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gerrit-public.fairphone.software / toolchain / llvm-project / ddffe620e434cf37ad779c637e22c5ead51eaed8 / . / llvm / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencercb84e432004-08-26 20:44:00 +0000[diff] [blame]6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
7 <meta name="author" content="Chris Lattner">
8 <meta name="description"
9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a></li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]24 <li><a href="#callingconv">Calling Conventions</a></li>
Chris 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>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]27 <li><a href="#aliasstructure">Aliases</a></li>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]28 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]29 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]30 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]31 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]32 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]33 </ol>
34 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]35 <li><a href="#typesystem">Type System</a>
36 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]37 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]38 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]39 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]40 <li><a href="#t_floating">Floating Point Types</a></li>
41 <li><a href="#t_void">Void Type</a></li>
42 <li><a href="#t_label">Label Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]43 </ol>
44 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]45 <li><a href="#t_derived">Derived Types</a>
46 <ol>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]47 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]48 <li><a href="#t_array">Array Type</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]49 <li><a href="#t_function">Function Type</a></li>
50 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]51 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]52 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]53 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]54 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]55 </ol>
56 </li>
57 </ol>
58 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]59 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]60 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]61 <li><a href="#simpleconstants">Simple Constants</a></li>
62 <li><a href="#aggregateconstants">Aggregate Constants</a></li>
63 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
64 <li><a href="#undefvalues">Undefined Values</a></li>
65 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]66 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]67 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]68 <li><a href="#othervalues">Other Values</a>
69 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]70 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]71 </ol>
72 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]73 <li><a href="#instref">Instruction Reference</a>
74 <ol>
75 <li><a href="#terminators">Terminator Instructions</a>
76 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]77 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
78 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]79 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
80 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]81 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]82 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]83 </ol>
84 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]85 <li><a href="#binaryops">Binary Operations</a>
86 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]87 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
88 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
89 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]90 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
91 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
92 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]93 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
94 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
95 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]96 </ol>
97 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]98 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
99 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]100 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
101 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
102 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]103 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]104 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]105 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]106 </ol>
107 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]108 <li><a href="#vectorops">Vector Operations</a>
109 <ol>
110 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
111 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
112 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]113 </ol>
114 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]115 <li><a href="#aggregateops">Aggregate Operations</a>
116 <ol>
117 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
118 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
119 </ol>
120 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]121 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]122 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]123 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
124 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
125 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]126 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
127 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
128 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]129 </ol>
130 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]131 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]132 <ol>
133 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
134 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
135 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
136 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
137 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]138 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
139 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
140 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
141 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]142 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
143 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]144 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]145 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]146 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]147 <li><a href="#otherops">Other Operations</a>
148 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]149 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
150 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]151 <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
152 <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]153 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]154 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]155 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]156 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]157 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]158 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]159 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]160 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]161 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]162 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]163 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
164 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]165 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
166 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
167 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]168 </ol>
169 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]170 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
171 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]172 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
173 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
174 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]175 </ol>
176 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]177 <li><a href="#int_codegen">Code Generator Intrinsics</a>
178 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]179 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
180 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
181 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
182 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
183 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
184 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
185 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]186 </ol>
187 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]188 <li><a href="#int_libc">Standard C Library Intrinsics</a>
189 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]190 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
191 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
192 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
193 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
194 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]195 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
196 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
197 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]198 </ol>
199 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]200 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]201 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]202 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]203 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
204 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
205 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]206 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
207 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]208 </ol>
209 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]210 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]211 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]212 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]213 <ol>
214 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]215 </ol>
216 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]217 <li><a href="#int_atomics">Atomic intrinsics</a>
218 <ol>
219 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
220 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
221 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
222 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
223 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
224 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
225 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
226 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
227 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
228 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
229 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
230 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
231 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
232 </ol>
233 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]234 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]235 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]236 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]237 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]238 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]239 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]240 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]241 '<tt>llvm.trap</tt>' Intrinsic</a></li>
242 <li><a href="#int_stackprotector">
243 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]244 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]245 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]246 </ol>
247 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]248</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]249
250<div class="doc_author">
251 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
252 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]253</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]254
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]255<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]256<div class="doc_section"> <a name="abstract">Abstract </a></div>
257<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]258
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]259<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]260<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling6e03f9a2008-08-05 22:29:16 +0000[diff] [blame]261LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]262type safety, low-level operations, flexibility, and the capability of
263representing 'all' high-level languages cleanly. It is the common code
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]264representation used throughout all phases of the LLVM compilation
265strategy.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]266</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]267
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]268<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]269<div class="doc_section"> <a name="introduction">Introduction</a> </div>
270<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]271
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]272<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]273
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]274<p>The LLVM code representation is designed to be used in three
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]275different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]276representation (suitable for fast loading by a Just-In-Time compiler),
277and as a human readable assembly language representation. This allows
278LLVM to provide a powerful intermediate representation for efficient
279compiler transformations and analysis, while providing a natural means
280to debug and visualize the transformations. The three different forms
281of LLVM are all equivalent. This document describes the human readable
282representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]283
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]284<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]285while being expressive, typed, and extensible at the same time. It
286aims to be a "universal IR" of sorts, by being at a low enough level
287that high-level ideas may be cleanly mapped to it (similar to how
288microprocessors are "universal IR's", allowing many source languages to
289be mapped to them). By providing type information, LLVM can be used as
290the target of optimizations: for example, through pointer analysis, it
291can be proven that a C automatic variable is never accessed outside of
292the current function... allowing it to be promoted to a simple SSA
293value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]294
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]295</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]296
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]297<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]298<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]299
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]300<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]301
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]302<p>It is important to note that this document describes 'well formed'
303LLVM assembly language. There is a difference between what the parser
304accepts and what is considered 'well formed'. For example, the
305following instruction is syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]306
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]307<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]308<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]309%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]310</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]311</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]312
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]313<p>...because the definition of <tt>%x</tt> does not dominate all of
314its uses. The LLVM infrastructure provides a verification pass that may
315be used to verify that an LLVM module is well formed. This pass is
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]316automatically run by the parser after parsing input assembly and by
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]317the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]318by the verifier pass indicate bugs in transformation passes or input to
319the parser.</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]320</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]321
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]322<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]323
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]324<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]325<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]326<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]327
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]328<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]329
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]330 <p>LLVM identifiers come in two basic types: global and local. Global
331 identifiers (functions, global variables) begin with the @ character. Local
332 identifiers (register names, types) begin with the % character. Additionally,
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]333 there are three different formats for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]334
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]335<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]336 <li>Named values are represented as a string of characters with their prefix.
337 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
338 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]339 Identifiers which require other characters in their names can be surrounded
Daniel Dunbar0f8155a2008-10-14 23:51:43 +0000[diff] [blame]340 with quotes. Special characters may be escaped using "\xx" where xx is the
341 ASCII code for the character in hexadecimal. In this way, any character can
342 be used in a name value, even quotes themselves.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]343
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]344 <li>Unnamed values are represented as an unsigned numeric value with their
345 prefix. For example, %12, @2, %44.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]346
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]347 <li>Constants, which are described in a <a href="#constants">section about
348 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]349</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]350
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]351<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]352don't need to worry about name clashes with reserved words, and the set of
353reserved words may be expanded in the future without penalty. Additionally,
354unnamed identifiers allow a compiler to quickly come up with a temporary
355variable without having to avoid symbol table conflicts.</p>
356
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]357<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]358languages. There are keywords for different opcodes
359('<tt><a href="#i_add">add</a></tt>',
360 '<tt><a href="#i_bitcast">bitcast</a></tt>',
361 '<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]362href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]363and others. These reserved words cannot conflict with variable names, because
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]364none of them start with a prefix character ('%' or '@').</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]365
366<p>Here is an example of LLVM code to multiply the integer variable
367'<tt>%X</tt>' by 8:</p>
368
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]369<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]370
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]371<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]372<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]373%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]374</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]375</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]376
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]377<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]378
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]379<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]380<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]381%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]382</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]383</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]384
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]385<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]386
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]387<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]388<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]389<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
390<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
391%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]392</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]393</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]394
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]395<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
396important lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]397
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]398<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]399
400 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
401 line.</li>
402
403 <li>Unnamed temporaries are created when the result of a computation is not
404 assigned to a named value.</li>
405
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]406 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]407
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]408</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]409
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]410<p>...and it also shows a convention that we follow in this document. When
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]411demonstrating instructions, we will follow an instruction with a comment that
412defines the type and name of value produced. Comments are shown in italic
413text.</p>
414
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]415</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]416
417<!-- *********************************************************************** -->
418<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
419<!-- *********************************************************************** -->
420
421<!-- ======================================================================= -->
422<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
423</div>
424
425<div class="doc_text">
426
427<p>LLVM programs are composed of "Module"s, each of which is a
428translation unit of the input programs. Each module consists of
429functions, global variables, and symbol table entries. Modules may be
430combined together with the LLVM linker, which merges function (and
431global variable) definitions, resolves forward declarations, and merges
432symbol table entries. Here is an example of the "hello world" module:</p>
433
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]434<div class="doc_code">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]435<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]436<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
437 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]438
439<i>; External declaration of the puts function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]440<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]441
442<i>; Definition of main function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]443define i32 @main() { <i>; i32()* </i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]444 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]445 %cast210 = <a
Chris Lattner2150cde2007-06-12 17:01:15 +0000[diff] [blame]446 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]447
448 <i>; Call puts function to write out the string to stdout...</i>
449 <a
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]450 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]451 <a
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]452 href="#i_ret">ret</a> i32 0<br>}<br>
453</pre>
454</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]455
456<p>This example is made up of a <a href="#globalvars">global variable</a>
457named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
458function, and a <a href="#functionstructure">function definition</a>
459for "<tt>main</tt>".</p>
460
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]461<p>In general, a module is made up of a list of global values,
462where both functions and global variables are global values. Global values are
463represented by a pointer to a memory location (in this case, a pointer to an
464array of char, and a pointer to a function), and have one of the following <a
465href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]466
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]467</div>
468
469<!-- ======================================================================= -->
470<div class="doc_subsection">
471 <a name="linkage">Linkage Types</a>
472</div>
473
474<div class="doc_text">
475
476<p>
477All Global Variables and Functions have one of the following types of linkage:
478</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]479
480<dl>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]481
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]482 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]483
484 <dd>Global values with internal linkage are only directly accessible by
485 objects in the current module. In particular, linking code into a module with
486 an internal global value may cause the internal to be renamed as necessary to
487 avoid collisions. Because the symbol is internal to the module, all
488 references can be updated. This corresponds to the notion of the
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]489 '<tt>static</tt>' keyword in C.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]490 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]491
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]492 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]493
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]494 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
495 the same name when linkage occurs. This is typically used to implement
496 inline functions, templates, or other code which must be generated in each
497 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
498 allowed to be discarded.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]499 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]500
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]501 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
502
503 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
504 linkage, except that unreferenced <tt>common</tt> globals may not be
505 discarded. This is used for globals that may be emitted in multiple
506 translation units, but that are not guaranteed to be emitted into every
507 translation unit that uses them. One example of this is tentative
508 definitions in C, such as "<tt>int X;</tt>" at global scope.
509 </dd>
510
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]511 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]512
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]513 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
514 that some targets may choose to emit different assembly sequences for them
515 for target-dependent reasons. This is used for globals that are declared
516 "weak" in C source code.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]517 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]518
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]519 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]520
521 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
522 pointer to array type. When two global variables with appending linkage are
523 linked together, the two global arrays are appended together. This is the
524 LLVM, typesafe, equivalent of having the system linker append together
525 "sections" with identical names when .o files are linked.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]526 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]527
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]528 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]529 <dd>The semantics of this linkage follow the ELF object file model: the
530 symbol is weak until linked, if not linked, the symbol becomes null instead
531 of being an undefined reference.
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]532 </dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]533
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]534 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]535
536 <dd>If none of the above identifiers are used, the global is externally
537 visible, meaning that it participates in linkage and can be used to resolve
538 external symbol references.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]539 </dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]540</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]541
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]542 <p>
543 The next two types of linkage are targeted for Microsoft Windows platform
544 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]545 DLLs (Dynamic Link Libraries).
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]546 </p>
547
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]548 <dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]549 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
550
551 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
552 or variable via a global pointer to a pointer that is set up by the DLL
553 exporting the symbol. On Microsoft Windows targets, the pointer name is
554 formed by combining <code>_imp__</code> and the function or variable name.
555 </dd>
556
557 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
558
559 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
560 pointer to a pointer in a DLL, so that it can be referenced with the
561 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
562 name is formed by combining <code>_imp__</code> and the function or variable
563 name.
564 </dd>
565
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]566</dl>
567
Dan Gohman8ef44982008-11-24 17:18:39 +0000[diff] [blame]568<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]569variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
570variable and was linked with this one, one of the two would be renamed,
571preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
572external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer92c671e2007-01-05 00:59:10 +0000[diff] [blame]573outside of the current module.</p>
574<p>It is illegal for a function <i>declaration</i>
575to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]576or <tt>extern_weak</tt>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]577<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]578linkages.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]579</div>
580
581<!-- ======================================================================= -->
582<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]583 <a name="callingconv">Calling Conventions</a>
584</div>
585
586<div class="doc_text">
587
588<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
589and <a href="#i_invoke">invokes</a> can all have an optional calling convention
590specified for the call. The calling convention of any pair of dynamic
591caller/callee must match, or the behavior of the program is undefined. The
592following calling conventions are supported by LLVM, and more may be added in
593the future:</p>
594
595<dl>
596 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
597
598 <dd>This calling convention (the default if no other calling convention is
599 specified) matches the target C calling conventions. This calling convention
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]600 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer72ba4992006-12-31 21:30:18 +0000[diff] [blame]601 prototype and implemented declaration of the function (as does normal C).
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]602 </dd>
603
604 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
605
606 <dd>This calling convention attempts to make calls as fast as possible
607 (e.g. by passing things in registers). This calling convention allows the
608 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]609 without having to conform to an externally specified ABI (Application Binary
610 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer2c6b8882008-05-14 09:17:12 +0000[diff] [blame]611 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
612 supported. This calling convention does not support varargs and requires the
613 prototype of all callees to exactly match the prototype of the function
614 definition.
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]615 </dd>
616
617 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
618
619 <dd>This calling convention attempts to make code in the caller as efficient
620 as possible under the assumption that the call is not commonly executed. As
621 such, these calls often preserve all registers so that the call does not break
622 any live ranges in the caller side. This calling convention does not support
623 varargs and requires the prototype of all callees to exactly match the
624 prototype of the function definition.
625 </dd>
626
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]627 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]628
629 <dd>Any calling convention may be specified by number, allowing
630 target-specific calling conventions to be used. Target specific calling
631 conventions start at 64.
