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gerrit-public.fairphone.software / toolchain / llvm-project / 98b5c16e3bf2f26264925e74f89b8a1d77ea2a1a / . / llvm / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
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7 <meta name="author" content="Chris Lattner">
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 Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]25 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]26 <li><a href="#functionstructure">Functions</a></li>
Anton Korobeynikov546ea7e2007-04-29 18:02:48 +0000[diff] [blame]27 <li><a href="#aliasstructure">Aliases</a>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]28 <li><a href="#paramattrs">Parameter Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]29 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]30 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]31 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]32 </ol>
33 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]34 <li><a href="#typesystem">Type System</a>
35 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]36 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]37 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]38 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]39 <li><a href="#t_floating">Floating Point Types</a></li>
40 <li><a href="#t_void">Void Type</a></li>
41 <li><a href="#t_label">Label Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]42 </ol>
43 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]44 <li><a href="#t_derived">Derived Types</a>
45 <ol>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]46 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]47 <li><a href="#t_array">Array Type</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]48 <li><a href="#t_function">Function Type</a></li>
49 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]50 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]51 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]52 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]53 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]54 </ol>
55 </li>
56 </ol>
57 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]58 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]59 <ol>
60 <li><a href="#simpleconstants">Simple Constants</a>
61 <li><a href="#aggregateconstants">Aggregate Constants</a>
62 <li><a href="#globalconstants">Global Variable and Function Addresses</a>
63 <li><a href="#undefvalues">Undefined Values</a>
64 <li><a href="#constantexprs">Constant Expressions</a>
65 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]66 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]67 <li><a href="#othervalues">Other Values</a>
68 <ol>
69 <li><a href="#inlineasm">Inline Assembler Expressions</a>
70 </ol>
71 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]72 <li><a href="#instref">Instruction Reference</a>
73 <ol>
74 <li><a href="#terminators">Terminator Instructions</a>
75 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]76 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
77 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]78 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
79 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]80 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]81 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]82 </ol>
83 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]84 <li><a href="#binaryops">Binary Operations</a>
85 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]86 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
87 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
88 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]89 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
90 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
91 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]92 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
93 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
94 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]95 </ol>
96 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]97 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
98 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]99 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
100 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
101 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]102 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]103 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]104 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]105 </ol>
106 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]107 <li><a href="#vectorops">Vector Operations</a>
108 <ol>
109 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
110 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
111 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]112 </ol>
113 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]114 <li><a href="#aggregateops">Aggregate Operations</a>
115 <ol>
116 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
117 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
118 </ol>
119 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]120 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]121 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]122 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
123 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
124 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]125 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
126 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
127 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]128 </ol>
129 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]130 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]131 <ol>
132 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
133 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
134 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
135 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
136 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]137 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
138 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
139 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
140 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]141 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
142 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]143 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]144 </ol>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]145 <li><a href="#otherops">Other Operations</a>
146 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]147 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
148 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]149 <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
150 <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]151 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]152 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]153 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]154 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]155 <li><a href="#i_getresult">'<tt>getresult</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]156 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]157 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]158 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]159 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]160 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]161 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]162 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
163 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]164 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
165 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
166 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]167 </ol>
168 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]169 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
170 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]171 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
172 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
173 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]174 </ol>
175 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]176 <li><a href="#int_codegen">Code Generator Intrinsics</a>
177 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]178 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
179 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
180 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
181 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
182 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
183 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
184 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]185 </ol>
186 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]187 <li><a href="#int_libc">Standard C Library Intrinsics</a>
188 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]189 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
190 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
191 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
192 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
193 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]194 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
195 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
196 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]197 </ol>
198 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]199 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]200 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]201 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]202 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
203 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
204 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]205 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
206 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]207 </ol>
208 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]209 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]210 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]211 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]212 <ol>
213 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]214 </ol>
215 </li>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]216 <li><a href="#int_atomics">Atomic intrinsics</a>
217 <ol>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]218 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]219 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]220 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]221 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
222 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
223 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
224 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
225 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
226 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
227 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
228 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
229 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
230 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]231 </ol>
232 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]233 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]234 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]235 <li><a href="#int_var_annotation">
Tanya Lattner08abc812007-09-22 00:01:26 +0000[diff] [blame]236 <tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]237 <li><a href="#int_annotation">
Tanya Lattner08abc812007-09-22 00:01:26 +0000[diff] [blame]238 <tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]239 <li><a href="#int_trap">
240 <tt>llvm.trap</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]241 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]242 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]243 </ol>
244 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]245</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]246
247<div class="doc_author">
248 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
249 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]250</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]251
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]252<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]253<div class="doc_section"> <a name="abstract">Abstract </a></div>
254<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]255
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]256<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]257<p>This document is a reference manual for the LLVM assembly language.
258LLVM is an SSA based representation that provides type safety,
259low-level operations, flexibility, and the capability of representing
260'all' high-level languages cleanly. It is the common code
261representation used throughout all phases of the LLVM compilation
262strategy.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]263</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]264
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]265<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]266<div class="doc_section"> <a name="introduction">Introduction</a> </div>
267<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]268
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]269<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]270
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]271<p>The LLVM code representation is designed to be used in three
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]272different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]273representation (suitable for fast loading by a Just-In-Time compiler),
274and as a human readable assembly language representation. This allows
275LLVM to provide a powerful intermediate representation for efficient
276compiler transformations and analysis, while providing a natural means
277to debug and visualize the transformations. The three different forms
278of LLVM are all equivalent. This document describes the human readable
279representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]280
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]281<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]282while being expressive, typed, and extensible at the same time. It
283aims to be a "universal IR" of sorts, by being at a low enough level
284that high-level ideas may be cleanly mapped to it (similar to how
285microprocessors are "universal IR's", allowing many source languages to
286be mapped to them). By providing type information, LLVM can be used as
287the target of optimizations: for example, through pointer analysis, it
288can be proven that a C automatic variable is never accessed outside of
289the current function... allowing it to be promoted to a simple SSA
290value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]291
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]292</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]293
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]294<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]295<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]296
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]297<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]298
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]299<p>It is important to note that this document describes 'well formed'
300LLVM assembly language. There is a difference between what the parser
301accepts and what is considered 'well formed'. For example, the
302following instruction is syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]303
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]304<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]305<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]306%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]307</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]308</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]309
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]310<p>...because the definition of <tt>%x</tt> does not dominate all of
311its uses. The LLVM infrastructure provides a verification pass that may
312be used to verify that an LLVM module is well formed. This pass is
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]313automatically run by the parser after parsing input assembly and by
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]314the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]315by the verifier pass indicate bugs in transformation passes or input to
316the parser.</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]317</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]318
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]319<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]320
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]321<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]322<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]323<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]324
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]325<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]326
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]327 <p>LLVM identifiers come in two basic types: global and local. Global
328 identifiers (functions, global variables) begin with the @ character. Local
329 identifiers (register names, types) begin with the % character. Additionally,
330 there are three different formats for identifiers, for different purposes:
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]331
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]332<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]333 <li>Named values are represented as a string of characters with their prefix.
334 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
335 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]336 Identifiers which require other characters in their names can be surrounded
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]337 with quotes. In this way, anything except a <tt>&quot;</tt> character can
338 be used in a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]339
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]340 <li>Unnamed values are represented as an unsigned numeric value with their
341 prefix. For example, %12, @2, %44.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]342
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]343 <li>Constants, which are described in a <a href="#constants">section about
344 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]345</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]346
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]347<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]348don't need to worry about name clashes with reserved words, and the set of
349reserved words may be expanded in the future without penalty. Additionally,
350unnamed identifiers allow a compiler to quickly come up with a temporary
351variable without having to avoid symbol table conflicts.</p>
352
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]353<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]354languages. There are keywords for different opcodes
355('<tt><a href="#i_add">add</a></tt>',
356 '<tt><a href="#i_bitcast">bitcast</a></tt>',
357 '<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]358href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]359and others. These reserved words cannot conflict with variable names, because
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]360none of them start with a prefix character ('%' or '@').</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]361
362<p>Here is an example of LLVM code to multiply the integer variable
363'<tt>%X</tt>' by 8:</p>
364
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]365<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]366
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]367<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]368<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]369%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]370</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]371</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]372
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]373<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]374
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]375<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]376<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]377%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]378</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]379</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]380
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]381<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]382
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]383<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]384<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]385<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
386<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
387%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]388</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]389</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]390
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]391<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
392important lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]393
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]394<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]395
396 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
397 line.</li>
398
399 <li>Unnamed temporaries are created when the result of a computation is not
400 assigned to a named value.</li>
401
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]402 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]403
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]404</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]405
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]406<p>...and it also shows a convention that we follow in this document. When
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]407demonstrating instructions, we will follow an instruction with a comment that
408defines the type and name of value produced. Comments are shown in italic
409text.</p>
410
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]411</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]412
413<!-- *********************************************************************** -->
414<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
415<!-- *********************************************************************** -->
416
417<!-- ======================================================================= -->
418<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
419</div>
420
421<div class="doc_text">
422
423<p>LLVM programs are composed of "Module"s, each of which is a
424translation unit of the input programs. Each module consists of
425functions, global variables, and symbol table entries. Modules may be
426combined together with the LLVM linker, which merges function (and
427global variable) definitions, resolves forward declarations, and merges
428symbol table entries. Here is an example of the "hello world" module:</p>
429
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]430<div class="doc_code">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]431<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]432<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
433 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]434
435<i>; External declaration of the puts function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]436<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]437
438<i>; Definition of main function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]439define i32 @main() { <i>; i32()* </i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]440 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]441 %cast210 = <a
Chris Lattner2150cde2007-06-12 17:01:15 +0000[diff] [blame]442 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]443
444 <i>; Call puts function to write out the string to stdout...</i>
445 <a
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]446 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]447 <a
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]448 href="#i_ret">ret</a> i32 0<br>}<br>
449</pre>
450</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]451
452<p>This example is made up of a <a href="#globalvars">global variable</a>
453named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
454function, and a <a href="#functionstructure">function definition</a>
455for "<tt>main</tt>".</p>
456
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]457<p>In general, a module is made up of a list of global values,
458where both functions and global variables are global values. Global values are
459represented by a pointer to a memory location (in this case, a pointer to an
460array of char, and a pointer to a function), and have one of the following <a
461href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]462
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]463</div>
464
465<!-- ======================================================================= -->
466<div class="doc_subsection">
467 <a name="linkage">Linkage Types</a>
468</div>
469
470<div class="doc_text">
471
472<p>
473All Global Variables and Functions have one of the following types of linkage:
474</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]475
476<dl>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]477
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]478 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]479
480 <dd>Global values with internal linkage are only directly accessible by
481 objects in the current module. In particular, linking code into a module with
482 an internal global value may cause the internal to be renamed as necessary to
483 avoid collisions. Because the symbol is internal to the module, all
484 references can be updated. This corresponds to the notion of the
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]485 '<tt>static</tt>' keyword in C.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]486 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]487
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]488 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]489
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]490 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
491 the same name when linkage occurs. This is typically used to implement
492 inline functions, templates, or other code which must be generated in each
493 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
494 allowed to be discarded.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]495 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]496
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]497 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
498
499 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
500 linkage, except that unreferenced <tt>common</tt> globals may not be
501 discarded. This is used for globals that may be emitted in multiple
502 translation units, but that are not guaranteed to be emitted into every
503 translation unit that uses them. One example of this is tentative
504 definitions in C, such as "<tt>int X;</tt>" at global scope.
505 </dd>
506
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]507 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]508
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]509 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
510 that some targets may choose to emit different assembly sequences for them
511 for target-dependent reasons. This is used for globals that are declared
512 "weak" in C source code.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]513 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]514
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]515 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]516
517 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
518 pointer to array type. When two global variables with appending linkage are
519 linked together, the two global arrays are appended together. This is the
520 LLVM, typesafe, equivalent of having the system linker append together
521 "sections" with identical names when .o files are linked.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]522 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]523
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]524 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
525 <dd>The semantics of this linkage follow the ELF model: the symbol is weak
526 until linked, if not linked, the symbol becomes null instead of being an
527 undefined reference.
528 </dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]529
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]530 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]531
532 <dd>If none of the above identifiers are used, the global is externally
533 visible, meaning that it participates in linkage and can be used to resolve
534 external symbol references.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]535 </dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]536</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]537
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]538 <p>
539 The next two types of linkage are targeted for Microsoft Windows platform
540 only. They are designed to support importing (exporting) symbols from (to)
541 DLLs.
542 </p>
543
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]544 <dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]545 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
546
547 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
548 or variable via a global pointer to a pointer that is set up by the DLL
549 exporting the symbol. On Microsoft Windows targets, the pointer name is
550 formed by combining <code>_imp__</code> and the function or variable name.
551 </dd>
552
553 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
554
555 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
556 pointer to a pointer in a DLL, so that it can be referenced with the
557 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
558 name is formed by combining <code>_imp__</code> and the function or variable
559 name.
560 </dd>
561
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]562</dl>
563
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]564<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]565variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
566variable and was linked with this one, one of the two would be renamed,
567preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
568external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer92c671e2007-01-05 00:59:10 +0000[diff] [blame]569outside of the current module.</p>
570<p>It is illegal for a function <i>declaration</i>
571to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]572or <tt>extern_weak</tt>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]573<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
574linkages.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]575</div>
576
577<!-- ======================================================================= -->
578<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]579 <a name="callingconv">Calling Conventions</a>
580</div>
581
582<div class="doc_text">
583
584<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
585and <a href="#i_invoke">invokes</a> can all have an optional calling convention
586specified for the call. The calling convention of any pair of dynamic
587caller/callee must match, or the behavior of the program is undefined. The
588following calling conventions are supported by LLVM, and more may be added in
589the future:</p>
590
591<dl>
592 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
593
594 <dd>This calling convention (the default if no other calling convention is
595 specified) matches the target C calling conventions. This calling convention
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]596 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer72ba4992006-12-31 21:30:18 +0000[diff] [blame]597 prototype and implemented declaration of the function (as does normal C).
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]598 </dd>
599
600 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
601
602 <dd>This calling convention attempts to make calls as fast as possible
603 (e.g. by passing things in registers). This calling convention allows the
604 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattnerc792eb32005-05-06 23:08:23 +0000[diff] [blame]605 without having to conform to an externally specified ABI. Implementations of
Arnold Schwaighofer2c6b8882008-05-14 09:17:12 +0000[diff] [blame]606 this convention should allow arbitrary
607 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
608 supported. This calling convention does not support varargs and requires the
609 prototype of all callees to exactly match the prototype of the function
610 definition.
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]611 </dd>
612
613 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
614
615 <dd>This calling convention attempts to make code in the caller as efficient
616 as possible under the assumption that the call is not commonly executed. As
617 such, these calls often preserve all registers so that the call does not break
618 any live ranges in the caller side. This calling convention does not support
619 varargs and requires the prototype of all callees to exactly match the
620 prototype of the function definition.
621 </dd>
622
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]623 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]624
625 <dd>Any calling convention may be specified by number, allowing
626 target-specific calling conventions to be used. Target specific calling
627 conventions start at 64.
628 </dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]629</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]630
631<p>More calling conventions can be added/defined on an as-needed basis, to
632support pascal conventions or any other well-known target-independent
633convention.</p>
634
635</div>
636
637<!-- ======================================================================= -->
638<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]639 <a name="visibility">Visibility Styles</a>
640</div>
641
642<div class="doc_text">
643
644<p>
645All Global Variables and Functions have one of the following visibility styles:
646</p>
647
648<dl>
649 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
650
651 <dd>On ELF, default visibility means that the declaration is visible to other
652 modules and, in shared libraries, means that the declared entity may be
653 overridden. On Darwin, default visibility means that the declaration is
654 visible to other modules. Default visibility corresponds to "external
655 linkage" in the language.
656 </dd>
657
658 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
659
660 <dd>Two declarations of an object with hidden visibility refer to the same
661 object if they are in the same shared object. Usually, hidden visibility
662 indicates that the symbol will not be placed into the dynamic symbol table,
663 so no other module (executable or shared library) can reference it
664 directly.
665 </dd>
666
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]667 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
668
669 <dd>On ELF, protected visibility indicates that the symbol will be placed in
670 the dynamic symbol table, but that references within the defining module will
671 bind to the local symbol. That is, the symbol cannot be overridden by another
672 module.
673 </dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]674</dl>
675
676</div>
677
678<!-- ======================================================================= -->
679<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]680 <a name="globalvars">Global Variables</a>
681</div>
682
683<div class="doc_text">
684
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]685<p>Global variables define regions of memory allocated at compilation time
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]686instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]687an explicit section to be placed in, and may have an optional explicit alignment
688specified. A variable may be defined as "thread_local", which means that it
689will not be shared by threads (each thread will have a separated copy of the
690variable). A variable may be defined as a global "constant," which indicates
691that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]692optimization, allowing the global data to be placed in the read-only section of
693an executable, etc). Note that variables that need runtime initialization
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]694cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]695
696<p>
697LLVM explicitly allows <em>declarations</em> of global variables to be marked
698constant, even if the final definition of the global is not. This capability
699can be used to enable slightly better optimization of the program, but requires
700the language definition to guarantee that optimizations based on the
701'constantness' are valid for the translation units that do not include the
702definition.
