a> operand into the nearest (rounding
3841towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3842the results are undefined.</p>
3843
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3844<h5>Example:</h5>
3845<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3846 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3847 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3848 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3849</pre>
3850</div>
3851
3852<!-- _______________________________________________________________________ -->
3853<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3854 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3855</div>
3856<div class="doc_text">
3857
3858<h5>Syntax:</h5>
3859<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3860 &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]3861</pre>
3862
3863<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3864<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3865<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3866</p>
3867
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3868<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3869<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3870scalar or vector <a href="#t_floating">floating point</a> value, and a type
3871to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3872type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3873vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3874
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3875<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3876<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3877<a href="#t_floating">floating point</a> operand into the nearest (rounding
3878towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3879the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3880
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3881<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3882<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3883 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3884 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3885 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3886</pre>
3887</div>
3888
3889<!-- _______________________________________________________________________ -->
3890<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3891 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3892</div>
3893<div class="doc_text">
3894
3895<h5>Syntax:</h5>
3896<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3897 &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]3898</pre>
3899
3900<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3901<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3902integer and converts that value to the <tt>ty2</tt> type.</p>
3903
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3904<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3905<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3906scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3907to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3908type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3909floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3910
3911<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3912<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3913integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3914the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3915
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3916<h5>Example:</h5>
3917<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3918 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3919 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3920</pre>
3921</div>
3922
3923<!-- _______________________________________________________________________ -->
3924<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3925 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3926</div>
3927<div class="doc_text">
3928
3929<h5>Syntax:</h5>
3930<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3931 &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]3932</pre>
3933
3934<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3935<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3936integer and converts that value to the <tt>ty2</tt> type.</p>
3937
3938<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3939<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3940scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3941to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3942type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3943floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3944
3945<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3946<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3947integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3948the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3949
3950<h5>Example:</h5>
3951<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3952 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3953 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3954</pre>
3955</div>
3956
3957<!-- _______________________________________________________________________ -->
3958<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3959 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3960</div>
3961<div class="doc_text">
3962
3963<h5>Syntax:</h5>
3964<pre>
3965 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3966</pre>
3967
3968<h5>Overview:</h5>
3969<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3970the integer type <tt>ty2</tt>.</p>
3971
3972<h5>Arguments:</h5>
3973<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3974must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3975<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]3976
3977<h5>Semantics:</h5>
3978<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3979<tt>ty2</tt> by interpreting the pointer value as an integer and either
3980truncating or zero extending that value to the size of the integer type. If
3981<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3982<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3983are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3984change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3985
3986<h5>Example:</h5>
3987<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3988 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3989 %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]3990</pre>
3991</div>
3992
3993<!-- _______________________________________________________________________ -->
3994<div class="doc_subsubsection">
3995 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3996</div>
3997<div class="doc_text">
3998
3999<h5>Syntax:</h5>
4000<pre>
4001 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4002</pre>
4003
4004<h5>Overview:</h5>
4005<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
4006a pointer type, <tt>ty2</tt>.</p>
4007
4008<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4009<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4010value to cast, and a type to cast it to, which must be a
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4011<a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4012
4013<h5>Semantics:</h5>
4014<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
4015<tt>ty2</tt> by applying either a zero extension or a truncation depending on
4016the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4017size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
4018the size of a pointer then a zero extension is done. If they are the same size,
4019nothing is done (<i>no-op cast</i>).</p>
4020
4021<h5>Example:</h5>
4022<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4023 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
4024 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4025 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4026</pre>
4027</div>
4028
4029<!-- _______________________________________________________________________ -->
4030<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4031 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4032</div>
4033<div class="doc_text">
4034
4035<h5>Syntax:</h5>
4036<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4037 &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]4038</pre>
4039
4040<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4041
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4042<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4043<tt>ty2</tt> without changing any bits.</p>
4044
4045<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4046
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4047<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohmanc05dca92008-09-08 16:45:59 +0000[diff] [blame]4048a non-aggregate first class value, and a type to cast it to, which must also be
4049a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
4050<tt>value</tt>
Reid Spencere3db84c2007-01-09 20:08:58 +0000[diff] [blame]4051and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4052type is a pointer, the destination type must also be a pointer. This
4053instruction supports bitwise conversion of vectors to integers and to vectors
4054of other types (as long as they have the same size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4055
4056<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]4057<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4058<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4059this conversion. The conversion is done as if the <tt>value</tt> had been
4060stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
4061converted to other pointer types with this instruction. To convert pointers to
4062other types, use the <a href="#i_inttoptr">inttoptr</a> or
4063<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4064
4065<h5>Example:</h5>
4066<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4067 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4068 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4069 %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]4070</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4071</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4072
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4073<!-- ======================================================================= -->
4074<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
4075<div class="doc_text">
4076<p>The instructions in this category are the "miscellaneous"
4077instructions, which defy better classification.</p>
4078</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4079
4080<!-- _______________________________________________________________________ -->
4081<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4082</div>
4083<div class="doc_text">
4084<h5>Syntax:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4085<pre> &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]4086</pre>
4087<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4088<p>The '<tt>icmp</tt>' instruction returns a boolean value or
4089a vector of boolean values based on comparison
4090of its two integer, integer vector, or pointer operands.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4091<h5>Arguments:</h5>
4092<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4093the condition code indicating the kind of comparison to perform. It is not
4094a value, just a keyword. The possible condition code are:
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4095</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4096<ol>
4097 <li><tt>eq</tt>: equal</li>
4098 <li><tt>ne</tt>: not equal </li>
4099 <li><tt>ugt</tt>: unsigned greater than</li>
4100 <li><tt>uge</tt>: unsigned greater or equal</li>
4101 <li><tt>ult</tt>: unsigned less than</li>
4102 <li><tt>ule</tt>: unsigned less or equal</li>
4103 <li><tt>sgt</tt>: signed greater than</li>
4104 <li><tt>sge</tt>: signed greater or equal</li>
4105 <li><tt>slt</tt>: signed less than</li>
4106 <li><tt>sle</tt>: signed less or equal</li>
4107</ol>
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]4108<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4109<a href="#t_pointer">pointer</a>
4110or integer <a href="#t_vector">vector</a> typed.
4111They must also be identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4112<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4113<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4114the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4115yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4116</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4117<ol>
4118 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
4119 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
4120 </li>
4121 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4122 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4123 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4124 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4125 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4126 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4127 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4128 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4129 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4130 <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]4131 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4132 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4133 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4134 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4135 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4136 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4137 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4138 <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]4139</ol>
4140<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4141values are compared as if they were integers.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4142<p>If the operands are integer vectors, then they are compared
4143element by element. The result is an <tt>i1</tt> vector with
4144the same number of elements as the values being compared.
4145Otherwise, the result is an <tt>i1</tt>.
4146</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4147
4148<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4149<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
4150 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4151 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4152 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4153 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4154 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4155</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4156
4157<p>Note that the code generator does not yet support vector types with
4158 the <tt>icmp</tt> instruction.</p>
4159
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4160</div>
4161
4162<!-- _______________________________________________________________________ -->
4163<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4164</div>
4165<div class="doc_text">
4166<h5>Syntax:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4167<pre> &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]4168</pre>
4169<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4170<p>The '<tt>fcmp</tt>' instruction returns a boolean value
4171or vector of boolean values based on comparison
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4172of its operands.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4173<p>
4174If the operands are floating point scalars, then the result
4175type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
4176</p>
4177<p>If the operands are floating point vectors, then the result type
4178is a vector of boolean with the same number of elements as the
4179operands being compared.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4180<h5>Arguments:</h5>
4181<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4182the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4183a value, just a keyword. The possible condition code are:</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4184<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4185 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4186 <li><tt>oeq</tt>: ordered and equal</li>
4187 <li><tt>ogt</tt>: ordered and greater than </li>
4188 <li><tt>oge</tt>: ordered and greater than or equal</li>
4189 <li><tt>olt</tt>: ordered and less than </li>
4190 <li><tt>ole</tt>: ordered and less than or equal</li>
4191 <li><tt>one</tt>: ordered and not equal</li>
4192 <li><tt>ord</tt>: ordered (no nans)</li>
4193 <li><tt>ueq</tt>: unordered or equal</li>
4194 <li><tt>ugt</tt>: unordered or greater than </li>
4195 <li><tt>uge</tt>: unordered or greater than or equal</li>
4196 <li><tt>ult</tt>: unordered or less than </li>
4197 <li><tt>ule</tt>: unordered or less than or equal</li>
4198 <li><tt>une</tt>: unordered or not equal</li>
4199 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4200 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4201</ol>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4202<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer02e0d1d2006-12-06 07:08:07 +0000[diff] [blame]4203<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4204<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4205either a <a href="#t_floating">floating point</a> type
4206or a <a href="#t_vector">vector</a> of floating point type.