632 </dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]633</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]634
635<p>More calling conventions can be added/defined on an as-needed basis, to
636support pascal conventions or any other well-known target-independent
637convention.</p>
638
639</div>
640
641<!-- ======================================================================= -->
642<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]643 <a name="visibility">Visibility Styles</a>
644</div>
645
646<div class="doc_text">
647
648<p>
649All Global Variables and Functions have one of the following visibility styles:
650</p>
651
652<dl>
653 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
654
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]655 <dd>On targets that use the ELF object file format, default visibility means
656 that the declaration is visible to other
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]657 modules and, in shared libraries, means that the declared entity may be
658 overridden. On Darwin, default visibility means that the declaration is
659 visible to other modules. Default visibility corresponds to "external
660 linkage" in the language.
661 </dd>
662
663 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
664
665 <dd>Two declarations of an object with hidden visibility refer to the same
666 object if they are in the same shared object. Usually, hidden visibility
667 indicates that the symbol will not be placed into the dynamic symbol table,
668 so no other module (executable or shared library) can reference it
669 directly.
670 </dd>
671
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]672 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
673
674 <dd>On ELF, protected visibility indicates that the symbol will be placed in
675 the dynamic symbol table, but that references within the defining module will
676 bind to the local symbol. That is, the symbol cannot be overridden by another
677 module.
678 </dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]679</dl>
680
681</div>
682
683<!-- ======================================================================= -->
684<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]685 <a name="globalvars">Global Variables</a>
686</div>
687
688<div class="doc_text">
689
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]690<p>Global variables define regions of memory allocated at compilation time
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]691instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]692an explicit section to be placed in, and may have an optional explicit alignment
693specified. A variable may be defined as "thread_local", which means that it
694will not be shared by threads (each thread will have a separated copy of the
695variable). A variable may be defined as a global "constant," which indicates
696that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]697optimization, allowing the global data to be placed in the read-only section of
698an executable, etc). Note that variables that need runtime initialization
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]699cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]700
701<p>
702LLVM explicitly allows <em>declarations</em> of global variables to be marked
703constant, even if the final definition of the global is not. This capability
704can be used to enable slightly better optimization of the program, but requires
705the language definition to guarantee that optimizations based on the
706'constantness' are valid for the translation units that do not include the
707definition.
708</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]709
710<p>As SSA values, global variables define pointer values that are in
711scope (i.e. they dominate) all basic blocks in the program. Global
712variables always define a pointer to their "content" type because they
713describe a region of memory, and all memory objects in LLVM are
714accessed through pointers.</p>
715
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]716<p>A global variable may be declared to reside in a target-specifc numbered
717address space. For targets that support them, address spaces may affect how
718optimizations are performed and/or what target instructions are used to access
Christopher Lamb25f50762007-12-12 08:44:39 +0000[diff] [blame]719the variable. The default address space is zero. The address space qualifier
720must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]721
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]722<p>LLVM allows an explicit section to be specified for globals. If the target
723supports it, it will emit globals to the section specified.</p>
724
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]725<p>An explicit alignment may be specified for a global. If not present, or if
726the alignment is set to zero, the alignment of the global is set by the target
727to whatever it feels convenient. If an explicit alignment is specified, the
728global is forced to have at least that much alignment. All alignments must be
729a power of 2.</p>
730
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]731<p>For example, the following defines a global in a numbered address space with
732an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]733
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]734<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]735<pre>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]736@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]737</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]738</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]739
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]740</div>
741
742
743<!-- ======================================================================= -->
744<div class="doc_subsection">
745 <a name="functionstructure">Functions</a>
746</div>
747
748<div class="doc_text">
749
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]750<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
751an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]752<a href="#visibility">visibility style</a>, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]753<a href="#callingconv">calling convention</a>, a return type, an optional
754<a href="#paramattrs">parameter attribute</a> for the return type, a function
755name, a (possibly empty) argument list (each with optional
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]756<a href="#paramattrs">parameter attributes</a>), optional
757<a href="#fnattrs">function attributes</a>, an optional section,
758an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattnercbc4d2a2008-10-04 18:10:21 +0000[diff] [blame]759an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]760
761LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
762optional <a href="#linkage">linkage type</a>, an optional
763<a href="#visibility">visibility style</a>, an optional
764<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]765<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]766name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksendc5cafb2007-12-10 03:30:21 +0000[diff] [blame]767<a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]768
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]769<p>A function definition contains a list of basic blocks, forming the CFG
770(Control Flow Graph) for
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]771the function. Each basic block may optionally start with a label (giving the
772basic block a symbol table entry), contains a list of instructions, and ends
773with a <a href="#terminators">terminator</a> instruction (such as a branch or
774function return).</p>
775
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]776<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]777executed on entrance to the function, and it is not allowed to have predecessor
778basic blocks (i.e. there can not be any branches to the entry block of a
779function). Because the block can have no predecessors, it also cannot have any
780<a href="#i_phi">PHI nodes</a>.</p>
781
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]782<p>LLVM allows an explicit section to be specified for functions. If the target
783supports it, it will emit functions to the section specified.</p>
784
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]785<p>An explicit alignment may be specified for a function. If not present, or if
786the alignment is set to zero, the alignment of the function is set by the target
787to whatever it feels convenient. If an explicit alignment is specified, the
788function is forced to have at least that much alignment. All alignments must be
789a power of 2.</p>
790
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]791 <h5>Syntax:</h5>
792
793<div class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]794<tt>
795define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
796 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
797 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
798 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
799 [<a href="#gc">gc</a>] { ... }
800</tt>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]801</div>
802
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]803</div>
804
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]805
806<!-- ======================================================================= -->
807<div class="doc_subsection">
808 <a name="aliasstructure">Aliases</a>
809</div>
810<div class="doc_text">
811 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov25b2e822008-03-22 08:36:14 +0000[diff] [blame]812 function, global variable, another alias or bitcast of global value). Aliases
813 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]814 optional <a href="#visibility">visibility style</a>.</p>
815
816 <h5>Syntax:</h5>
817
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]818<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]819<pre>
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]820@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]821</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]822</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]823
824</div>
825
826
827
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]828<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]829<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
830<div class="doc_text">
831 <p>The return type and each parameter of a function type may have a set of
832 <i>parameter attributes</i> associated with them. Parameter attributes are
833 used to communicate additional information about the result or parameters of
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]834 a function. Parameter attributes are considered to be part of the function,
835 not of the function type, so functions with different parameter attributes
836 can have the same function type.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]837
Reid Spencercf7ebf52007-01-15 18:27:39 +0000[diff] [blame]838 <p>Parameter attributes are simple keywords that follow the type specified. If
839 multiple parameter attributes are needed, they are space separated. For
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]840 example:</p>
841
842<div class="doc_code">
843<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]844declare i32 @printf(i8* noalias , ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]845declare i32 @atoi(i8 zeroext)
846declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]847</pre>
848</div>
849
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]850 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
851 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]852
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]853 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]854 <dl>
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]855 <dt><tt>zeroext</tt></dt>
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]856 <dd>This indicates to the code generator that the parameter or return value
857 should be zero-extended to a 32-bit value by the caller (for a parameter)
858 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]859
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]860 <dt><tt>signext</tt></dt>
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]861 <dd>This indicates to the code generator that the parameter or return value
862 should be sign-extended to a 32-bit value by the caller (for a parameter)
863 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]864
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]865 <dt><tt>inreg</tt></dt>
Dale Johannesenc50ada22008-09-25 20:47:45 +0000[diff] [blame]866 <dd>This indicates that this parameter or return value should be treated
867 in a special target-dependent fashion during while emitting code for a
868 function call or return (usually, by putting it in a register as opposed
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]869 to memory, though some targets use it to distinguish between two different
870 kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]871
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]872 <dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner352ab9b2008-01-15 04:34:22 +0000[diff] [blame]873 <dd>This indicates that the pointer parameter should really be passed by
874 value to the function. The attribute implies that a hidden copy of the
875 pointee is made between the caller and the callee, so the callee is unable
Chris Lattner1ca5c642008-08-05 18:21:08 +0000[diff] [blame]876 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner352ab9b2008-01-15 04:34:22 +0000[diff] [blame]877 pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]878 value, but is also valid on pointers to scalars. The copy is considered to
879 belong to the caller not the callee (for example,
880 <tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]881 <tt>byval</tt> parameters). This is not a valid attribute for return
882 values. </dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]883
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]884 <dt><tt>sret</tt></dt>
Duncan Sandsfa4b6732008-02-18 04:19:38 +0000[diff] [blame]885 <dd>This indicates that the pointer parameter specifies the address of a
886 structure that is the return value of the function in the source program.
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]887 This pointer must be guaranteed by the caller to be valid: loads and stores
888 to the structure may be assumed by the callee to not to trap. This may only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]889 be applied to the first parameter. This is not a valid attribute for
890 return values. </dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]891
Zhou Sheng2444a9a2007-06-05 05:28:26 +0000[diff] [blame]892 <dt><tt>noalias</tt></dt>
Nick Lewyckyf5ffcbc2008-11-24 03:41:24 +0000[diff] [blame]893 <dd>This indicates that the pointer does not alias any global or any other
894 parameter. The caller is responsible for ensuring that this is the
Nick Lewyckyd59572c2008-11-24 05:00:44 +0000[diff] [blame]895 case. On a function return value, <tt>noalias</tt> additionally indicates
896 that the pointer does not alias any other pointers visible to the
Nick Lewyckyddffe622008-12-15 01:34:58 +0000[diff] [blame^]897 caller. For further details, please see the discussion of the NoAlias
898 response in
899 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
900 analysis</a>.</dd>
901
902 <dt><tt>nocapture</tt></dt>
903 <dd>This indicates that the callee does not make any copies of the pointer
904 that outlive the callee itself. This is not a valid attribute for return
905 values.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]906
Duncan Sands27e91592007-07-27 19:57:41 +0000[diff] [blame]907 <dt><tt>nest</tt></dt>
Duncan Sands825bde42008-07-08 09:27:25 +0000[diff] [blame]908 <dd>This indicates that the pointer parameter can be excised using the
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]909 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
910 attribute for return values.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]911 </dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]912
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]913</div>
914
915<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]916<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]917 <a name="gc">Garbage Collector Names</a>
918</div>
919
920<div class="doc_text">
921<p>Each function may specify a garbage collector name, which is simply a
922string.</p>
923
924<div class="doc_code"><pre
925>define void @f() gc "name" { ...</pre></div>
926
927<p>The compiler declares the supported values of <i>name</i>. Specifying a
928collector which will cause the compiler to alter its output in order to support
929the named garbage collection algorithm.</p>
930</div>
931
932<!-- ======================================================================= -->
933<div class="doc_subsection">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]934 <a name="fnattrs">Function Attributes</a>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]935</div>
936
937<div class="doc_text">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]938
939<p>Function attributes are set to communicate additional information about
940 a function. Function attributes are considered to be part of the function,
941 not of the function type, so functions with different parameter attributes
942 can have the same function type.</p>
943
944 <p>Function attributes are simple keywords that follow the type specified. If
945 multiple attributes are needed, they are space separated. For
946 example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]947
948<div class="doc_code">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]949<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]950define void @f() noinline { ... }
951define void @f() alwaysinline { ... }
952define void @f() alwaysinline optsize { ... }
953define void @f() optsize
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]954</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]955</div>
956
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]957<dl>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]958<dt><tt>alwaysinline</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]959<dd>This attribute indicates that the inliner should attempt to inline this
960function into callers whenever possible, ignoring any active inlining size
961threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]962
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]963<dt><tt>noinline</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]964<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner0625c282008-10-05 17:14:59 +0000[diff] [blame]965in any situation. This attribute may not be used together with the
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]966<tt>alwaysinline</tt> attribute.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]967
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]968<dt><tt>optsize</tt></dt>
Devang Patele9743902008-09-29 18:34:44 +0000[diff] [blame]969<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]970make choices that keep the code size of this function low, and otherwise do
971optimizations specifically to reduce code size.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]972
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]973<dt><tt>noreturn</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]974<dd>This function attribute indicates that the function never returns normally.
975This produces undefined behavior at runtime if the function ever does
976dynamically return.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]977
978<dt><tt>nounwind</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]979<dd>This function attribute indicates that the function never returns with an
980unwind or exceptional control flow. If the function does unwind, its runtime
981behavior is undefined.</dd>
982
983<dt><tt>readnone</tt></dt>
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]984<dd>This attribute indicates that the function computes its result (or the
985exception it throws) based strictly on its arguments, without dereferencing any
986pointer arguments or otherwise accessing any mutable state (e.g. memory, control
987registers, etc) visible to caller functions. It does not write through any
988pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
989never changes any state visible to callers.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]990
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]991<dt><tt><a name="readonly">readonly</a></tt></dt>
992<dd>This attribute indicates that the function does not write through any
993pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
994or otherwise modify any state (e.g. memory, control registers, etc) visible to
995caller functions. It may dereference pointer arguments and read state that may
996be set in the caller. A readonly function always returns the same value (or
997throws the same exception) when called with the same set of arguments and global
998state.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]999
1000<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1001<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1002protector. It is in the form of a "canary"&mdash;a random value placed on the
1003stack before the local variables that's checked upon return from the function to
1004see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1005needs stack protectors or not.
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1006
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1007<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
1008that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
1009have an <tt>ssp</tt> attribute.</p></dd>
1010
1011<dt><tt>sspreq</tt></dt>
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1012<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1013stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1014function attribute.
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1015
1016<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
1017function that doesn't have an <tt>sspreq</tt> attribute or which has
1018an <tt>ssp</tt> attribute, then the resulting function will have
1019an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1020</dl>
1021
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1022</div>
1023
1024<!-- ======================================================================= -->
1025<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1026 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1027</div>
1028
1029<div class="doc_text">
1030<p>
1031Modules may contain "module-level inline asm" blocks, which corresponds to the
1032GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1033LLVM and treated as a single unit, but may be separated in the .ll file if
1034desired. The syntax is very simple:
1035</p>
1036
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1037<div class="doc_code">
1038<pre>
1039module asm "inline asm code goes here"
1040module asm "more can go here"
1041</pre>
1042</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1043
1044<p>The strings can contain any character by escaping non-printable characters.
1045 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1046 for the number.
1047</p>
1048
1049<p>
1050 The inline asm code is simply printed to the machine code .s file when
1051 assembly code is generated.