703</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]704
705<p>As SSA values, global variables define pointer values that are in
706scope (i.e. they dominate) all basic blocks in the program. Global
707variables always define a pointer to their "content" type because they
708describe a region of memory, and all memory objects in LLVM are
709accessed through pointers.</p>
710
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]711<p>A global variable may be declared to reside in a target-specifc numbered
712address space. For targets that support them, address spaces may affect how
713optimizations are performed and/or what target instructions are used to access
Christopher Lamb25f50762007-12-12 08:44:39 +0000[diff] [blame]714the variable. The default address space is zero. The address space qualifier
715must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]716
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]717<p>LLVM allows an explicit section to be specified for globals. If the target
718supports it, it will emit globals to the section specified.</p>
719
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]720<p>An explicit alignment may be specified for a global. If not present, or if
721the alignment is set to zero, the alignment of the global is set by the target
722to whatever it feels convenient. If an explicit alignment is specified, the
723global is forced to have at least that much alignment. All alignments must be
724a power of 2.</p>
725
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]726<p>For example, the following defines a global in a numbered address space with
727an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]728
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]729<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]730<pre>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]731@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]732</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]733</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]734
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]735</div>
736
737
738<!-- ======================================================================= -->
739<div class="doc_subsection">
740 <a name="functionstructure">Functions</a>
741</div>
742
743<div class="doc_text">
744
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]745<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
746an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]747<a href="#visibility">visibility style</a>, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]748<a href="#callingconv">calling convention</a>, a return type, an optional
749<a href="#paramattrs">parameter attribute</a> for the return type, a function
750name, a (possibly empty) argument list (each with optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]751<a href="#paramattrs">parameter attributes</a>), an optional section, an
Gordon Henriksendc5cafb2007-12-10 03:30:21 +0000[diff] [blame]752optional alignment, an optional <a href="#gc">garbage collector name</a>, an
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]753opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]754
755LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
756optional <a href="#linkage">linkage type</a>, an optional
757<a href="#visibility">visibility style</a>, an optional
758<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]759<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]760name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksendc5cafb2007-12-10 03:30:21 +0000[diff] [blame]761<a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]762
763<p>A function definition contains a list of basic blocks, forming the CFG for
764the function. Each basic block may optionally start with a label (giving the
765basic block a symbol table entry), contains a list of instructions, and ends
766with a <a href="#terminators">terminator</a> instruction (such as a branch or
767function return).</p>
768
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]769<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]770executed on entrance to the function, and it is not allowed to have predecessor
771basic blocks (i.e. there can not be any branches to the entry block of a
772function). Because the block can have no predecessors, it also cannot have any
773<a href="#i_phi">PHI nodes</a>.</p>
774
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]775<p>LLVM allows an explicit section to be specified for functions. If the target
776supports it, it will emit functions to the section specified.</p>
777
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]778<p>An explicit alignment may be specified for a function. If not present, or if
779the alignment is set to zero, the alignment of the function is set by the target
780to whatever it feels convenient. If an explicit alignment is specified, the
781function is forced to have at least that much alignment. All alignments must be
782a power of 2.</p>
783
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]784</div>
785
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]786
787<!-- ======================================================================= -->
788<div class="doc_subsection">
789 <a name="aliasstructure">Aliases</a>
790</div>
791<div class="doc_text">
792 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov25b2e822008-03-22 08:36:14 +0000[diff] [blame]793 function, global variable, another alias or bitcast of global value). Aliases
794 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]795 optional <a href="#visibility">visibility style</a>.</p>
796
797 <h5>Syntax:</h5>
798
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]799<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]800<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]801@&lt;Name&gt; = [Linkage] [Visibility] alias &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]802</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]803</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]804
805</div>
806
807
808
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]809<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]810<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
811<div class="doc_text">
812 <p>The return type and each parameter of a function type may have a set of
813 <i>parameter attributes</i> associated with them. Parameter attributes are
814 used to communicate additional information about the result or parameters of
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]815 a function. Parameter attributes are considered to be part of the function,
816 not of the function type, so functions with different parameter attributes
817 can have the same function type.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]818
Reid Spencercf7ebf52007-01-15 18:27:39 +0000[diff] [blame]819 <p>Parameter attributes are simple keywords that follow the type specified. If
820 multiple parameter attributes are needed, they are space separated. For
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]821 example:</p>
822
823<div class="doc_code">
824<pre>
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]825declare i32 @printf(i8* noalias , ...) nounwind
826declare i32 @atoi(i8*) nounwind readonly
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]827</pre>
828</div>
829
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]830 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
831 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]832
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]833 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]834 <dl>
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]835 <dt><tt>zeroext</tt></dt>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]836 <dd>This indicates that the parameter should be zero extended just before
837 a call to this function.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]838
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]839 <dt><tt>signext</tt></dt>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]840 <dd>This indicates that the parameter should be sign extended just before
841 a call to this function.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]842
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]843 <dt><tt>inreg</tt></dt>
844 <dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikove93c6e82007-01-28 15:27:21 +0000[diff] [blame]845 possible) during assembling function call. Support for this attribute is
846 target-specific</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]847
848 <dt><tt>byval</tt></dt>
Chris Lattner352ab9b2008-01-15 04:34:22 +0000[diff] [blame]849 <dd>This indicates that the pointer parameter should really be passed by
850 value to the function. The attribute implies that a hidden copy of the
851 pointee is made between the caller and the callee, so the callee is unable
852 to modify the value in the callee. This attribute is only valid on llvm
853 pointer arguments. It is generally used to pass structs and arrays by
854 value, but is also valid on scalars (even though this is silly).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]855
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]856 <dt><tt>sret</tt></dt>
Duncan Sandsfa4b6732008-02-18 04:19:38 +0000[diff] [blame]857 <dd>This indicates that the pointer parameter specifies the address of a
858 structure that is the return value of the function in the source program.
Duncan Sandsc572c1e2008-03-17 12:17:41 +0000[diff] [blame]859 Loads and stores to the structure are assumed not to trap.
Duncan Sandsfa4b6732008-02-18 04:19:38 +0000[diff] [blame]860 May only be applied to the first parameter.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]861
Zhou Sheng2444a9a2007-06-05 05:28:26 +0000[diff] [blame]862 <dt><tt>noalias</tt></dt>
Owen Anderson61101282008-02-18 04:09:01 +0000[diff] [blame]863 <dd>This indicates that the parameter does not alias any global or any other
864 parameter. The caller is responsible for ensuring that this is the case,
865 usually by placing the value in a stack allocation.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]866
Reid Spencer9d1700e2007-03-22 02:18:56 +0000[diff] [blame]867 <dt><tt>noreturn</tt></dt>
868 <dd>This function attribute indicates that the function never returns. This
869 indicates to LLVM that every call to this function should be treated as if
870 an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]871
Reid Spencer05dbb9d2007-03-22 02:02:11 +0000[diff] [blame]872 <dt><tt>nounwind</tt></dt>
Duncan Sandsc572c1e2008-03-17 12:17:41 +0000[diff] [blame]873 <dd>This function attribute indicates that no exceptions unwind out of the
874 function. Usually this is because the function makes no use of exceptions,
875 but it may also be that the function catches any exceptions thrown when
876 executing it.</dd>
877
Duncan Sands27e91592007-07-27 19:57:41 +0000[diff] [blame]878 <dt><tt>nest</tt></dt>
Duncan Sands825bde42008-07-08 09:27:25 +0000[diff] [blame]879 <dd>This indicates that the pointer parameter can be excised using the
Duncan Sands27e91592007-07-27 19:57:41 +0000[diff] [blame]880 <a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sandsa89a1132007-11-22 20:23:04 +0000[diff] [blame]881 <dt><tt>readonly</tt></dt>
Duncan Sands730a3262007-11-14 21:14:02 +0000[diff] [blame]882 <dd>This function attribute indicates that the function has no side-effects
Duncan Sandsa89a1132007-11-22 20:23:04 +0000[diff] [blame]883 except for producing a return value or throwing an exception. The value
884 returned must only depend on the function arguments and/or global variables.
885 It may use values obtained by dereferencing pointers.</dd>
886 <dt><tt>readnone</tt></dt>
887 <dd>A <tt>readnone</tt> function has the same restrictions as a <tt>readonly</tt>
Duncan Sands730a3262007-11-14 21:14:02 +0000[diff] [blame]888 function, but in addition it is not allowed to dereference any pointer arguments
889 or global variables.
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]890 </dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]891
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]892</div>
893
894<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]895<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]896 <a name="gc">Garbage Collector Names</a>
897</div>
898
899<div class="doc_text">
900<p>Each function may specify a garbage collector name, which is simply a
901string.</p>
902
903<div class="doc_code"><pre
904>define void @f() gc "name" { ...</pre></div>
905
906<p>The compiler declares the supported values of <i>name</i>. Specifying a
907collector which will cause the compiler to alter its output in order to support
908the named garbage collection algorithm.</p>
909</div>
910
911<!-- ======================================================================= -->
912<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]913 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]914</div>
915
916<div class="doc_text">
917<p>
918Modules may contain "module-level inline asm" blocks, which corresponds to the
919GCC "file scope inline asm" blocks. These blocks are internally concatenated by
920LLVM and treated as a single unit, but may be separated in the .ll file if
921desired. The syntax is very simple:
922</p>
923
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]924<div class="doc_code">
925<pre>
926module asm "inline asm code goes here"
927module asm "more can go here"
928</pre>
929</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]930
931<p>The strings can contain any character by escaping non-printable characters.
932 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
933 for the number.
934</p>
935
936<p>
937 The inline asm code is simply printed to the machine code .s file when
938 assembly code is generated.
939</p>
940</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]941
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]942<!-- ======================================================================= -->
943<div class="doc_subsection">
944 <a name="datalayout">Data Layout</a>
945</div>
946
947<div class="doc_text">
948<p>A module may specify a target specific data layout string that specifies how
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]949data is to be laid out in memory. The syntax for the data layout is simply:</p>
950<pre> target datalayout = "<i>layout specification</i>"</pre>
951<p>The <i>layout specification</i> consists of a list of specifications
952separated by the minus sign character ('-'). Each specification starts with a
953letter and may include other information after the letter to define some
954aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]955<dl>
956 <dt><tt>E</tt></dt>
957 <dd>Specifies that the target lays out data in big-endian form. That is, the
958 bits with the most significance have the lowest address location.</dd>
959 <dt><tt>e</tt></dt>
960 <dd>Specifies that hte target lays out data in little-endian form. That is,
961 the bits with the least significance have the lowest address location.</dd>
962 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
963 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
964 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
965 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
966 too.</dd>
967 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
968 <dd>This specifies the alignment for an integer type of a given bit
969 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
970 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
971 <dd>This specifies the alignment for a vector type of a given bit
972 <i>size</i>.</dd>
973 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
974 <dd>This specifies the alignment for a floating point type of a given bit
975 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
976 (double).</dd>
977 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
978 <dd>This specifies the alignment for an aggregate type of a given bit
979 <i>size</i>.</dd>
980</dl>
981<p>When constructing the data layout for a given target, LLVM starts with a
982default set of specifications which are then (possibly) overriden by the
983specifications in the <tt>datalayout</tt> keyword. The default specifications
984are given in this list:</p>
985<ul>
986 <li><tt>E</tt> - big endian</li>
987 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
988 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
989 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
990 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
991 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
992 <li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
993 alignment of 64-bits</li>
994 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
995 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
996 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
997 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
998 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
999</ul>
1000<p>When llvm is determining the alignment for a given type, it uses the
1001following rules:
1002<ol>
1003 <li>If the type sought is an exact match for one of the specifications, that
1004 specification is used.</li>
1005 <li>If no match is found, and the type sought is an integer type, then the
1006 smallest integer type that is larger than the bitwidth of the sought type is
1007 used. If none of the specifications are larger than the bitwidth then the the
1008 largest integer type is used. For example, given the default specifications
1009 above, the i7 type will use the alignment of i8 (next largest) while both
1010 i65 and i256 will use the alignment of i64 (largest specified).</li>
1011 <li>If no match is found, and the type sought is a vector type, then the
1012 largest vector type that is smaller than the sought vector type will be used
1013 as a fall back. This happens because <128 x double> can be implemented in
1014 terms of 64 <2 x double>, for example.</li>
1015</ol>
1016</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1017
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1018<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1019<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1020<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1021
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1022<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1023
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1024<p>The LLVM type system is one of the most important features of the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1025intermediate representation. Being typed enables a number of
1026optimizations to be performed on the IR directly, without having to do
1027extra analyses on the side before the transformation. A strong type
1028system makes it easier to read the generated code and enables novel
1029analyses and transformations that are not feasible to perform on normal
1030three address code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1031
1032</div>
1033
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1034<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1035<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1036Classifications</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1037<div class="doc_text">
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1038<p>The types fall into a few useful
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1039classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1040
1041<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1042 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1043 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1044 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1045 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1046 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1047 </tr>
1048 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1049 <td><a href="#t_floating">floating point</a></td>
1050 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1051 </tr>
1052 <tr>
1053 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1054 <td><a href="#t_integer">integer</a>,
1055 <a href="#t_floating">floating point</a>,
1056 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1057 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1058 <a href="#t_struct">structure</a>,
1059 <a href="#t_array">array</a>,
Dan Gohmanda52d212008-05-23 22:50:26 +0000[diff] [blame]1060 <a href="#t_label">label</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1061 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1062 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1063 <tr>
1064 <td><a href="#t_primitive">primitive</a></td>
1065 <td><a href="#t_label">label</a>,
1066 <a href="#t_void">void</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1067 <a href="#t_floating">floating point</a>.</td>
1068 </tr>
1069 <tr>
1070 <td><a href="#t_derived">derived</a></td>
1071 <td><a href="#t_integer">integer</a>,
1072 <a href="#t_array">array</a>,
1073 <a href="#t_function">function</a>,
1074 <a href="#t_pointer">pointer</a>,
1075 <a href="#t_struct">structure</a>,
1076 <a href="#t_pstruct">packed structure</a>,
1077 <a href="#t_vector">vector</a>,
1078 <a href="#t_opaque">opaque</a>.
1079 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1080 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1081</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1082
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1083<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1084most important. Values of these types are the only ones which can be
1085produced by instructions, passed as arguments, or used as operands to
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]1086instructions.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1087</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1088
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1089<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1090<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1091
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1092<div class="doc_text">
1093<p>The primitive types are the fundamental building blocks of the LLVM
1094system.</p>
1095
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1096</div>
1097
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1098<!-- _______________________________________________________________________ -->
1099<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1100
1101<div class="doc_text">
1102 <table>
1103 <tbody>
1104 <tr><th>Type</th><th>Description</th></tr>
1105 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1106 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1107 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1108 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1109 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1110 </tbody>
1111 </table>
1112</div>
1113
1114<!-- _______________________________________________________________________ -->
1115<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1116
1117<div class="doc_text">
1118<h5>Overview:</h5>
1119<p>The void type does not represent any value and has no size.</p>
1120
1121<h5>Syntax:</h5>
1122
1123<pre>
1124 void
1125</pre>
1126</div>
1127
1128<!-- _______________________________________________________________________ -->
1129<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1130
1131<div class="doc_text">
1132<h5>Overview:</h5>
1133<p>The label type represents code labels.</p>
1134
1135<h5>Syntax:</h5>
1136
1137<pre>
1138 label
1139</pre>
1140</div>
1141
1142
1143<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1144<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1145
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1146<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1147
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1148<p>The real power in LLVM comes from the derived types in the system.
1149This is what allows a programmer to represent arrays, functions,
1150pointers, and other useful types. Note that these derived types may be
1151recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1152
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1153</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1154
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1155<!-- _______________________________________________________________________ -->
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1156<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1157
1158<div class="doc_text">
1159
1160<h5>Overview:</h5>
1161<p>The integer type is a very simple derived type that simply specifies an
1162arbitrary bit width for the integer type desired. Any bit width from 1 bit to
11632^23-1 (about 8 million) can be specified.</p>
1164
1165<h5>Syntax:</h5>
1166
1167<pre>
1168 iN
1169</pre>
1170
1171<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1172value.</p>
1173
1174<h5>Examples:</h5>
1175<table class="layout">
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1176 <tbody>
1177 <tr>
1178 <td><tt>i1</tt></td>
1179 <td>a single-bit integer.</td>
1180 </tr><tr>
1181 <td><tt>i32</tt></td>
1182 <td>a 32-bit integer.</td>
1183 </tr><tr>
1184 <td><tt>i1942652</tt></td>
1185 <td>a really big integer of over 1 million bits.</td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1186 </tr>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1187 </tbody>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1188</table>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1189</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1190
1191<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1192<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1193
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1194<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1195
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1196<h5>Overview:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1197
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1198<p>The array type is a very simple derived type that arranges elements
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1199sequentially in memory. The array type requires a size (number of
1200elements) and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1201
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1202<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1203
1204<pre>
1205 [&lt;# elements&gt; x &lt;elementtype&gt;]
1206</pre>
1207
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1208<p>The number of elements is a constant integer value; elementtype may
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1209be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1210
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1211<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1212<table class="layout">
1213 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1214 <td class="left"><tt>[40 x i32]</tt></td>
1215 <td class="left">Array of 40 32-bit integer values.</td>
1216 </tr>
1217 <tr class="layout">
1218 <td class="left"><tt>[41 x i32]</tt></td>
1219 <td class="left">Array of 41 32-bit integer values.</td>
1220 </tr>
1221 <tr class="layout">
1222 <td class="left"><tt>[4 x i8]</tt></td>
1223 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1224 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1225</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1226<p>Here are some examples of multidimensional arrays:</p>
1227<table class="layout">
1228 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1229 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1230 <td class="left">3x4 array of 32-bit integer values.</td>
1231 </tr>
1232 <tr class="layout">
1233 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1234 <td class="left">12x10 array of single precision floating point values.</td>
1235 </tr>
1236 <tr class="layout">
1237 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1238 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1239 </tr>
1240</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1241
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1242<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1243length array. Normally, accesses past the end of an array are undefined in
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1244LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1245As a special case, however, zero length arrays are recognized to be variable
1246length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1247type "{ i32, [0 x float]}", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1248
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1249</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1250
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1251<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1252<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1253<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1254
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1255<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1256
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1257<p>The function type can be thought of as a function signature. It
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1258consists of a return type and a list of formal parameter types. The
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1259return 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]1260If 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]1261class types, and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1262
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1263<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1264
1265<pre>
1266 &lt;returntype list&gt; (&lt;parameter list&gt;)
1267</pre>
1268
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1269<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]1270specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1271which indicates that the function takes a variable number of arguments.
1272Variable argument functions can access their arguments with the <a
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1273 href="#int_varargs">variable argument handling intrinsic</a> functions.
1274'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1275<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1276
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1277<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1278<table class="layout">
1279 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1280 <td class="left"><tt>i32 (i32)</tt></td>
1281 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1282 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1283 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]1284 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1285 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1286 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1287 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1288 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1289 <tt>float</tt>.
1290 </td>
1291 </tr><tr class="layout">
1292 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1293 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1294 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1295 which returns an integer. This is the signature for <tt>printf</tt> in
1296 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1297 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1298 </tr><tr class="layout">
1299 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel8dec6c22008-03-24 18:10:52 +0000[diff] [blame]1300 <td class="left">A function taking an <tt>i32></tt>, returning two
1301 <tt> i32 </tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1302 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1303 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1304</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1305
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1306</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1307<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1308<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1309<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1310<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1311<p>The structure type is used to represent a collection of data members
1312together in memory. The packing of the field types is defined to match
1313the ABI of the underlying processor. The elements of a structure may
1314be any type that has a size.</p>
1315<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1316and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1317field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1318instruction.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1319<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1320<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1321<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1322<table class="layout">
1323 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1324 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1325 <td class="left">A triple of three <tt>i32</tt> values</td>
1326 </tr><tr class="layout">
1327 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1328 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1329 second element is a <a href="#t_pointer">pointer</a> to a
1330 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1331 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1332 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1333</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1334</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1335
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1336<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1337<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1338</div>
1339<div class="doc_text">
1340<h5>Overview:</h5>
1341<p>The packed structure type is used to represent a collection of data members
1342together in memory. There is no padding between fields. Further, the alignment
1343of a packed structure is 1 byte. The elements of a packed structure may
1344be any type that has a size.</p>
1345<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1346and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1347field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1348instruction.</p>
1349<h5>Syntax:</h5>
1350<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1351<h5>Examples:</h5>
1352<table class="layout">
1353 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1354 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1355 <td class="left">A triple of three <tt>i32</tt> values</td>
1356 </tr><tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1357 <td class="left"><tt>&lt; { float, i32 (i32)* } &gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1358 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1359 second element is a <a href="#t_pointer">pointer</a> to a
1360 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1361 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1362 </tr>
1363</table>
1364</div>
1365
1366<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1367<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1368<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1369<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1370<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]1371reference to another object, which must live in memory. Pointer types may have
1372an optional address space attribute defining the target-specific numbered
1373address space where the pointed-to object resides. The default address space is
1374zero.</p>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1375<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1376<pre> &lt;type&gt; *<br></pre>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1377<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1378<table class="layout">
1379 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1380 <td class="left"><tt>[4x i32]*</tt></td>
1381 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1382 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1383 </tr>
1384 <tr class="layout">
1385 <td class="left"><tt>i32 (i32 *) *</tt></td>
1386 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1387 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1388 <tt>i32</tt>.</td>
1389 </tr>
1390 <tr class="layout">
1391 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1392 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1393 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1394 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1395</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1396</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1397
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1398<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1399<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1400<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1401
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1402<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1403
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1404<p>A vector type is a simple derived type that represents a vector
1405of elements. Vector types are used when multiple primitive data
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1406are operated in parallel using a single instruction (SIMD).