4207They must have identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4208<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4209<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4210according to the condition code given as <tt>cond</tt>.
4211If the operands are vectors, then the vectors are compared
4212element by element.
4213Each comparison performed
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4214always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4215<ol>
4216 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4217 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4218 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4219 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4220 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4221 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4222 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4223 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4224 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4225 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4226 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4227 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4228 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4229 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4230 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4231 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4232 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4233 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4234 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4235 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4236 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4237 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4238 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4239 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4240 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4241 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4242 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4243 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4244</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4245
4246<h5>Example:</h5>
4247<pre> &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]4248 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4249 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4250 &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]4251</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4252
4253<p>Note that the code generator does not yet support vector types with
4254 the <tt>fcmp</tt> instruction.</p>
4255
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4256</div>
4257
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4258<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4259<div class="doc_subsubsection">
4260 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4261</div>
4262<div class="doc_text">
4263<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4264<pre> &lt;result&gt; = vicmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4265</pre>
4266<h5>Overview:</h5>
4267<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4268element-wise comparison of its two integer vector operands.</p>
4269<h5>Arguments:</h5>
4270<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4271the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4272a value, just a keyword. The possible condition code are:</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4273<ol>
4274 <li><tt>eq</tt>: equal</li>
4275 <li><tt>ne</tt>: not equal </li>
4276 <li><tt>ugt</tt>: unsigned greater than</li>
4277 <li><tt>uge</tt>: unsigned greater or equal</li>
4278 <li><tt>ult</tt>: unsigned less than</li>
4279 <li><tt>ule</tt>: unsigned less or equal</li>
4280 <li><tt>sgt</tt>: signed greater than</li>
4281 <li><tt>sge</tt>: signed greater or equal</li>
4282 <li><tt>slt</tt>: signed less than</li>
4283 <li><tt>sle</tt>: signed less or equal</li>
4284</ol>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4285<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4286<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4287<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4288<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4289according to the condition code given as <tt>cond</tt>. The comparison yields a
4290<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4291identical type as the values being compared. The most significant bit in each
4292element is 1 if the element-wise comparison evaluates to true, and is 0
4293otherwise. All other bits of the result are undefined. The condition codes
4294are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4295instruction</a>.</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4296
4297<h5>Example:</h5>
4298<pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4299 &lt;result&gt; = vicmp eq &lt;2 x i32&gt; &lt; i32 4, i32 0&gt;, &lt; i32 5, i32 0&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4300 &lt;result&gt; = vicmp ult &lt;2 x i8 &gt; &lt; i8 1, i8 2&gt;, &lt; i8 2, i8 2 &gt; <i>; yields: result=&lt;2 x i8&gt; &lt; i8 -1, i8 0 &gt;</i>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4301</pre>
4302</div>
4303
4304<!-- _______________________________________________________________________ -->
4305<div class="doc_subsubsection">
4306 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4307</div>
4308<div class="doc_text">
4309<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4310<pre> &lt;result&gt; = vfcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt;</pre>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4311<h5>Overview:</h5>
4312<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4313element-wise comparison of its two floating point vector operands. The output
4314elements have the same width as the input elements.</p>
4315<h5>Arguments:</h5>
4316<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4317the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4318a value, just a keyword. The possible condition code are:</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4319<ol>
4320 <li><tt>false</tt>: no comparison, always returns false</li>
4321 <li><tt>oeq</tt>: ordered and equal</li>
4322 <li><tt>ogt</tt>: ordered and greater than </li>
4323 <li><tt>oge</tt>: ordered and greater than or equal</li>
4324 <li><tt>olt</tt>: ordered and less than </li>
4325 <li><tt>ole</tt>: ordered and less than or equal</li>
4326 <li><tt>one</tt>: ordered and not equal</li>
4327 <li><tt>ord</tt>: ordered (no nans)</li>
4328 <li><tt>ueq</tt>: unordered or equal</li>
4329 <li><tt>ugt</tt>: unordered or greater than </li>
4330 <li><tt>uge</tt>: unordered or greater than or equal</li>
4331 <li><tt>ult</tt>: unordered or less than </li>
4332 <li><tt>ule</tt>: unordered or less than or equal</li>
4333 <li><tt>une</tt>: unordered or not equal</li>
4334 <li><tt>uno</tt>: unordered (either nans)</li>
4335 <li><tt>true</tt>: no comparison, always returns true</li>
4336</ol>
4337<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4338<a href="#t_floating">floating point</a> typed. They must also be identical
4339types.</p>
4340<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4341<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4342according to the condition code given as <tt>cond</tt>. The comparison yields a
4343<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4344an identical number of elements as the values being compared, and each element
4345having identical with to the width of the floating point elements. The most
4346significant bit in each element is 1 if the element-wise comparison evaluates to
4347true, and is 0 otherwise. All other bits of the result are undefined. The
4348condition codes are evaluated identically to the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4349<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4350
4351<h5>Example:</h5>
4352<pre>
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]4353 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4354 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4355
4356 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4357 &lt;result&gt; = vfcmp ult &lt;2 x double&gt; &lt; double 1, double 2 &gt;, &lt; double 2, double 2&gt;
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4358</pre>
4359</div>
4360
4361<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4362<div class="doc_subsubsection">
4363 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4364</div>
4365
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4366<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4367
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4368<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4369
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4370<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4371<h5>Overview:</h5>
4372<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4373the SSA graph representing the function.</p>
4374<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4375
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4376<p>The type of the incoming values is specified with the first type
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4377field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4378as arguments, with one pair for each predecessor basic block of the
4379current block. Only values of <a href="#t_firstclass">first class</a>
4380type may be used as the value arguments to the PHI node. Only labels
4381may be used as the label arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4382
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4383<p>There must be no non-phi instructions between the start of a basic
4384block and the PHI instructions: i.e. PHI instructions must be first in
4385a basic block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4386
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4387<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4388
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4389<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4390specified by the pair corresponding to the predecessor basic block that executed
4391just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4392
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4393<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4394<pre>
4395Loop: ; Infinite loop that counts from 0 on up...
4396 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4397 %nextindvar = add i32 %indvar, 1
4398 br label %Loop
4399</pre>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4400</div>
4401
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4402<!-- _______________________________________________________________________ -->
4403<div class="doc_subsubsection">
4404 <a name="i_select">'<tt>select</tt>' Instruction</a>
4405</div>
4406
4407<div class="doc_text">
4408
4409<h5>Syntax:</h5>
4410
4411<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4412 &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>
4413
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4414 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4415</pre>
4416
4417<h5>Overview:</h5>
4418
4419<p>
4420The '<tt>select</tt>' instruction is used to choose one value based on a
4421condition, without branching.
4422</p>
4423
4424
4425<h5>Arguments:</h5>
4426
4427<p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4428The '<tt>select</tt>' instruction requires an 'i1' value or
4429a vector of 'i1' values indicating the
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4430condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4431type. If the val1/val2 are vectors and
4432the condition is a scalar, then entire vectors are selected, not
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4433individual elements.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4434</p>
4435
4436<h5>Semantics:</h5>
4437
4438<p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4439If the condition is an i1 and it evaluates to 1, the instruction returns the first
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4440value argument; otherwise, it returns the second value argument.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4441</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4442<p>
4443If the condition is a vector of i1, then the value arguments must
4444be vectors of the same size, and the selection is done element
4445by element.