1052</p>
1053</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1054
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1055<!-- ======================================================================= -->
1056<div class="doc_subsection">
1057 <a name="datalayout">Data Layout</a>
1058</div>
1059
1060<div class="doc_text">
1061<p>A module may specify a target specific data layout string that specifies how
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]1062data is to be laid out in memory. The syntax for the data layout is simply:</p>
1063<pre> target datalayout = "<i>layout specification</i>"</pre>
1064<p>The <i>layout specification</i> consists of a list of specifications
1065separated by the minus sign character ('-'). Each specification starts with a
1066letter and may include other information after the letter to define some
1067aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1068<dl>
1069 <dt><tt>E</tt></dt>
1070 <dd>Specifies that the target lays out data in big-endian form. That is, the
1071 bits with the most significance have the lowest address location.</dd>
1072 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1073 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1074 the bits with the least significance have the lowest address location.</dd>
1075 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1076 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1077 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1078 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1079 too.</dd>
1080 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1081 <dd>This specifies the alignment for an integer type of a given bit
1082 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1083 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1084 <dd>This specifies the alignment for a vector type of a given bit
1085 <i>size</i>.</dd>
1086 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1087 <dd>This specifies the alignment for a floating point type of a given bit
1088 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1089 (double).</dd>
1090 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1091 <dd>This specifies the alignment for an aggregate type of a given bit
1092 <i>size</i>.</dd>
1093</dl>
1094<p>When constructing the data layout for a given target, LLVM starts with a
1095default set of specifications which are then (possibly) overriden by the
1096specifications in the <tt>datalayout</tt> keyword. The default specifications
1097are given in this list:</p>
1098<ul>
1099 <li><tt>E</tt> - big endian</li>
1100 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1101 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1102 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1103 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1104 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1105 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1106 alignment of 64-bits</li>
1107 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1108 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1109 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1110 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1111 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1112</ul>
Chris Lattner1ca5c642008-08-05 18:21:08 +0000[diff] [blame]1113<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1114following rules:</p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1115<ol>
1116 <li>If the type sought is an exact match for one of the specifications, that
1117 specification is used.</li>
1118 <li>If no match is found, and the type sought is an integer type, then the
1119 smallest integer type that is larger than the bitwidth of the sought type is
1120 used. If none of the specifications are larger than the bitwidth then the the
1121 largest integer type is used. For example, given the default specifications
1122 above, the i7 type will use the alignment of i8 (next largest) while both
1123 i65 and i256 will use the alignment of i64 (largest specified).</li>
1124 <li>If no match is found, and the type sought is a vector type, then the
1125 largest vector type that is smaller than the sought vector type will be used
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1126 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1127 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1128</ol>
1129</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1130
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1131<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1132<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1133<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1134
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1135<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1136
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1137<p>The LLVM type system is one of the most important features of the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1138intermediate representation. Being typed enables a number of
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1139optimizations to be performed on the intermediate representation directly,
1140without having to do
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1141extra analyses on the side before the transformation. A strong type
1142system makes it easier to read the generated code and enables novel
1143analyses and transformations that are not feasible to perform on normal
1144three address code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1145
1146</div>
1147
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1148<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1149<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1150Classifications</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1151<div class="doc_text">
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1152<p>The types fall into a few useful
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1153classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1154
1155<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1156 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1157 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1158 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1159 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1160 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1161 </tr>
1162 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1163 <td><a href="#t_floating">floating point</a></td>
1164 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1165 </tr>
1166 <tr>
1167 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1168 <td><a href="#t_integer">integer</a>,
1169 <a href="#t_floating">floating point</a>,
1170 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1171 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1172 <a href="#t_struct">structure</a>,
1173 <a href="#t_array">array</a>,
Dan Gohmanda52d212008-05-23 22:50:26 +0000[diff] [blame]1174 <a href="#t_label">label</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1175 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1176 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1177 <tr>
1178 <td><a href="#t_primitive">primitive</a></td>
1179 <td><a href="#t_label">label</a>,
1180 <a href="#t_void">void</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1181 <a href="#t_floating">floating point</a>.</td>
1182 </tr>
1183 <tr>
1184 <td><a href="#t_derived">derived</a></td>
1185 <td><a href="#t_integer">integer</a>,
1186 <a href="#t_array">array</a>,
1187 <a href="#t_function">function</a>,
1188 <a href="#t_pointer">pointer</a>,
1189 <a href="#t_struct">structure</a>,
1190 <a href="#t_pstruct">packed structure</a>,
1191 <a href="#t_vector">vector</a>,
1192 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1193 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1194 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1195 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1196</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1197
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1198<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1199most important. Values of these types are the only ones which can be
1200produced by instructions, passed as arguments, or used as operands to
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]1201instructions.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1202</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1203
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1204<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1205<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1206
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1207<div class="doc_text">
1208<p>The primitive types are the fundamental building blocks of the LLVM
1209system.</p>
1210
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1211</div>
1212
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1213<!-- _______________________________________________________________________ -->
1214<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1215
1216<div class="doc_text">
1217 <table>
1218 <tbody>
1219 <tr><th>Type</th><th>Description</th></tr>
1220 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1221 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1222 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1223 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1224 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1225 </tbody>
1226 </table>
1227</div>
1228
1229<!-- _______________________________________________________________________ -->
1230<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1231
1232<div class="doc_text">
1233<h5>Overview:</h5>
1234<p>The void type does not represent any value and has no size.</p>
1235
1236<h5>Syntax:</h5>
1237
1238<pre>
1239 void
1240</pre>
1241</div>
1242
1243<!-- _______________________________________________________________________ -->
1244<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1245
1246<div class="doc_text">
1247<h5>Overview:</h5>
1248<p>The label type represents code labels.</p>
1249
1250<h5>Syntax:</h5>
1251
1252<pre>
1253 label
1254</pre>
1255</div>
1256
1257
1258<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1259<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1260
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1261<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1262
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1263<p>The real power in LLVM comes from the derived types in the system.
1264This is what allows a programmer to represent arrays, functions,
1265pointers, and other useful types. Note that these derived types may be
1266recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1267
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1268</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1269
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1270<!-- _______________________________________________________________________ -->
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1271<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1272
1273<div class="doc_text">
1274
1275<h5>Overview:</h5>
1276<p>The integer type is a very simple derived type that simply specifies an
1277arbitrary bit width for the integer type desired. Any bit width from 1 bit to
12782^23-1 (about 8 million) can be specified.</p>
1279
1280<h5>Syntax:</h5>
1281
1282<pre>
1283 iN
1284</pre>
1285
1286<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1287value.</p>
1288
1289<h5>Examples:</h5>
1290<table class="layout">
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1291 <tbody>
1292 <tr>
1293 <td><tt>i1</tt></td>
1294 <td>a single-bit integer.</td>
1295 </tr><tr>
1296 <td><tt>i32</tt></td>
1297 <td>a 32-bit integer.</td>
1298 </tr><tr>
1299 <td><tt>i1942652</tt></td>
1300 <td>a really big integer of over 1 million bits.</td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1301 </tr>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1302 </tbody>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1303</table>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1304</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1305
1306<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1307<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1308
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1309<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1310
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1311<h5>Overview:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1312
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1313<p>The array type is a very simple derived type that arranges elements
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1314sequentially in memory. The array type requires a size (number of
1315elements) and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1316
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1317<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1318
1319<pre>
1320 [&lt;# elements&gt; x &lt;elementtype&gt;]
1321</pre>
1322
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1323<p>The number of elements is a constant integer value; elementtype may
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1324be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1325
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1326<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1327<table class="layout">
1328 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1329 <td class="left"><tt>[40 x i32]</tt></td>
1330 <td class="left">Array of 40 32-bit integer values.</td>
1331 </tr>
1332 <tr class="layout">
1333 <td class="left"><tt>[41 x i32]</tt></td>
1334 <td class="left">Array of 41 32-bit integer values.</td>
1335 </tr>
1336 <tr class="layout">
1337 <td class="left"><tt>[4 x i8]</tt></td>
1338 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1339 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1340</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1341<p>Here are some examples of multidimensional arrays:</p>
1342<table class="layout">
1343 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1344 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1345 <td class="left">3x4 array of 32-bit integer values.</td>
1346 </tr>
1347 <tr class="layout">
1348 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1349 <td class="left">12x10 array of single precision floating point values.</td>
1350 </tr>
1351 <tr class="layout">
1352 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1353 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1354 </tr>
1355</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1356
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1357<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1358length array. Normally, accesses past the end of an array are undefined in
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1359LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1360As a special case, however, zero length arrays are recognized to be variable
1361length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1362type "{ i32, [0 x float]}", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1363
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1364</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1365
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1366<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1367<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1368<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1369
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1370<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1371
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1372<p>The function type can be thought of as a function signature. It
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1373consists of a return type and a list of formal parameter types. The
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1374return 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]1375If 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]1376class types, and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1377
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1378<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1379
1380<pre>
1381 &lt;returntype list&gt; (&lt;parameter list&gt;)
1382</pre>
1383
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1384<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]1385specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1386which indicates that the function takes a variable number of arguments.
1387Variable argument functions can access their arguments with the <a
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1388 href="#int_varargs">variable argument handling intrinsic</a> functions.
1389'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1390<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1391
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1392<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1393<table class="layout">
1394 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1395 <td class="left"><tt>i32 (i32)</tt></td>
1396 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1397 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1398 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]1399 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1400 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1401 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1402 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1403 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1404 <tt>float</tt>.
1405 </td>
1406 </tr><tr class="layout">
1407 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1408 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1409 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1410 which returns an integer. This is the signature for <tt>printf</tt> in
1411 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1412 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1413 </tr><tr class="layout">
1414 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanc9813bd2008-11-27 06:41:20 +0000[diff] [blame]1415 <td class="left">A function taking an <tt>i32</tt>, returning two
1416 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1417 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1418 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1419</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1420
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1421</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1422<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1423<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1424<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1425<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1426<p>The structure type is used to represent a collection of data members
1427together in memory. The packing of the field types is defined to match
1428the ABI of the underlying processor. The elements of a structure may
1429be any type that has a size.</p>
1430<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1431and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1432field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1433instruction.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1434<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1435<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1436<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1437<table class="layout">
1438 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1439 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1440 <td class="left">A triple of three <tt>i32</tt> values</td>
1441 </tr><tr class="layout">
1442 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1443 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1444 second element is a <a href="#t_pointer">pointer</a> to a
1445 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1446 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1447 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1448</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1449</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1450
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1451<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1452<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1453</div>
1454<div class="doc_text">
1455<h5>Overview:</h5>
1456<p>The packed structure type is used to represent a collection of data members
1457together in memory. There is no padding between fields. Further, the alignment
1458of a packed structure is 1 byte. The elements of a packed structure may
1459be any type that has a size.</p>
1460<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1461and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1462field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1463instruction.</p>
1464<h5>Syntax:</h5>
1465<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1466<h5>Examples:</h5>
1467<table class="layout">
1468 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1469 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1470 <td class="left">A triple of three <tt>i32</tt> values</td>
1471 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1472 <td class="left">
1473<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1474 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1475 second element is a <a href="#t_pointer">pointer</a> to a
1476 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1477 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1478 </tr>
1479</table>
1480</div>
1481
1482<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1483<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1484<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1485<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1486<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]1487reference to another object, which must live in memory. Pointer types may have
1488an optional address space attribute defining the target-specific numbered
1489address space where the pointed-to object resides. The default address space is
1490zero.</p>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1491<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1492<pre> &lt;type&gt; *<br></pre>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1493<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1494<table class="layout">
1495 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1496 <td class="left"><tt>[4x i32]*</tt></td>
1497 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1498 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1499 </tr>
1500 <tr class="layout">
1501 <td class="left"><tt>i32 (i32 *) *</tt></td>
1502 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1503 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1504 <tt>i32</tt>.</td>
1505 </tr>
1506 <tr class="layout">
1507 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1508 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1509 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1510 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1511</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1512</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1513
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1514<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1515<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1516<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1517
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1518<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1519
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1520<p>A vector type is a simple derived type that represents a vector
1521of elements. Vector types are used when multiple primitive data
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1522are operated in parallel using a single instruction (SIMD).
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1523A vector type requires a size (number of
Chris Lattner330ce692005-11-10 01:44:22 +0000[diff] [blame]1524elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1525of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1526considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1527
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1528<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1529
1530<pre>
1531 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1532</pre>
1533
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1534<p>The number of elements is a constant integer value; elementtype may
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1535be any integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1536
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1537<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1538
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1539<table class="layout">
1540 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1541 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1542 <td class="left">Vector of 4 32-bit integer values.</td>
1543 </tr>
1544 <tr class="layout">
1545 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1546 <td class="left">Vector of 8 32-bit floating-point values.</td>
1547 </tr>
1548 <tr class="layout">
1549 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1550 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1551 </tr>
1552</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1553</div>
1554
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1555<!-- _______________________________________________________________________ -->
1556<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1557<div class="doc_text">
1558
1559<h5>Overview:</h5>
1560
1561<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksena699c4d2007-10-14 00:34:53 +0000[diff] [blame]1562corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1563In LLVM, opaque types can eventually be resolved to any type (not just a
1564structure type).</p>
1565
1566<h5>Syntax:</h5>
1567
1568<pre>
1569 opaque
1570</pre>
1571
1572<h5>Examples:</h5>
1573
1574<table class="layout">
1575 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1576 <td class="left"><tt>opaque</tt></td>
1577 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1578 </tr>
1579</table>
1580</div>
1581
1582
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1583<!-- *********************************************************************** -->
1584<div class="doc_section"> <a name="constants">Constants</a> </div>
1585<!-- *********************************************************************** -->
1586
1587<div class="doc_text">
1588
1589<p>LLVM has several different basic types of constants. This section describes
1590them all and their syntax.</p>
1591
1592</div>
1593
1594<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1595<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1596
1597<div class="doc_text">
1598
1599<dl>
1600 <dt><b>Boolean constants</b></dt>
1601
1602 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1603 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1604 </dd>
1605
1606 <dt><b>Integer constants</b></dt>
1607
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1608 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1609 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1610 integer types.
1611 </dd>
1612
1613 <dt><b>Floating point constants</b></dt>
1614
1615 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1616 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]1617 notation (see below). The assembler requires the exact decimal value of
1618 a floating-point constant. For example, the assembler accepts 1.25 but
1619 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1620 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1621
1622 <dt><b>Null pointer constants</b></dt>
1623
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1624 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1625 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1626
1627</dl>
1628
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1629<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1630of floating point constants. For example, the form '<tt>double
16310x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
16324.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1633(and the only time that they are generated by the disassembler) is when a
1634floating point constant must be emitted but it cannot be represented as a
1635decimal floating point number. For example, NaN's, infinities, and other
1636special values are represented in their IEEE hexadecimal format so that
1637assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1638
1639</div>
1640
1641<!-- ======================================================================= -->
1642<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1643</div>
1644
1645<div class="doc_text">
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]1646<p>Aggregate constants arise from aggregation of simple constants
1647and smaller aggregate constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1648
1649<dl>
1650 <dt><b>Structure constants</b></dt>
1651
1652 <dd>Structure constants are represented with notation similar to structure
1653 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattnerbea11172007-12-25 20:34:52 +0000[diff] [blame]1654 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1655 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]1656 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1657 types of elements must match those specified by the type.
1658 </dd>
1659
1660 <dt><b>Array constants</b></dt>
1661
1662 <dd>Array constants are represented with notation similar to array type
1663 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1664 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1665 constants must have <a href="#t_array">array type</a>, and the number and
1666 types of elements must match those specified by the type.