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1407A vector type requires a size (number of
Chris Lattner330ce692005-11-10 01:44:22 +0000[diff] [blame]1408elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1409of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1410considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1411
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1412<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1413
1414<pre>
1415 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1416</pre>
1417
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1418<p>The number of elements is a constant integer value; elementtype may
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1419be any integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1420
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1421<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1422
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1423<table class="layout">
1424 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1425 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1426 <td class="left">Vector of 4 32-bit integer values.</td>
1427 </tr>
1428 <tr class="layout">
1429 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1430 <td class="left">Vector of 8 32-bit floating-point values.</td>
1431 </tr>
1432 <tr class="layout">
1433 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1434 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1435 </tr>
1436</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1437</div>
1438
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1439<!-- _______________________________________________________________________ -->
1440<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1441<div class="doc_text">
1442
1443<h5>Overview:</h5>
1444
1445<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksena699c4d2007-10-14 00:34:53 +0000[diff] [blame]1446corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1447In LLVM, opaque types can eventually be resolved to any type (not just a
1448structure type).</p>
1449
1450<h5>Syntax:</h5>
1451
1452<pre>
1453 opaque
1454</pre>
1455
1456<h5>Examples:</h5>
1457
1458<table class="layout">
1459 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1460 <td class="left"><tt>opaque</tt></td>
1461 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1462 </tr>
1463</table>
1464</div>
1465
1466
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1467<!-- *********************************************************************** -->
1468<div class="doc_section"> <a name="constants">Constants</a> </div>
1469<!-- *********************************************************************** -->
1470
1471<div class="doc_text">
1472
1473<p>LLVM has several different basic types of constants. This section describes
1474them all and their syntax.</p>
1475
1476</div>
1477
1478<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1479<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1480
1481<div class="doc_text">
1482
1483<dl>
1484 <dt><b>Boolean constants</b></dt>
1485
1486 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1487 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1488 </dd>
1489
1490 <dt><b>Integer constants</b></dt>
1491
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1492 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1493 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1494 integer types.
1495 </dd>
1496
1497 <dt><b>Floating point constants</b></dt>
1498
1499 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1500 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]1501 notation (see below). The assembler requires the exact decimal value of
1502 a floating-point constant. For example, the assembler accepts 1.25 but
1503 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1504 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1505
1506 <dt><b>Null pointer constants</b></dt>
1507
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1508 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1509 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1510
1511</dl>
1512
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1513<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1514of floating point constants. For example, the form '<tt>double
15150x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
15164.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1517(and the only time that they are generated by the disassembler) is when a
1518floating point constant must be emitted but it cannot be represented as a
1519decimal floating point number. For example, NaN's, infinities, and other
1520special values are represented in their IEEE hexadecimal format so that
1521assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1522
1523</div>
1524
1525<!-- ======================================================================= -->
1526<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1527</div>
1528
1529<div class="doc_text">
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]1530<p>Aggregate constants arise from aggregation of simple constants
1531and smaller aggregate constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1532
1533<dl>
1534 <dt><b>Structure constants</b></dt>
1535
1536 <dd>Structure constants are represented with notation similar to structure
1537 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattnerbea11172007-12-25 20:34:52 +0000[diff] [blame]1538 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1539 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]1540 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1541 types of elements must match those specified by the type.
1542 </dd>
1543
1544 <dt><b>Array constants</b></dt>
1545
1546 <dd>Array constants are represented with notation similar to array type
1547 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1548 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1549 constants must have <a href="#t_array">array type</a>, and the number and
1550 types of elements must match those specified by the type.
1551 </dd>
1552
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1553 <dt><b>Vector constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1554
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1555 <dd>Vector constants are represented with notation similar to vector type
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1556 definitions (a comma separated list of elements, surrounded by
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1557 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]1558 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1559 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1560 match those specified by the type.
1561 </dd>
1562
1563 <dt><b>Zero initialization</b></dt>
1564
1565 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1566 value to zero of <em>any</em> type, including scalar and aggregate types.
1567 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]1568 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1569 initializers.
1570 </dd>
1571</dl>
1572
1573</div>
1574
1575<!-- ======================================================================= -->
1576<div class="doc_subsection">
1577 <a name="globalconstants">Global Variable and Function Addresses</a>
1578</div>
1579
1580<div class="doc_text">
1581
1582<p>The addresses of <a href="#globalvars">global variables</a> and <a
1583href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1584constants. These constants are explicitly referenced when the <a
1585href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1586href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1587file:</p>
1588
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1589<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1590<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]1591@X = global i32 17
1592@Y = global i32 42
1593@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1594</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1595</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1596
1597</div>
1598
1599<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1600<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1601<div class="doc_text">
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1602 <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]1603 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1604 a constant is permitted.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1605
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1606 <p>Undefined values indicate to the compiler that the program is well defined
1607 no matter what value is used, giving the compiler more freedom to optimize.
1608 </p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1609</div>
1610
1611<!-- ======================================================================= -->
1612<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1613</div>
1614
1615<div class="doc_text">
1616
1617<p>Constant expressions are used to allow expressions involving other constants
1618to be used as constants. Constant expressions may be of any <a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1619href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1620that does not have side effects (e.g. load and call are not supported). The
1621following is the syntax for constant expressions:</p>
1622
1623<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1624 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1625 <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]1626 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1627
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1628 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1629 <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]1630 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]1631
1632 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1633 <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]1634 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]1635
1636 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1637 <dd>Truncate a floating point constant to another floating point type. The
1638 size of CST must be larger than the size of TYPE. Both types must be
1639 floating point.</dd>
1640
1641 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1642 <dd>Floating point extend a constant to another type. The size of CST must be
1643 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1644
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]1645 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1646 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1647 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1648 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1649 of the same number of elements. If the value won't fit in the integer type,
1650 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1651
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1652 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1653 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1654 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1655 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1656 of the same number of elements. If the value won't fit in the integer type,
1657 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1658
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1659 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1660 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1661 constant. TYPE must be a scalar or vector floating point type. CST must be of
1662 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1663 of the same number of elements. If the value won't fit in the floating point
1664 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1665
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1666 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1667 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1668 constant. TYPE must be a scalar or vector floating point type. CST must be of
1669 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1670 of the same number of elements. If the value won't fit in the floating point
1671 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1672
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1673 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1674 <dd>Convert a pointer typed constant to the corresponding integer constant
1675 TYPE must be an integer type. CST must be of pointer type. The CST value is
1676 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1677
1678 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1679 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1680 pointer type. CST must be of integer type. The CST value is zero extended,
1681 truncated, or unchanged to make it fit in a pointer size. This one is
1682 <i>really</i> dangerous!</dd>
1683
1684 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1685 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1686 identical (same number of bits). The conversion is done as if the CST value
1687 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]1688 with this operator, just the type. This can be used for conversion of
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1689 vector types to any other type, as long as they have the same bit width. For
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1690 pointers it is only valid to cast to another pointer type.
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1691 </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1692
1693 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1694
1695 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1696 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1697 instruction, the index list may have zero or more indexes, which are required
1698 to make sense for the type of "CSTPTR".</dd>
1699
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1700 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1701
1702 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1703 constants.</dd>
1704
1705 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1706 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1707
1708 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1709 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1710
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]1711 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1712 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1713
1714 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1715 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1716
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1717 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1718
1719 <dd>Perform the <a href="#i_extractelement">extractelement
1720 operation</a> on constants.
1721
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1722 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1723
1724 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1725 operation</a> on constants.</dd>
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1726
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1727
1728 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1729
1730 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1731 operation</a> on constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1732
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1733 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1734
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1735 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1736 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1737 binary</a> operations. The constraints on operands are the same as those for
1738 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1739 values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1740</dl>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1741</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]1742
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1743<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1744<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1745<!-- *********************************************************************** -->
1746
1747<!-- ======================================================================= -->
1748<div class="doc_subsection">
1749<a name="inlineasm">Inline Assembler Expressions</a>
1750</div>
1751
1752<div class="doc_text">
1753
1754<p>
1755LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1756Module-Level Inline Assembly</a>) through the use of a special value. This
1757value represents the inline assembler as a string (containing the instructions
1758to emit), a list of operand constraints (stored as a string), and a flag that
1759indicates whether or not the inline asm expression has side effects. An example
1760inline assembler expression is:
1761</p>
1762
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1763<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1764<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1765i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1766</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1767</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1768
1769<p>
1770Inline assembler expressions may <b>only</b> be used as the callee operand of
1771a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1772</p>
1773
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1774<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1775<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1776%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]1777</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1778</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1779
1780<p>
1781Inline asms with side effects not visible in the constraint list must be marked
1782as having side effects. This is done through the use of the
1783'<tt>sideeffect</tt>' keyword, like so:
1784</p>
1785
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1786<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1787<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1788call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1789</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1790</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1791
1792<p>TODO: The format of the asm and constraints string still need to be
1793documented here. Constraints on what can be done (e.g. duplication, moving, etc
1794need to be documented).
1795</p>
1796
1797</div>
1798
1799<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1800<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1801<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1802
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1803<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1804
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1805<p>The LLVM instruction set consists of several different
1806classifications of instructions: <a href="#terminators">terminator
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1807instructions</a>, <a href="#binaryops">binary instructions</a>,
1808<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1809 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1810instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1811
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1812</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1813
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1814<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1815<div class="doc_subsection"> <a name="terminators">Terminator
1816Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1817
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1818<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1819
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1820<p>As mentioned <a href="#functionstructure">previously</a>, every
1821basic block in a program ends with a "Terminator" instruction, which
1822indicates which block should be executed after the current block is
1823finished. These terminator instructions typically yield a '<tt>void</tt>'
1824value: they produce control flow, not values (the one exception being
1825the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1826<p>There are six different terminator instructions: the '<a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1827 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1828instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1829the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1830 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1831 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1832
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1833</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1834
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1835<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1836<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1837Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1838<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1839<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1840<pre> 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]1841 ret void <i>; Return from void function</i>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1842 ret &lt;type&gt; &lt;value&gt;, &lt;type&gt; &lt;value&gt; <i>; Return two values from a non-void function </i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1843</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1844
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1845<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1846
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1847<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1848value) from a function back to the caller.</p>
John Criswell417228d2004-04-09 16:48:45 +0000[diff] [blame]1849<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1850returns value(s) and then causes control flow, and one that just causes
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1851control flow to occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1852
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1853<h5>Arguments:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1854
1855<p>The '<tt>ret</tt>' instruction may return zero, one or multiple values.
1856The type of each return value must be a '<a href="#t_firstclass">first
1857class</a>' type. Note that a function is not <a href="#wellformed">well
1858formed</a> if there exists a '<tt>ret</tt>' instruction inside of the
1859function that returns values that do not match the return type of the
1860function.</p>
1861
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1862<h5>Semantics:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1863
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1864<p>When the '<tt>ret</tt>' instruction is executed, control flow
1865returns back to the calling function's context. If the caller is a "<a
John Criswell40db33f2004-06-25 15:16:57 +0000[diff] [blame]1866 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1867the instruction after the call. If the caller was an "<a
1868 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1869at the beginning of the "normal" destination block. If the instruction
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1870returns a value, that value shall set the call or invoke instruction's
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1871return value. If the instruction returns multiple values then these
Devang Pateld0f47642008-03-11 05:51:59 +0000[diff] [blame]1872values can only be accessed through a '<a href="#i_getresult"><tt>getresult</tt>
1873</a>' instruction.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1874
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1875<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1876
1877<pre>
1878 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1879 ret void <i>; Return from a void function</i>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1880 ret i32 4, i8 2 <i>; Return two values 4 and 2 </i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1881</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1882</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1883<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1884<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1885<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1886<h5>Syntax:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1887<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]1888</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1889<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1890<p>The '<tt>br</tt>' instruction is used to cause control flow to
1891transfer to a different basic block in the current function. There are
1892two forms of this instruction, corresponding to a conditional branch
1893and an unconditional branch.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1894<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1895<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1896single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1897unconditional form of the '<tt>br</tt>' instruction takes a single
1898'<tt>label</tt>' value as a target.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1899<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1900<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1901argument is evaluated. If the value is <tt>true</tt>, control flows
1902to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1903control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1904<h5>Example:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1905<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]1906 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]1907</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1908<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1909<div class="doc_subsubsection">
1910 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1911</div>
1912
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1913<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1914<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1915
1916<pre>
1917 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
1918</pre>
1919
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1920<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1921
1922<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
1923several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1924instruction, allowing a branch to occur to one of many possible
1925destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1926
1927
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1928<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1929
1930<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
1931comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
1932an array of pairs of comparison value constants and '<tt>label</tt>'s. The
1933table is not allowed to contain duplicate constant entries.</p>
1934
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1935<h5>Semantics:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1936
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1937<p>The <tt>switch</tt> instruction specifies a table of values and
1938destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]1939table is searched for the given value. If the value is found, control flow is
1940transfered to the corresponding destination; otherwise, control flow is
1941transfered to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1942
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1943<h5>Implementation:</h5>
1944
1945<p>Depending on properties of the target machine and the particular
1946<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]1947ways. For example, it could be generated as a series of chained conditional
1948branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1949
1950<h5>Example:</h5>
1951
1952<pre>
1953 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1954 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1955 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1956
1957 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1958 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1959
1960 <i>; Implement a jump table:</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1961 switch i32 %val, label %otherwise [ i32 0, label %onzero
1962 i32 1, label %onone
1963 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1964</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1965</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1966
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1967<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1968<div class="doc_subsubsection">
1969 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
1970</div>
1971
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1972<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1973
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1974<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1975
1976<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]1977 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] &lt;ptr to function ty&gt; &lt;function ptr val&gt;(&lt;function args&gt;)
Chris Lattner6b7a0082006-05-14 18:23:06 +0000[diff] [blame]1978 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1979</pre>
1980
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]1981<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1982
1983<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
1984function, with the possibility of control flow transfer to either the
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1985'<tt>normal</tt>' label or the
1986'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1987"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
1988"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1989href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1990continued at the dynamically nearest "exception" label. If the callee function
Devang Pateld0f47642008-03-11 05:51:59 +0000[diff] [blame]1991returns multiple values then individual return values are only accessible through
1992a '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1993
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1994<h5>Arguments:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1995
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1996<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1997
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1998<ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1999 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]2000 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2001 convention</a> the call should use. If none is specified, the call defaults
2002 to using C calling conventions.
2003 </li>
2004 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2005 function value being invoked. In most cases, this is a direct function
2006 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2007 an arbitrary pointer to function value.
2008 </li>
2009
2010 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2011 function to be invoked. </li>
2012
2013 <li>'<tt>function args</tt>': argument list whose types match the function
2014 signature argument types. If the function signature indicates the function
2015 accepts a variable number of arguments, the extra arguments can be
2016 specified. </li>
2017
2018 <li>'<tt>normal label</tt>': the label reached when the called function
2019 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2020
2021 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2022 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2023
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2024</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2025
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2026<h5>Semantics:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2027
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2028<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2029href="#i_call">call</a></tt>' instruction in most regards. The primary
2030difference is that it establishes an association with a label, which is used by
2031the runtime library to unwind the stack.</p>
2032
2033<p>This instruction is used in languages with destructors to ensure that proper
2034cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2035exception. Additionally, this is important for implementation of
2036'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2037
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2038<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2039<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2040 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2041 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2042 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2043 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2044</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2045</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2046
2047
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2048<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2049
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2050<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2051Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2052
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2053<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2054
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2055<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2056<pre>
2057 unwind
2058</pre>
2059
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2060<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2061
2062<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2063at the first callee in the dynamic call stack which used an <a
2064href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2065primarily used to implement exception handling.</p>
2066
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2067<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2068
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2069<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2070immediately halt. The dynamic call stack is then searched for the first <a
2071href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2072execution continues at the "exceptional" destination block specified by the
2073<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2074dynamic call chain, undefined behavior results.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2075</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2076
2077<!-- _______________________________________________________________________ -->
2078
2079<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2080Instruction</a> </div>
2081
2082<div class="doc_text">
2083
2084<h5>Syntax:</h5>
2085<pre>
2086 unreachable
2087</pre>
2088
2089<h5>Overview:</h5>
2090
2091<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2092instruction is used to inform the optimizer that a particular portion of the
2093code is not reachable. This can be used to indicate that the code after a
2094no-return function cannot be reached, and other facts.</p>
2095
2096<h5>Semantics:</h5>
2097
2098<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2099</div>
2100
2101
2102
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2103<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2104<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2105<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2106<p>Binary operators are used to do most of the computation in a
Chris Lattner81f92972008-04-01 18:47:32 +0000[diff] [blame]2107program. They require two operands of the same type, execute an operation on them, and
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2108produce a single value. The operands might represent
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2109multiple 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]2110The result value has the same type as its operands.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2111<p>There are several different binary operators:</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2112</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2113<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2114<div class="doc_subsubsection">
2115 <a name="i_add">'<tt>add</tt>' Instruction</a>
2116</div>
2117
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2118<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2119
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2120<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2121
2122<pre>
2123 &lt;result&gt; = add &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2124</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2125
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2126<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2127
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2128<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2129
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2130<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2131
2132<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2133 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2134 <a href="#t_vector">vector</a> values. Both arguments must have identical
2135 types.</p>
2136
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2137<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2138
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2139<p>The value produced is the integer or floating point sum of the two
2140operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2141
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2142<p>If an integer sum has unsigned overflow, the result returned is the
2143mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2144the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2145
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2146<p>Because LLVM integers use a two's complement representation, this
2147instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2148
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2149<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2150
2151<pre>
2152 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2153</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2154</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2155<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2156<div class="doc_subsubsection">
2157 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2158</div>
2159
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2160<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2161
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2162<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2163
2164<pre>
2165 &lt;result&gt; = sub &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2166</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2167
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2168<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2169
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2170<p>The '<tt>sub</tt>' instruction returns the difference of its two
2171operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2172
2173<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2174'<tt>neg</tt>' instruction present in most other intermediate
2175representations.</p>
2176
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2177<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2178
2179<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2180 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2181 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2182 types.</p>
2183
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2184<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2185
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2186<p>The value produced is the integer or floating point difference of
2187the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2188
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2189<p>If an integer difference has unsigned overflow, the result returned is the
2190mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2191the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2192
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2193<p>Because LLVM integers use a two's complement representation, this
2194instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2195
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2196<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2197<pre>
2198 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2199 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2200</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2201</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2202
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2203<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2204<div class="doc_subsubsection">
2205 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2206</div>
2207
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2208<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2209
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2210<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2211<pre> &lt;result&gt; = mul &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2212</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2213<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2214<p>The '<tt>mul</tt>' instruction returns the product of its two
2215operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2216
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2217<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2218
2219<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2220href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2221or <a href="#t_vector">vector</a> values. Both arguments must have identical
2222types.</p>
2223
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2224<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2225
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2226<p>The value produced is the integer or floating point product of the
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2227two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2228
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2229<p>If the result of an integer multiplication has unsigned overflow,
2230the result returned is the mathematical result modulo
22312<sup>n</sup>, where n is the bit width of the result.</p>
2232<p>Because LLVM integers use a two's complement representation, and the
2233result is the same width as the operands, this instruction returns the
2234correct result for both signed and unsigned integers. If a full product
2235(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2236should be sign-extended or zero-extended as appropriate to the
2237width of the full product.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2238<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2239<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]2240</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2241</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2242
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2243<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2244<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2245</a></div>
2246<div class="doc_text">
2247<h5>Syntax:</h5>
2248<pre> &lt;result&gt; = udiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2249</pre>
2250<h5>Overview:</h5>
2251<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2252operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2253
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2254<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2255
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2256<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2257<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2258values. Both arguments must have identical types.</p>
2259
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2260<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2261
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2262<p>The value produced is the unsigned integer quotient of the two operands.</p>
2263<p>Note that unsigned integer division and signed integer division are distinct
2264operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2265<p>Division by zero leads to undefined behavior.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2266<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2267<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]2268</pre>
2269</div>
2270<!-- _______________________________________________________________________ -->
2271<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2272</a> </div>
2273<div class="doc_text">
2274<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2275<pre>
2276 &lt;result&gt; = sdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2277</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2278
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2279<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2280
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2281<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2282operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2283
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2284<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2285
2286<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2287<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2288values. Both arguments must have identical types.</p>
2289
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2290<h5>Semantics:</h5>
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2291<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]2292<p>Note that signed integer division and unsigned integer division are distinct
2293operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2294<p>Division by zero leads to undefined behavior. Overflow also leads to
2295undefined behavior; this is a rare case, but can occur, for example,
2296by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2297<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2298<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]2299</pre>
2300</div>
2301<!-- _______________________________________________________________________ -->
2302<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2303Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2304<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2305<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2306<pre>
2307 &lt;result&gt; = fdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2308</pre>
2309<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2310
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2311<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2312operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2313
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2314<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2315
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2316<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2317<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2318of floating point values. Both arguments must have identical types.</p>
2319
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2320<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2321
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2322<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2323
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2324<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2325
2326<pre>
2327 &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]2328</pre>
2329</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2330
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2331<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2332<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2333</div>
2334<div class="doc_text">
2335<h5>Syntax:</h5>
2336<pre> &lt;result&gt; = urem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2337</pre>
2338<h5>Overview:</h5>
2339<p>The '<tt>urem</tt>' instruction returns the remainder from the
2340unsigned division of its two arguments.</p>
2341<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2342<p>The two arguments to the '<tt>urem</tt>' instruction must be
2343<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2344values. Both arguments must have identical types.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2345<h5>Semantics:</h5>
2346<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2347This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2348<p>Note that unsigned integer remainder and signed integer remainder are
2349distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2350<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2351<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2352<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]2353</pre>
2354
2355</div>
2356<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2357<div class="doc_subsubsection">
2358 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2359</div>
2360
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2361<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2362
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2363<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2364
2365<pre>
2366 &lt;result&gt; = srem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2367</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2368
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2369<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2370
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2371<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame]2372signed division of its two operands. This instruction can also take
2373<a href="#t_vector">vector</a> versions of the values in which case
2374the elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]2375
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2376<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2377
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2378<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2379<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2380values. Both arguments must have identical types.</p>
2381
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2382<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2383
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2384<p>This instruction returns the <i>remainder</i> of a division (where the result
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2385has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
2386operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
2387a value. For more information about the difference, see <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2388 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2389Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencerdb3b93b2007-03-24 22:40:44 +0000[diff] [blame]2390please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2391Wikipedia: modulo operation</a>.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2392<p>Note that signed integer remainder and unsigned integer remainder are
2393distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2394<p>Taking the remainder of a division by zero leads to undefined behavior.