4446</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4447
4448<h5>Example:</h5>
4449
4450<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4451 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4452</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]4453
4454<p>Note that the code generator does not yet support conditions
4455 with vector type.</p>
4456
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4457</div>
4458
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]4459
4460<!-- _______________________________________________________________________ -->
4461<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4462 <a name="i_call">'<tt>call</tt>' Instruction</a>
4463</div>
4464
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4465<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4466
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4467<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4468<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4469 &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]4470</pre>
4471
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4472<h5>Overview:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4473
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4474<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4475
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4476<h5>Arguments:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4477
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4478<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4479
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4480<ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4481 <li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4482 <p>The optional "tail" marker indicates whether the callee function accesses
4483 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4484 function call is eligible for tail call optimization. Note that calls may
4485 be marked "tail" even if they do not occur before a <a
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4486 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4487 </li>
4488 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4489 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4490 convention</a> the call should use. If none is specified, the call defaults
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4491 to using C calling conventions.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4492 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4493
4494 <li>
4495 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4496 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4497 and '<tt>inreg</tt>' attributes are valid here.</p>
4498 </li>
4499
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4500 <li>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4501 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4502 the type of the return value. Functions that return no value are marked
4503 <tt><a href="#t_void">void</a></tt>.</p>
4504 </li>
4505 <li>
4506 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4507 value being invoked. The argument types must match the types implied by
4508 this signature. This type can be omitted if the function is not varargs
4509 and if the function type does not return a pointer to a function.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4510 </li>
4511 <li>
4512 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4513 be invoked. In most cases, this is a direct function invocation, but
4514 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4515 to function value.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4516 </li>
4517 <li>
4518 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencerd845d162005-05-01 22:22:57 +0000[diff] [blame]4519 function signature argument types. All arguments must be of
4520 <a href="#t_firstclass">first class</a> type. If the function signature
4521 indicates the function accepts a variable number of arguments, the extra
4522 arguments can be specified.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4523 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4524 <li>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4525 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4526 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4527 '<tt>readnone</tt>' attributes are valid here.</p>
4528 </li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4529</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4530
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4531<h5>Semantics:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4532
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4533<p>The '<tt>call</tt>' instruction is used to cause control flow to
4534transfer to a specified function, with its incoming arguments bound to
4535the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4536instruction in the called function, control flow continues with the
4537instruction after the function call, and the return value of the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4538function is bound to the result argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4539
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4540<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4541
4542<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4543 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]4544 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4545 %X = tail call i32 @foo() <i>; yields i32</i>
4546 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4547 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4548
4549 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4550 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]4551 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4552 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]4553 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]4554 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4555</pre>
4556
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4557</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4558
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4559<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4560<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4561 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4562</div>
4563
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4564<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4565
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4566<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4567
4568<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4569 &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]4570</pre>
4571
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4572<h5>Overview:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4573
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4574<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4575the "variable argument" area of a function call. It is used to implement the
4576<tt>va_arg</tt> macro in C.</p>
4577
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4578<h5>Arguments:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4579
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4580<p>This instruction takes a <tt>va_list*</tt> value and the type of
4581the argument. It returns a value of the specified argument type and
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4582increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4583actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4584
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4585<h5>Semantics:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4586
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4587<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4588type from the specified <tt>va_list</tt> and causes the
4589<tt>va_list</tt> to point to the next argument. For more information,
4590see the variable argument handling <a href="#int_varargs">Intrinsic
4591Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4592
4593<p>It is legal for this instruction to be called in a function which does not
4594take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4595function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4596
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4597<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4598href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4599argument.</p>
4600
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4601<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4602
4603<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4604
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]4605<p>Note that the code generator does not yet fully support va_arg
4606 on many targets. Also, it does not currently support va_arg with
4607 aggregate types on any target.</p>
4608
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4609</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4610
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4611<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4612<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4613<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4614
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4615<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4616
4617<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4618well known names and semantics and are required to follow certain restrictions.
4619Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4620language that does not require changing all of the transformations in LLVM when
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]4621adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4622
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4623<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4624prefix is reserved in LLVM for intrinsic names; thus, function names may not
4625begin with this prefix. Intrinsic functions must always be external functions:
4626you cannot define the body of intrinsic functions. Intrinsic functions may
4627only be used in call or invoke instructions: it is illegal to take the address
4628of an intrinsic function. Additionally, because intrinsic functions are part
4629of the LLVM language, it is required if any are added that they be documented
4630here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4631
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4632<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4633a family of functions that perform the same operation but on different data
4634types. Because LLVM can represent over 8 million different integer types,
4635overloading is used commonly to allow an intrinsic function to operate on any
4636integer type. One or more of the argument types or the result type can be
4637overloaded to accept any integer type. Argument types may also be defined as
4638exactly matching a previous argument's type or the result type. This allows an
4639intrinsic function which accepts multiple arguments, but needs all of them to
4640be of the same type, to only be overloaded with respect to a single argument or
4641the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4642
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4643<p>Overloaded intrinsics will have the names of its overloaded argument types
4644encoded into its function name, each preceded by a period. Only those types
4645which are overloaded result in a name suffix. Arguments whose type is matched
4646against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4647take an integer of any width and returns an integer of exactly the same integer
4648width. This leads to a family of functions such as
4649<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4650Only one type, the return type, is overloaded, and only one type suffix is
4651required. Because the argument's type is matched against the return type, it
4652does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4653
4654<p>To learn how to add an intrinsic function, please see the
4655<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4656</p>
4657
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4658</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4659
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4660<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4661<div class="doc_subsection">
4662 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4663</div>
4664
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4665<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4666
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4667<p>Variable argument support is defined in LLVM with the <a
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4668 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4669intrinsic functions. These functions are related to the similarly
4670named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4671
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4672<p>All of these functions operate on arguments that use a
4673target-specific value type "<tt>va_list</tt>". The LLVM assembly
4674language reference manual does not define what this type is, so all
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4675transformations should be prepared to handle these functions regardless of
4676the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4677
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]4678<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4679instruction and the variable argument handling intrinsic functions are
4680used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4681
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4682<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4683<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4684define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4685 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4686 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4687 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4688 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4689
4690 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4691 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4692
4693 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4694 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4695 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4696 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4697 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4698
4699 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4700 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4701 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4702}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4703
4704declare void @llvm.va_start(i8*)
4705declare void @llvm.va_copy(i8*, i8*)
4706declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4707</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4708</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4709
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4710</div>
4711
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4712<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4713<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4714 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4715</div>
4716
4717
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4718<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4719<h5>Syntax:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4720<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4721<h5>Overview:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4722<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4723<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4724href="#i_va_arg">va_arg</a></tt>.</p>
4725
4726<h5>Arguments:</h5>
4727
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4728<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]4729
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4730<h5>Semantics:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4731
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4732<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4733macro available in C. In a target-dependent way, it initializes the
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4734<tt>va_list</tt> element to which the argument points, so that the next call to
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4735<tt>va_arg</tt> will produce the first variable argument passed to the function.
4736Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4737last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4738
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4739</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4740
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4741<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4742<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4743 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4744</div>
4745
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4746<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4747<h5>Syntax:</h5>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4748<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4749<h5>Overview:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4750
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4751<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4752which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4753or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4754
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4755<h5>Arguments:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4756
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4757<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]4758
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4759<h5>Semantics:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4760
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4761<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4762macro available in C. In a target-dependent way, it destroys the
4763<tt>va_list</tt> element to which the argument points. Calls to <a
4764href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4765<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4766<tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4767
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4768</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4769
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4770<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4771<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4772 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4773</div>
4774
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4775<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4776
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4777<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4778
4779<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4780 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4781</pre>
4782
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4783<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4784
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4785<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4786from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4787
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4788<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4789
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4790<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Andrew Lenharth5305ea52005-06-22 20:38:11 +0000[diff] [blame]4791The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4792
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4793
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4794<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4795
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4796<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4797macro available in C. In a target-dependent way, it copies the source
4798<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4799intrinsic is necessary because the <tt><a href="#int_va_start">
4800llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4801example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4802
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4803</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4804
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4805<!-- ======================================================================= -->
4806<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4807 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4808</div>
4809
4810<div class="doc_text">
4811
4812<p>
4813LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]4814Collection</a> (GC) requires the implementation and generation of these
4815intrinsics.