1667 </dd>
1668
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1669 <dt><b>Vector constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1670
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1671 <dd>Vector constants are represented with notation similar to vector type
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1672 definitions (a comma separated list of elements, surrounded by
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1673 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]1674 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1675 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1676 match those specified by the type.
1677 </dd>
1678
1679 <dt><b>Zero initialization</b></dt>
1680
1681 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1682 value to zero of <em>any</em> type, including scalar and aggregate types.
1683 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]1684 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1685 initializers.
1686 </dd>
1687</dl>
1688
1689</div>
1690
1691<!-- ======================================================================= -->
1692<div class="doc_subsection">
1693 <a name="globalconstants">Global Variable and Function Addresses</a>
1694</div>
1695
1696<div class="doc_text">
1697
1698<p>The addresses of <a href="#globalvars">global variables</a> and <a
1699href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1700constants. These constants are explicitly referenced when the <a
1701href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1702href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1703file:</p>
1704
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1705<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1706<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]1707@X = global i32 17
1708@Y = global i32 42
1709@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1710</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1711</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1712
1713</div>
1714
1715<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1716<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1717<div class="doc_text">
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1718 <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]1719 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1720 a constant is permitted.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1721
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1722 <p>Undefined values indicate to the compiler that the program is well defined
1723 no matter what value is used, giving the compiler more freedom to optimize.
1724 </p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1725</div>
1726
1727<!-- ======================================================================= -->
1728<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1729</div>
1730
1731<div class="doc_text">
1732
1733<p>Constant expressions are used to allow expressions involving other constants
1734to be used as constants. Constant expressions may be of any <a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1735href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1736that does not have side effects (e.g. load and call are not supported). The
1737following is the syntax for constant expressions:</p>
1738
1739<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1740 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1741 <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]1742 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1743
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1744 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1745 <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]1746 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]1747
1748 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1749 <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]1750 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]1751
1752 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1753 <dd>Truncate a floating point constant to another floating point type. The
1754 size of CST must be larger than the size of TYPE. Both types must be
1755 floating point.</dd>
1756
1757 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1758 <dd>Floating point extend a constant to another type. The size of CST must be
1759 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1760
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]1761 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1762 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1763 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1764 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1765 of the same number of elements. If the value won't fit in the integer type,
1766 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1767
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1768 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1769 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1770 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1771 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1772 of the same number of elements. If the value won't fit in the integer type,
1773 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1774
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1775 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1776 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1777 constant. TYPE must be a scalar or vector floating point type. CST must be of
1778 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1779 of the same number of elements. If the value won't fit in the floating point
1780 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1781
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1782 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1783 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1784 constant. TYPE must be a scalar or vector floating point type. CST must be of
1785 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1786 of the same number of elements. If the value won't fit in the floating point
1787 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1788
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1789 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1790 <dd>Convert a pointer typed constant to the corresponding integer constant
1791 TYPE must be an integer type. CST must be of pointer type. The CST value is
1792 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1793
1794 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1795 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1796 pointer type. CST must be of integer type. The CST value is zero extended,
1797 truncated, or unchanged to make it fit in a pointer size. This one is
1798 <i>really</i> dangerous!</dd>
1799
1800 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1801 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1802 identical (same number of bits). The conversion is done as if the CST value
1803 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]1804 with this operator, just the type. This can be used for conversion of
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1805 vector types to any other type, as long as they have the same bit width. For
Dan Gohmanc05dca92008-09-08 16:45:59 +0000[diff] [blame]1806 pointers it is only valid to cast to another pointer type. It is not valid
1807 to bitcast to or from an aggregate type.
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1808 </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1809
1810 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1811
1812 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1813 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1814 instruction, the index list may have zero or more indexes, which are required
1815 to make sense for the type of "CSTPTR".</dd>
1816
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1817 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1818
1819 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1820 constants.</dd>
1821
1822 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1823 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1824
1825 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1826 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1827
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]1828 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1829 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1830
1831 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1832 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1833
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1834 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1835
1836 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1837 operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1838
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1839 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1840
1841 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1842 operation</a> on constants.</dd>
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1843
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1844
1845 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1846
1847 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1848 operation</a> on constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1849
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1850 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1851
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1852 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1853 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1854 binary</a> operations. The constraints on operands are the same as those for
1855 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1856 values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1857</dl>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1858</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]1859
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1860<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1861<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1862<!-- *********************************************************************** -->
1863
1864<!-- ======================================================================= -->
1865<div class="doc_subsection">
1866<a name="inlineasm">Inline Assembler Expressions</a>
1867</div>
1868
1869<div class="doc_text">
1870
1871<p>
1872LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1873Module-Level Inline Assembly</a>) through the use of a special value. This
1874value represents the inline assembler as a string (containing the instructions
1875to emit), a list of operand constraints (stored as a string), and a flag that
1876indicates whether or not the inline asm expression has side effects. An example
1877inline assembler expression is:
1878</p>
1879
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1880<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1881<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1882i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1883</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1884</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1885
1886<p>
1887Inline assembler expressions may <b>only</b> be used as the callee operand of
1888a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1889</p>
1890
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1891<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1892<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1893%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]1894</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1895</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1896
1897<p>
1898Inline asms with side effects not visible in the constraint list must be marked
1899as having side effects. This is done through the use of the
1900'<tt>sideeffect</tt>' keyword, like so:
1901</p>
1902
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1903<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1904<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1905call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1906</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1907</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1908
1909<p>TODO: The format of the asm and constraints string still need to be
1910documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattnerd5528262008-10-04 18:36:02 +0000[diff] [blame]1911need to be documented). This is probably best done by reference to another
1912document that covers inline asm from a holistic perspective.
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1913</p>
1914
1915</div>
1916
1917<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1918<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1919<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1920
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1921<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1922
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1923<p>The LLVM instruction set consists of several different
1924classifications of instructions: <a href="#terminators">terminator
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1925instructions</a>, <a href="#binaryops">binary instructions</a>,
1926<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1927 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1928instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1929
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1930</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1931
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1932<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1933<div class="doc_subsection"> <a name="terminators">Terminator
1934Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1935
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1936<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1937
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1938<p>As mentioned <a href="#functionstructure">previously</a>, every
1939basic block in a program ends with a "Terminator" instruction, which
1940indicates which block should be executed after the current block is
1941finished. These terminator instructions typically yield a '<tt>void</tt>'
1942value: they produce control flow, not values (the one exception being
1943the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1944<p>There are six different terminator instructions: the '<a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1945 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1946instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1947the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1948 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1949 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1950
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1951</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1952
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1953<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1954<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1955Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1956<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1957<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1958<pre>
1959 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]1960 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1961</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1962
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1963<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1964
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1965<p>The '<tt>ret</tt>' instruction is used to return control flow (and
1966optionally a value) from a function back to the caller.</p>
John Criswell417228d2004-04-09 16:48:45 +0000[diff] [blame]1967<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1968returns a value and then causes control flow, and one that just causes
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1969control flow to occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1970
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1971<h5>Arguments:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1972
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1973<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
1974the return value. The type of the return value must be a
1975'<a href="#t_firstclass">first class</a>' type.</p>
1976
1977<p>A function is not <a href="#wellformed">well formed</a> if
1978it it has a non-void return type and contains a '<tt>ret</tt>'
1979instruction with no return value or a return value with a type that
1980does not match its type, or if it has a void return type and contains
1981a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1982
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1983<h5>Semantics:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1984
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1985<p>When the '<tt>ret</tt>' instruction is executed, control flow
1986returns back to the calling function's context. If the caller is a "<a
John Criswell40db33f2004-06-25 15:16:57 +0000[diff] [blame]1987 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1988the instruction after the call. If the caller was an "<a
1989 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1990at the beginning of the "normal" destination block. If the instruction
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1991returns a value, that value shall set the call or invoke instruction's
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1992return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1993
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1994<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1995
1996<pre>
1997 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1998 ret void <i>; Return from a void function</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1999 ret { i32, i8 } { i32 4, i8 2 } <i>; Return an aggregate of values 4 and 2</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2000</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2001</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2002<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2003<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2004<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2005<h5>Syntax:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2006<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]2007</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2008<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2009<p>The '<tt>br</tt>' instruction is used to cause control flow to
2010transfer to a different basic block in the current function. There are
2011two forms of this instruction, corresponding to a conditional branch
2012and an unconditional branch.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2013<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2014<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2015single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]2016unconditional form of the '<tt>br</tt>' instruction takes a single
2017'<tt>label</tt>' value as a target.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2018<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2019<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2020argument is evaluated. If the value is <tt>true</tt>, control flows
2021to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2022control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2023<h5>Example:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2024<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]2025 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]2026</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2027<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2028<div class="doc_subsubsection">
2029 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2030</div>
2031
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2032<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2033<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2034
2035<pre>
2036 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2037</pre>
2038
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2039<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2040
2041<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2042several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2043instruction, allowing a branch to occur to one of many possible
2044destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2045
2046
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2047<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2048
2049<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2050comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2051an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2052table is not allowed to contain duplicate constant entries.</p>
2053
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2054<h5>Semantics:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2055
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2056<p>The <tt>switch</tt> instruction specifies a table of values and
2057destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]2058table is searched for the given value. If the value is found, control flow is
2059transfered to the corresponding destination; otherwise, control flow is
2060transfered to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2061
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2062<h5>Implementation:</h5>
2063
2064<p>Depending on properties of the target machine and the particular
2065<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]2066ways. For example, it could be generated as a series of chained conditional
2067branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2068
2069<h5>Example:</h5>
2070
2071<pre>
2072 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2073 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2074 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2075
2076 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2077 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2078
2079 <i>; Implement a jump table:</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2080 switch i32 %val, label %otherwise [ i32 0, label %onzero
2081 i32 1, label %onone
2082 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2083</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2084</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2085
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2086<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2087<div class="doc_subsubsection">
2088 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2089</div>
2090
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2091<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2092
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2093<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2094
2095<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2096 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ptr to function ty&gt; &lt;function ptr val&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner6b7a0082006-05-14 18:23:06 +0000[diff] [blame]2097 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2098</pre>
2099
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2100<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2101
2102<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2103function, with the possibility of control flow transfer to either the
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2104'<tt>normal</tt>' label or the
2105'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2106"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2107"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2108href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]2109continued at the dynamically nearest "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2110
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2111<h5>Arguments:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2112
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2113<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2114
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2115<ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2116 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]2117 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2118 convention</a> the call should use. If none is specified, the call defaults
2119 to using C calling conventions.
2120 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2121
2122 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2123 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2124 and '<tt>inreg</tt>' attributes are valid here.</li>
2125
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2126 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2127 function value being invoked. In most cases, this is a direct function
2128 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2129 an arbitrary pointer to function value.
2130 </li>
2131
2132 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2133 function to be invoked. </li>
2134
2135 <li>'<tt>function args</tt>': argument list whose types match the function
2136 signature argument types. If the function signature indicates the function
2137 accepts a variable number of arguments, the extra arguments can be
2138 specified. </li>
2139
2140 <li>'<tt>normal label</tt>': the label reached when the called function
2141 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2142
2143 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2144 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2145
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2146 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2147 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2148 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2149</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2150
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2151<h5>Semantics:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2152
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2153<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2154href="#i_call">call</a></tt>' instruction in most regards. The primary
2155difference is that it establishes an association with a label, which is used by
2156the runtime library to unwind the stack.</p>
2157
2158<p>This instruction is used in languages with destructors to ensure that proper
2159cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2160exception. Additionally, this is important for implementation of
2161'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2162
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2163<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2164<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2165 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2166 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2167 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2168 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2169</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2170</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2171
2172
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2173<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2174
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2175<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2176Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2177
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2178<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2179
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2180<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2181<pre>
2182 unwind
2183</pre>
2184
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2185<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2186
2187<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2188at the first callee in the dynamic call stack which used an <a
2189href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2190primarily used to implement exception handling.</p>
2191
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2192<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2193
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2194<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2195immediately halt. The dynamic call stack is then searched for the first <a
2196href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2197execution continues at the "exceptional" destination block specified by the
2198<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2199dynamic call chain, undefined behavior results.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2200</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2201
2202<!-- _______________________________________________________________________ -->
2203
2204<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2205Instruction</a> </div>
2206
2207<div class="doc_text">
2208
2209<h5>Syntax:</h5>
2210<pre>
2211 unreachable
2212</pre>
2213
2214<h5>Overview:</h5>
2215
2216<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2217instruction is used to inform the optimizer that a particular portion of the
2218code is not reachable. This can be used to indicate that the code after a
2219no-return function cannot be reached, and other facts.</p>
2220
2221<h5>Semantics:</h5>
2222
2223<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2224</div>
2225
2226
2227
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2228<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2229<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2230<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2231<p>Binary operators are used to do most of the computation in a
Chris Lattner81f92972008-04-01 18:47:32 +0000[diff] [blame]2232program. They require two operands of the same type, execute an operation on them, and
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2233produce a single value. The operands might represent
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2234multiple 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]2235The result value has the same type as its operands.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2236<p>There are several different binary operators:</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2237</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2238<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2239<div class="doc_subsubsection">
2240 <a name="i_add">'<tt>add</tt>' Instruction</a>
2241</div>
2242
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2243<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2244
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2245<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2246
2247<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2248 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2249</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2250
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2251<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2252
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2253<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2254
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2255<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2256
2257<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2258 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2259 <a href="#t_vector">vector</a> values. Both arguments must have identical
2260 types.</p>
2261
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2262<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2263
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2264<p>The value produced is the integer or floating point sum of the two
2265operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2266
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2267<p>If an integer sum has unsigned overflow, the result returned is the
2268mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2269the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2270
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2271<p>Because LLVM integers use a two's complement representation, this
2272instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2273
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2274<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2275
2276<pre>
2277 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2278</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2279</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2280<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2281<div class="doc_subsubsection">
2282 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2283</div>
2284
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2285<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2286
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2287<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2288
2289<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2290 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2291</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2292
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2293<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2294
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2295<p>The '<tt>sub</tt>' instruction returns the difference of its two
2296operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2297
2298<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2299'<tt>neg</tt>' instruction present in most other intermediate
2300representations.</p>
2301
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2302<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2303
2304<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2305 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2306 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2307 types.</p>
2308
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2309<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2310
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2311<p>The value produced is the integer or floating point difference of
2312the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2313
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2314<p>If an integer difference has unsigned overflow, the result returned is the
2315mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2316the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2317
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2318<p>Because LLVM integers use a two's complement representation, this
2319instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2320
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2321<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2322<pre>
2323 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2324 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2325</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2326</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2327
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2328<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2329<div class="doc_subsubsection">
2330 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2331</div>
2332
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2333<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2334
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2335<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2336<pre> &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2337</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2338<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2339<p>The '<tt>mul</tt>' instruction returns the product of its two
2340operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2341
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2342<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2343
2344<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2345href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2346or <a href="#t_vector">vector</a> values. Both arguments must have identical
2347types.</p>
2348
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2349<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2350
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2351<p>The value produced is the integer or floating point product of the
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2352two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2353
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2354<p>If the result of an integer multiplication has unsigned overflow,
2355the result returned is the mathematical result modulo
23562<sup>n</sup>, where n is the bit width of the result.</p>
2357<p>Because LLVM integers use a two's complement representation, and the
2358result is the same width as the operands, this instruction returns the
2359correct result for both signed and unsigned integers. If a full product
2360(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2361should be sign-extended or zero-extended as appropriate to the
2362width of the full product.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2363<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2364<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]2365</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2366</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2367
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2368<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2369<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2370</a></div>
2371<div class="doc_text">
2372<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2373<pre> &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2374</pre>
2375<h5>Overview:</h5>
2376<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2377operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2378
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2379<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2380
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2381<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2382<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2383values. Both arguments must have identical types.</p>
2384
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2385<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2386
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2387<p>The value produced is the unsigned integer quotient of the two operands.</p>
2388<p>Note that unsigned integer division and signed integer division are distinct
2389operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2390<p>Division by zero leads to undefined behavior.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2391<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2392<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]2393</pre>
2394</div>
2395<!-- _______________________________________________________________________ -->
2396<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2397</a> </div>
2398<div class="doc_text">
2399<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2400<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2401 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2402</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2403
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2404<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2405
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2406<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2407operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2408
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2409<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2410
2411<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2412<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2413values. Both arguments must have identical types.</p>
2414
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2415<h5>Semantics:</h5>
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2416<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]2417<p>Note that signed integer division and unsigned integer division are distinct
2418operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2419<p>Division by zero leads to undefined behavior. Overflow also leads to
2420undefined behavior; this is a rare case, but can occur, for example,
2421by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2422<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2423<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]2424</pre>
2425</div>
2426<!-- _______________________________________________________________________ -->
2427<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2428Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2429<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2430<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2431<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2432 &lt;result&gt; = fdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2433</pre>
2434<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2435
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2436<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2437operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2438
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2439<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2440
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2441<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2442<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2443of floating point values. Both arguments must have identical types.</p>
2444
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2445<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2446
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2447<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2448
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2449<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2450
2451<pre>
2452 &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]2453</pre>
2454</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2455
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2456<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2457<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2458</div>
2459<div class="doc_text">
2460<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2461<pre> &lt;result&gt; = urem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2462</pre>
2463<h5>Overview:</h5>
2464<p>The '<tt>urem</tt>' instruction returns the remainder from the
2465unsigned division of its two arguments.</p>
2466<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2467<p>The two arguments to the '<tt>urem</tt>' instruction must be
2468<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2469values. Both arguments must have identical types.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2470<h5>Semantics:</h5>
2471<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2472This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2473<p>Note that unsigned integer remainder and signed integer remainder are
2474distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2475<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2476<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2477<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]2478</pre>
2479
2480</div>
2481<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2482<div class="doc_subsubsection">
2483 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2484</div>
2485
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2486<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2487
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2488<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2489
2490<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2491 &lt;result&gt; = srem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2492</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2493
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2494<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2495
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2496<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame]2497signed division of its two operands. This instruction can also take
2498<a href="#t_vector">vector</a> versions of the values in which case
2499the elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]2500
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2501<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2502
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2503<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2504<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2505values. Both arguments must have identical types.</p>
2506
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2507<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2508
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2509<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2510has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2511operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2512a value. For more information about the difference, see <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2513 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2514Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencerdb3b93b2007-03-24 22:40:44 +0000[diff] [blame]2515please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2516Wikipedia: modulo operation</a>.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2517<p>Note that signed integer remainder and unsigned integer remainder are
2518distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2519<p>Taking the remainder of a division by zero leads to undefined behavior.