2395Overflow also leads to undefined behavior; this is a rare case, but can occur,
2396for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2397(The remainder doesn't actually overflow, but this rule lets srem be
2398implemented using instructions that return both the result of the division
2399and the remainder.)</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2400<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2401<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]2402</pre>
2403
2404</div>
2405<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2406<div class="doc_subsubsection">
2407 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2408
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2409<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2410
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2411<h5>Syntax:</h5>
2412<pre> &lt;result&gt; = frem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2413</pre>
2414<h5>Overview:</h5>
2415<p>The '<tt>frem</tt>' instruction returns the remainder from the
2416division of its two operands.</p>
2417<h5>Arguments:</h5>
2418<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2419<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2420of floating point values. Both arguments must have identical types.</p>
2421
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2422<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2423
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2424<p>This instruction returns the <i>remainder</i> of a division.
2425The remainder has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2426
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2427<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2428
2429<pre>
2430 &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]2431</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2432</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]2433
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2434<!-- ======================================================================= -->
2435<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2436Operations</a> </div>
2437<div class="doc_text">
2438<p>Bitwise binary operators are used to do various forms of
2439bit-twiddling in a program. They are generally very efficient
2440instructions and can commonly be strength reduced from other
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2441instructions. They require two operands of the same type, execute an operation on them,
2442and 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]2443</div>
2444
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2445<!-- _______________________________________________________________________ -->
2446<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2447Instruction</a> </div>
2448<div class="doc_text">
2449<h5>Syntax:</h5>
2450<pre> &lt;result&gt; = shl &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2451</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2452
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2453<h5>Overview:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2454
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2455<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2456the left a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2457
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2458<h5>Arguments:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2459
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2460<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2461 href="#t_integer">integer</a> type. '<tt>var2</tt>' is treated as an
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2462unsigned value. This instruction does not support
2463<a href="#t_vector">vector</a> operands.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2464
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2465<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2466
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2467<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup> mod 2<sup>n</sup>,
2468where n is the width of the result. If <tt>var2</tt> is (statically or dynamically) negative or
2469equal to or larger than the number of bits in <tt>var1</tt>, the result is undefined.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2470
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2471<h5>Example:</h5><pre>
2472 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2473 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2474 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2475 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2476</pre>
2477</div>
2478<!-- _______________________________________________________________________ -->
2479<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2480Instruction</a> </div>
2481<div class="doc_text">
2482<h5>Syntax:</h5>
2483<pre> &lt;result&gt; = lshr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2484</pre>
2485
2486<h5>Overview:</h5>
2487<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2488operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2489
2490<h5>Arguments:</h5>
2491<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2492<a href="#t_integer">integer</a> type. '<tt>var2</tt>' is treated as an
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2493unsigned value. This instruction does not support
2494<a href="#t_vector">vector</a> operands.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2495
2496<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2497
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2498<p>This instruction always performs a logical shift right operation. The most
2499significant bits of the result will be filled with zero bits after the
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2500shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
2501the number of bits in <tt>var1</tt>, the result is undefined.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2502
2503<h5>Example:</h5>
2504<pre>
2505 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2506 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2507 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2508 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2509 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2510</pre>
2511</div>
2512
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2513<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2514<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2515Instruction</a> </div>
2516<div class="doc_text">
2517
2518<h5>Syntax:</h5>
2519<pre> &lt;result&gt; = ashr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2520</pre>
2521
2522<h5>Overview:</h5>
2523<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2524operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2525
2526<h5>Arguments:</h5>
2527<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2528<a href="#t_integer">integer</a> type. '<tt>var2</tt>' is treated as an
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2529unsigned value. This instruction does not support
2530<a href="#t_vector">vector</a> operands.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2531
2532<h5>Semantics:</h5>
2533<p>This instruction always performs an arithmetic shift right operation,
2534The most significant bits of the result will be filled with the sign bit
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2535of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
2536larger than the number of bits in <tt>var1</tt>, the result is undefined.
2537</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2538
2539<h5>Example:</h5>
2540<pre>
2541 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2542 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2543 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2544 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2545 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2546</pre>
2547</div>
2548
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2549<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2550<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2551Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2552
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2553<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2554
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2555<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2556
2557<pre>
2558 &lt;result&gt; = and &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2559</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2560
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2561<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2562
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2563<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2564its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2565
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2566<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2567
2568<p>The two arguments to the '<tt>and</tt>' instruction must be
2569<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2570values. Both arguments must have identical types.</p>
2571
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2572<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2573<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2574<p> </p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2575<div style="align: center">
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2576<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2577 <tbody>
2578 <tr>
2579 <td>In0</td>
2580 <td>In1</td>
2581 <td>Out</td>
2582 </tr>
2583 <tr>
2584 <td>0</td>
2585 <td>0</td>
2586 <td>0</td>
2587 </tr>
2588 <tr>
2589 <td>0</td>
2590 <td>1</td>
2591 <td>0</td>
2592 </tr>
2593 <tr>
2594 <td>1</td>
2595 <td>0</td>
2596 <td>0</td>
2597 </tr>
2598 <tr>
2599 <td>1</td>
2600 <td>1</td>
2601 <td>1</td>
2602 </tr>
2603 </tbody>
2604</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2605</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2606<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2607<pre>
2608 &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]2609 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2610 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2611</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2612</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2613<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2614<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2615<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2616<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2617<pre> &lt;result&gt; = or &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2618</pre>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2619<h5>Overview:</h5>
2620<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2621or of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2622<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2623
2624<p>The two arguments to the '<tt>or</tt>' instruction must be
2625<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2626values. Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2627<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2628<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2629<p> </p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2630<div style="align: center">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2631<table border="1" cellspacing="0" cellpadding="4">
2632 <tbody>
2633 <tr>
2634 <td>In0</td>
2635 <td>In1</td>
2636 <td>Out</td>
2637 </tr>
2638 <tr>
2639 <td>0</td>
2640 <td>0</td>
2641 <td>0</td>
2642 </tr>
2643 <tr>
2644 <td>0</td>
2645 <td>1</td>
2646 <td>1</td>
2647 </tr>
2648 <tr>
2649 <td>1</td>
2650 <td>0</td>
2651 <td>1</td>
2652 </tr>
2653 <tr>
2654 <td>1</td>
2655 <td>1</td>
2656 <td>1</td>
2657 </tr>
2658 </tbody>
2659</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2660</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2661<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2662<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2663 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2664 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2665</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2666</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2667<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2668<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2669Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2670<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2671<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2672<pre> &lt;result&gt; = xor &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2673</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2674<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2675<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2676or of its two operands. The <tt>xor</tt> is used to implement the
2677"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2678<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2679<p>The two arguments to the '<tt>xor</tt>' instruction must be
2680<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2681values. Both arguments must have identical types.</p>
2682
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2683<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2684
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2685<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2686<p> </p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2687<div style="align: center">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2688<table border="1" cellspacing="0" cellpadding="4">
2689 <tbody>
2690 <tr>
2691 <td>In0</td>
2692 <td>In1</td>
2693 <td>Out</td>
2694 </tr>
2695 <tr>
2696 <td>0</td>
2697 <td>0</td>
2698 <td>0</td>
2699 </tr>
2700 <tr>
2701 <td>0</td>
2702 <td>1</td>
2703 <td>1</td>
2704 </tr>
2705 <tr>
2706 <td>1</td>
2707 <td>0</td>
2708 <td>1</td>
2709 </tr>
2710 <tr>
2711 <td>1</td>
2712 <td>1</td>
2713 <td>0</td>
2714 </tr>
2715 </tbody>
2716</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2717</div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2718<p> </p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2719<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2720<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2721 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2722 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2723 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2724</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2725</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2726
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2727<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2728<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2729 <a name="vectorops">Vector Operations</a>
2730</div>
2731
2732<div class="doc_text">
2733
2734<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2735target-independent manner. These instructions cover the element-access and
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2736vector-specific operations needed to process vectors effectively. While LLVM
2737does directly support these vector operations, many sophisticated algorithms
2738will want to use target-specific intrinsics to take full advantage of a specific
2739target.</p>
2740
2741</div>
2742
2743<!-- _______________________________________________________________________ -->
2744<div class="doc_subsubsection">
2745 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2746</div>
2747
2748<div class="doc_text">
2749
2750<h5>Syntax:</h5>
2751
2752<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2753 &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]2754</pre>
2755
2756<h5>Overview:</h5>
2757
2758<p>
2759The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2760element from a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2761</p>
2762
2763
2764<h5>Arguments:</h5>
2765
2766<p>
2767The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2768value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2769an index indicating the position from which to extract the element.
2770The index may be a variable.</p>
2771
2772<h5>Semantics:</h5>
2773
2774<p>
2775The result is a scalar of the same type as the element type of
2776<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2777<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2778results are undefined.
2779</p>
2780
2781<h5>Example:</h5>
2782
2783<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2784 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2785</pre>
2786</div>
2787
2788
2789<!-- _______________________________________________________________________ -->
2790<div class="doc_subsubsection">
2791 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2792</div>
2793
2794<div class="doc_text">
2795
2796<h5>Syntax:</h5>
2797
2798<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]2799 &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]2800</pre>
2801
2802<h5>Overview:</h5>
2803
2804<p>
2805The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2806element into a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2807</p>
2808
2809
2810<h5>Arguments:</h5>
2811
2812<p>
2813The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2814value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2815scalar value whose type must equal the element type of the first
2816operand. The third operand is an index indicating the position at
2817which to insert the value. The index may be a variable.</p>
2818
2819<h5>Semantics:</h5>
2820
2821<p>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2822The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2823element values are those of <tt>val</tt> except at position
2824<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2825exceeds the length of <tt>val</tt>, the results are undefined.
2826</p>
2827
2828<h5>Example:</h5>
2829
2830<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2831 %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]2832</pre>
2833</div>
2834
2835<!-- _______________________________________________________________________ -->
2836<div class="doc_subsubsection">
2837 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2838</div>
2839
2840<div class="doc_text">
2841
2842<h5>Syntax:</h5>
2843
2844<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2845 &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;n x i32&gt; &lt;mask&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2846</pre>
2847
2848<h5>Overview:</h5>
2849
2850<p>
2851The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2852from two input vectors, returning a vector of the same type.
2853</p>
2854
2855<h5>Arguments:</h5>
2856
2857<p>
2858The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2859with types that match each other and types that match the result of the
2860instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2861of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2862</p>
2863
2864<p>
2865The shuffle mask operand is required to be a constant vector with either
2866constant integer or undef values.
2867</p>
2868
2869<h5>Semantics:</h5>
2870
2871<p>
2872The elements of the two input vectors are numbered from left to right across
2873both of the vectors. The shuffle mask operand specifies, for each element of
2874the result vector, which element of the two input registers the result element
2875gets. The element selector may be undef (meaning "don't care") and the second
2876operand may be undef if performing a shuffle from only one vector.
2877</p>
2878
2879<h5>Example:</h5>
2880
2881<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2882 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2883 &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]2884 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2885 &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.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2886</pre>
2887</div>
2888
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]2889
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2890<!-- ======================================================================= -->
2891<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]2892 <a name="aggregateops">Aggregate Operations</a>
2893</div>
2894
2895<div class="doc_text">
2896
2897<p>LLVM supports several instructions for working with aggregate values.
2898</p>
2899
2900</div>
2901
2902<!-- _______________________________________________________________________ -->
2903<div class="doc_subsubsection">
2904 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
2905</div>
2906
2907<div class="doc_text">
2908
2909<h5>Syntax:</h5>
2910
2911<pre>
2912 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
2913</pre>
2914
2915<h5>Overview:</h5>
2916
2917<p>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]2918The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
2919or array element from an aggregate value.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]2920</p>
2921
2922
2923<h5>Arguments:</h5>
2924
2925<p>
2926The first operand of an '<tt>extractvalue</tt>' instruction is a
2927value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]2928type. The operands are constant indices to specify which value to extract
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]2929in a similar manner as indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]2930'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
2931</p>
2932
2933<h5>Semantics:</h5>
2934
2935<p>
2936The result is the value at the position in the aggregate specified by
2937the index operands.
2938</p>
2939
2940<h5>Example:</h5>
2941
2942<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]2943 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]2944</pre>
2945</div>
2946
2947
2948<!-- _______________________________________________________________________ -->
2949<div class="doc_subsubsection">
2950 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
2951</div>
2952
2953<div class="doc_text">
2954
2955<h5>Syntax:</h5>
2956
2957<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]2958 &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]2959</pre>
2960
2961<h5>Overview:</h5>
2962
2963<p>
2964The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]2965into a struct field or array element in an aggregate.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]2966</p>
2967
2968
2969<h5>Arguments:</h5>
2970
2971<p>
2972The first operand of an '<tt>insertvalue</tt>' instruction is a
2973value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
2974The second operand is a first-class value to insert.
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]2975The following operands are constant indices
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]2976indicating the position at which to insert the value in a similar manner as
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]2977indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]2978'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
2979The value to insert must have the same type as the value identified
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]2980by the indices.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]2981
2982<h5>Semantics:</h5>
2983
2984<p>
2985The result is an aggregate of the same type as <tt>val</tt>. Its
2986value is that of <tt>val</tt> except that the value at the position
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]2987specified by the indices is that of <tt>elt</tt>.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]2988</p>
2989
2990<h5>Example:</h5>
2991
2992<pre>
Dan Gohman88ce1a52008-06-23 15:26:37 +0000[diff] [blame]2993 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]2994</pre>
2995</div>
2996
2997
2998<!-- ======================================================================= -->
2999<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3000 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3001</div>
3002
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3003<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3004
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3005<p>A key design point of an SSA-based representation is how it
3006represents memory. In LLVM, no memory locations are in SSA form, which
3007makes things very simple. This section describes how to read, write,
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3008allocate, and free memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3009
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3010</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3011
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3012<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3013<div class="doc_subsubsection">
3014 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3015</div>
3016
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3017<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3018
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3019<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3020
3021<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3022 &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]3023</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3024
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3025<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3026
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3027<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3028heap and returns a pointer to it. The object is always allocated in the generic
3029address space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3030
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3031<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3032
3033<p>The '<tt>malloc</tt>' instruction allocates
3034<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswella92e5862004-02-24 16:13:56 +0000[diff] [blame]3035bytes of memory from the operating system and returns a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3036appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3037number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3038If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3039be aligned to at least that boundary. If not specified, or if zero, the target can
3040choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3041
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3042<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3043
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3044<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3045
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3046<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3047a pointer is returned. The result of a zero byte allocattion is undefined. The
3048result is null if there is insufficient memory available.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3049
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3050<h5>Example:</h5>
3051
3052<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3053 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3054
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3055 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3056 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3057 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3058 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3059 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3060</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3061</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3062
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3063<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3064<div class="doc_subsubsection">
3065 <a name="i_free">'<tt>free</tt>' Instruction</a>
3066</div>
3067
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3068<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3069
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3070<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3071
3072<pre>
3073 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3074</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3075
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3076<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3077
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3078<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3079memory heap to be reallocated in the future.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3080
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3081<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3082
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3083<p>'<tt>value</tt>' shall be a pointer value that points to a value
3084that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3085instruction.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3086
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3087<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3088
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3089<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner0f103e12008-04-19 22:41:32 +0000[diff] [blame]3090after this instruction executes. If the pointer is null, the operation
3091is a noop.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3092
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3093<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3094
3095<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3096 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
3097 free [4 x i8]* %array
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3098</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3099</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3100
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3101<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3102<div class="doc_subsubsection">
3103 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3104</div>
3105
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3106<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3107
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3108<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3109
3110<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3111 &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]3112</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3113
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3114<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3115
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3116<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3117currently executing function, to be automatically released when this function
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3118returns to its caller. The object is always allocated in the generic address
3119space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3120
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3121<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3122
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3123<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3124bytes of memory on the runtime stack, returning a pointer of the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3125appropriate type to the program. If "NumElements" is specified, it is the
3126number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3127If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3128to be aligned to at least that boundary. If not specified, or if zero, the target
3129can choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3130
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3131<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3132
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3133<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3134
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3135<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3136there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3137memory is automatically released when the function returns. The '<tt>alloca</tt>'
3138instruction is commonly used to represent automatic variables that must
3139have an address available. When the function returns (either with the <tt><a
John Criswellc932bef2005-05-12 16:55:34 +0000[diff] [blame]3140 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]3141instructions), the memory is reclaimed. Allocating zero bytes
3142is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3143
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3144<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3145
3146<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3147 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3148 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3149 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3150 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3151</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3152</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3153
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3154<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3155<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3156Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3157<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3158<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3159<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]3160<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3161<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3162<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3163<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3164address from which to load. The pointer must point to a <a
Chris Lattner10ee9652004-06-03 22:57:15 +0000[diff] [blame]3165 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3166marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3167the number or order of execution of this <tt>load</tt> with other
3168volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3169instructions. </p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3170<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3171The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3172(that is, the alignment of the memory address). A value of 0 or an
3173omitted "align" argument means that the operation has the preferential
3174alignment for the target. It is the responsibility of the code emitter
3175to ensure that the alignment information is correct. Overestimating
3176the alignment results in an undefined behavior. Underestimating the
3177alignment may produce less efficient code. An alignment of 1 is always
3178safe.