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4816These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4817stack</a>, as well as garbage collector implementations that require <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4818href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4819Front-ends for type-safe garbage collected languages should generate these
4820intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4821href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4822</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]4823
4824<p>The garbage collection intrinsics only operate on objects in the generic
4825 address space (address space zero).</p>
4826
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4827</div>
4828
4829<!-- _______________________________________________________________________ -->
4830<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4831 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4832</div>
4833
4834<div class="doc_text">
4835
4836<h5>Syntax:</h5>
4837
4838<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4839 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4840</pre>
4841
4842<h5>Overview:</h5>
4843
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]4844<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4845the code generator, and allows some metadata to be associated with it.</p>
4846
4847<h5>Arguments:</h5>
4848
4849<p>The first argument specifies the address of a stack object that contains the
4850root pointer. The second pointer (which must be either a constant or a global
4851value address) contains the meta-data to be associated with the root.</p>
4852
4853<h5>Semantics:</h5>
4854
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]4855<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4856location. At compile-time, the code generator generates information to allow
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4857the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4858intrinsic may only be used in a function which <a href="#gc">specifies a GC
4859algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4860
4861</div>
4862
4863
4864<!-- _______________________________________________________________________ -->
4865<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4866 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4867</div>
4868
4869<div class="doc_text">
4870
4871<h5>Syntax:</h5>
4872
4873<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4874 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4875</pre>
4876
4877<h5>Overview:</h5>
4878
4879<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4880locations, allowing garbage collector implementations that require read
4881barriers.</p>
4882
4883<h5>Arguments:</h5>
4884
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4885<p>The second argument is the address to read from, which should be an address
4886allocated from the garbage collector. The first object is a pointer to the
4887start of the referenced object, if needed by the language runtime (otherwise
4888null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4889
4890<h5>Semantics:</h5>
4891
4892<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4893instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4894garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4895may only be used in a function which <a href="#gc">specifies a GC
4896algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4897
4898</div>
4899
4900
4901<!-- _______________________________________________________________________ -->
4902<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4903 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4904</div>
4905
4906<div class="doc_text">
4907
4908<h5>Syntax:</h5>
4909
4910<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4911 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4912</pre>
4913
4914<h5>Overview:</h5>
4915
4916<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4917locations, allowing garbage collector implementations that require write
4918barriers (such as generational or reference counting collectors).</p>
4919
4920<h5>Arguments:</h5>
4921
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4922<p>The first argument is the reference to store, the second is the start of the
4923object to store it to, and the third is the address of the field of Obj to
4924store to. If the runtime does not require a pointer to the object, Obj may be
4925null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4926
4927<h5>Semantics:</h5>
4928
4929<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4930instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4931garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4932may only be used in a function which <a href="#gc">specifies a GC
4933algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4934
4935</div>
4936
4937
4938
4939<!-- ======================================================================= -->
4940<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4941 <a name="int_codegen">Code Generator Intrinsics</a>
4942</div>
4943
4944<div class="doc_text">
4945<p>
4946These intrinsics are provided by LLVM to expose special features that may only
4947be implemented with code generator support.
4948</p>
4949
4950</div>
4951
4952<!-- _______________________________________________________________________ -->
4953<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4954 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4955</div>
4956
4957<div class="doc_text">
4958
4959<h5>Syntax:</h5>
4960<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4961 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4962</pre>
4963
4964<h5>Overview:</h5>
4965
4966<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4967The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4968target-specific value indicating the return address of the current function
4969or one of its callers.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4970</p>
4971
4972<h5>Arguments:</h5>
4973
4974<p>
4975The argument to this intrinsic indicates which function to return the address
4976for. Zero indicates the calling function, one indicates its caller, etc. The
4977argument is <b>required</b> to be a constant integer value.
4978</p>
4979
4980<h5>Semantics:</h5>
4981
4982<p>
4983The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4984the return address of the specified call frame, or zero if it cannot be
4985identified. The value returned by this intrinsic is likely to be incorrect or 0
4986for arguments other than zero, so it should only be used for debugging purposes.
4987</p>
4988
4989<p>
4990Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4991aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4992source-language caller.
4993</p>
4994</div>
4995
4996
4997<!-- _______________________________________________________________________ -->
4998<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4999 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5000</div>
5001
5002<div class="doc_text">
5003
5004<h5>Syntax:</h5>
5005<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5006 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5007</pre>
5008
5009<h5>Overview:</h5>
5010
5011<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]5012The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5013target-specific frame pointer value for the specified stack frame.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5014</p>
5015
5016<h5>Arguments:</h5>
5017
5018<p>
5019The argument to this intrinsic indicates which function to return the frame
5020pointer for. Zero indicates the calling function, one indicates its caller,
5021etc. The argument is <b>required</b> to be a constant integer value.
5022</p>
5023
5024<h5>Semantics:</h5>
5025
5026<p>
5027The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
5028the frame address of the specified call frame, or zero if it cannot be
5029identified. The value returned by this intrinsic is likely to be incorrect or 0
5030for arguments other than zero, so it should only be used for debugging purposes.
5031</p>
5032
5033<p>
5034Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]5035aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5036source-language caller.
5037</p>
5038</div>
5039
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5040<!-- _______________________________________________________________________ -->
5041<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5042 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5043</div>
5044
5045<div class="doc_text">
5046
5047<h5>Syntax:</h5>
5048<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5049 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5050</pre>
5051
5052<h5>Overview:</h5>
5053
5054<p>
5055The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5056the function stack, for use with <a href="#int_stackrestore">
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5057<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
5058features like scoped automatic variable sized arrays in C99.
5059</p>
5060
5061<h5>Semantics:</h5>
5062
5063<p>
5064This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5065href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5066<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
5067<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
5068state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
5069practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
5070that were allocated after the <tt>llvm.stacksave</tt> was executed.
5071</p>
5072
5073</div>
5074
5075<!-- _______________________________________________________________________ -->
5076<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5077 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5078</div>
5079
5080<div class="doc_text">
5081
5082<h5>Syntax:</h5>
5083<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5084 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5085</pre>
5086
5087<h5>Overview:</h5>
5088
5089<p>
5090The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5091the function stack to the state it was in when the corresponding <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5092href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5093useful for implementing language features like scoped automatic variable sized
5094arrays in C99.
5095</p>
5096
5097<h5>Semantics:</h5>
5098
5099<p>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5100See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5101</p>
5102
5103</div>
5104
5105
5106<!-- _______________________________________________________________________ -->
5107<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5108 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5109</div>
5110
5111<div class="doc_text">
5112
5113<h5>Syntax:</h5>
5114<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5115 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]5116</pre>
5117
5118<h5>Overview:</h5>
5119
5120
5121<p>
5122The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5123a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
5124no
5125effect on the behavior of the program but can change its performance
Chris Lattnerff851072005-02-28 19:47:14 +0000[diff] [blame]5126characteristics.
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5127</p>
5128
5129<h5>Arguments:</h5>
5130
5131<p>
5132<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
5133determining if the fetch should be for a read (0) or write (1), and
5134<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattnerd3e641c2005-03-07 20:31:38 +0000[diff] [blame]5135locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5136<tt>locality</tt> arguments must be constant integers.
5137</p>
5138
5139<h5>Semantics:</h5>
5140
5141<p>
5142This intrinsic does not modify the behavior of the program. In particular,
5143prefetches cannot trap and do not produce a value. On targets that support this
5144intrinsic, the prefetch can provide hints to the processor cache for better
5145performance.
5146</p>
5147
5148</div>
5149
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5150<!-- _______________________________________________________________________ -->
5151<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5152 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5153</div>
5154
5155<div class="doc_text">
5156
5157<h5>Syntax:</h5>
5158<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5159 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5160</pre>
5161
5162<h5>Overview:</h5>
5163
5164
5165<p>
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5166The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5167(PC) in a region of
5168code to simulators and other tools. The method is target specific, but it is
5169expected that the marker will use exported symbols to transmit the PC of the
5170marker.
5171The marker makes no guarantees that it will remain with any specific instruction
5172after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb40261e2006-03-24 07:16:10 +0000[diff] [blame]5173optimizations. The intended use is to be inserted after optimizations to allow
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5174correlations of simulation runs.
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5175</p>
5176
5177<h5>Arguments:</h5>
5178
5179<p>
5180<tt>id</tt> is a numerical id identifying the marker.
5181</p>
5182
5183<h5>Semantics:</h5>
5184
5185<p>
5186This intrinsic does not modify the behavior of the program. Backends that do not
5187support this intrinisic may ignore it.
5188</p>
5189
5190</div>
5191
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5192<!-- _______________________________________________________________________ -->
5193<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5194 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5195</div>
5196
5197<div class="doc_text">
5198
5199<h5>Syntax:</h5>
5200<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5201 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5202</pre>
5203
5204<h5>Overview:</h5>
5205
5206
5207<p>
5208The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5209counter register (or similar low latency, high accuracy clocks) on those targets
5210that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5211As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5212should only be used for small timings.
5213</p>
5214
5215<h5>Semantics:</h5>
5216
5217<p>
5218When directly supported, reading the cycle counter should not modify any memory.