2520Overflow also leads to undefined behavior; this is a rare case, but can occur,
2521for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2522(The remainder doesn't actually overflow, but this rule lets srem be
2523implemented using instructions that return both the result of the division
2524and the remainder.)</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2525<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2526<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]2527</pre>
2528
2529</div>
2530<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2531<div class="doc_subsubsection">
2532 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2533
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2534<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2535
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2536<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2537<pre> &lt;result&gt; = frem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2538</pre>
2539<h5>Overview:</h5>
2540<p>The '<tt>frem</tt>' instruction returns the remainder from the
2541division of its two operands.</p>
2542<h5>Arguments:</h5>
2543<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2544<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2545of floating point values. Both arguments must have identical types.</p>
2546
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2547<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2548
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2549<p>This instruction returns the <i>remainder</i> of a division.
2550The remainder has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2551
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2552<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2553
2554<pre>
2555 &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]2556</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2557</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]2558
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2559<!-- ======================================================================= -->
2560<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2561Operations</a> </div>
2562<div class="doc_text">
2563<p>Bitwise binary operators are used to do various forms of
2564bit-twiddling in a program. They are generally very efficient
2565instructions and can commonly be strength reduced from other
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2566instructions. They require two operands of the same type, execute an operation on them,
2567and 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]2568</div>
2569
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2570<!-- _______________________________________________________________________ -->
2571<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2572Instruction</a> </div>
2573<div class="doc_text">
2574<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2575<pre> &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2576</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2577
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2578<h5>Overview:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2579
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2580<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2581the left a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2582
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2583<h5>Arguments:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2584
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2585<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2586 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2587type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2588
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2589<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2590
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2591<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2592where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
Mon P Wang68d4eee2008-12-10 08:55:09 +0000[diff] [blame]2593equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
2594If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2595corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2596
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2597<h5>Example:</h5><pre>
2598 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2599 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2600 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2601 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]2602 &lt;result&gt; = shl &lt;2 x i32&gt; &lt; i32 1, i32 1&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 2, i32 4&gt;</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2603</pre>
2604</div>
2605<!-- _______________________________________________________________________ -->
2606<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2607Instruction</a> </div>
2608<div class="doc_text">
2609<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2610<pre> &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2611</pre>
2612
2613<h5>Overview:</h5>
2614<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2615operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2616
2617<h5>Arguments:</h5>
2618<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2619<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2620type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2621
2622<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2623
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2624<p>This instruction always performs a logical shift right operation. The most
2625significant bits of the result will be filled with zero bits after the
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2626shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang68d4eee2008-12-10 08:55:09 +0000[diff] [blame]2627the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
2628vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
2629amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2630
2631<h5>Example:</h5>
2632<pre>
2633 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2634 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2635 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2636 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2637 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]2638 &lt;result&gt; = lshr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0x7FFFFFFF, i32 1&gt;</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2639</pre>
2640</div>
2641
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2642<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2643<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2644Instruction</a> </div>
2645<div class="doc_text">
2646
2647<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2648<pre> &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2649</pre>
2650
2651<h5>Overview:</h5>
2652<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2653operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2654
2655<h5>Arguments:</h5>
2656<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2657<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2658type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2659
2660<h5>Semantics:</h5>
2661<p>This instruction always performs an arithmetic shift right operation,
2662The most significant bits of the result will be filled with the sign bit
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2663of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
Mon P Wang68d4eee2008-12-10 08:55:09 +0000[diff] [blame]2664larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
2665arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2666corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2667
2668<h5>Example:</h5>
2669<pre>
2670 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2671 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2672 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2673 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2674 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]2675 &lt;result&gt; = ashr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 3&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 -1, i32 0&gt;</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2676</pre>
2677</div>
2678
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2679<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2680<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2681Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2682
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2683<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2684
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2685<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2686
2687<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2688 &lt;result&gt; = and &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2689</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2690
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2691<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2692
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2693<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2694its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2695
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2696<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2697
2698<p>The two arguments to the '<tt>and</tt>' instruction must be
2699<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2700values. Both arguments must have identical types.</p>
2701
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2702<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2703<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2704<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2705<div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2706<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2707 <tbody>
2708 <tr>
2709 <td>In0</td>
2710 <td>In1</td>
2711 <td>Out</td>
2712 </tr>
2713 <tr>
2714 <td>0</td>
2715 <td>0</td>
2716 <td>0</td>
2717 </tr>
2718 <tr>
2719 <td>0</td>
2720 <td>1</td>
2721 <td>0</td>
2722 </tr>
2723 <tr>
2724 <td>1</td>
2725 <td>0</td>
2726 <td>0</td>
2727 </tr>
2728 <tr>
2729 <td>1</td>
2730 <td>1</td>
2731 <td>1</td>
2732 </tr>
2733 </tbody>
2734</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2735</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2736<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2737<pre>
2738 &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]2739 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2740 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2741</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2742</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2743<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2744<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2745<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2746<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2747<pre> &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2748</pre>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2749<h5>Overview:</h5>
2750<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2751or of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2752<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2753
2754<p>The two arguments to the '<tt>or</tt>' instruction must be
2755<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2756values. Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2757<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2758<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2759<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2760<div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2761<table border="1" cellspacing="0" cellpadding="4">
2762 <tbody>
2763 <tr>
2764 <td>In0</td>
2765 <td>In1</td>
2766 <td>Out</td>
2767 </tr>
2768 <tr>
2769 <td>0</td>
2770 <td>0</td>
2771 <td>0</td>
2772 </tr>
2773 <tr>
2774 <td>0</td>
2775 <td>1</td>
2776 <td>1</td>
2777 </tr>
2778 <tr>
2779 <td>1</td>
2780 <td>0</td>
2781 <td>1</td>
2782 </tr>
2783 <tr>
2784 <td>1</td>
2785 <td>1</td>
2786 <td>1</td>
2787 </tr>
2788 </tbody>
2789</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2790</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2791<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2792<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2793 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2794 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2795</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2796</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2797<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2798<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2799Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2800<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2801<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2802<pre> &lt;result&gt; = xor &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2803</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2804<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2805<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2806or of its two operands. The <tt>xor</tt> is used to implement the
2807"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2808<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2809<p>The two arguments to the '<tt>xor</tt>' instruction must be
2810<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2811values. Both arguments must have identical types.</p>
2812
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2813<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2814
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2815<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2816<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2817<div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2818<table border="1" cellspacing="0" cellpadding="4">
2819 <tbody>
2820 <tr>
2821 <td>In0</td>
2822 <td>In1</td>
2823 <td>Out</td>
2824 </tr>
2825 <tr>
2826 <td>0</td>
2827 <td>0</td>
2828 <td>0</td>
2829 </tr>
2830 <tr>
2831 <td>0</td>
2832 <td>1</td>
2833 <td>1</td>
2834 </tr>
2835 <tr>
2836 <td>1</td>
2837 <td>0</td>
2838 <td>1</td>
2839 </tr>
2840 <tr>
2841 <td>1</td>
2842 <td>1</td>
2843 <td>0</td>
2844 </tr>
2845 </tbody>
2846</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2847</div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2848<p> </p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2849<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2850<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2851 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2852 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2853 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2854</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2855</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2856
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2857<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2858<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2859 <a name="vectorops">Vector Operations</a>
2860</div>
2861
2862<div class="doc_text">
2863
2864<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2865target-independent manner. These instructions cover the element-access and
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2866vector-specific operations needed to process vectors effectively. While LLVM
2867does directly support these vector operations, many sophisticated algorithms
2868will want to use target-specific intrinsics to take full advantage of a specific
2869target.</p>
2870
2871</div>
2872
2873<!-- _______________________________________________________________________ -->
2874<div class="doc_subsubsection">
2875 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2876</div>
2877
2878<div class="doc_text">
2879
2880<h5>Syntax:</h5>
2881
2882<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2883 &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]2884</pre>
2885
2886<h5>Overview:</h5>
2887
2888<p>
2889The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2890element from a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2891</p>
2892
2893
2894<h5>Arguments:</h5>
2895
2896<p>
2897The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2898value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2899an index indicating the position from which to extract the element.
2900The index may be a variable.</p>
2901
2902<h5>Semantics:</h5>
2903
2904<p>
2905The result is a scalar of the same type as the element type of
2906<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2907<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2908results are undefined.
2909</p>
2910
2911<h5>Example:</h5>
2912
2913<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2914 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2915</pre>
2916</div>
2917
2918
2919<!-- _______________________________________________________________________ -->
2920<div class="doc_subsubsection">
2921 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2922</div>
2923
2924<div class="doc_text">
2925
2926<h5>Syntax:</h5>
2927
2928<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]2929 &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]2930</pre>
2931
2932<h5>Overview:</h5>
2933
2934<p>
2935The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2936element into a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2937</p>
2938
2939
2940<h5>Arguments:</h5>
2941
2942<p>
2943The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2944value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2945scalar value whose type must equal the element type of the first
2946operand. The third operand is an index indicating the position at
2947which to insert the value. The index may be a variable.</p>
2948
2949<h5>Semantics:</h5>
2950
2951<p>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2952The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2953element values are those of <tt>val</tt> except at position
2954<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2955exceeds the length of <tt>val</tt>, the results are undefined.
2956</p>
2957
2958<h5>Example:</h5>
2959
2960<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2961 %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]2962</pre>
2963</div>
2964
2965<!-- _______________________________________________________________________ -->
2966<div class="doc_subsubsection">
2967 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2968</div>
2969
2970<div class="doc_text">
2971
2972<h5>Syntax:</h5>
2973
2974<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]2975 &lt;result&gt; = shufflevector &lt;n x &lt;ty&gt;&gt; &lt;v1&gt;, &lt;n x &lt;ty&gt;&gt; &lt;v2&gt;, &lt;m x i32&gt; &lt;mask&gt; <i>; yields &lt;m x &lt;ty&gt;&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2976</pre>
2977
2978<h5>Overview:</h5>
2979
2980<p>
2981The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]2982from two input vectors, returning a vector with the same element type as
2983the input and length that is the same as the shuffle mask.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2984</p>
2985
2986<h5>Arguments:</h5>
2987
2988<p>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]2989The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2990with types that match each other. The third argument is a shuffle mask whose
2991element type is always 'i32'. The result of the instruction is a vector whose
2992length is the same as the shuffle mask and whose element type is the same as
2993the element type of the first two operands.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2994</p>
2995
2996<p>
2997The shuffle mask operand is required to be a constant vector with either
2998constant integer or undef values.
2999</p>
3000
3001<h5>Semantics:</h5>
3002
3003<p>
3004The elements of the two input vectors are numbered from left to right across
3005both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3006the result vector, which element of the two input vectors the result element
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3007gets. The element selector may be undef (meaning "don't care") and the second
3008operand may be undef if performing a shuffle from only one vector.
3009</p>
3010
3011<h5>Example:</h5>
3012
3013<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3014 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3015 &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]3016 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3017 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i> - Identity shuffle.
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3018 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3019 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3020 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3021 &lt;8 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 &gt; <i>; yields &lt;8 x i32&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3022</pre>
3023</div>
3024
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]3025
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3026<!-- ======================================================================= -->
3027<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3028 <a name="aggregateops">Aggregate Operations</a>
3029</div>
3030
3031<div class="doc_text">
3032
3033<p>LLVM supports several instructions for working with aggregate values.