3179</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3180<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3181<p>The location of memory pointed to is loaded.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3182<h5>Examples:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3183<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3184 <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3185 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3186 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3187</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3188</div>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3189<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3190<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3191Instruction</a> </div>
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]3192<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3193<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3194<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3195 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]3196</pre>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3197<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3198<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3199<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3200<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3201to 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]3202operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3203of the '<tt>&lt;value&gt;</tt>'
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3204operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3205optimizer is not allowed to modify the number or order of execution of
3206this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3207 href="#i_store">store</a></tt> instructions.</p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3208<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3209The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3210(that is, the alignment of the memory address). A value of 0 or an
3211omitted "align" argument means that the operation has the preferential
3212alignment for the target. It is the responsibility of the code emitter
3213to ensure that the alignment information is correct. Overestimating
3214the alignment results in an undefined behavior. Underestimating the
3215alignment may produce less efficient code. An alignment of 1 is always
3216safe.
3217</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3218<h5>Semantics:</h5>
3219<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3220at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3221<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3222<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]3223 store i32 3, i32* %ptr <i>; yields {void}</i>
3224 %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]3225</pre>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3226</div>
3227
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3228<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3229<div class="doc_subsubsection">
3230 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3231</div>
3232
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3233<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3234<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3235<pre>
3236 &lt;result&gt; = getelementptr &lt;ty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
3237</pre>
3238
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3239<h5>Overview:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3240
3241<p>
3242The '<tt>getelementptr</tt>' instruction is used to get the address of a
3243subelement of an aggregate data structure.</p>
3244
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3245<h5>Arguments:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3246
Reid Spencercee005c2006-12-04 21:29:24 +0000[diff] [blame]3247<p>This instruction takes a list of integer operands that indicate what
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3248elements of the aggregate object to index to. The actual types of the arguments
3249provided depend on the type of the first pointer argument. The
3250'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3251levels of a structure or to a specific index in an array. When indexing into a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3252structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]3253into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
3254values will be sign extended to 64-bits if required.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3255
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3256<p>For example, let's consider a C code fragment and how it gets
3257compiled to LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3258
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3259<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3260<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3261struct RT {
3262 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3263 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3264 char C;
3265};
3266struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3267 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3268 double Y;
3269 struct RT Z;
3270};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3271
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3272int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3273 return &amp;s[1].Z.B[5][13];
3274}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3275</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3276</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3277
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3278<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3279
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3280<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3281<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3282%RT = type { i8 , [10 x [20 x i32]], i8 }
3283%ST = type { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3284
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3285define i32* %foo(%ST* %s) {
3286entry:
3287 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3288 ret i32* %reg
3289}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3290</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3291</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3292
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3293<h5>Semantics:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3294
3295<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3296on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencercee005c2006-12-04 21:29:24 +0000[diff] [blame]3297and <a href="#t_array">array</a> types can use a 32-bit or 64-bit
Reid Spencerc0312692006-12-03 16:53:48 +0000[diff] [blame]3298<a href="#t_integer">integer</a> type but the value will always be sign extended
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3299to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
3300structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3301
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3302<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]3303type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3304}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3305the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3306i8 }</tt>' type, another structure. The third index indexes into the second
3307element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3308array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3309'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3310to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3311
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3312<p>Note that it is perfectly legal to index partially through a
3313structure, returning a pointer to an inner element. Because of this,
3314the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3315
3316<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3317 define i32* %foo(%ST* %s) {
3318 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3319 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3320 %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]3321 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3322 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3323 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3324 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3325</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3326
3327<p>Note that it is undefined to access an array out of bounds: array and
3328pointer indexes must always be within the defined bounds of the array type.
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]3329The one exception for this rule is zero length arrays. These arrays are
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3330defined to be accessible as variable length arrays, which requires access
3331beyond the zero'th element.</p>
3332
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3333<p>The getelementptr instruction is often confusing. For some more insight
3334into how it works, see <a href="GetElementPtr.html">the getelementptr
3335FAQ</a>.</p>
3336
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3337<h5>Example:</h5>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3338
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3339<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3340 <i>; yields [12 x i8]*:aptr</i>
3341 %aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3342</pre>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3343</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3344
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3345<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3346<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3347</div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3348<div class="doc_text">
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3349<p>The instructions in this category are the conversion instructions (casting)
3350which all take a single operand and a type. They perform various bit conversions
3351on the operand.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3352</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3353
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3354<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3355<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3356 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3357</div>
3358<div class="doc_text">
3359
3360<h5>Syntax:</h5>
3361<pre>
3362 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3363</pre>
3364
3365<h5>Overview:</h5>
3366<p>
3367The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3368</p>
3369
3370<h5>Arguments:</h5>
3371<p>
3372The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3373be 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]3374and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3375type. The bit size of <tt>value</tt> must be larger than the bit size of
3376<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3377
3378<h5>Semantics:</h5>
3379<p>
3380The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3381and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3382larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3383It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3384
3385<h5>Example:</h5>
3386<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3387 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3388 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3389 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3390</pre>
3391</div>
3392
3393<!-- _______________________________________________________________________ -->
3394<div class="doc_subsubsection">
3395 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3396</div>
3397<div class="doc_text">
3398
3399<h5>Syntax:</h5>
3400<pre>
3401 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3402</pre>
3403
3404<h5>Overview:</h5>
3405<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3406<tt>ty2</tt>.</p>
3407
3408
3409<h5>Arguments:</h5>
3410<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]3411<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3412also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3413<tt>value</tt> must be smaller than the bit size of the destination type,
3414<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3415
3416<h5>Semantics:</h5>
3417<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]3418bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3419
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]3420<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]3421
3422<h5>Example:</h5>
3423<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3424 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3425 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3426</pre>
3427</div>
3428
3429<!-- _______________________________________________________________________ -->
3430<div class="doc_subsubsection">
3431 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3432</div>
3433<div class="doc_text">
3434
3435<h5>Syntax:</h5>
3436<pre>
3437 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3438</pre>
3439
3440<h5>Overview:</h5>
3441<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3442
3443<h5>Arguments:</h5>
3444<p>
3445The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3446<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3447also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3448<tt>value</tt> must be smaller than the bit size of the destination type,
3449<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3450
3451<h5>Semantics:</h5>
3452<p>
3453The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3454bit (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]3455the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3456
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3457<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]3458
3459<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3460<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3461 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3462 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3463</pre>
3464</div>
3465
3466<!-- _______________________________________________________________________ -->
3467<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3468 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3469</div>
3470
3471<div class="doc_text">
3472
3473<h5>Syntax:</h5>
3474
3475<pre>
3476 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3477</pre>
3478
3479<h5>Overview:</h5>
3480<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3481<tt>ty2</tt>.</p>
3482
3483
3484<h5>Arguments:</h5>
3485<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3486 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3487cast it to. The size of <tt>value</tt> must be larger than the size of
3488<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3489<i>no-op cast</i>.</p>
3490
3491<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3492<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3493<a href="#t_floating">floating point</a> type to a smaller
3494<a href="#t_floating">floating point</a> type. If the value cannot fit within
3495the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3496
3497<h5>Example:</h5>
3498<pre>
3499 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3500 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3501</pre>
3502</div>
3503
3504<!-- _______________________________________________________________________ -->
3505<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3506 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3507</div>
3508<div class="doc_text">
3509
3510<h5>Syntax:</h5>
3511<pre>
3512 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3513</pre>
3514
3515<h5>Overview:</h5>
3516<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3517floating point value.</p>
3518
3519<h5>Arguments:</h5>
3520<p>The '<tt>fpext</tt>' instruction takes a
3521<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3522and a <a href="#t_floating">floating point</a> type to cast it to. The source
3523type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3524
3525<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3526<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3527<a href="#t_floating">floating point</a> type to a larger
3528<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3529used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3530<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]3531
3532<h5>Example:</h5>
3533<pre>
3534 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3535 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3536</pre>
3537</div>
3538
3539<!-- _______________________________________________________________________ -->
3540<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]3541 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3542</div>
3543<div class="doc_text">
3544
3545<h5>Syntax:</h5>
3546<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3547 &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]3548</pre>
3549
3550<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3551<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3552unsigned integer equivalent of type <tt>ty2</tt>.
3553</p>
3554
3555<h5>Arguments:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3556<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]3557scalar or vector <a href="#t_floating">floating point</a> value, and a type
3558to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3559type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3560vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3561
3562<h5>Semantics:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3563<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3564<a href="#t_floating">floating point</a> operand into the nearest (rounding
3565towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3566the results are undefined.</p>
3567
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3568<h5>Example:</h5>
3569<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3570 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3571 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3572 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3573</pre>
3574</div>
3575
3576<!-- _______________________________________________________________________ -->
3577<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3578 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3579</div>
3580<div class="doc_text">
3581
3582<h5>Syntax:</h5>
3583<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3584 &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]3585</pre>
3586
3587<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3588<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3589<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]3590</p>
3591
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3592<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3593<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]3594scalar or vector <a href="#t_floating">floating point</a> value, and a type
3595to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3596type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3597vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3598
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3599<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3600<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3601<a href="#t_floating">floating point</a> operand into the nearest (rounding
3602towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3603the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3604
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3605<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3606<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3607 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3608 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3609 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3610</pre>
3611</div>
3612
3613<!-- _______________________________________________________________________ -->
3614<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3615 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3616</div>
3617<div class="doc_text">
3618
3619<h5>Syntax:</h5>
3620<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3621 &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]3622</pre>
3623
3624<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3625<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3626integer and converts that value to the <tt>ty2</tt> type.</p>
3627
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3628<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3629<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3630scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3631to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3632type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3633floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3634
3635<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3636<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3637integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3638the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3639
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3640<h5>Example:</h5>
3641<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3642 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3643 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3644</pre>
3645</div>
3646
3647<!-- _______________________________________________________________________ -->
3648<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3649 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3650</div>
3651<div class="doc_text">
3652
3653<h5>Syntax:</h5>
3654<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3655 &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]3656</pre>
3657
3658<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3659<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3660integer and converts that value to the <tt>ty2</tt> type.</p>
3661
3662<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3663<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3664scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3665to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3666type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3667floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3668
3669<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3670<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3671integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3672the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3673
3674<h5>Example:</h5>
3675<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3676 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3677 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3678</pre>
3679</div>
3680
3681<!-- _______________________________________________________________________ -->
3682<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3683 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3684</div>
3685<div class="doc_text">
3686
3687<h5>Syntax:</h5>
3688<pre>
3689 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3690</pre>
3691
3692<h5>Overview:</h5>
3693<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3694the integer type <tt>ty2</tt>.</p>
3695
3696<h5>Arguments:</h5>
3697<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3698must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3699<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
3700
3701<h5>Semantics:</h5>
3702<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3703<tt>ty2</tt> by interpreting the pointer value as an integer and either
3704truncating or zero extending that value to the size of the integer type. If
3705<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3706<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]3707are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3708change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3709
3710<h5>Example:</h5>
3711<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3712 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3713 %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]3714</pre>
3715</div>
3716
3717<!-- _______________________________________________________________________ -->
3718<div class="doc_subsubsection">
3719 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3720</div>
3721<div class="doc_text">
3722
3723<h5>Syntax:</h5>
3724<pre>
3725 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3726</pre>
3727
3728<h5>Overview:</h5>
3729<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3730a pointer type, <tt>ty2</tt>.</p>
3731
3732<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3733<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3734value to cast, and a type to cast it to, which must be a
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]3735<a href="#t_pointer">pointer</a> type.
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3736
3737<h5>Semantics:</h5>
3738<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3739<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3740the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3741size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3742the size of a pointer then a zero extension is done. If they are the same size,
3743nothing is done (<i>no-op cast</i>).</p>
3744
3745<h5>Example:</h5>
3746<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3747 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3748 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3749 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3750</pre>
3751</div>
3752
3753<!-- _______________________________________________________________________ -->
3754<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3755 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3756</div>
3757<div class="doc_text">
3758
3759<h5>Syntax:</h5>
3760<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3761 &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]3762</pre>
3763
3764<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3765
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3766<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3767<tt>ty2</tt> without changing any bits.</p>
3768
3769<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3770
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3771<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3772a first class value, and a type to cast it to, which must also be a <a
3773 href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
Reid Spencere3db84c2007-01-09 20:08:58 +0000[diff] [blame]3774and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3775type is a pointer, the destination type must also be a pointer. This
3776instruction supports bitwise conversion of vectors to integers and to vectors
3777of other types (as long as they have the same size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3778
3779<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3780<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3781<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3782this conversion. The conversion is done as if the <tt>value</tt> had been
3783stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3784converted to other pointer types with this instruction. To convert pointers to
3785other types, use the <a href="#i_inttoptr">inttoptr</a> or
3786<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3787
3788<h5>Example:</h5>
3789<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3790 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3791 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
3792 %Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3793</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3794</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3795
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3796<!-- ======================================================================= -->
3797<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3798<div class="doc_text">
3799<p>The instructions in this category are the "miscellaneous"
3800instructions, which defy better classification.</p>
3801</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3802
3803<!-- _______________________________________________________________________ -->
3804<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3805</div>
3806<div class="doc_text">
3807<h5>Syntax:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3808<pre> &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {i1}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3809</pre>
3810<h5>Overview:</h5>
3811<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3812of its two integer or pointer operands.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3813<h5>Arguments:</h5>
3814<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3815the condition code indicating the kind of comparison to perform. It is not
3816a value, just a keyword. The possible condition code are:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3817<ol>
3818 <li><tt>eq</tt>: equal</li>
3819 <li><tt>ne</tt>: not equal </li>
3820 <li><tt>ugt</tt>: unsigned greater than</li>
3821 <li><tt>uge</tt>: unsigned greater or equal</li>
3822 <li><tt>ult</tt>: unsigned less than</li>
3823 <li><tt>ule</tt>: unsigned less or equal</li>
3824 <li><tt>sgt</tt>: signed greater than</li>
3825 <li><tt>sge</tt>: signed greater or equal</li>
3826 <li><tt>slt</tt>: signed less than</li>
3827 <li><tt>sle</tt>: signed less or equal</li>
3828</ol>
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3829<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Reid Spencer784ef792007-01-04 05:19:58 +0000[diff] [blame]3830<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3831<h5>Semantics:</h5>
3832<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3833the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3834yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3835<ol>
3836 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3837 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3838 </li>
3839 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
3840 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3841 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
3842 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3843 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
3844 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3845 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
3846 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3847 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
3848 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
3849 <li><tt>sgt</tt>: interprets the operands as signed values and yields
3850 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3851 <li><tt>sge</tt>: interprets the operands as signed values and yields
3852 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3853 <li><tt>slt</tt>: interprets the operands as signed values and yields
3854 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3855 <li><tt>sle</tt>: interprets the operands as signed values and yields
3856 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3857</ol>
3858<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3859values are compared as if they were integers.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3860
3861<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3862<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3863 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3864 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3865 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3866 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3867 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3868</pre>
3869</div>
3870
3871<!-- _______________________________________________________________________ -->
3872<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3873</div>
3874<div class="doc_text">
3875<h5>Syntax:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3876<pre> &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {i1}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3877</pre>
3878<h5>Overview:</h5>
3879<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
3880of its floating point operands.</p>
3881<h5>Arguments:</h5>
3882<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3883the condition code indicating the kind of comparison to perform. It is not
3884a value, just a keyword. The possible condition code are:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3885<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3886 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3887 <li><tt>oeq</tt>: ordered and equal</li>
3888 <li><tt>ogt</tt>: ordered and greater than </li>
3889 <li><tt>oge</tt>: ordered and greater than or equal</li>
3890 <li><tt>olt</tt>: ordered and less than </li>
3891 <li><tt>ole</tt>: ordered and less than or equal</li>
3892 <li><tt>one</tt>: ordered and not equal</li>
3893 <li><tt>ord</tt>: ordered (no nans)</li>
3894 <li><tt>ueq</tt>: unordered or equal</li>
3895 <li><tt>ugt</tt>: unordered or greater than </li>
3896 <li><tt>uge</tt>: unordered or greater than or equal</li>
3897 <li><tt>ult</tt>: unordered or less than </li>
3898 <li><tt>ule</tt>: unordered or less than or equal</li>
3899 <li><tt>une</tt>: unordered or not equal</li>
3900 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3901 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3902</ol>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3903<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer02e0d1d2006-12-06 07:08:07 +0000[diff] [blame]3904<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer784ef792007-01-04 05:19:58 +0000[diff] [blame]3905<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
3906<a href="#t_floating">floating point</a> typed. They must have identical
3907types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3908<h5>Semantics:</h5>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]3909<p>The '<tt>fcmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
3910according to the condition code given as <tt>cond</tt>. The comparison performed
3911always yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3912<ol>
3913 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3914 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3915 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3916 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3917 <tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3918 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3919 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3920 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3921 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3922 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3923 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3924 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3925 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3926 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
3927 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3928 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3929 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3930 <tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3931 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3932 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3933 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3934 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3935 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3936 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3937 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3938 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3939 <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]3940 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
3941</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3942
3943<h5>Example:</h5>
3944<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
3945 &lt;result&gt; = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
3946 &lt;result&gt; = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
3947 &lt;result&gt; = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
3948</pre>
3949</div>
3950
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3951<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]3952<div class="doc_subsubsection">
3953 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
3954</div>
3955<div class="doc_text">
3956<h5>Syntax:</h5>
3957<pre> &lt;result&gt; = vicmp &lt;cond&gt; &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
3958</pre>
3959<h5>Overview:</h5>
3960<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
3961element-wise comparison of its two integer vector operands.</p>
3962<h5>Arguments:</h5>
3963<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
3964the condition code indicating the kind of comparison to perform. It is not
3965a value, just a keyword. The possible condition code are:
3966<ol>
3967 <li><tt>eq</tt>: equal</li>
3968 <li><tt>ne</tt>: not equal </li>
3969 <li><tt>ugt</tt>: unsigned greater than</li>
3970 <li><tt>uge</tt>: unsigned greater or equal</li>
3971 <li><tt>ult</tt>: unsigned less than</li>
3972 <li><tt>ule</tt>: unsigned less or equal</li>
3973 <li><tt>sgt</tt>: signed greater than</li>
3974 <li><tt>sge</tt>: signed greater or equal</li>
3975 <li><tt>slt</tt>: signed less than</li>
3976 <li><tt>sle</tt>: signed less or equal</li>
3977</ol>
3978<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
3979<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
3980<h5>Semantics:</h5>
3981<p>The '<tt>vicmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
3982according to the condition code given as <tt>cond</tt>. The comparison yields a
3983<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
3984identical type as the values being compared. The most significant bit in each
3985element is 1 if the element-wise comparison evaluates to true, and is 0
3986otherwise. All other bits of the result are undefined. The condition codes
3987are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
3988instruction</a>.