5219Implementations are allowed to either return a application specific value or a
5220system wide value. On backends without support, this is lowered to a constant 0.
5221</p>
5222
5223</div>
5224
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5225<!-- ======================================================================= -->
5226<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5227 <a name="int_libc">Standard C Library Intrinsics</a>
5228</div>
5229
5230<div class="doc_text">
5231<p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5232LLVM provides intrinsics for a few important standard C library functions.
5233These intrinsics allow source-language front-ends to pass information about the
5234alignment of the pointer arguments to the code generator, providing opportunity
5235for more efficient code generation.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5236</p>
5237
5238</div>
5239
5240<!-- _______________________________________________________________________ -->
5241<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5242 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5243</div>
5244
5245<div class="doc_text">
5246
5247<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5248<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
5249width. Not all targets support all bit widths however.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5250<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5251 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5252 i8 &lt;len&gt;, i32 &lt;align&gt;)
5253 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5254 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5255 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5256 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5257 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5258 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5259</pre>
5260
5261<h5>Overview:</h5>
5262
5263<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5264The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5265location to the destination location.
5266</p>
5267
5268<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5269Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5270intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5271</p>
5272
5273<h5>Arguments:</h5>
5274
5275<p>
5276The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5277the source. The third argument is an integer argument
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5278specifying the number of bytes to copy, and the fourth argument is the alignment
5279of the source and destination locations.
5280</p>
5281
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5282<p>
5283If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner5316e5d2006-03-04 00:02:10 +0000[diff] [blame]5284the caller guarantees that both the source and destination pointers are aligned
5285to that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5286</p>
5287
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5288<h5>Semantics:</h5>
5289
5290<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5291The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5292location to the destination location, which are not allowed to overlap. It
5293copies "len" bytes of memory over. If the argument is known to be aligned to
5294some boundary, this can be specified as the fourth argument, otherwise it should
5295be set to 0 or 1.
5296</p>
5297</div>
5298
5299
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5300<!-- _______________________________________________________________________ -->
5301<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5302 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5303</div>
5304
5305<div class="doc_text">
5306
5307<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5308<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
5309width. Not all targets support all bit widths however.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5310<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5311 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5312 i8 &lt;len&gt;, i32 &lt;align&gt;)
5313 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5314 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5315 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5316 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5317 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5318 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5319</pre>
5320
5321<h5>Overview:</h5>
5322
5323<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5324The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5325location to the destination location. It is similar to the
Chris Lattnerec564022008-01-06 19:51:52 +0000[diff] [blame]5326'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5327</p>
5328
5329<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5330Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5331intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5332</p>
5333
5334<h5>Arguments:</h5>
5335
5336<p>
5337The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5338the source. The third argument is an integer argument
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5339specifying the number of bytes to copy, and the fourth argument is the alignment
5340of the source and destination locations.
5341</p>
5342
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5343<p>
5344If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner5316e5d2006-03-04 00:02:10 +0000[diff] [blame]5345the caller guarantees that the source and destination pointers are aligned to
5346that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5347</p>
5348
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5349<h5>Semantics:</h5>
5350
5351<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5352The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5353location to the destination location, which may overlap. It
5354copies "len" bytes of memory over. If the argument is known to be aligned to
5355some boundary, this can be specified as the fourth argument, otherwise it should
5356be set to 0 or 1.
5357</p>
5358</div>
5359
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5360
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5361<!-- _______________________________________________________________________ -->
5362<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5363 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5364</div>
5365
5366<div class="doc_text">
5367
5368<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5369<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
5370width. Not all targets support all bit widths however.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5371<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5372 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5373 i8 &lt;len&gt;, i32 &lt;align&gt;)
5374 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5375 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5376 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5377 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5378 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5379 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5380</pre>
5381
5382<h5>Overview:</h5>
5383
5384<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5385The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5386byte value.
5387</p>
5388
5389<p>
5390Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5391does not return a value, and takes an extra alignment argument.
5392</p>
5393
5394<h5>Arguments:</h5>
5395
5396<p>
5397The first argument is a pointer to the destination to fill, the second is the
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5398byte value to fill it with, the third argument is an integer
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5399argument specifying the number of bytes to fill, and the fourth argument is the
5400known alignment of destination location.
5401</p>
5402
5403<p>
5404If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner5316e5d2006-03-04 00:02:10 +0000[diff] [blame]5405the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5406</p>
5407
5408<h5>Semantics:</h5>
5409
5410<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5411The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5412the
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5413destination location. If the argument is known to be aligned to some boundary,
5414this can be specified as the fourth argument, otherwise it should be set to 0 or
54151.
5416</p>
5417</div>
5418
5419
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5420<!-- _______________________________________________________________________ -->
5421<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5422 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5423</div>
5424
5425<div class="doc_text">
5426
5427<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5428<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5429floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5430types however.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5431<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5432 declare float @llvm.sqrt.f32(float %Val)
5433 declare double @llvm.sqrt.f64(double %Val)
5434 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5435 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5436 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5437</pre>
5438
5439<h5>Overview:</h5>
5440
5441<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5442The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5443returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5444<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner00d7cb92008-01-29 07:00:44 +0000[diff] [blame]5445negative numbers other than -0.0 (which allows for better optimization, because
5446there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5447defined to return -0.0 like IEEE sqrt.
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5448</p>
5449
5450<h5>Arguments:</h5>
5451
5452<p>
5453The argument and return value are floating point numbers of the same type.
5454</p>
5455
5456<h5>Semantics:</h5>
5457
5458<p>
Dan Gohman33988db2007-07-16 14:37:41 +0000[diff] [blame]5459This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5460floating point number.
5461</p>
5462</div>
5463
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5464<!-- _______________________________________________________________________ -->
5465<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5466 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5467</div>
5468
5469<div class="doc_text">
5470
5471<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5472<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5473floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5474types however.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5475<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5476 declare float @llvm.powi.f32(float %Val, i32 %power)
5477 declare double @llvm.powi.f64(double %Val, i32 %power)
5478 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5479 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5480 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5481</pre>
5482
5483<h5>Overview:</h5>
5484
5485<p>
5486The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5487specified (positive or negative) power. The order of evaluation of
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5488multiplications is not defined. When a vector of floating point type is
5489used, the second argument remains a scalar integer value.
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5490</p>
5491
5492<h5>Arguments:</h5>
5493
5494<p>
5495The second argument is an integer power, and the first is a value to raise to
5496that power.
5497</p>
5498
5499<h5>Semantics:</h5>
5500
5501<p>
5502This function returns the first value raised to the second power with an
5503unspecified sequence of rounding operations.</p>
5504</div>
5505
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5506<!-- _______________________________________________________________________ -->
5507<div class="doc_subsubsection">
5508 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5509</div>
5510
5511<div class="doc_text">
5512
5513<h5>Syntax:</h5>
5514<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5515floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5516types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5517<pre>
5518 declare float @llvm.sin.f32(float %Val)
5519 declare double @llvm.sin.f64(double %Val)
5520 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5521 declare fp128 @llvm.sin.f128(fp128 %Val)
5522 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5523</pre>
5524
5525<h5>Overview:</h5>
5526
5527<p>
5528The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5529</p>
5530
5531<h5>Arguments:</h5>
5532
5533<p>
5534The argument and return value are floating point numbers of the same type.
5535</p>
5536
5537<h5>Semantics:</h5>
5538
5539<p>
5540This function returns the sine of the specified operand, returning the
5541same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5542conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5543</div>
5544
5545<!-- _______________________________________________________________________ -->
5546<div class="doc_subsubsection">
5547 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5548</div>
5549
5550<div class="doc_text">
5551
5552<h5>Syntax:</h5>
5553<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5554floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5555types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5556<pre>
5557 declare float @llvm.cos.f32(float %Val)
5558 declare double @llvm.cos.f64(double %Val)
5559 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5560 declare fp128 @llvm.cos.f128(fp128 %Val)
5561 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5562</pre>
5563
5564<h5>Overview:</h5>
5565
5566<p>
5567The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5568</p>
5569
5570<h5>Arguments:</h5>
5571
5572<p>
5573The argument and return value are floating point numbers of the same type.