3034</p>
3035
3036</div>
3037
3038<!-- _______________________________________________________________________ -->
3039<div class="doc_subsubsection">
3040 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3041</div>
3042
3043<div class="doc_text">
3044
3045<h5>Syntax:</h5>
3046
3047<pre>
3048 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3049</pre>
3050
3051<h5>Overview:</h5>
3052
3053<p>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3054The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3055or array element from an aggregate value.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3056</p>
3057
3058
3059<h5>Arguments:</h5>
3060
3061<p>
3062The first operand of an '<tt>extractvalue</tt>' instruction is a
3063value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3064type. The operands are constant indices to specify which value to extract
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3065in a similar manner as indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3066'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3067</p>
3068
3069<h5>Semantics:</h5>
3070
3071<p>
3072The result is the value at the position in the aggregate specified by
3073the index operands.
3074</p>
3075
3076<h5>Example:</h5>
3077
3078<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3079 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3080</pre>
3081</div>
3082
3083
3084<!-- _______________________________________________________________________ -->
3085<div class="doc_subsubsection">
3086 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3087</div>
3088
3089<div class="doc_text">
3090
3091<h5>Syntax:</h5>
3092
3093<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3094 &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]3095</pre>
3096
3097<h5>Overview:</h5>
3098
3099<p>
3100The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3101into a struct field or array element in an aggregate.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3102</p>
3103
3104
3105<h5>Arguments:</h5>
3106
3107<p>
3108The first operand of an '<tt>insertvalue</tt>' instruction is a
3109value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3110The second operand is a first-class value to insert.
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]3111The following operands are constant indices
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3112indicating the position at which to insert the value in a similar manner as
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3113indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3114'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3115The value to insert must have the same type as the value identified
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3116by the indices.
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3117</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3118
3119<h5>Semantics:</h5>
3120
3121<p>
3122The result is an aggregate of the same type as <tt>val</tt>. Its
3123value is that of <tt>val</tt> except that the value at the position
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3124specified by the indices is that of <tt>elt</tt>.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3125</p>
3126
3127<h5>Example:</h5>
3128
3129<pre>
Dan Gohman88ce1a52008-06-23 15:26:37 +0000[diff] [blame]3130 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3131</pre>
3132</div>
3133
3134
3135<!-- ======================================================================= -->
3136<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3137 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3138</div>
3139
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3140<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3141
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3142<p>A key design point of an SSA-based representation is how it
3143represents memory. In LLVM, no memory locations are in SSA form, which
3144makes things very simple. This section describes how to read, write,
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3145allocate, and free memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3146
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3147</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3148
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3149<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3150<div class="doc_subsubsection">
3151 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3152</div>
3153
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3154<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3155
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3156<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3157
3158<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3159 &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]3160</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3161
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3162<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3163
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3164<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3165heap and returns a pointer to it. The object is always allocated in the generic
3166address space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3167
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3168<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3169
3170<p>The '<tt>malloc</tt>' instruction allocates
3171<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswella92e5862004-02-24 16:13:56 +0000[diff] [blame]3172bytes of memory from the operating system and returns a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3173appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3174number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3175If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3176be aligned to at least that boundary. If not specified, or if zero, the target can
3177choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3178
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3179<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3180
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3181<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3182
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3183<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewyckyf5ffcbc2008-11-24 03:41:24 +0000[diff] [blame]3184a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3185result is null if there is insufficient memory available.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3186
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3187<h5>Example:</h5>
3188
3189<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3190 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3191
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3192 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3193 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3194 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3195 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3196 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3197</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3198</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3199
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3200<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3201<div class="doc_subsubsection">
3202 <a name="i_free">'<tt>free</tt>' Instruction</a>
3203</div>
3204
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3205<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3206
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3207<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3208
3209<pre>
3210 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3211</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3212
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3213<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3214
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3215<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3216memory heap to be reallocated in the future.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3217
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3218<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3219
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3220<p>'<tt>value</tt>' shall be a pointer value that points to a value
3221that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3222instruction.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3223
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3224<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3225
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3226<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner0f103e12008-04-19 22:41:32 +0000[diff] [blame]3227after this instruction executes. If the pointer is null, the operation
3228is a noop.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3229
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3230<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3231
3232<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3233 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
3234 free [4 x i8]* %array
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3235</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3236</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3237
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3238<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3239<div class="doc_subsubsection">
3240 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3241</div>
3242
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3243<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3244
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3245<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3246
3247<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3248 &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]3249</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3250
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3251<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3252
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3253<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3254currently executing function, to be automatically released when this function
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3255returns to its caller. The object is always allocated in the generic address
3256space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3257
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3258<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3259
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3260<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3261bytes of memory on the runtime stack, returning a pointer of the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3262appropriate type to the program. If "NumElements" is specified, it is the
3263number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3264If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3265to be aligned to at least that boundary. If not specified, or if zero, the target
3266can choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3267
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3268<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3269
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3270<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3271
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3272<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3273there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3274memory is automatically released when the function returns. The '<tt>alloca</tt>'
3275instruction is commonly used to represent automatic variables that must
3276have an address available. When the function returns (either with the <tt><a
John Criswellc932bef2005-05-12 16:55:34 +0000[diff] [blame]3277 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]3278instructions), the memory is reclaimed. Allocating zero bytes
3279is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3280
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3281<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3282
3283<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3284 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3285 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3286 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3287 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3288</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3289</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3290
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3291<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3292<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3293Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3294<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3295<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3296<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]3297<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3298<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3299<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3300<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3301address from which to load. The pointer must point to a <a
Chris Lattner10ee9652004-06-03 22:57:15 +0000[diff] [blame]3302 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3303marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3304the number or order of execution of this <tt>load</tt> with other
3305volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3306instructions. </p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3307<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3308The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3309(that is, the alignment of the memory address). A value of 0 or an
3310omitted "align" argument means that the operation has the preferential
3311alignment for the target. It is the responsibility of the code emitter
3312to ensure that the alignment information is correct. Overestimating
3313the alignment results in an undefined behavior. Underestimating the
3314alignment may produce less efficient code. An alignment of 1 is always
3315safe.
3316</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3317<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3318<p>The location of memory pointed to is loaded.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3319<h5>Examples:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3320<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3321 <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3322 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3323 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3324</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3325</div>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3326<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3327<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3328Instruction</a> </div>
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]3329<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3330<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3331<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3332 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]3333</pre>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3334<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3335<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3336<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3337<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3338to 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]3339operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3340of the '<tt>&lt;value&gt;</tt>'
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3341operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3342optimizer is not allowed to modify the number or order of execution of
3343this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3344 href="#i_store">store</a></tt> instructions.</p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3345<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3346The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3347(that is, the alignment of the memory address). A value of 0 or an
3348omitted "align" argument means that the operation has the preferential
3349alignment for the target. It is the responsibility of the code emitter
3350to ensure that the alignment information is correct. Overestimating
3351the alignment results in an undefined behavior. Underestimating the
3352alignment may produce less efficient code. An alignment of 1 is always
3353safe.
3354</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3355<h5>Semantics:</h5>
3356<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3357at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3358<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3359<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]3360 store i32 3, i32* %ptr <i>; yields {void}</i>
3361 %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]3362</pre>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3363</div>
3364
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3365<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3366<div class="doc_subsubsection">
3367 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3368</div>
3369
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3370<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3371<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3372<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3373 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3374</pre>
3375
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3376<h5>Overview:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3377
3378<p>
3379The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3380subelement of an aggregate data structure. It performs address calculation only
3381and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3382
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3383<h5>Arguments:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3384
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3385<p>The first argument is always a pointer, and forms the basis of the
3386calculation. The remaining arguments are indices, that indicate which of the
3387elements of the aggregate object are indexed. The interpretation of each index
3388is dependent on the type being indexed into. The first index always indexes the
3389pointer value given as the first argument, the second index indexes a value of
3390the type pointed to (not necessarily the value directly pointed to, since the
3391first index can be non-zero), etc. The first type indexed into must be a pointer
3392value, subsequent types can be arrays, vectors and structs. Note that subsequent
3393types being indexed into can never be pointers, since that would require loading
3394the pointer before continuing calculation.</p>
3395
3396<p>The type of each index argument depends on the type it is indexing into.
3397When indexing into a (packed) structure, only <tt>i32</tt> integer
3398<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3399only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3400will be sign extended to 64-bits if required.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3401
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3402<p>For example, let's consider a C code fragment and how it gets
3403compiled to LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3404
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3405<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3406<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3407struct RT {
3408 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3409 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3410 char C;
3411};
3412struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3413 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3414 double Y;
3415 struct RT Z;
3416};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3417
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3418int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3419 return &amp;s[1].Z.B[5][13];
3420}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3421</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3422</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3423
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3424<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3425
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3426<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3427<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3428%RT = type { i8 , [10 x [20 x i32]], i8 }
3429%ST = type { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3430
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3431define i32* %foo(%ST* %s) {
3432entry:
3433 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3434 ret i32* %reg
3435}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3436</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3437</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3438
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3439<h5>Semantics:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3440
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3441<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]3442type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3443}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3444the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3445i8 }</tt>' type, another structure. The third index indexes into the second
3446element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3447array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3448'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3449to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3450
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3451<p>Note that it is perfectly legal to index partially through a
3452structure, returning a pointer to an inner element. Because of this,
3453the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3454
3455<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3456 define i32* %foo(%ST* %s) {
3457 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3458 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3459 %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]3460 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3461 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3462 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3463 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3464</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3465
3466<p>Note that it is undefined to access an array out of bounds: array and
3467pointer indexes must always be within the defined bounds of the array type.
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]3468The one exception for this rule is zero length arrays. These arrays are
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3469defined to be accessible as variable length arrays, which requires access
3470beyond the zero'th element.</p>
3471
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3472<p>The getelementptr instruction is often confusing. For some more insight
3473into how it works, see <a href="GetElementPtr.html">the getelementptr
3474FAQ</a>.</p>
3475
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3476<h5>Example:</h5>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3477
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3478<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3479 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3480 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3481 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3482 %vptr = getelementptr {i32, &lt;2 x i8&gt;}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3483 <i>; yields i8*:eptr</i>
3484 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3485</pre>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3486</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3487
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3488<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3489<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3490</div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3491<div class="doc_text">
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3492<p>The instructions in this category are the conversion instructions (casting)
3493which all take a single operand and a type. They perform various bit conversions
3494on the operand.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3495</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3496
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3497<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3498<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3499 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3500</div>
3501<div class="doc_text">
3502
3503<h5>Syntax:</h5>
3504<pre>
3505 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3506</pre>
3507
3508<h5>Overview:</h5>
3509<p>
3510The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3511</p>
3512
3513<h5>Arguments:</h5>
3514<p>
3515The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3516be 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]3517and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3518type. The bit size of <tt>value</tt> must be larger than the bit size of
3519<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3520
3521<h5>Semantics:</h5>
3522<p>
3523The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3524and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3525larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3526It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3527
3528<h5>Example:</h5>
3529<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3530 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3531 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3532 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3533</pre>
3534</div>
3535
3536<!-- _______________________________________________________________________ -->
3537<div class="doc_subsubsection">
3538 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3539</div>
3540<div class="doc_text">
3541
3542<h5>Syntax:</h5>
3543<pre>
3544 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3545</pre>
3546
3547<h5>Overview:</h5>
3548<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3549<tt>ty2</tt>.</p>
3550
3551
3552<h5>Arguments:</h5>
3553<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]3554<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3555also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3556<tt>value</tt> must be smaller than the bit size of the destination type,
3557<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3558
3559<h5>Semantics:</h5>
3560<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]3561bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3562
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]3563<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]3564
3565<h5>Example:</h5>
3566<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3567 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3568 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3569</pre>
3570</div>
3571
3572<!-- _______________________________________________________________________ -->
3573<div class="doc_subsubsection">
3574 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3575</div>
3576<div class="doc_text">
3577
3578<h5>Syntax:</h5>
3579<pre>
3580 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3581</pre>
3582
3583<h5>Overview:</h5>
3584<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3585
3586<h5>Arguments:</h5>
3587<p>
3588The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3589<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3590also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3591<tt>value</tt> must be smaller than the bit size of the destination type,
3592<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3593
3594<h5>Semantics:</h5>
3595<p>
3596The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3597bit (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]3598the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3599
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3600<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]3601
3602<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3603<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3604 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3605 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3606</pre>
3607</div>
3608
3609<!-- _______________________________________________________________________ -->
3610<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3611 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3612</div>
3613
3614<div class="doc_text">
3615
3616<h5>Syntax:</h5>
3617
3618<pre>
3619 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3620</pre>
3621
3622<h5>Overview:</h5>
3623<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3624<tt>ty2</tt>.</p>
3625
3626
3627<h5>Arguments:</h5>
3628<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3629 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3630cast it to. The size of <tt>value</tt> must be larger than the size of
3631<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3632<i>no-op cast</i>.</p>
3633
3634<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3635<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3636<a href="#t_floating">floating point</a> type to a smaller
3637<a href="#t_floating">floating point</a> type. If the value cannot fit within
3638the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3639
3640<h5>Example:</h5>
3641<pre>
3642 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3643 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3644</pre>
3645</div>
3646
3647<!-- _______________________________________________________________________ -->
3648<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3649 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3650</div>
3651<div class="doc_text">
3652
3653<h5>Syntax:</h5>
3654<pre>
3655 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3656</pre>
3657
3658<h5>Overview:</h5>
3659<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3660floating point value.</p>
3661
3662<h5>Arguments:</h5>
3663<p>The '<tt>fpext</tt>' instruction takes a
3664<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3665and a <a href="#t_floating">floating point</a> type to cast it to. The source
3666type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3667
3668<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3669<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3670<a href="#t_floating">floating point</a> type to a larger
3671<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3672used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3673<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]3674
3675<h5>Example:</h5>
3676<pre>
3677 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3678 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3679</pre>
3680</div>
3681
3682<!-- _______________________________________________________________________ -->
3683<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]3684 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3685</div>
3686<div class="doc_text">
3687
3688<h5>Syntax:</h5>
3689<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3690 &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]3691</pre>
3692
3693<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3694<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3695unsigned integer equivalent of type <tt>ty2</tt>.