3989
3990<h5>Example:</h5>
3991<pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3992 &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>
3993 &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]3994</pre>
3995</div>
3996
3997<!-- _______________________________________________________________________ -->
3998<div class="doc_subsubsection">
3999 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4000</div>
4001<div class="doc_text">
4002<h5>Syntax:</h5>
4003<pre> &lt;result&gt; = vfcmp &lt;cond&gt; &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt;</pre>
4004<h5>Overview:</h5>
4005<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4006element-wise comparison of its two floating point vector operands. The output
4007elements have the same width as the input elements.</p>
4008<h5>Arguments:</h5>
4009<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4010the condition code indicating the kind of comparison to perform. It is not
4011a value, just a keyword. The possible condition code are:
4012<ol>
4013 <li><tt>false</tt>: no comparison, always returns false</li>
4014 <li><tt>oeq</tt>: ordered and equal</li>
4015 <li><tt>ogt</tt>: ordered and greater than </li>
4016 <li><tt>oge</tt>: ordered and greater than or equal</li>
4017 <li><tt>olt</tt>: ordered and less than </li>
4018 <li><tt>ole</tt>: ordered and less than or equal</li>
4019 <li><tt>one</tt>: ordered and not equal</li>
4020 <li><tt>ord</tt>: ordered (no nans)</li>
4021 <li><tt>ueq</tt>: unordered or equal</li>
4022 <li><tt>ugt</tt>: unordered or greater than </li>
4023 <li><tt>uge</tt>: unordered or greater than or equal</li>
4024 <li><tt>ult</tt>: unordered or less than </li>
4025 <li><tt>ule</tt>: unordered or less than or equal</li>
4026 <li><tt>une</tt>: unordered or not equal</li>
4027 <li><tt>uno</tt>: unordered (either nans)</li>
4028 <li><tt>true</tt>: no comparison, always returns true</li>
4029</ol>
4030<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4031<a href="#t_floating">floating point</a> typed. They must also be identical
4032types.</p>
4033<h5>Semantics:</h5>
4034<p>The '<tt>vfcmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
4035according to the condition code given as <tt>cond</tt>. The comparison yields a
4036<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4037an identical number of elements as the values being compared, and each element
4038having identical with to the width of the floating point elements. The most
4039significant bit in each element is 1 if the element-wise comparison evaluates to
4040true, and is 0 otherwise. All other bits of the result are undefined. The
4041condition codes are evaluated identically to the
4042<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
4043
4044<h5>Example:</h5>
4045<pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4046 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4047 &lt;result&gt; = vfcmp ult &lt;2 x double&gt; &lt; double 1, double 2 &gt;, &lt; double 2, double 2&gt; <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4048</pre>
4049</div>
4050
4051<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4052<div class="doc_subsubsection">
4053 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4054</div>
4055
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4056<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4057
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4058<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4059
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4060<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4061<h5>Overview:</h5>
4062<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4063the SSA graph representing the function.</p>
4064<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4065
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4066<p>The type of the incoming values is specified with the first type
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4067field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4068as arguments, with one pair for each predecessor basic block of the
4069current block. Only values of <a href="#t_firstclass">first class</a>
4070type may be used as the value arguments to the PHI node. Only labels
4071may be used as the label arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4072
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4073<p>There must be no non-phi instructions between the start of a basic
4074block and the PHI instructions: i.e. PHI instructions must be first in
4075a basic block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4076
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4077<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4078
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4079<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4080specified by the pair corresponding to the predecessor basic block that executed
4081just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4082
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4083<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4084<pre>
4085Loop: ; Infinite loop that counts from 0 on up...
4086 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4087 %nextindvar = add i32 %indvar, 1
4088 br label %Loop
4089</pre>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4090</div>
4091
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4092<!-- _______________________________________________________________________ -->
4093<div class="doc_subsubsection">
4094 <a name="i_select">'<tt>select</tt>' Instruction</a>
4095</div>
4096
4097<div class="doc_text">
4098
4099<h5>Syntax:</h5>
4100
4101<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4102 &lt;result&gt; = select i1 &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4103</pre>
4104
4105<h5>Overview:</h5>
4106
4107<p>
4108The '<tt>select</tt>' instruction is used to choose one value based on a
4109condition, without branching.
4110</p>
4111
4112
4113<h5>Arguments:</h5>
4114
4115<p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4116The '<tt>select</tt>' instruction requires an 'i1' value indicating the
4117condition, and two values of the same <a href="#t_firstclass">first class</a>
4118type. If the val1/val2 are vectors, the entire vectors are selected, not
4119individual elements.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4120</p>
4121
4122<h5>Semantics:</h5>
4123
4124<p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4125If the i1 condition evaluates is 1, the instruction returns the first
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4126value argument; otherwise, it returns the second value argument.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4127</p>
4128
4129<h5>Example:</h5>
4130
4131<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4132 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4133</pre>
4134</div>
4135
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]4136
4137<!-- _______________________________________________________________________ -->
4138<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4139 <a name="i_call">'<tt>call</tt>' Instruction</a>
4140</div>
4141
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4142<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4143
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4144<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4145<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4146 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;param list&gt;)
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4147</pre>
4148
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4149<h5>Overview:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4150
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4151<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4152
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4153<h5>Arguments:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4154
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4155<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4156
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4157<ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4158 <li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4159 <p>The optional "tail" marker indicates whether the callee function accesses
4160 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4161 function call is eligible for tail call optimization. Note that calls may
4162 be marked "tail" even if they do not occur before a <a
4163 href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4164 </li>
4165 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4166 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4167 convention</a> the call should use. If none is specified, the call defaults
4168 to using C calling conventions.
4169 </li>
4170 <li>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4171 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4172 the type of the return value. Functions that return no value are marked
4173 <tt><a href="#t_void">void</a></tt>.</p>
4174 </li>
4175 <li>
4176 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4177 value being invoked. The argument types must match the types implied by
4178 this signature. This type can be omitted if the function is not varargs
4179 and if the function type does not return a pointer to a function.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4180 </li>
4181 <li>
4182 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4183 be invoked. In most cases, this is a direct function invocation, but
4184 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4185 to function value.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4186 </li>
4187 <li>
4188 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencerd845d162005-05-01 22:22:57 +0000[diff] [blame]4189 function signature argument types. All arguments must be of
4190 <a href="#t_firstclass">first class</a> type. If the function signature
4191 indicates the function accepts a variable number of arguments, the extra
4192 arguments can be specified.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4193 </li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4194</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4195
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4196<h5>Semantics:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4197
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4198<p>The '<tt>call</tt>' instruction is used to cause control flow to
4199transfer to a specified function, with its incoming arguments bound to
4200the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4201instruction in the called function, control flow continues with the
4202instruction after the function call, and the return value of the
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]4203function is bound to the result argument. If the callee returns multiple
4204values then the return values of the function are only accessible through
4205the '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4206
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4207<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4208
4209<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4210 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]4211 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4212 %X = tail call i32 @foo() <i>; yields i32</i>
4213 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4214 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4215
4216 %struct.A = type { i32, i8 }
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]4217 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
4218 %gr = getresult %struct.A %r, 0 <i>; yields i32</i>
4219 %gr1 = getresult %struct.A %r, 1 <i>; yields i8</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4220</pre>
4221
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4222</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4223
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4224<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4225<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4226 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4227</div>
4228
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4229<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4230
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4231<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4232
4233<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4234 &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]4235</pre>
4236
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4237<h5>Overview:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4238
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4239<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4240the "variable argument" area of a function call. It is used to implement the
4241<tt>va_arg</tt> macro in C.</p>
4242
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4243<h5>Arguments:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4244
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4245<p>This instruction takes a <tt>va_list*</tt> value and the type of
4246the argument. It returns a value of the specified argument type and
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4247increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4248actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4249
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4250<h5>Semantics:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4251
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4252<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4253type from the specified <tt>va_list</tt> and causes the
4254<tt>va_list</tt> to point to the next argument. For more information,
4255see the variable argument handling <a href="#int_varargs">Intrinsic
4256Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4257
4258<p>It is legal for this instruction to be called in a function which does not
4259take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4260function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4261
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4262<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4263href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4264argument.</p>
4265
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4266<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4267
4268<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4269
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4270</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4271
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4272<!-- _______________________________________________________________________ -->
4273<div class="doc_subsubsection">
4274 <a name="i_getresult">'<tt>getresult</tt>' Instruction</a>
4275</div>
4276
4277<div class="doc_text">
4278
4279<h5>Syntax:</h5>
4280<pre>
Chris Lattner141b6132008-03-21 17:20:51 +0000[diff] [blame]4281 &lt;resultval&gt; = getresult &lt;type&gt; &lt;retval&gt;, &lt;index&gt;
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4282</pre>
Chris Lattner141b6132008-03-21 17:20:51 +0000[diff] [blame]4283
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4284<h5>Overview:</h5>
4285
4286<p> The '<tt>getresult</tt>' instruction is used to extract individual values
Chris Lattner141b6132008-03-21 17:20:51 +0000[diff] [blame]4287from a '<tt><a href="#i_call">call</a></tt>'
4288or '<tt><a href="#i_invoke">invoke</a></tt>' instruction that returns multiple
4289results.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4290
4291<h5>Arguments:</h5>
4292
Chris Lattner141b6132008-03-21 17:20:51 +0000[diff] [blame]4293<p>The '<tt>getresult</tt>' instruction takes a call or invoke value as its
Chris Lattner1a640a62008-04-23 04:06:52 +0000[diff] [blame]4294first argument, or an undef value. The value must have <a
4295href="#t_struct">structure type</a>. The second argument is a constant
4296unsigned index value which must be in range for the number of values returned
4297by the call.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4298
4299<h5>Semantics:</h5>
4300
Chris Lattner141b6132008-03-21 17:20:51 +0000[diff] [blame]4301<p>The '<tt>getresult</tt>' instruction extracts the element identified by
4302'<tt>index</tt>' from the aggregate value.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4303
4304<h5>Example:</h5>
4305
4306<pre>
4307 %struct.A = type { i32, i8 }
4308
4309 %r = call %struct.A @foo()
Chris Lattner141b6132008-03-21 17:20:51 +0000[diff] [blame]4310 %gr = getresult %struct.A %r, 0 <i>; yields i32:%gr</i>
4311 %gr1 = getresult %struct.A %r, 1 <i>; yields i8:%gr1</i>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4312 add i32 %gr, 42
4313 add i8 %gr1, 41
4314</pre>
4315
4316</div>
4317
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4318<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4319<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4320<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4321
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4322<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4323
4324<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4325well known names and semantics and are required to follow certain restrictions.
4326Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4327language that does not require changing all of the transformations in LLVM when
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]4328adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4329
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4330<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4331prefix is reserved in LLVM for intrinsic names; thus, function names may not
4332begin with this prefix. Intrinsic functions must always be external functions:
4333you cannot define the body of intrinsic functions. Intrinsic functions may
4334only be used in call or invoke instructions: it is illegal to take the address
4335of an intrinsic function. Additionally, because intrinsic functions are part
4336of the LLVM language, it is required if any are added that they be documented
4337here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4338
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4339<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4340a family of functions that perform the same operation but on different data
4341types. Because LLVM can represent over 8 million different integer types,
4342overloading is used commonly to allow an intrinsic function to operate on any
4343integer type. One or more of the argument types or the result type can be
4344overloaded to accept any integer type. Argument types may also be defined as
4345exactly matching a previous argument's type or the result type. This allows an
4346intrinsic function which accepts multiple arguments, but needs all of them to
4347be of the same type, to only be overloaded with respect to a single argument or
4348the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4349
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4350<p>Overloaded intrinsics will have the names of its overloaded argument types
4351encoded into its function name, each preceded by a period. Only those types
4352which are overloaded result in a name suffix. Arguments whose type is matched
4353against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4354take an integer of any width and returns an integer of exactly the same integer
4355width. This leads to a family of functions such as
4356<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4357Only one type, the return type, is overloaded, and only one type suffix is
4358required. Because the argument's type is matched against the return type, it
4359does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4360
4361<p>To learn how to add an intrinsic function, please see the
4362<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4363</p>
4364
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4365</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4366
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4367<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4368<div class="doc_subsection">
4369 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4370</div>
4371
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4372<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4373
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4374<p>Variable argument support is defined in LLVM with the <a
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4375 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4376intrinsic functions. These functions are related to the similarly
4377named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4378
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4379<p>All of these functions operate on arguments that use a
4380target-specific value type "<tt>va_list</tt>". The LLVM assembly
4381language reference manual does not define what this type is, so all
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4382transformations should be prepared to handle these functions regardless of
4383the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4384
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]4385<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]4386instruction and the variable argument handling intrinsic functions are
4387used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4388
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4389<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4390<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4391define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4392 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4393 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4394 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4395 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4396
4397 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4398 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4399
4400 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4401 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4402 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4403 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4404 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4405
4406 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4407 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4408 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4409}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4410
4411declare void @llvm.va_start(i8*)
4412declare void @llvm.va_copy(i8*, i8*)
4413declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4414</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4415</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4416
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4417</div>
4418
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4419<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4420<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4421 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4422</div>
4423
4424
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4425<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4426<h5>Syntax:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4427<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4428<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4429<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
4430<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4431href="#i_va_arg">va_arg</a></tt>.</p>
4432
4433<h5>Arguments:</h5>
4434
4435<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
4436
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4437<h5>Semantics:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4438
4439<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
4440macro available in C. In a target-dependent way, it initializes the
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4441<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]4442<tt>va_arg</tt> will produce the first variable argument passed to the function.
4443Unlike 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]4444last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4445
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4446</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4447
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4448<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4449<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4450 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4451</div>
4452
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4453<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4454<h5>Syntax:</h5>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4455<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4456<h5>Overview:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4457
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4458<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4459which 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]4460or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4461
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4462<h5>Arguments:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4463
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4464<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]4465
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4466<h5>Semantics:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4467
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4468<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]4469macro available in C. In a target-dependent way, it destroys the
4470<tt>va_list</tt> element to which the argument points. Calls to <a
4471href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4472<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4473<tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4474
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4475</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4476
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4477<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4478<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4479 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4480</div>
4481
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4482<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4483
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4484<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4485
4486<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4487 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4488</pre>
4489
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4490<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4491
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4492<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4493from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4494
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4495<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4496
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4497<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]4498The 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]4499
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4500
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4501<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4502
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4503<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4504macro available in C. In a target-dependent way, it copies the source
4505<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4506intrinsic is necessary because the <tt><a href="#int_va_start">
4507llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4508example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4509
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4510</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4511
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4512<!-- ======================================================================= -->
4513<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4514 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4515</div>
4516
4517<div class="doc_text">
4518
4519<p>
4520LLVM support for <a href="GarbageCollection.html">Accurate Garbage
4521Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4522These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4523stack</a>, as well as garbage collector implementations that require <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4524href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4525Front-ends for type-safe garbage collected languages should generate these
4526intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4527href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4528</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]4529
4530<p>The garbage collection intrinsics only operate on objects in the generic
4531 address space (address space zero).</p>
4532
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4533</div>
4534
4535<!-- _______________________________________________________________________ -->
4536<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4537 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4538</div>
4539
4540<div class="doc_text">
4541
4542<h5>Syntax:</h5>
4543
4544<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4545 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4546</pre>
4547
4548<h5>Overview:</h5>
4549
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]4550<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]4551the code generator, and allows some metadata to be associated with it.</p>
4552
4553<h5>Arguments:</h5>
4554
4555<p>The first argument specifies the address of a stack object that contains the
4556root pointer. The second pointer (which must be either a constant or a global
4557value address) contains the meta-data to be associated with the root.</p>
4558
4559<h5>Semantics:</h5>
4560
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]4561<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]4562location. At compile-time, the code generator generates information to allow
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4563the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4564intrinsic may only be used in a function which <a href="#gc">specifies a GC
4565algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4566
4567</div>
4568
4569
4570<!-- _______________________________________________________________________ -->
4571<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4572 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4573</div>
4574
4575<div class="doc_text">
4576
4577<h5>Syntax:</h5>
4578
4579<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4580 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4581</pre>
4582
4583<h5>Overview:</h5>
4584
4585<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4586locations, allowing garbage collector implementations that require read
4587barriers.</p>
4588
4589<h5>Arguments:</h5>
4590
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4591<p>The second argument is the address to read from, which should be an address
4592allocated from the garbage collector. The first object is a pointer to the
4593start of the referenced object, if needed by the language runtime (otherwise
4594null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4595
4596<h5>Semantics:</h5>
4597
4598<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4599instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4600garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4601may only be used in a function which <a href="#gc">specifies a GC
4602algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4603
4604</div>
4605
4606
4607<!-- _______________________________________________________________________ -->
4608<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4609 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4610</div>
4611
4612<div class="doc_text">
4613
4614<h5>Syntax:</h5>
4615
4616<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4617 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4618</pre>
4619
4620<h5>Overview:</h5>
4621
4622<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4623locations, allowing garbage collector implementations that require write
4624barriers (such as generational or reference counting collectors).</p>
4625
4626<h5>Arguments:</h5>
4627
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4628<p>The first argument is the reference to store, the second is the start of the
4629object to store it to, and the third is the address of the field of Obj to
4630store to. If the runtime does not require a pointer to the object, Obj may be
4631null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4632
4633<h5>Semantics:</h5>
4634
4635<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4636instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4637garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4638may only be used in a function which <a href="#gc">specifies a GC
4639algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4640
4641</div>
4642
4643
4644
4645<!-- ======================================================================= -->
4646<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4647 <a name="int_codegen">Code Generator Intrinsics</a>
4648</div>
4649
4650<div class="doc_text">
4651<p>
4652These intrinsics are provided by LLVM to expose special features that may only
4653be implemented with code generator support.
4654</p>
4655
4656</div>
4657
4658<!-- _______________________________________________________________________ -->
4659<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4660 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4661</div>
4662
4663<div class="doc_text">
4664
4665<h5>Syntax:</h5>
4666<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4667 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4668</pre>
4669
4670<h5>Overview:</h5>
4671
4672<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4673The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4674target-specific value indicating the return address of the current function
4675or one of its callers.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4676</p>
4677
4678<h5>Arguments:</h5>
4679
4680<p>
4681The argument to this intrinsic indicates which function to return the address
4682for. Zero indicates the calling function, one indicates its caller, etc. The
4683argument is <b>required</b> to be a constant integer value.
4684</p>
4685
4686<h5>Semantics:</h5>
4687
4688<p>
4689The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4690the return address of the specified call frame, or zero if it cannot be
4691identified. The value returned by this intrinsic is likely to be incorrect or 0
4692for arguments other than zero, so it should only be used for debugging purposes.
4693</p>
4694
4695<p>
4696Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4697aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4698source-language caller.
4699</p>
4700</div>
4701
4702
4703<!-- _______________________________________________________________________ -->
4704<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4705 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4706</div>
4707
4708<div class="doc_text">
4709
4710<h5>Syntax:</h5>
4711<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4712 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4713</pre>
4714
4715<h5>Overview:</h5>
4716
4717<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4718The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4719target-specific frame pointer value for the specified stack frame.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4720</p>
4721
4722<h5>Arguments:</h5>
4723
4724<p>
4725The argument to this intrinsic indicates which function to return the frame
4726pointer for. Zero indicates the calling function, one indicates its caller,
4727etc. The argument is <b>required</b> to be a constant integer value.
4728</p>
4729
4730<h5>Semantics:</h5>
4731
4732<p>
4733The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4734the frame address of the specified call frame, or zero if it cannot be
4735identified. The value returned by this intrinsic is likely to be incorrect or 0
4736for arguments other than zero, so it should only be used for debugging purposes.
4737</p>
4738
4739<p>
4740Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4741aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4742source-language caller.
4743</p>
4744</div>
4745
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4746<!-- _______________________________________________________________________ -->
4747<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4748 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4749</div>
4750
4751<div class="doc_text">
4752
4753<h5>Syntax:</h5>
4754<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4755 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4756</pre>
4757
4758<h5>Overview:</h5>
4759
4760<p>
4761The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4762the function stack, for use with <a href="#int_stackrestore">
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4763<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4764features like scoped automatic variable sized arrays in C99.
4765</p>
4766
4767<h5>Semantics:</h5>
4768
4769<p>
4770This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4771href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4772<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4773<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4774state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4775practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4776that were allocated after the <tt>llvm.stacksave</tt> was executed.
4777</p>
4778
4779</div>
4780
4781<!-- _______________________________________________________________________ -->
4782<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4783 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4784</div>
4785
4786<div class="doc_text">
4787
4788<h5>Syntax:</h5>
4789<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4790 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4791</pre>
4792
4793<h5>Overview:</h5>
4794
4795<p>
4796The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4797the function stack to the state it was in when the corresponding <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4798href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4799useful for implementing language features like scoped automatic variable sized
4800arrays in C99.
4801</p>
4802
4803<h5>Semantics:</h5>
4804
4805<p>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4806See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4807</p>
4808
4809</div>
4810
4811
4812<!-- _______________________________________________________________________ -->
4813<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4814 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4815</div>
4816
4817<div class="doc_text">
4818
4819<h5>Syntax:</h5>
4820<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4821 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]4822</pre>
4823
4824<h5>Overview:</h5>
4825
4826
4827<p>
4828The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4829a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4830no
4831effect on the behavior of the program but can change its performance
Chris Lattnerff851072005-02-28 19:47:14 +0000[diff] [blame]4832characteristics.