5574</p>
5575
5576<h5>Semantics:</h5>
5577
5578<p>
5579This function returns the cosine of the specified operand, returning the
5580same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5581conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5582</div>
5583
5584<!-- _______________________________________________________________________ -->
5585<div class="doc_subsubsection">
5586 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5587</div>
5588
5589<div class="doc_text">
5590
5591<h5>Syntax:</h5>
5592<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5593floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5594types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5595<pre>
5596 declare float @llvm.pow.f32(float %Val, float %Power)
5597 declare double @llvm.pow.f64(double %Val, double %Power)
5598 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5599 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5600 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5601</pre>
5602
5603<h5>Overview:</h5>
5604
5605<p>
5606The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5607specified (positive or negative) power.
5608</p>
5609
5610<h5>Arguments:</h5>
5611
5612<p>
5613The second argument is a floating point power, and the first is a value to
5614raise to that power.
5615</p>
5616
5617<h5>Semantics:</h5>
5618
5619<p>
5620This function returns the first value raised to the second power,
5621returning the
5622same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5623conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5624</div>
5625
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5626
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5627<!-- ======================================================================= -->
5628<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5629 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5630</div>
5631
5632<div class="doc_text">
5633<p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5634LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5635These allow efficient code generation for some algorithms.
5636</p>
5637
5638</div>
5639
5640<!-- _______________________________________________________________________ -->
5641<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5642 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5643</div>
5644
5645<div class="doc_text">
5646
5647<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5648<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5649type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5650<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5651 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5652 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5653 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5654</pre>
5655
5656<h5>Overview:</h5>
5657
5658<p>
Reid Spencerf361c4f2007-04-02 02:25:19 +0000[diff] [blame]5659The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5660values with an even number of bytes (positive multiple of 16 bits). These are
5661useful for performing operations on data that is not in the target's native
5662byte order.
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5663</p>
5664
5665<h5>Semantics:</h5>
5666
5667<p>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5668The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5669and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5670intrinsic returns an i32 value that has the four bytes of the input i32
5671swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5672i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5673<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5674additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5675</p>
5676
5677</div>
5678
5679<!-- _______________________________________________________________________ -->
5680<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5681 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5682</div>
5683
5684<div class="doc_text">
5685
5686<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5687<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5688width. Not all targets support all bit widths however.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5689<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5690 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
5691 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5692 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5693 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5694 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5695</pre>
5696
5697<h5>Overview:</h5>
5698
5699<p>
Chris Lattner069b5bd2006-01-16 22:38:59 +0000[diff] [blame]5700The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5701value.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5702</p>
5703
5704<h5>Arguments:</h5>
5705
5706<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5707The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5708integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5709</p>
5710
5711<h5>Semantics:</h5>
5712
5713<p>
5714The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5715</p>
5716</div>
5717
5718<!-- _______________________________________________________________________ -->
5719<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5720 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5721</div>
5722
5723<div class="doc_text">
5724
5725<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5726<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5727integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5728<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5729 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5730 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5731 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5732 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5733 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5734</pre>
5735
5736<h5>Overview:</h5>
5737
5738<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5739The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5740leading zeros in a variable.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5741</p>
5742
5743<h5>Arguments:</h5>
5744
5745<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5746The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5747integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5748</p>
5749
5750<h5>Semantics:</h5>
5751
5752<p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5753The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5754in a variable. If the src == 0 then the result is the size in bits of the type
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5755of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5756</p>
5757</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5758
5759
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5760
5761<!-- _______________________________________________________________________ -->
5762<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5763 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5764</div>
5765
5766<div class="doc_text">
5767
5768<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5769<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5770integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5771<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5772 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5773 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5774 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5775 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5776 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5777</pre>
5778
5779<h5>Overview:</h5>
5780
5781<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5782The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5783trailing zeros.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5784</p>
5785
5786<h5>Arguments:</h5>
5787
5788<p>
5789The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5790integer type. The return type must match the argument type.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5791</p>
5792
5793<h5>Semantics:</h5>
5794
5795<p>
5796The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5797in a variable. If the src == 0 then the result is the size in bits of the type
5798of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5799</p>
5800</div>
5801
Reid Spencer8a5799f2007-04-01 08:27:01 +0000[diff] [blame]5802<!-- _______________________________________________________________________ -->
5803<div class="doc_subsubsection">
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5804 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5805</div>
5806
5807<div class="doc_text">
5808
5809<h5>Syntax:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5810<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5811on any integer bit width.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5812<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5813 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5814 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5815</pre>
5816
5817<h5>Overview:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5818<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5819range of bits from an integer value and returns them in the same bit width as
5820the original value.</p>
5821
5822<h5>Arguments:</h5>
5823<p>The first argument, <tt>%val</tt> and the result may be integer types of
5824any bit width but they must have the same bit width. The second and third
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5825arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5826
5827<h5>Semantics:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5828<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5829of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5830<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5831operates in forward mode.</p>
5832<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5833right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5834only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5835<ol>
5836 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5837 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5838 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5839 to determine the number of bits to retain.</li>
5840 <li>A mask of the retained bits is created by shifting a -1 value.</li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5841 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5842</ol>
Reid Spencer70845c02007-05-14 16:14:57 +0000[diff] [blame]5843<p>In reverse mode, a similar computation is made except that the bits are
5844returned in the reverse order. So, for example, if <tt>X</tt> has the value
5845<tt>i16 0x0ACF (101011001111)</tt> and we apply
5846<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5847<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5848</div>
5849
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5850<div class="doc_subsubsection">
5851 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5852</div>
5853
5854<div class="doc_text">
5855
5856<h5>Syntax:</h5>
5857<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5858on any integer bit width.</p>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5859<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5860 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5861 declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5862</pre>
5863
5864<h5>Overview:</h5>
5865<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5866of bits in an integer value with another integer value. It returns the integer
5867with the replaced bits.</p>
5868
5869<h5>Arguments:</h5>
5870<p>The first argument, <tt>%val</tt> and the result may be integer types of
5871any bit width but they must have the same bit width. <tt>%val</tt> is the value
5872whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5873integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5874type since they specify only a bit index.</p>
5875
5876<h5>Semantics:</h5>
5877<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5878of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5879<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5880operates in forward mode.</p>
5881<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5882truncating it down to the size of the replacement area or zero extending it
5883up to that size.</p>
5884<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5885are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5886in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5887to the <tt>%hi</tt>th bit.</p>
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5888<p>In reverse mode, a similar computation is made except that the bits are
5889reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5890<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5891<h5>Examples:</h5>
5892<pre>
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5893 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5894 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5895 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5896 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5897 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]5898</pre>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5899</div>
5900
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5901<!-- ======================================================================= -->
5902<div class="doc_subsection">
5903 <a name="int_debugger">Debugger Intrinsics</a>
5904</div>
5905
5906<div class="doc_text">
5907<p>
5908The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5909are described in the <a
5910href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5911Debugging</a> document.
5912</p>
5913</div>
5914
5915
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]5916<!-- ======================================================================= -->
5917<div class="doc_subsection">
5918 <a name="int_eh">Exception Handling Intrinsics</a>
5919</div>
5920
5921<div class="doc_text">
5922<p> The LLVM exception handling intrinsics (which all start with
5923<tt>llvm.eh.</tt> prefix), are described in the <a
5924href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5925Handling</a> document. </p>
5926</div>
5927
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]5928<!-- ======================================================================= -->
5929<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5930 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5931</div>
5932
5933<div class="doc_text">
5934<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5935 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5936 the <tt>nest</tt> attribute, from a function. The result is a callable
5937 function pointer lacking the nest parameter - the caller does not need
5938 to provide a value for it. Instead, the value to use is stored in
5939 advance in a "trampoline", a block of memory usually allocated
5940 on the stack, which also contains code to splice the nest value into the
5941 argument list. This is used to implement the GCC nested function address
5942 extension.
5943</p>
5944<p>
5945 For example, if the function is
5946 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling252570f2007-09-22 09:23:55 +0000[diff] [blame]5947 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5948<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5949 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5950 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5951 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5952 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5953</pre>
Bill Wendling252570f2007-09-22 09:23:55 +0000[diff] [blame]5954 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5955 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5956</div>
5957
5958<!-- _______________________________________________________________________ -->
5959<div class="doc_subsubsection">
5960 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5961</div>
5962<div class="doc_text">
5963<h5>Syntax:</h5>
5964<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5965declare 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]5966</pre>
5967<h5>Overview:</h5>
5968<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5969 This fills the memory pointed to by <tt>tramp</tt> with code
5970 and returns a function pointer suitable for executing it.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5971</p>
5972<h5>Arguments:</h5>
5973<p>
5974 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5975 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5976 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsf2bcd372007-08-22 23:39:54 +0000[diff] [blame]5977 intrinsic. Note that the size and the alignment are target-specific - LLVM
5978 currently provides no portable way of determining them, so a front-end that
5979 generates this intrinsic needs to have some target-specific knowledge.