3696</p>
3697
3698<h5>Arguments:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3699<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]3700scalar or vector <a href="#t_floating">floating point</a> value, and a type
3701to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3702type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3703vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3704
3705<h5>Semantics:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3706<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3707<a href="#t_floating">floating point</a> operand into the nearest (rounding
3708towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3709the results are undefined.</p>
3710
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3711<h5>Example:</h5>
3712<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3713 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3714 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3715 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3716</pre>
3717</div>
3718
3719<!-- _______________________________________________________________________ -->
3720<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3721 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3722</div>
3723<div class="doc_text">
3724
3725<h5>Syntax:</h5>
3726<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3727 &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]3728</pre>
3729
3730<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3731<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3732<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]3733</p>
3734
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3735<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3736<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]3737scalar or vector <a href="#t_floating">floating point</a> value, and a type
3738to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3739type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3740vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3741
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3742<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3743<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3744<a href="#t_floating">floating point</a> operand into the nearest (rounding
3745towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3746the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3747
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3748<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3749<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3750 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3751 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3752 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3753</pre>
3754</div>
3755
3756<!-- _______________________________________________________________________ -->
3757<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3758 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3759</div>
3760<div class="doc_text">
3761
3762<h5>Syntax:</h5>
3763<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3764 &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]3765</pre>
3766
3767<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3768<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3769integer and converts that value to the <tt>ty2</tt> type.</p>
3770
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3771<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3772<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3773scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3774to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3775type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3776floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3777
3778<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3779<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3780integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3781the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3782
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3783<h5>Example:</h5>
3784<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3785 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3786 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3787</pre>
3788</div>
3789
3790<!-- _______________________________________________________________________ -->
3791<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3792 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3793</div>
3794<div class="doc_text">
3795
3796<h5>Syntax:</h5>
3797<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3798 &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]3799</pre>
3800
3801<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3802<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3803integer and converts that value to the <tt>ty2</tt> type.</p>
3804
3805<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3806<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3807scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3808to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3809type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3810floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3811
3812<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3813<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3814integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3815the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3816
3817<h5>Example:</h5>
3818<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3819 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3820 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3821</pre>
3822</div>
3823
3824<!-- _______________________________________________________________________ -->
3825<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3826 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3827</div>
3828<div class="doc_text">
3829
3830<h5>Syntax:</h5>
3831<pre>
3832 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3833</pre>
3834
3835<h5>Overview:</h5>
3836<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3837the integer type <tt>ty2</tt>.</p>
3838
3839<h5>Arguments:</h5>
3840<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3841must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3842<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3843
3844<h5>Semantics:</h5>
3845<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3846<tt>ty2</tt> by interpreting the pointer value as an integer and either
3847truncating or zero extending that value to the size of the integer type. If
3848<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3849<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]3850are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3851change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3852
3853<h5>Example:</h5>
3854<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3855 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3856 %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]3857</pre>
3858</div>
3859
3860<!-- _______________________________________________________________________ -->
3861<div class="doc_subsubsection">
3862 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3863</div>
3864<div class="doc_text">
3865
3866<h5>Syntax:</h5>
3867<pre>
3868 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3869</pre>
3870
3871<h5>Overview:</h5>
3872<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3873a pointer type, <tt>ty2</tt>.</p>
3874
3875<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3876<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3877value to cast, and a type to cast it to, which must be a
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3878<a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3879
3880<h5>Semantics:</h5>
3881<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3882<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3883the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3884size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3885the size of a pointer then a zero extension is done. If they are the same size,
3886nothing is done (<i>no-op cast</i>).</p>
3887
3888<h5>Example:</h5>
3889<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3890 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3891 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3892 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3893</pre>
3894</div>
3895
3896<!-- _______________________________________________________________________ -->
3897<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3898 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3899</div>
3900<div class="doc_text">
3901
3902<h5>Syntax:</h5>
3903<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3904 &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]3905</pre>
3906
3907<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3908
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3909<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3910<tt>ty2</tt> without changing any bits.</p>
3911
3912<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3913
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3914<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohmanc05dca92008-09-08 16:45:59 +0000[diff] [blame]3915a non-aggregate first class value, and a type to cast it to, which must also be
3916a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
3917<tt>value</tt>
Reid Spencere3db84c2007-01-09 20:08:58 +0000[diff] [blame]3918and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3919type is a pointer, the destination type must also be a pointer. This
3920instruction supports bitwise conversion of vectors to integers and to vectors
3921of other types (as long as they have the same size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3922
3923<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3924<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3925<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3926this conversion. The conversion is done as if the <tt>value</tt> had been
3927stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3928converted to other pointer types with this instruction. To convert pointers to
3929other types, use the <a href="#i_inttoptr">inttoptr</a> or
3930<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3931
3932<h5>Example:</h5>
3933<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3934 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3935 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3936 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3937</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3938</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3939
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3940<!-- ======================================================================= -->
3941<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3942<div class="doc_text">
3943<p>The instructions in this category are the "miscellaneous"
3944instructions, which defy better classification.</p>
3945</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3946
3947<!-- _______________________________________________________________________ -->
3948<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3949</div>
3950<div class="doc_text">
3951<h5>Syntax:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3952<pre> &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3953</pre>
3954<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3955<p>The '<tt>icmp</tt>' instruction returns a boolean value or
3956a vector of boolean values based on comparison
3957of its two integer, integer vector, or pointer operands.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3958<h5>Arguments:</h5>
3959<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3960the condition code indicating the kind of comparison to perform. It is not
3961a value, just a keyword. The possible condition code are:
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3962</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3963<ol>
3964 <li><tt>eq</tt>: equal</li>
3965 <li><tt>ne</tt>: not equal </li>
3966 <li><tt>ugt</tt>: unsigned greater than</li>
3967 <li><tt>uge</tt>: unsigned greater or equal</li>
3968 <li><tt>ult</tt>: unsigned less than</li>
3969 <li><tt>ule</tt>: unsigned less or equal</li>
3970 <li><tt>sgt</tt>: signed greater than</li>
3971 <li><tt>sge</tt>: signed greater or equal</li>
3972 <li><tt>slt</tt>: signed less than</li>
3973 <li><tt>sle</tt>: signed less or equal</li>
3974</ol>
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3975<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3976<a href="#t_pointer">pointer</a>
3977or integer <a href="#t_vector">vector</a> typed.
3978They must also be identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3979<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3980<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3981the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3982yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3983</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3984<ol>
3985 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3986 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3987 </li>
3988 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3989 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3990 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3991 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3992 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3993 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3994 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3995 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3996 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3997 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3998 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3999 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4000 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4001 <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4002 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4003 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4004 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4005 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4006</ol>
4007<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4008values are compared as if they were integers.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4009<p>If the operands are integer vectors, then they are compared
4010element by element. The result is an <tt>i1</tt> vector with
4011the same number of elements as the values being compared.
4012Otherwise, the result is an <tt>i1</tt>.
4013</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4014
4015<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4016<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
4017 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4018 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4019 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4020 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4021 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4022</pre>
4023</div>
4024
4025<!-- _______________________________________________________________________ -->
4026<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4027</div>
4028<div class="doc_text">
4029<h5>Syntax:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4030<pre> &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4031</pre>
4032<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4033<p>The '<tt>fcmp</tt>' instruction returns a boolean value
4034or vector of boolean values based on comparison
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4035of its operands.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4036<p>
4037If the operands are floating point scalars, then the result
4038type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
4039</p>
4040<p>If the operands are floating point vectors, then the result type
4041is a vector of boolean with the same number of elements as the
4042operands being compared.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4043<h5>Arguments:</h5>
4044<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4045the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4046a value, just a keyword. The possible condition code are:</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4047<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4048 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4049 <li><tt>oeq</tt>: ordered and equal</li>
4050 <li><tt>ogt</tt>: ordered and greater than </li>
4051 <li><tt>oge</tt>: ordered and greater than or equal</li>
4052 <li><tt>olt</tt>: ordered and less than </li>
4053 <li><tt>ole</tt>: ordered and less than or equal</li>
4054 <li><tt>one</tt>: ordered and not equal</li>
4055 <li><tt>ord</tt>: ordered (no nans)</li>
4056 <li><tt>ueq</tt>: unordered or equal</li>
4057 <li><tt>ugt</tt>: unordered or greater than </li>
4058 <li><tt>uge</tt>: unordered or greater than or equal</li>
4059 <li><tt>ult</tt>: unordered or less than </li>
4060 <li><tt>ule</tt>: unordered or less than or equal</li>
4061 <li><tt>une</tt>: unordered or not equal</li>
4062 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4063 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4064</ol>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4065<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer02e0d1d2006-12-06 07:08:07 +0000[diff] [blame]4066<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4067<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4068either a <a href="#t_floating">floating point</a> type
4069or a <a href="#t_vector">vector</a> of floating point type.
4070They must have identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4071<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4072<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4073according to the condition code given as <tt>cond</tt>.
4074If the operands are vectors, then the vectors are compared
4075element by element.
4076Each comparison performed
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4077always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4078<ol>
4079 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4080 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4081 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4082 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4083 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4084 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4085 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4086 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4087 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4088 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4089 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4090 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4091 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4092 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4093 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4094 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4095 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4096 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4097 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4098 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4099 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4100 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4101 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4102 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4103 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4104 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4105 <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]4106 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4107</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4108
4109<h5>Example:</h5>
4110<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4111 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4112 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4113 &lt;result&gt; = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4114</pre>
4115</div>
4116
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4117<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4118<div class="doc_subsubsection">
4119 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4120</div>
4121<div class="doc_text">
4122<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4123<pre> &lt;result&gt; = vicmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4124</pre>
4125<h5>Overview:</h5>
4126<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4127element-wise comparison of its two integer vector operands.</p>
4128<h5>Arguments:</h5>
4129<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4130the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4131a value, just a keyword. The possible condition code are:</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4132<ol>
4133 <li><tt>eq</tt>: equal</li>
4134 <li><tt>ne</tt>: not equal </li>
4135 <li><tt>ugt</tt>: unsigned greater than</li>
4136 <li><tt>uge</tt>: unsigned greater or equal</li>
4137 <li><tt>ult</tt>: unsigned less than</li>
4138 <li><tt>ule</tt>: unsigned less or equal</li>
4139 <li><tt>sgt</tt>: signed greater than</li>
4140 <li><tt>sge</tt>: signed greater or equal</li>
4141 <li><tt>slt</tt>: signed less than</li>
4142 <li><tt>sle</tt>: signed less or equal</li>
4143</ol>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4144<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4145<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4146<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4147<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4148according to the condition code given as <tt>cond</tt>. The comparison yields a
4149<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4150identical type as the values being compared. The most significant bit in each
4151element is 1 if the element-wise comparison evaluates to true, and is 0
4152otherwise. All other bits of the result are undefined. The condition codes
4153are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4154instruction</a>.</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4155
4156<h5>Example:</h5>
4157<pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4158 &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>
4159 &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]4160</pre>
4161</div>
4162
4163<!-- _______________________________________________________________________ -->
4164<div class="doc_subsubsection">
4165 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4166</div>
4167<div class="doc_text">
4168<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4169<pre> &lt;result&gt; = vfcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt;</pre>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4170<h5>Overview:</h5>
4171<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4172element-wise comparison of its two floating point vector operands. The output
4173elements have the same width as the input elements.</p>
4174<h5>Arguments:</h5>
4175<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4176the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4177a value, just a keyword. The possible condition code are:</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4178<ol>
4179 <li><tt>false</tt>: no comparison, always returns false</li>
4180 <li><tt>oeq</tt>: ordered and equal</li>
4181 <li><tt>ogt</tt>: ordered and greater than </li>
4182 <li><tt>oge</tt>: ordered and greater than or equal</li>
4183 <li><tt>olt</tt>: ordered and less than </li>
4184 <li><tt>ole</tt>: ordered and less than or equal</li>
4185 <li><tt>one</tt>: ordered and not equal</li>
4186 <li><tt>ord</tt>: ordered (no nans)</li>
4187 <li><tt>ueq</tt>: unordered or equal</li>
4188 <li><tt>ugt</tt>: unordered or greater than </li>
4189 <li><tt>uge</tt>: unordered or greater than or equal</li>
4190 <li><tt>ult</tt>: unordered or less than </li>
4191 <li><tt>ule</tt>: unordered or less than or equal</li>
4192 <li><tt>une</tt>: unordered or not equal</li>
4193 <li><tt>uno</tt>: unordered (either nans)</li>
4194 <li><tt>true</tt>: no comparison, always returns true</li>
4195</ol>
4196<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4197<a href="#t_floating">floating point</a> typed. They must also be identical
4198types.</p>
4199<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4200<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4201according to the condition code given as <tt>cond</tt>. The comparison yields a
4202<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4203an identical number of elements as the values being compared, and each element
4204having identical with to the width of the floating point elements. The most
4205significant bit in each element is 1 if the element-wise comparison evaluates to
4206true, and is 0 otherwise. All other bits of the result are undefined. The
4207condition codes are evaluated identically to the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4208<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4209
4210<h5>Example:</h5>
4211<pre>
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]4212 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4213 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4214
4215 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4216 &lt;result&gt; = vfcmp ult &lt;2 x double&gt; &lt; double 1, double 2 &gt;, &lt; double 2, double 2&gt;
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4217</pre>
4218</div>
4219
4220<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4221<div class="doc_subsubsection">
4222 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4223</div>
4224
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4225<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4226
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4227<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4228
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4229<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4230<h5>Overview:</h5>
4231<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4232the SSA graph representing the function.</p>
4233<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4234
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4235<p>The type of the incoming values is specified with the first type
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4236field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4237as arguments, with one pair for each predecessor basic block of the
4238current block. Only values of <a href="#t_firstclass">first class</a>
4239type may be used as the value arguments to the PHI node. Only labels
4240may be used as the label arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4241
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4242<p>There must be no non-phi instructions between the start of a basic
4243block and the PHI instructions: i.e. PHI instructions must be first in
4244a basic block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4245
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4246<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4247
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4248<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4249specified by the pair corresponding to the predecessor basic block that executed
4250just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4251
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4252<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4253<pre>
4254Loop: ; Infinite loop that counts from 0 on up...
4255 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4256 %nextindvar = add i32 %indvar, 1
4257 br label %Loop
4258</pre>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4259</div>
4260
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4261<!-- _______________________________________________________________________ -->
4262<div class="doc_subsubsection">
4263 <a name="i_select">'<tt>select</tt>' Instruction</a>
4264</div>
4265
4266<div class="doc_text">
4267
4268<h5>Syntax:</h5>
4269
4270<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4271 &lt;result&gt; = select <i>selty</i> &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
4272
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4273 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4274</pre>
4275
4276<h5>Overview:</h5>
4277
4278<p>
4279The '<tt>select</tt>' instruction is used to choose one value based on a
4280condition, without branching.
4281</p>
4282
4283
4284<h5>Arguments:</h5>
4285
4286<p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4287The '<tt>select</tt>' instruction requires an 'i1' value or
4288a vector of 'i1' values indicating the
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4289condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4290type. If the val1/val2 are vectors and
4291the condition is a scalar, then entire vectors are selected, not
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4292individual elements.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4293</p>
4294
4295<h5>Semantics:</h5>
4296
4297<p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4298If the condition is an i1 and it evaluates to 1, the instruction returns the first
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4299value argument; otherwise, it returns the second value argument.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4300</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4301<p>
4302If the condition is a vector of i1, then the value arguments must
4303be vectors of the same size, and the selection is done element
4304by element.