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4833</p>
4834
4835<h5>Arguments:</h5>
4836
4837<p>
4838<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4839determining if the fetch should be for a read (0) or write (1), and
4840<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattnerd3e641c2005-03-07 20:31:38 +0000[diff] [blame]4841locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4842<tt>locality</tt> arguments must be constant integers.
4843</p>
4844
4845<h5>Semantics:</h5>
4846
4847<p>
4848This intrinsic does not modify the behavior of the program. In particular,
4849prefetches cannot trap and do not produce a value. On targets that support this
4850intrinsic, the prefetch can provide hints to the processor cache for better
4851performance.
4852</p>
4853
4854</div>
4855
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4856<!-- _______________________________________________________________________ -->
4857<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4858 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4859</div>
4860
4861<div class="doc_text">
4862
4863<h5>Syntax:</h5>
4864<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4865 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4866</pre>
4867
4868<h5>Overview:</h5>
4869
4870
4871<p>
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4872The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
4873(PC) in a region of
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4874code to simulators and other tools. The method is target specific, but it is
4875expected that the marker will use exported symbols to transmit the PC of the marker.
Jeff Cohendc6bfea2005-11-11 02:15:27 +0000[diff] [blame]4876The marker makes no guarantees that it will remain with any specific instruction
Chris Lattnere64d41d2005-11-15 06:07:55 +0000[diff] [blame]4877after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb40261e2006-03-24 07:16:10 +0000[diff] [blame]4878optimizations. The intended use is to be inserted after optimizations to allow
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4879correlations of simulation runs.
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4880</p>
4881
4882<h5>Arguments:</h5>
4883
4884<p>
4885<tt>id</tt> is a numerical id identifying the marker.
4886</p>
4887
4888<h5>Semantics:</h5>
4889
4890<p>
4891This intrinsic does not modify the behavior of the program. Backends that do not
4892support this intrinisic may ignore it.
4893</p>
4894
4895</div>
4896
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]4897<!-- _______________________________________________________________________ -->
4898<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4899 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]4900</div>
4901
4902<div class="doc_text">
4903
4904<h5>Syntax:</h5>
4905<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4906 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]4907</pre>
4908
4909<h5>Overview:</h5>
4910
4911
4912<p>
4913The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
4914counter register (or similar low latency, high accuracy clocks) on those targets
4915that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
4916As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
4917should only be used for small timings.
4918</p>
4919
4920<h5>Semantics:</h5>
4921
4922<p>
4923When directly supported, reading the cycle counter should not modify any memory.
4924Implementations are allowed to either return a application specific value or a
4925system wide value. On backends without support, this is lowered to a constant 0.
4926</p>
4927
4928</div>
4929
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4930<!-- ======================================================================= -->
4931<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4932 <a name="int_libc">Standard C Library Intrinsics</a>
4933</div>
4934
4935<div class="doc_text">
4936<p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4937LLVM provides intrinsics for a few important standard C library functions.
4938These intrinsics allow source-language front-ends to pass information about the
4939alignment of the pointer arguments to the code generator, providing opportunity
4940for more efficient code generation.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4941</p>
4942
4943</div>
4944
4945<!-- _______________________________________________________________________ -->
4946<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4947 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4948</div>
4949
4950<div class="doc_text">
4951
4952<h5>Syntax:</h5>
4953<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4954 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4955 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4956 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4957 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4958</pre>
4959
4960<h5>Overview:</h5>
4961
4962<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4963The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4964location to the destination location.
4965</p>
4966
4967<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4968Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
4969intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4970</p>
4971
4972<h5>Arguments:</h5>
4973
4974<p>
4975The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4976the source. The third argument is an integer argument
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4977specifying the number of bytes to copy, and the fourth argument is the alignment
4978of the source and destination locations.
4979</p>
4980
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4981<p>
4982If 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]4983the caller guarantees that both the source and destination pointers are aligned
4984to that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4985</p>
4986
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4987<h5>Semantics:</h5>
4988
4989<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4990The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4991location to the destination location, which are not allowed to overlap. It
4992copies "len" bytes of memory over. If the argument is known to be aligned to
4993some boundary, this can be specified as the fourth argument, otherwise it should
4994be set to 0 or 1.
4995</p>
4996</div>
4997
4998
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4999<!-- _______________________________________________________________________ -->
5000<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5001 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5002</div>
5003
5004<div class="doc_text">
5005
5006<h5>Syntax:</h5>
5007<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5008 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5009 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5010 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5011 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5012</pre>
5013
5014<h5>Overview:</h5>
5015
5016<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5017The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5018location to the destination location. It is similar to the
Chris Lattnerec564022008-01-06 19:51:52 +0000[diff] [blame]5019'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5020</p>
5021
5022<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5023Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5024intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5025</p>
5026
5027<h5>Arguments:</h5>
5028
5029<p>
5030The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5031the source. The third argument is an integer argument
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5032specifying the number of bytes to copy, and the fourth argument is the alignment
5033of the source and destination locations.
5034</p>
5035
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5036<p>
5037If 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]5038the caller guarantees that the source and destination pointers are aligned to
5039that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5040</p>
5041
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5042<h5>Semantics:</h5>
5043
5044<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5045The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5046location to the destination location, which may overlap. It
5047copies "len" bytes of memory over. If the argument is known to be aligned to
5048some boundary, this can be specified as the fourth argument, otherwise it should
5049be set to 0 or 1.
5050</p>
5051</div>
5052
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5053
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5054<!-- _______________________________________________________________________ -->
5055<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5056 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5057</div>
5058
5059<div class="doc_text">
5060
5061<h5>Syntax:</h5>
5062<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5063 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5064 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5065 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5066 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5067</pre>
5068
5069<h5>Overview:</h5>
5070
5071<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5072The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5073byte value.
5074</p>
5075
5076<p>
5077Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5078does not return a value, and takes an extra alignment argument.
5079</p>
5080
5081<h5>Arguments:</h5>
5082
5083<p>
5084The first argument is a pointer to the destination to fill, the second is the
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5085byte value to fill it with, the third argument is an integer
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5086argument specifying the number of bytes to fill, and the fourth argument is the
5087known alignment of destination location.
5088</p>
5089
5090<p>
5091If 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]5092the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5093</p>
5094
5095<h5>Semantics:</h5>
5096
5097<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5098The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5099the
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5100destination location. If the argument is known to be aligned to some boundary,
5101this can be specified as the fourth argument, otherwise it should be set to 0 or
51021.
5103</p>
5104</div>
5105
5106
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5107<!-- _______________________________________________________________________ -->
5108<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5109 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5110</div>
5111
5112<div class="doc_text">
5113
5114<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5115<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]5116floating point or vector of floating point type. Not all targets support all
5117types however.
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5118<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5119 declare float @llvm.sqrt.f32(float %Val)
5120 declare double @llvm.sqrt.f64(double %Val)
5121 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5122 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5123 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5124</pre>
5125
5126<h5>Overview:</h5>
5127
5128<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5129The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5130returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5131<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner00d7cb92008-01-29 07:00:44 +0000[diff] [blame]5132negative numbers other than -0.0 (which allows for better optimization, because
5133there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5134defined to return -0.0 like IEEE sqrt.
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5135</p>
5136
5137<h5>Arguments:</h5>
5138
5139<p>
5140The argument and return value are floating point numbers of the same type.
5141</p>
5142
5143<h5>Semantics:</h5>
5144
5145<p>
Dan Gohman33988db2007-07-16 14:37:41 +0000[diff] [blame]5146This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5147floating point number.
5148</p>
5149</div>
5150
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5151<!-- _______________________________________________________________________ -->
5152<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5153 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5154</div>
5155
5156<div class="doc_text">
5157
5158<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5159<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]5160floating point or vector of floating point type. Not all targets support all
5161types however.
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5162<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5163 declare float @llvm.powi.f32(float %Val, i32 %power)
5164 declare double @llvm.powi.f64(double %Val, i32 %power)
5165 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5166 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5167 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5168</pre>
5169
5170<h5>Overview:</h5>
5171
5172<p>
5173The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5174specified (positive or negative) power. The order of evaluation of
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5175multiplications is not defined. When a vector of floating point type is
5176used, the second argument remains a scalar integer value.
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5177</p>
5178
5179<h5>Arguments:</h5>
5180
5181<p>
5182The second argument is an integer power, and the first is a value to raise to
5183that power.
5184</p>
5185
5186<h5>Semantics:</h5>
5187
5188<p>
5189This function returns the first value raised to the second power with an
5190unspecified sequence of rounding operations.</p>
5191</div>
5192
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5193<!-- _______________________________________________________________________ -->
5194<div class="doc_subsubsection">
5195 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5196</div>
5197
5198<div class="doc_text">
5199
5200<h5>Syntax:</h5>
5201<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5202floating point or vector of floating point type. Not all targets support all
5203types however.
5204<pre>
5205 declare float @llvm.sin.f32(float %Val)
5206 declare double @llvm.sin.f64(double %Val)
5207 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5208 declare fp128 @llvm.sin.f128(fp128 %Val)
5209 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5210</pre>
5211
5212<h5>Overview:</h5>
5213
5214<p>
5215The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5216</p>
5217
5218<h5>Arguments:</h5>
5219
5220<p>
5221The argument and return value are floating point numbers of the same type.
5222</p>
5223
5224<h5>Semantics:</h5>
5225
5226<p>
5227This function returns the sine of the specified operand, returning the
5228same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5229conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5230</div>
5231
5232<!-- _______________________________________________________________________ -->
5233<div class="doc_subsubsection">
5234 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5235</div>
5236
5237<div class="doc_text">
5238
5239<h5>Syntax:</h5>
5240<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5241floating point or vector of floating point type. Not all targets support all
5242types however.
5243<pre>
5244 declare float @llvm.cos.f32(float %Val)
5245 declare double @llvm.cos.f64(double %Val)
5246 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5247 declare fp128 @llvm.cos.f128(fp128 %Val)
5248 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5249</pre>
5250
5251<h5>Overview:</h5>
5252
5253<p>
5254The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5255</p>
5256
5257<h5>Arguments:</h5>
5258
5259<p>
5260The argument and return value are floating point numbers of the same type.
5261</p>
5262
5263<h5>Semantics:</h5>
5264
5265<p>
5266This function returns the cosine of the specified operand, returning the
5267same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5268conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5269</div>
5270
5271<!-- _______________________________________________________________________ -->
5272<div class="doc_subsubsection">
5273 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5274</div>
5275
5276<div class="doc_text">
5277
5278<h5>Syntax:</h5>
5279<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5280floating point or vector of floating point type. Not all targets support all
5281types however.
5282<pre>
5283 declare float @llvm.pow.f32(float %Val, float %Power)
5284 declare double @llvm.pow.f64(double %Val, double %Power)
5285 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5286 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5287 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5288</pre>
5289
5290<h5>Overview:</h5>
5291
5292<p>
5293The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5294specified (positive or negative) power.
5295</p>
5296
5297<h5>Arguments:</h5>
5298
5299<p>
5300The second argument is a floating point power, and the first is a value to
5301raise to that power.
5302</p>
5303
5304<h5>Semantics:</h5>
5305
5306<p>
5307This function returns the first value raised to the second power,
5308returning the
5309same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5310conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5311</div>
5312
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5313
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5314<!-- ======================================================================= -->
5315<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5316 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5317</div>
5318
5319<div class="doc_text">
5320<p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5321LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5322These allow efficient code generation for some algorithms.
5323</p>
5324
5325</div>
5326
5327<!-- _______________________________________________________________________ -->
5328<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5329 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5330</div>
5331
5332<div class="doc_text">
5333
5334<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5335<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5336type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5337<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5338 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5339 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5340 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5341</pre>
5342
5343<h5>Overview:</h5>
5344
5345<p>
Reid Spencerf361c4f2007-04-02 02:25:19 +0000[diff] [blame]5346The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5347values with an even number of bytes (positive multiple of 16 bits). These are
5348useful for performing operations on data that is not in the target's native
5349byte order.
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5350</p>
5351
5352<h5>Semantics:</h5>
5353
5354<p>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5355The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5356and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5357intrinsic returns an i32 value that has the four bytes of the input i32
5358swapped, 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]5359i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5360<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5361additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5362</p>
5363
5364</div>
5365
5366<!-- _______________________________________________________________________ -->
5367<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5368 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5369</div>
5370
5371<div class="doc_text">
5372
5373<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5374<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
5375width. Not all targets support all bit widths however.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5376<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5377 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
5378 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5379 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5380 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5381 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5382</pre>
5383
5384<h5>Overview:</h5>
5385
5386<p>
Chris Lattner069b5bd2006-01-16 22:38:59 +0000[diff] [blame]5387The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5388value.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5389</p>
5390
5391<h5>Arguments:</h5>
5392
5393<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5394The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5395integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5396</p>
5397
5398<h5>Semantics:</h5>
5399
5400<p>
5401The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5402</p>
5403</div>
5404
5405<!-- _______________________________________________________________________ -->
5406<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5407 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5408</div>
5409
5410<div class="doc_text">
5411
5412<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5413<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
5414integer bit width. Not all targets support all bit widths however.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5415<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5416 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5417 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5418 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5419 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5420 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5421</pre>
5422
5423<h5>Overview:</h5>
5424
5425<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5426The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5427leading zeros in a variable.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5428</p>
5429
5430<h5>Arguments:</h5>
5431
5432<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5433The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5434integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5435</p>
5436
5437<h5>Semantics:</h5>
5438
5439<p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5440The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5441in 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]5442of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5443</p>
5444</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5445
5446
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5447
5448<!-- _______________________________________________________________________ -->
5449<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5450 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5451</div>
5452
5453<div class="doc_text">
5454
5455<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5456<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
5457integer bit width. Not all targets support all bit widths however.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5458<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5459 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5460 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5461 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5462 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5463 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5464</pre>
5465
5466<h5>Overview:</h5>
5467
5468<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5469The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5470trailing zeros.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5471</p>
5472
5473<h5>Arguments:</h5>
5474
5475<p>
5476The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5477integer type. The return type must match the argument type.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5478</p>
5479
5480<h5>Semantics:</h5>
5481
5482<p>
5483The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5484in a variable. If the src == 0 then the result is the size in bits of the type
5485of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5486</p>
5487</div>
5488
Reid Spencer8a5799f2007-04-01 08:27:01 +0000[diff] [blame]5489<!-- _______________________________________________________________________ -->
5490<div class="doc_subsubsection">
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5491 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5492</div>
5493
5494<div class="doc_text">
5495
5496<h5>Syntax:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5497<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5498on any integer bit width.
5499<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5500 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5501 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5502</pre>
5503
5504<h5>Overview:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5505<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5506range of bits from an integer value and returns them in the same bit width as
5507the original value.</p>
5508
5509<h5>Arguments:</h5>
5510<p>The first argument, <tt>%val</tt> and the result may be integer types of
5511any bit width but they must have the same bit width. The second and third
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5512arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5513
5514<h5>Semantics:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5515<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5516of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5517<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5518operates in forward mode.</p>
5519<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5520right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5521only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5522<ol>
5523 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5524 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5525 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5526 to determine the number of bits to retain.</li>
5527 <li>A mask of the retained bits is created by shifting a -1 value.</li>
5528 <li>The mask is ANDed with <tt>%val</tt> to produce the result.
5529</ol>
Reid Spencer70845c02007-05-14 16:14:57 +0000[diff] [blame]5530<p>In reverse mode, a similar computation is made except that the bits are
5531returned in the reverse order. So, for example, if <tt>X</tt> has the value
5532<tt>i16 0x0ACF (101011001111)</tt> and we apply
5533<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5534<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5535</div>
5536
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5537<div class="doc_subsubsection">
5538 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5539</div>
5540
5541<div class="doc_text">
5542
5543<h5>Syntax:</h5>
5544<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
5545on any integer bit width.
5546<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5547 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5548 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]5549</pre>
5550
5551<h5>Overview:</h5>
5552<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5553of bits in an integer value with another integer value. It returns the integer
5554with the replaced bits.</p>
5555
5556<h5>Arguments:</h5>
5557<p>The first argument, <tt>%val</tt> and the result may be integer types of
5558any bit width but they must have the same bit width. <tt>%val</tt> is the value
5559whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5560integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5561type since they specify only a bit index.</p>
5562
5563<h5>Semantics:</h5>
5564<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5565of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5566<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5567operates in forward mode.</p>
5568<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5569truncating it down to the size of the replacement area or zero extending it
5570up to that size.</p>
5571<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5572are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5573in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
5574to the <tt>%hi</tt>th bit.
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5575<p>In reverse mode, a similar computation is made except that the bits are
5576reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
5577<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5578<h5>Examples:</h5>
5579<pre>
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5580 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5581 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5582 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5583 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5584 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]5585</pre>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5586</div>
5587
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5588<!-- ======================================================================= -->
5589<div class="doc_subsection">
5590 <a name="int_debugger">Debugger Intrinsics</a>
5591</div>
5592
5593<div class="doc_text">
5594<p>
5595The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5596are described in the <a
5597href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5598Debugging</a> document.
5599</p>
5600</div>
5601
5602
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]5603<!-- ======================================================================= -->
5604<div class="doc_subsection">
5605 <a name="int_eh">Exception Handling Intrinsics</a>
5606</div>
5607
5608<div class="doc_text">
5609<p> The LLVM exception handling intrinsics (which all start with
5610<tt>llvm.eh.</tt> prefix), are described in the <a
5611href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5612Handling</a> document. </p>
5613</div>
5614
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]5615<!-- ======================================================================= -->
5616<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5617 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5618</div>
5619
5620<div class="doc_text">
5621<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5622 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5623 the <tt>nest</tt> attribute, from a function. The result is a callable
5624 function pointer lacking the nest parameter - the caller does not need
5625 to provide a value for it. Instead, the value to use is stored in
5626 advance in a "trampoline", a block of memory usually allocated
5627 on the stack, which also contains code to splice the nest value into the
5628 argument list. This is used to implement the GCC nested function address
5629 extension.
5630</p>
5631<p>
5632 For example, if the function is
5633 <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]5634 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]5635<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5636 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5637 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5638 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5639 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5640</pre>
Bill Wendling252570f2007-09-22 09:23:55 +0000[diff] [blame]5641 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5642 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5643</div>
5644
5645<!-- _______________________________________________________________________ -->
5646<div class="doc_subsubsection">
5647 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5648</div>
5649<div class="doc_text">
5650<h5>Syntax:</h5>
5651<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5652declare 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]5653</pre>
5654<h5>Overview:</h5>
5655<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5656 This fills the memory pointed to by <tt>tramp</tt> with code
5657 and returns a function pointer suitable for executing it.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5658</p>
5659<h5>Arguments:</h5>
5660<p>
5661 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5662 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5663 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsf2bcd372007-08-22 23:39:54 +0000[diff] [blame]5664 intrinsic. Note that the size and the alignment are target-specific - LLVM
5665 currently provides no portable way of determining them, so a front-end that
5666 generates this intrinsic needs to have some target-specific knowledge.
5667 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]5668</p>
5669<h5>Semantics:</h5>
5670<p>
5671 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5672 dependent code, turning it into a function. A pointer to this function is
5673 returned, but needs to be bitcast to an
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5674 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5675 before being called. The new function's signature is the same as that of
5676 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5677 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5678 of pointer type. Calling the new function is equivalent to calling
5679 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5680 missing <tt>nest</tt> argument. If, after calling
5681 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5682 modified, then the effect of any later call to the returned function pointer is
5683 undefined.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5684</p>
5685</div>
5686
5687<!-- ======================================================================= -->
5688<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5689 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
5690</div>
5691
5692<div class="doc_text">
5693<p>
5694 These intrinsic functions expand the "universal IR" of LLVM to represent
5695 hardware constructs for atomic operations and memory synchronization. This
5696 provides an interface to the hardware, not an interface to the programmer. It
5697 is aimed at a low enough level to allow any programming models or APIs which
5698 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
5699 hardware behavior. Just as hardware provides a "universal IR" for source
5700 languages, it also provides a starting point for developing a "universal"
5701 atomic operation and synchronization IR.