5980 The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5981</p>
5982<h5>Semantics:</h5>
5983<p>
5984 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5985 dependent code, turning it into a function. A pointer to this function is
5986 returned, but needs to be bitcast to an
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5987 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5988 before being called. The new function's signature is the same as that of
5989 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5990 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5991 of pointer type. Calling the new function is equivalent to calling
5992 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5993 missing <tt>nest</tt> argument. If, after calling
5994 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5995 modified, then the effect of any later call to the returned function pointer is
5996 undefined.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5997</p>
5998</div>
5999
6000<!-- ======================================================================= -->
6001<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6002 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6003</div>
6004
6005<div class="doc_text">
6006<p>
6007 These intrinsic functions expand the "universal IR" of LLVM to represent
6008 hardware constructs for atomic operations and memory synchronization. This
6009 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]6010 is aimed at a low enough level to allow any programming models or APIs
6011 (Application Programming Interfaces) which
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6012 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
6013 hardware behavior. Just as hardware provides a "universal IR" for source
6014 languages, it also provides a starting point for developing a "universal"
6015 atomic operation and synchronization IR.
6016</p>
6017<p>
6018 These do <em>not</em> form an API such as high-level threading libraries,
6019 software transaction memory systems, atomic primitives, and intrinsic
6020 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6021 application libraries. The hardware interface provided by LLVM should allow
6022 a clean implementation of all of these APIs and parallel programming models.
6023 No one model or paradigm should be selected above others unless the hardware
6024 itself ubiquitously does so.
6025
6026</p>
6027</div>
6028
6029<!-- _______________________________________________________________________ -->
6030<div class="doc_subsubsection">
6031 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6032</div>
6033<div class="doc_text">
6034<h5>Syntax:</h5>
6035<pre>
6036declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
6037i1 &lt;device&gt; )
6038
6039</pre>
6040<h5>Overview:</h5>
6041<p>
6042 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6043 specific pairs of memory access types.
6044</p>
6045<h5>Arguments:</h5>
6046<p>
6047 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6048 The first four arguments enables a specific barrier as listed below. The fith
6049 argument specifies that the barrier applies to io or device or uncached memory.
6050
6051</p>
6052 <ul>
6053 <li><tt>ll</tt>: load-load barrier</li>
6054 <li><tt>ls</tt>: load-store barrier</li>
6055 <li><tt>sl</tt>: store-load barrier</li>
6056 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6057 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6058 </ul>
6059<h5>Semantics:</h5>
6060<p>
6061 This intrinsic causes the system to enforce some ordering constraints upon
6062 the loads and stores of the program. This barrier does not indicate
6063 <em>when</em> any events will occur, it only enforces an <em>order</em> in
6064 which they occur. For any of the specified pairs of load and store operations
6065 (f.ex. load-load, or store-load), all of the first operations preceding the
6066 barrier will complete before any of the second operations succeeding the
6067 barrier begin. Specifically the semantics for each pairing is as follows:
6068</p>
6069 <ul>
6070 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6071 after the barrier begins.</li>
6072
6073 <li><tt>ls</tt>: All loads before the barrier must complete before any
6074 store after the barrier begins.</li>
6075 <li><tt>ss</tt>: All stores before the barrier must complete before any
6076 store after the barrier begins.</li>
6077 <li><tt>sl</tt>: All stores before the barrier must complete before any
6078 load after the barrier begins.</li>
6079 </ul>
6080<p>
6081 These semantics are applied with a logical "and" behavior when more than one
6082 is enabled in a single memory barrier intrinsic.
6083</p>
6084<p>
6085 Backends may implement stronger barriers than those requested when they do not
6086 support as fine grained a barrier as requested. Some architectures do not
6087 need all types of barriers and on such architectures, these become noops.
6088</p>
6089<h5>Example:</h5>
6090<pre>
6091%ptr = malloc i32
6092 store i32 4, %ptr
6093
6094%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6095 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6096 <i>; guarantee the above finishes</i>
6097 store i32 8, %ptr <i>; before this begins</i>
6098</pre>
6099</div>
6100
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6101<!-- _______________________________________________________________________ -->
6102<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6103 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6104</div>
6105<div class="doc_text">
6106<h5>Syntax:</h5>
6107<p>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6108 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6109 any integer bit width and for different address spaces. Not all targets
6110 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6111
6112<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6113declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6114declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6115declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6116declare 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]6117
6118</pre>
6119<h5>Overview:</h5>
6120<p>
6121 This loads a value in memory and compares it to a given value. If they are
6122 equal, it stores a new value into the memory.
6123</p>
6124<h5>Arguments:</h5>
6125<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6126 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6127 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6128 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6129 this integer type. While any bit width integer may be used, targets may only
6130 lower representations they support in hardware.
6131
6132</p>
6133<h5>Semantics:</h5>
6134<p>
6135 This entire intrinsic must be executed atomically. It first loads the value
6136 in memory pointed to by <tt>ptr</tt> and compares it with the value
6137 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
6138 loaded value is yielded in all cases. This provides the equivalent of an
6139 atomic compare-and-swap operation within the SSA framework.
6140</p>
6141<h5>Examples:</h5>
6142
6143<pre>
6144%ptr = malloc i32
6145 store i32 4, %ptr
6146
6147%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6148%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6149 <i>; yields {i32}:result1 = 4</i>
6150%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6151%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6152
6153%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6154%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6155 <i>; yields {i32}:result2 = 8</i>
6156%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6157
6158%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6159</pre>
6160</div>
6161
6162<!-- _______________________________________________________________________ -->
6163<div class="doc_subsubsection">
6164 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6165</div>
6166<div class="doc_text">
6167<h5>Syntax:</h5>
6168
6169<p>
6170 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6171 integer bit width. Not all targets support all bit widths however.</p>
6172<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6173declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6174declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6175declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6176declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6177
6178</pre>
6179<h5>Overview:</h5>
6180<p>
6181 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6182 the value from memory. It then stores the value in <tt>val</tt> in the memory
6183 at <tt>ptr</tt>.
6184</p>
6185<h5>Arguments:</h5>
6186
6187<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6188 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6189 <tt>val</tt> argument and the result must be integers of the same bit width.
6190 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6191 integer type. The targets may only lower integer representations they
6192 support.
6193</p>
6194<h5>Semantics:</h5>
6195<p>
6196 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6197 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6198 equivalent of an atomic swap operation within the SSA framework.
6199
6200</p>
6201<h5>Examples:</h5>
6202<pre>
6203%ptr = malloc i32
6204 store i32 4, %ptr
6205
6206%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6207%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6208 <i>; yields {i32}:result1 = 4</i>
6209%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6210%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6211
6212%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6213%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6214 <i>; yields {i32}:result2 = 8</i>
6215
6216%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6217%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6218</pre>
6219</div>
6220
6221<!-- _______________________________________________________________________ -->
6222<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6223 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6224
6225</div>
6226<div class="doc_text">
6227<h5>Syntax:</h5>
6228<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6229 This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on any
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6230 integer bit width. Not all targets support all bit widths however.</p>
6231<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6232declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6233declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6234declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6235declare 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]6236
6237</pre>
6238<h5>Overview:</h5>
6239<p>
6240 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6241 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6242</p>
6243<h5>Arguments:</h5>
6244<p>
6245
6246 The intrinsic takes two arguments, the first a pointer to an integer value
6247 and the second an integer value. The result is also an integer value. These
6248 integer types can have any bit width, but they must all have the same bit
6249 width. The targets may only lower integer representations they support.
6250</p>
6251<h5>Semantics:</h5>
6252<p>
6253 This intrinsic does a series of operations atomically. It first loads the
6254 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6255 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6256</p>
6257
6258<h5>Examples:</h5>
6259<pre>
6260%ptr = malloc i32
6261 store i32 4, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6262%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6263 <i>; yields {i32}:result1 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6264%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6265 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6266%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6267 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6268%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6269</pre>
6270</div>
6271
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6272<!-- _______________________________________________________________________ -->
6273<div class="doc_subsubsection">
6274 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6275
6276</div>
6277<div class="doc_text">
6278<h5>Syntax:</h5>
6279<p>
6280 This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6281 any integer bit width and for different address spaces. Not all targets
6282 support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6283<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6284declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6285declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6286declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6287declare 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]6288
6289</pre>
6290<h5>Overview:</h5>
6291<p>
6292 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6293 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6294</p>
6295<h5>Arguments:</h5>
6296<p>
6297
6298 The intrinsic takes two arguments, the first a pointer to an integer value
6299 and the second an integer value. The result is also an integer value. These
6300 integer types can have any bit width, but they must all have the same bit
6301 width. The targets may only lower integer representations they support.
6302</p>
6303<h5>Semantics:</h5>
6304<p>
6305 This intrinsic does a series of operations atomically. It first loads the
6306 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6307 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6308</p>
6309
6310<h5>Examples:</h5>
6311<pre>
6312%ptr = malloc i32
6313 store i32 8, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6314%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6315 <i>; yields {i32}:result1 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6316%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6317 <i>; yields {i32}:result2 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6318%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6319 <i>; yields {i32}:result3 = 2</i>
6320%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6321</pre>
6322</div>
6323
6324<!-- _______________________________________________________________________ -->
6325<div class="doc_subsubsection">
6326 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6327 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6328 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6329 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6330
6331</div>
6332<div class="doc_text">
6333<h5>Syntax:</h5>
6334<p>
6335 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6336 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6337 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6338 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6339<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6340declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6341declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6342declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6343declare 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]6344
6345</pre>
6346
6347<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6348declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6349declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6350declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6351declare 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]6352
6353</pre>
6354
6355<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6356declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6357declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6358declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6359declare 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]6360
6361</pre>
6362
6363<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6364declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6365declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6366declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6367declare 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]6368
6369</pre>
6370<h5>Overview:</h5>
6371<p>
6372 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6373 the value stored in memory at <tt>ptr</tt>. It yields the original value
6374 at <tt>ptr</tt>.
6375</p>
6376<h5>Arguments:</h5>
6377<p>
6378
6379 These intrinsics take two arguments, the first a pointer to an integer value
6380 and the second an integer value. The result is also an integer value. These
6381 integer types can have any bit width, but they must all have the same bit
6382 width. The targets may only lower integer representations they support.
6383</p>
6384<h5>Semantics:</h5>
6385<p>
6386 These intrinsics does a series of operations atomically. They first load the
6387 value stored at <tt>ptr</tt>. They then do the bitwise operation
6388 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6389 value stored at <tt>ptr</tt>.
6390</p>
6391
6392<h5>Examples:</h5>
6393<pre>
6394%ptr = malloc i32
6395 store i32 0x0F0F, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6396%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6397 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6398%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6399 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6400%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6401 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6402%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6403 <i>; yields {i32}:result3 = FF</i>
6404%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6405</pre>
6406</div>
6407
6408
6409<!-- _______________________________________________________________________ -->
6410<div class="doc_subsubsection">
6411 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6412 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6413 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6414 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6415
6416</div>
6417<div class="doc_text">
6418<h5>Syntax:</h5>
6419<p>
6420 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6421 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6422 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6423 address spaces. Not all targets
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6424 support all bit widths however.</p>
6425<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6426declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6427declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6428declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6429declare 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]6430
6431</pre>
6432
6433<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6434declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6435declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6436declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6437declare 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]6438
6439</pre>
6440
6441<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6442declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6443declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6444declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6445declare 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]6446
6447</pre>
6448
6449<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6450declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6451declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6452declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6453declare 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]6454
6455</pre>
6456<h5>Overview:</h5>
6457<p>
6458 These intrinsics takes the signed or unsigned minimum or maximum of
6459 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6460 original value at <tt>ptr</tt>.
6461</p>
6462<h5>Arguments:</h5>
6463<p>
6464
6465 These intrinsics take two arguments, the first a pointer to an integer value
6466 and the second an integer value. The result is also an integer value. These
6467 integer types can have any bit width, but they must all have the same bit
6468 width. The targets may only lower integer representations they support.
6469</p>
6470<h5>Semantics:</h5>
6471<p>
6472 These intrinsics does a series of operations atomically. They first load the
6473 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6474 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6475 the original value stored at <tt>ptr</tt>.
6476</p>
6477
6478<h5>Examples:</h5>
6479<pre>
6480%ptr = malloc i32
6481 store i32 7, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6482%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6483 <i>; yields {i32}:result0 = 7</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6484%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6485 <i>; yields {i32}:result1 = -2</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6486%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6487 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6488%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6489 <i>; yields {i32}:result3 = 8</i>
6490%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6491</pre>
6492</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6493
6494<!-- ======================================================================= -->
6495<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6496 <a name="int_general">General Intrinsics</a>
6497</div>
6498
6499<div class="doc_text">
6500<p> This class of intrinsics is designed to be generic and has
6501no specific purpose. </p>
6502</div>
6503
6504<!-- _______________________________________________________________________ -->
6505<div class="doc_subsubsection">
6506 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6507</div>
6508
6509<div class="doc_text">
6510
6511<h5>Syntax:</h5>
6512<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6513 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]6514</pre>
6515
6516<h5>Overview:</h5>
6517
6518<p>
6519The '<tt>llvm.var.annotation</tt>' intrinsic
6520</p>
6521
6522<h5>Arguments:</h5>
6523
6524<p>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6525The first argument is a pointer to a value, the second is a pointer to a
6526global string, the third is a pointer to a global string which is the source
6527file name, and the last argument is the line number.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6528</p>
6529
6530<h5>Semantics:</h5>
6531
6532<p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6533This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6534This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6535annotations. These have no other defined use, they are ignored by code
6536generation and optimization.
6537</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6538</div>
6539
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6540<!-- _______________________________________________________________________ -->
6541<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]6542 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6543</div>
6544
6545<div class="doc_text">
6546
6547<h5>Syntax:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6548<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6549any integer bit width.
6550</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6551<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]6552 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6553 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6554 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6555 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6556 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]6557</pre>
6558
6559<h5>Overview:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6560
6561<p>
6562The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6563</p>
6564
6565<h5>Arguments:</h5>
6566
6567<p>
6568The first argument is an integer value (result of some expression),
6569the second is a pointer to a global string, the third is a pointer to a global
6570string which is the source file name, and the last argument is the line number.
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6571It returns the value of the first argument.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6572</p>
6573
6574<h5>Semantics:</h5>
6575
6576<p>
6577This intrinsic allows annotations to be put on arbitrary expressions
6578with arbitrary strings. This can be useful for special purpose optimizations
6579that want to look for these annotations. These have no other defined use, they
6580are ignored by code generation and optimization.
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6581</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6582</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6583
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6584<!-- _______________________________________________________________________ -->
6585<div class="doc_subsubsection">
6586 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6587</div>
6588
6589<div class="doc_text">
6590
6591<h5>Syntax:</h5>
6592<pre>
6593 declare void @llvm.trap()
6594</pre>
6595
6596<h5>Overview:</h5>
6597
6598<p>
6599The '<tt>llvm.trap</tt>' intrinsic
6600</p>
6601
6602<h5>Arguments:</h5>
6603
6604<p>
6605None
6606</p>
6607
6608<h5>Semantics:</h5>
6609
6610<p>
6611This intrinsics is lowered to the target dependent trap instruction. If the
6612target does not have a trap instruction, this intrinsic will be lowered to the
6613call of the abort() function.
6614</p>
6615</div>
6616
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6617<!-- _______________________________________________________________________ -->
6618<div class="doc_subsubsection">
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]6619 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6620</div>
6621<div class="doc_text">
6622<h5>Syntax:</h5>
6623<pre>
6624declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
6625
6626</pre>
6627<h5>Overview:</h5>
6628<p>
6629 The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
6630 it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
6631 it is placed on the stack before local variables.
6632</p>
6633<h5>Arguments:</h5>
6634<p>
6635 The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
6636 first argument is the value loaded from the stack guard
6637 <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
6638 has enough space to hold the value of the guard.
6639</p>
6640<h5>Semantics:</h5>
6641<p>
6642 This intrinsic causes the prologue/epilogue inserter to force the position of
6643 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6644 stack. This is to ensure that if a local variable on the stack is overwritten,
6645 it will destroy the value of the guard. When the function exits, the guard on
6646 the stack is checked against the original guard. If they're different, then
6647 the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
6648</p>
6649</div>
6650
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6659 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]6660 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
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