5702</p>
5703<p>
5704 These do <em>not</em> form an API such as high-level threading libraries,
5705 software transaction memory systems, atomic primitives, and intrinsic
5706 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
5707 application libraries. The hardware interface provided by LLVM should allow
5708 a clean implementation of all of these APIs and parallel programming models.
5709 No one model or paradigm should be selected above others unless the hardware
5710 itself ubiquitously does so.
5711
5712</p>
5713</div>
5714
5715<!-- _______________________________________________________________________ -->
5716<div class="doc_subsubsection">
5717 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
5718</div>
5719<div class="doc_text">
5720<h5>Syntax:</h5>
5721<pre>
5722declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
5723i1 &lt;device&gt; )
5724
5725</pre>
5726<h5>Overview:</h5>
5727<p>
5728 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
5729 specific pairs of memory access types.
5730</p>
5731<h5>Arguments:</h5>
5732<p>
5733 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
5734 The first four arguments enables a specific barrier as listed below. The fith
5735 argument specifies that the barrier applies to io or device or uncached memory.
5736
5737</p>
5738 <ul>
5739 <li><tt>ll</tt>: load-load barrier</li>
5740 <li><tt>ls</tt>: load-store barrier</li>
5741 <li><tt>sl</tt>: store-load barrier</li>
5742 <li><tt>ss</tt>: store-store barrier</li>
5743 <li><tt>device</tt>: barrier applies to device and uncached memory also.
5744 </ul>
5745<h5>Semantics:</h5>
5746<p>
5747 This intrinsic causes the system to enforce some ordering constraints upon
5748 the loads and stores of the program. This barrier does not indicate
5749 <em>when</em> any events will occur, it only enforces an <em>order</em> in
5750 which they occur. For any of the specified pairs of load and store operations
5751 (f.ex. load-load, or store-load), all of the first operations preceding the
5752 barrier will complete before any of the second operations succeeding the
5753 barrier begin. Specifically the semantics for each pairing is as follows:
5754</p>
5755 <ul>
5756 <li><tt>ll</tt>: All loads before the barrier must complete before any load
5757 after the barrier begins.</li>
5758
5759 <li><tt>ls</tt>: All loads before the barrier must complete before any
5760 store after the barrier begins.</li>
5761 <li><tt>ss</tt>: All stores before the barrier must complete before any
5762 store after the barrier begins.</li>
5763 <li><tt>sl</tt>: All stores before the barrier must complete before any
5764 load after the barrier begins.</li>
5765 </ul>
5766<p>
5767 These semantics are applied with a logical "and" behavior when more than one
5768 is enabled in a single memory barrier intrinsic.
5769</p>
5770<p>
5771 Backends may implement stronger barriers than those requested when they do not
5772 support as fine grained a barrier as requested. Some architectures do not
5773 need all types of barriers and on such architectures, these become noops.
5774</p>
5775<h5>Example:</h5>
5776<pre>
5777%ptr = malloc i32
5778 store i32 4, %ptr
5779
5780%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
5781 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
5782 <i>; guarantee the above finishes</i>
5783 store i32 8, %ptr <i>; before this begins</i>
5784</pre>
5785</div>
5786
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5787<!-- _______________________________________________________________________ -->
5788<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5789 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5790</div>
5791<div class="doc_text">
5792<h5>Syntax:</h5>
5793<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5794 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on any
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5795 integer bit width. Not all targets support all bit widths however.</p>
5796
5797<pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5798declare i8 @llvm.atomic.cmp.swap.i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
5799declare i16 @llvm.atomic.cmp.swap.i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
5800declare i32 @llvm.atomic.cmp.swap.i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
5801declare i64 @llvm.atomic.cmp.swap.i64( i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5802
5803</pre>
5804<h5>Overview:</h5>
5805<p>
5806 This loads a value in memory and compares it to a given value. If they are
5807 equal, it stores a new value into the memory.
5808</p>
5809<h5>Arguments:</h5>
5810<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5811 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5812 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
5813 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
5814 this integer type. While any bit width integer may be used, targets may only
5815 lower representations they support in hardware.
5816
5817</p>
5818<h5>Semantics:</h5>
5819<p>
5820 This entire intrinsic must be executed atomically. It first loads the value
5821 in memory pointed to by <tt>ptr</tt> and compares it with the value
5822 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
5823 loaded value is yielded in all cases. This provides the equivalent of an
5824 atomic compare-and-swap operation within the SSA framework.
5825</p>
5826<h5>Examples:</h5>
5827
5828<pre>
5829%ptr = malloc i32
5830 store i32 4, %ptr
5831
5832%val1 = add i32 4, 4
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5833%result1 = call i32 @llvm.atomic.cmp.swap.i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5834 <i>; yields {i32}:result1 = 4</i>
5835%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
5836%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
5837
5838%val2 = add i32 1, 1
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5839%result2 = call i32 @llvm.atomic.cmp.swap.i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5840 <i>; yields {i32}:result2 = 8</i>
5841%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
5842
5843%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
5844</pre>
5845</div>
5846
5847<!-- _______________________________________________________________________ -->
5848<div class="doc_subsubsection">
5849 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
5850</div>
5851<div class="doc_text">
5852<h5>Syntax:</h5>
5853
5854<p>
5855 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
5856 integer bit width. Not all targets support all bit widths however.</p>
5857<pre>
5858declare i8 @llvm.atomic.swap.i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
5859declare i16 @llvm.atomic.swap.i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
5860declare i32 @llvm.atomic.swap.i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
5861declare i64 @llvm.atomic.swap.i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
5862
5863</pre>
5864<h5>Overview:</h5>
5865<p>
5866 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
5867 the value from memory. It then stores the value in <tt>val</tt> in the memory
5868 at <tt>ptr</tt>.
5869</p>
5870<h5>Arguments:</h5>
5871
5872<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5873 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5874 <tt>val</tt> argument and the result must be integers of the same bit width.
5875 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
5876 integer type. The targets may only lower integer representations they
5877 support.
5878</p>
5879<h5>Semantics:</h5>
5880<p>
5881 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
5882 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
5883 equivalent of an atomic swap operation within the SSA framework.
5884
5885</p>
5886<h5>Examples:</h5>
5887<pre>
5888%ptr = malloc i32
5889 store i32 4, %ptr
5890
5891%val1 = add i32 4, 4
5892%result1 = call i32 @llvm.atomic.swap.i32( i32* %ptr, i32 %val1 )
5893 <i>; yields {i32}:result1 = 4</i>
5894%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
5895%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
5896
5897%val2 = add i32 1, 1
5898%result2 = call i32 @llvm.atomic.swap.i32( i32* %ptr, i32 %val2 )
5899 <i>; yields {i32}:result2 = 8</i>
5900
5901%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
5902%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
5903</pre>
5904</div>
5905
5906<!-- _______________________________________________________________________ -->
5907<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5908 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5909
5910</div>
5911<div class="doc_text">
5912<h5>Syntax:</h5>
5913<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5914 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]5915 integer bit width. Not all targets support all bit widths however.</p>
5916<pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5917declare i8 @llvm.atomic.load.add.i8.( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
5918declare i16 @llvm.atomic.load.add.i16.( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
5919declare i32 @llvm.atomic.load.add.i32.( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
5920declare i64 @llvm.atomic.load.add.i64.( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5921
5922</pre>
5923<h5>Overview:</h5>
5924<p>
5925 This intrinsic adds <tt>delta</tt> to the value stored in memory at
5926 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
5927</p>
5928<h5>Arguments:</h5>
5929<p>
5930
5931 The intrinsic takes two arguments, the first a pointer to an integer value
5932 and the second an integer value. The result is also an integer value. These
5933 integer types can have any bit width, but they must all have the same bit
5934 width. The targets may only lower integer representations they support.
5935</p>
5936<h5>Semantics:</h5>
5937<p>
5938 This intrinsic does a series of operations atomically. It first loads the
5939 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
5940 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
5941</p>
5942
5943<h5>Examples:</h5>
5944<pre>
5945%ptr = malloc i32
5946 store i32 4, %ptr
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5947%result1 = call i32 @llvm.atomic.load.add.i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5948 <i>; yields {i32}:result1 = 4</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5949%result2 = call i32 @llvm.atomic.load.add.i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5950 <i>; yields {i32}:result2 = 8</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5951%result3 = call i32 @llvm.atomic.load.add.i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5952 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5953%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5954</pre>
5955</div>
5956
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5957<!-- _______________________________________________________________________ -->
5958<div class="doc_subsubsection">
5959 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
5960
5961</div>
5962<div class="doc_text">
5963<h5>Syntax:</h5>
5964<p>
5965 This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
5966 any integer bit width. Not all targets support all bit widths however.</p>
5967<pre>
5968declare i8 @llvm.atomic.load.sub.i8.( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
5969declare i16 @llvm.atomic.load.sub.i16.( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
5970declare i32 @llvm.atomic.load.sub.i32.( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
5971declare i64 @llvm.atomic.load.sub.i64.( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
5972
5973</pre>
5974<h5>Overview:</h5>
5975<p>
5976 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
5977 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
5978</p>
5979<h5>Arguments:</h5>
5980<p>
5981
5982 The intrinsic takes two arguments, the first a pointer to an integer value
5983 and the second an integer value. The result is also an integer value. These
5984 integer types can have any bit width, but they must all have the same bit
5985 width. The targets may only lower integer representations they support.
5986</p>
5987<h5>Semantics:</h5>
5988<p>
5989 This intrinsic does a series of operations atomically. It first loads the
5990 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
5991 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
5992</p>
5993
5994<h5>Examples:</h5>
5995<pre>
5996%ptr = malloc i32
5997 store i32 8, %ptr
5998%result1 = call i32 @llvm.atomic.load.sub.i32( i32* %ptr, i32 4 )
5999 <i>; yields {i32}:result1 = 8</i>
6000%result2 = call i32 @llvm.atomic.load.sub.i32( i32* %ptr, i32 2 )
6001 <i>; yields {i32}:result2 = 4</i>
6002%result3 = call i32 @llvm.atomic.load.sub.i32( i32* %ptr, i32 5 )
6003 <i>; yields {i32}:result3 = 2</i>
6004%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6005</pre>
6006</div>
6007
6008<!-- _______________________________________________________________________ -->
6009<div class="doc_subsubsection">
6010 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6011 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6012 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6013 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6014
6015</div>
6016<div class="doc_text">
6017<h5>Syntax:</h5>
6018<p>
6019 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6020 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
6021 <tt>llvm.atomic.load_xor</tt> on any integer bit width. Not all targets
6022 support all bit widths however.</p>
6023<pre>
6024declare i8 @llvm.atomic.load.and.i8.( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6025declare i16 @llvm.atomic.load.and.i16.( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6026declare i32 @llvm.atomic.load.and.i32.( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6027declare i64 @llvm.atomic.load.and.i64.( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
6028
6029</pre>
6030
6031<pre>
6032declare i8 @llvm.atomic.load.or.i8.( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6033declare i16 @llvm.atomic.load.or.i16.( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6034declare i32 @llvm.atomic.load.or.i32.( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6035declare i64 @llvm.atomic.load.or.i64.( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
6036
6037</pre>
6038
6039<pre>
6040declare i8 @llvm.atomic.load.nand.i8.( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6041declare i16 @llvm.atomic.load.nand.i16.( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6042declare i32 @llvm.atomic.load.nand.i32.( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6043declare i64 @llvm.atomic.load.nand.i64.( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
6044
6045</pre>
6046
6047<pre>
6048declare i8 @llvm.atomic.load.xor.i8.( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6049declare i16 @llvm.atomic.load.xor.i16.( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6050declare i32 @llvm.atomic.load.xor.i32.( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6051declare i64 @llvm.atomic.load.xor.i64.( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
6052
6053</pre>
6054<h5>Overview:</h5>
6055<p>
6056 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6057 the value stored in memory at <tt>ptr</tt>. It yields the original value
6058 at <tt>ptr</tt>.
6059</p>
6060<h5>Arguments:</h5>
6061<p>
6062
6063 These intrinsics take two arguments, the first a pointer to an integer value
6064 and the second an integer value. The result is also an integer value. These
6065 integer types can have any bit width, but they must all have the same bit
6066 width. The targets may only lower integer representations they support.
6067</p>
6068<h5>Semantics:</h5>
6069<p>
6070 These intrinsics does a series of operations atomically. They first load the
6071 value stored at <tt>ptr</tt>. They then do the bitwise operation
6072 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6073 value stored at <tt>ptr</tt>.
6074</p>
6075
6076<h5>Examples:</h5>
6077<pre>
6078%ptr = malloc i32
6079 store i32 0x0F0F, %ptr
6080%result0 = call i32 @llvm.atomic.load.nand.i32( i32* %ptr, i32 0xFF )
6081 <i>; yields {i32}:result0 = 0x0F0F</i>
6082%result1 = call i32 @llvm.atomic.load.and.i32( i32* %ptr, i32 0xFF )
6083 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
6084%result2 = call i32 @llvm.atomic.load.or.i32( i32* %ptr, i32 0F )
6085 <i>; yields {i32}:result2 = 0xF0</i>
6086%result3 = call i32 @llvm.atomic.load.xor.i32( i32* %ptr, i32 0F )
6087 <i>; yields {i32}:result3 = FF</i>
6088%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6089</pre>
6090</div>
6091
6092
6093<!-- _______________________________________________________________________ -->
6094<div class="doc_subsubsection">
6095 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6096 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6097 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6098 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6099
6100</div>
6101<div class="doc_text">
6102<h5>Syntax:</h5>
6103<p>
6104 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6105 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
6106 <tt>llvm.atomic.load_umin</tt> on any integer bit width. Not all targets
6107 support all bit widths however.</p>
6108<pre>
6109declare i8 @llvm.atomic.load.max.i8.( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6110declare i16 @llvm.atomic.load.max.i16.( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6111declare i32 @llvm.atomic.load.max.i32.( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6112declare i64 @llvm.atomic.load.max.i64.( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
6113
6114</pre>
6115
6116<pre>
6117declare i8 @llvm.atomic.load.min.i8.( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6118declare i16 @llvm.atomic.load.min.i16.( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6119declare i32 @llvm.atomic.load.min.i32.( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6120declare i64 @llvm.atomic.load.min.i64.( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
6121
6122</pre>
6123
6124<pre>
6125declare i8 @llvm.atomic.load.umax.i8.( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6126declare i16 @llvm.atomic.load.umax.i16.( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6127declare i32 @llvm.atomic.load.umax.i32.( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6128declare i64 @llvm.atomic.load.umax.i64.( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
6129
6130</pre>
6131
6132<pre>
6133declare i8 @llvm.atomic.load.umin.i8.( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6134declare i16 @llvm.atomic.load.umin.i16.( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6135declare i32 @llvm.atomic.load.umin.i32.( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6136declare i64 @llvm.atomic.load.umin.i64.( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
6137
6138</pre>
6139<h5>Overview:</h5>
6140<p>
6141 These intrinsics takes the signed or unsigned minimum or maximum of
6142 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6143 original value at <tt>ptr</tt>.
6144</p>
6145<h5>Arguments:</h5>
6146<p>
6147
6148 These intrinsics take two arguments, the first a pointer to an integer value
6149 and the second an integer value. The result is also an integer value. These
6150 integer types can have any bit width, but they must all have the same bit
6151 width. The targets may only lower integer representations they support.
6152</p>
6153<h5>Semantics:</h5>
6154<p>
6155 These intrinsics does a series of operations atomically. They first load the
6156 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6157 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6158 the original value stored at <tt>ptr</tt>.
6159</p>
6160
6161<h5>Examples:</h5>
6162<pre>
6163%ptr = malloc i32
6164 store i32 7, %ptr
6165%result0 = call i32 @llvm.atomic.load.min.i32( i32* %ptr, i32 -2 )
6166 <i>; yields {i32}:result0 = 7</i>
6167%result1 = call i32 @llvm.atomic.load.max.i32( i32* %ptr, i32 8 )
6168 <i>; yields {i32}:result1 = -2</i>
6169%result2 = call i32 @llvm.atomic.load.umin.i32( i32* %ptr, i32 10 )
6170 <i>; yields {i32}:result2 = 8</i>
6171%result3 = call i32 @llvm.atomic.load.umax.i32( i32* %ptr, i32 30 )
6172 <i>; yields {i32}:result3 = 8</i>
6173%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6174</pre>
6175</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6176
6177<!-- ======================================================================= -->
6178<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6179 <a name="int_general">General Intrinsics</a>
6180</div>
6181
6182<div class="doc_text">
6183<p> This class of intrinsics is designed to be generic and has
6184no specific purpose. </p>
6185</div>
6186
6187<!-- _______________________________________________________________________ -->
6188<div class="doc_subsubsection">
6189 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6190</div>
6191
6192<div class="doc_text">
6193
6194<h5>Syntax:</h5>
6195<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6196 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]6197</pre>
6198
6199<h5>Overview:</h5>
6200
6201<p>
6202The '<tt>llvm.var.annotation</tt>' intrinsic
6203</p>
6204
6205<h5>Arguments:</h5>
6206
6207<p>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6208The first argument is a pointer to a value, the second is a pointer to a
6209global string, the third is a pointer to a global string which is the source
6210file name, and the last argument is the line number.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6211</p>
6212
6213<h5>Semantics:</h5>
6214
6215<p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6216This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6217This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6218annotations. These have no other defined use, they are ignored by code
6219generation and optimization.
6220</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6221</div>
6222
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6223<!-- _______________________________________________________________________ -->
6224<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]6225 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6226</div>
6227
6228<div class="doc_text">
6229
6230<h5>Syntax:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6231<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6232any integer bit width.
6233</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6234<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]6235 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6236 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6237 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6238 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6239 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]6240</pre>
6241
6242<h5>Overview:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6243
6244<p>
6245The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6246</p>
6247
6248<h5>Arguments:</h5>
6249
6250<p>
6251The first argument is an integer value (result of some expression),
6252the second is a pointer to a global string, the third is a pointer to a global
6253string which is the source file name, and the last argument is the line number.
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6254It returns the value of the first argument.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6255</p>
6256
6257<h5>Semantics:</h5>
6258
6259<p>
6260This intrinsic allows annotations to be put on arbitrary expressions
6261with arbitrary strings. This can be useful for special purpose optimizations
6262that want to look for these annotations. These have no other defined use, they
6263are ignored by code generation and optimization.
6264</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6265
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6266<!-- _______________________________________________________________________ -->
6267<div class="doc_subsubsection">
6268 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6269</div>
6270
6271<div class="doc_text">
6272
6273<h5>Syntax:</h5>
6274<pre>
6275 declare void @llvm.trap()
6276</pre>
6277
6278<h5>Overview:</h5>
6279
6280<p>
6281The '<tt>llvm.trap</tt>' intrinsic
6282</p>
6283
6284<h5>Arguments:</h5>
6285
6286<p>
6287None
6288</p>
6289
6290<h5>Semantics:</h5>
6291
6292<p>
6293This intrinsics is lowered to the target dependent trap instruction. If the
6294target does not have a trap instruction, this intrinsic will be lowered to the
6295call of the abort() function.
6296</p>
6297</div>
6298
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6299<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6300<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6301<address>
6302 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
6303 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
6304 <a href="http://validator.w3.org/check/referer"><img
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Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6306
6307 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]6308 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6309 Last modified: $Date$
6310</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]6311
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6312</body>
6313</html>