4305</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4306
4307<h5>Example:</h5>
4308
4309<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4310 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4311</pre>
4312</div>
4313
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]4314
4315<!-- _______________________________________________________________________ -->
4316<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4317 <a name="i_call">'<tt>call</tt>' Instruction</a>
4318</div>
4319
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4320<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4321
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4322<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4323<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4324 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4325</pre>
4326
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4327<h5>Overview:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4328
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4329<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4330
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4331<h5>Arguments:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4332
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4333<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4334
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4335<ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4336 <li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4337 <p>The optional "tail" marker indicates whether the callee function accesses
4338 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4339 function call is eligible for tail call optimization. Note that calls may
4340 be marked "tail" even if they do not occur before a <a
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4341 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4342 </li>
4343 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4344 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4345 convention</a> the call should use. If none is specified, the call defaults
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4346 to using C calling conventions.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4347 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4348
4349 <li>
4350 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4351 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4352 and '<tt>inreg</tt>' attributes are valid here.</p>
4353 </li>
4354
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4355 <li>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4356 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4357 the type of the return value. Functions that return no value are marked
4358 <tt><a href="#t_void">void</a></tt>.</p>
4359 </li>
4360 <li>
4361 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4362 value being invoked. The argument types must match the types implied by
4363 this signature. This type can be omitted if the function is not varargs
4364 and if the function type does not return a pointer to a function.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4365 </li>
4366 <li>
4367 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4368 be invoked. In most cases, this is a direct function invocation, but
4369 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4370 to function value.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4371 </li>
4372 <li>
4373 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencerd845d162005-05-01 22:22:57 +0000[diff] [blame]4374 function signature argument types. All arguments must be of
4375 <a href="#t_firstclass">first class</a> type. If the function signature
4376 indicates the function accepts a variable number of arguments, the extra
4377 arguments can be specified.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4378 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4379 <li>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4380 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4381 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4382 '<tt>readnone</tt>' attributes are valid here.</p>
4383 </li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4384</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4385
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4386<h5>Semantics:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4387
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4388<p>The '<tt>call</tt>' instruction is used to cause control flow to
4389transfer to a specified function, with its incoming arguments bound to
4390the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4391instruction in the called function, control flow continues with the
4392instruction after the function call, and the return value of the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4393function is bound to the result argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4394
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4395<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4396
4397<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4398 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]4399 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4400 %X = tail call i32 @foo() <i>; yields i32</i>
4401 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4402 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4403
4404 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4405 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]4406 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4407 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]4408 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]4409 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4410</pre>
4411
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4412</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4413
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4414<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4415<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4416 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4417</div>
4418
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4419<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4420
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4421<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4422
4423<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4424 &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]4425</pre>
4426
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4427<h5>Overview:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4428
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4429<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4430the "variable argument" area of a function call. It is used to implement the
4431<tt>va_arg</tt> macro in C.</p>
4432
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4433<h5>Arguments:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4434
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4435<p>This instruction takes a <tt>va_list*</tt> value and the type of
4436the argument. It returns a value of the specified argument type and
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4437increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4438actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4439
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4440<h5>Semantics:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4441
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4442<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4443type from the specified <tt>va_list</tt> and causes the
4444<tt>va_list</tt> to point to the next argument. For more information,
4445see the variable argument handling <a href="#int_varargs">Intrinsic
4446Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4447
4448<p>It is legal for this instruction to be called in a function which does not
4449take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4450function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4451
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4452<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4453href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4454argument.</p>
4455
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4456<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4457
4458<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4459
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4460</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4461
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4462<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4463<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4464<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4465
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4466<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4467
4468<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4469well known names and semantics and are required to follow certain restrictions.
4470Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4471language that does not require changing all of the transformations in LLVM when
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]4472adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4473
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4474<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4475prefix is reserved in LLVM for intrinsic names; thus, function names may not
4476begin with this prefix. Intrinsic functions must always be external functions:
4477you cannot define the body of intrinsic functions. Intrinsic functions may
4478only be used in call or invoke instructions: it is illegal to take the address
4479of an intrinsic function. Additionally, because intrinsic functions are part
4480of the LLVM language, it is required if any are added that they be documented
4481here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4482
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4483<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4484a family of functions that perform the same operation but on different data
4485types. Because LLVM can represent over 8 million different integer types,
4486overloading is used commonly to allow an intrinsic function to operate on any
4487integer type. One or more of the argument types or the result type can be
4488overloaded to accept any integer type. Argument types may also be defined as
4489exactly matching a previous argument's type or the result type. This allows an
4490intrinsic function which accepts multiple arguments, but needs all of them to
4491be of the same type, to only be overloaded with respect to a single argument or
4492the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4493
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4494<p>Overloaded intrinsics will have the names of its overloaded argument types
4495encoded into its function name, each preceded by a period. Only those types
4496which are overloaded result in a name suffix. Arguments whose type is matched
4497against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4498take an integer of any width and returns an integer of exactly the same integer
4499width. This leads to a family of functions such as
4500<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4501Only one type, the return type, is overloaded, and only one type suffix is
4502required. Because the argument's type is matched against the return type, it
4503does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4504
4505<p>To learn how to add an intrinsic function, please see the
4506<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4507</p>
4508
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4509</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4510
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4511<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4512<div class="doc_subsection">
4513 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4514</div>
4515
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4516<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4517
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4518<p>Variable argument support is defined in LLVM with the <a
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4519 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4520intrinsic functions. These functions are related to the similarly
4521named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4522
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4523<p>All of these functions operate on arguments that use a
4524target-specific value type "<tt>va_list</tt>". The LLVM assembly
4525language reference manual does not define what this type is, so all
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4526transformations should be prepared to handle these functions regardless of
4527the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4528
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]4529<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]4530instruction and the variable argument handling intrinsic functions are
4531used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4532
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4533<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4534<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4535define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4536 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4537 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4538 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4539 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4540
4541 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4542 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4543
4544 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4545 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4546 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4547 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4548 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4549
4550 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4551 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4552 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4553}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4554
4555declare void @llvm.va_start(i8*)
4556declare void @llvm.va_copy(i8*, i8*)
4557declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4558</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4559</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4560
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4561</div>
4562
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4563<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4564<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4565 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4566</div>
4567
4568
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4569<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4570<h5>Syntax:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4571<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4572<h5>Overview:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4573<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4574<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4575href="#i_va_arg">va_arg</a></tt>.</p>
4576
4577<h5>Arguments:</h5>
4578
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4579<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4580
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4581<h5>Semantics:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4582
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4583<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4584macro available in C. In a target-dependent way, it initializes the
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4585<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]4586<tt>va_arg</tt> will produce the first variable argument passed to the function.
4587Unlike 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]4588last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4589
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4590</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4591
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4592<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4593<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4594 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4595</div>
4596
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4597<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4598<h5>Syntax:</h5>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4599<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4600<h5>Overview:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4601
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4602<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4603which 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]4604or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4605
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4606<h5>Arguments:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4607
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4608<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]4609
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4610<h5>Semantics:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4611
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4612<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]4613macro available in C. In a target-dependent way, it destroys the
4614<tt>va_list</tt> element to which the argument points. Calls to <a
4615href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4616<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4617<tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4618
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4619</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4620
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4621<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4622<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4623 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4624</div>
4625
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4626<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4627
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4628<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4629
4630<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4631 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4632</pre>
4633
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4634<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4635
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4636<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4637from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4638
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4639<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4640
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4641<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]4642The 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]4643
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4644
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4645<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4646
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4647<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4648macro available in C. In a target-dependent way, it copies the source
4649<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4650intrinsic is necessary because the <tt><a href="#int_va_start">
4651llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4652example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4653
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4654</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4655
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4656<!-- ======================================================================= -->
4657<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4658 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4659</div>
4660
4661<div class="doc_text">
4662
4663<p>
4664LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]4665Collection</a> (GC) requires the implementation and generation of these
4666intrinsics.
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4667These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4668stack</a>, as well as garbage collector implementations that require <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4669href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4670Front-ends for type-safe garbage collected languages should generate these
4671intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4672href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4673</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]4674
4675<p>The garbage collection intrinsics only operate on objects in the generic
4676 address space (address space zero).</p>
4677
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4678</div>
4679
4680<!-- _______________________________________________________________________ -->
4681<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4682 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4683</div>
4684
4685<div class="doc_text">
4686
4687<h5>Syntax:</h5>
4688
4689<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4690 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4691</pre>
4692
4693<h5>Overview:</h5>
4694
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]4695<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]4696the code generator, and allows some metadata to be associated with it.</p>
4697
4698<h5>Arguments:</h5>
4699
4700<p>The first argument specifies the address of a stack object that contains the
4701root pointer. The second pointer (which must be either a constant or a global
4702value address) contains the meta-data to be associated with the root.</p>
4703
4704<h5>Semantics:</h5>
4705
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]4706<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]4707location. At compile-time, the code generator generates information to allow
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4708the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4709intrinsic may only be used in a function which <a href="#gc">specifies a GC
4710algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4711
4712</div>
4713
4714
4715<!-- _______________________________________________________________________ -->
4716<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4717 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4718</div>
4719
4720<div class="doc_text">
4721
4722<h5>Syntax:</h5>
4723
4724<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4725 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4726</pre>
4727
4728<h5>Overview:</h5>
4729
4730<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4731locations, allowing garbage collector implementations that require read
4732barriers.</p>
4733
4734<h5>Arguments:</h5>
4735
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4736<p>The second argument is the address to read from, which should be an address
4737allocated from the garbage collector. The first object is a pointer to the
4738start of the referenced object, if needed by the language runtime (otherwise
4739null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4740
4741<h5>Semantics:</h5>
4742
4743<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4744instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4745garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4746may only be used in a function which <a href="#gc">specifies a GC
4747algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4748
4749</div>
4750
4751
4752<!-- _______________________________________________________________________ -->
4753<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4754 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4755</div>
4756
4757<div class="doc_text">
4758
4759<h5>Syntax:</h5>
4760
4761<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4762 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4763</pre>
4764
4765<h5>Overview:</h5>
4766
4767<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4768locations, allowing garbage collector implementations that require write
4769barriers (such as generational or reference counting collectors).</p>
4770
4771<h5>Arguments:</h5>
4772
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4773<p>The first argument is the reference to store, the second is the start of the
4774object to store it to, and the third is the address of the field of Obj to
4775store to. If the runtime does not require a pointer to the object, Obj may be
4776null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4777
4778<h5>Semantics:</h5>
4779
4780<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4781instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4782garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4783may only be used in a function which <a href="#gc">specifies a GC
4784algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4785
4786</div>
4787
4788
4789
4790<!-- ======================================================================= -->
4791<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4792 <a name="int_codegen">Code Generator Intrinsics</a>
4793</div>
4794
4795<div class="doc_text">
4796<p>
4797These intrinsics are provided by LLVM to expose special features that may only
4798be implemented with code generator support.
4799</p>
4800
4801</div>
4802
4803<!-- _______________________________________________________________________ -->
4804<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4805 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4806</div>
4807
4808<div class="doc_text">
4809
4810<h5>Syntax:</h5>
4811<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4812 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4813</pre>
4814
4815<h5>Overview:</h5>
4816
4817<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4818The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4819target-specific value indicating the return address of the current function
4820or one of its callers.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4821</p>
4822
4823<h5>Arguments:</h5>
4824
4825<p>
4826The argument to this intrinsic indicates which function to return the address
4827for. Zero indicates the calling function, one indicates its caller, etc. The
4828argument is <b>required</b> to be a constant integer value.
4829</p>
4830
4831<h5>Semantics:</h5>
4832
4833<p>
4834The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4835the return address of the specified call frame, or zero if it cannot be
4836identified. The value returned by this intrinsic is likely to be incorrect or 0
4837for arguments other than zero, so it should only be used for debugging purposes.
4838</p>
4839
4840<p>
4841Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4842aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4843source-language caller.
4844</p>
4845</div>
4846
4847
4848<!-- _______________________________________________________________________ -->
4849<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4850 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4851</div>
4852
4853<div class="doc_text">
4854
4855<h5>Syntax:</h5>
4856<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4857 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4858</pre>
4859
4860<h5>Overview:</h5>
4861
4862<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4863The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4864target-specific frame pointer value for the specified stack frame.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4865</p>
4866
4867<h5>Arguments:</h5>
4868
4869<p>
4870The argument to this intrinsic indicates which function to return the frame
4871pointer for. Zero indicates the calling function, one indicates its caller,
4872etc. The argument is <b>required</b> to be a constant integer value.
4873</p>
4874
4875<h5>Semantics:</h5>
4876
4877<p>
4878The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4879the frame address of the specified call frame, or zero if it cannot be
4880identified. The value returned by this intrinsic is likely to be incorrect or 0
4881for arguments other than zero, so it should only be used for debugging purposes.
4882</p>
4883
4884<p>
4885Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4886aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4887source-language caller.
4888</p>
4889</div>
4890
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4891<!-- _______________________________________________________________________ -->
4892<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4893 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4894</div>
4895
4896<div class="doc_text">
4897
4898<h5>Syntax:</h5>
4899<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4900 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4901</pre>
4902
4903<h5>Overview:</h5>
4904
4905<p>
4906The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4907the function stack, for use with <a href="#int_stackrestore">
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4908<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4909features like scoped automatic variable sized arrays in C99.
4910</p>
4911
4912<h5>Semantics:</h5>
4913
4914<p>
4915This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4916href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4917<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4918<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4919state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4920practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4921that were allocated after the <tt>llvm.stacksave</tt> was executed.
4922</p>
4923
4924</div>
4925
4926<!-- _______________________________________________________________________ -->
4927<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4928 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4929</div>
4930
4931<div class="doc_text">
4932
4933<h5>Syntax:</h5>
4934<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4935 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4936</pre>
4937
4938<h5>Overview:</h5>
4939
4940<p>
4941The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4942the function stack to the state it was in when the corresponding <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4943href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4944useful for implementing language features like scoped automatic variable sized
4945arrays in C99.
4946</p>
4947
4948<h5>Semantics:</h5>
4949
4950<p>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4951See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4952</p>
4953
4954</div>
4955
4956
4957<!-- _______________________________________________________________________ -->
4958<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4959 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4960</div>
4961
4962<div class="doc_text">
4963
4964<h5>Syntax:</h5>
4965<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4966 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]4967</pre>
4968
4969<h5>Overview:</h5>
4970
4971
4972<p>
4973The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4974a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4975no
4976effect on the behavior of the program but can change its performance
Chris Lattnerff851072005-02-28 19:47:14 +0000[diff] [blame]4977characteristics.
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4978</p>
4979
4980<h5>Arguments:</h5>
4981
4982<p>
4983<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4984determining if the fetch should be for a read (0) or write (1), and
4985<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattnerd3e641c2005-03-07 20:31:38 +0000[diff] [blame]4986locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4987<tt>locality</tt> arguments must be constant integers.
4988</p>
4989
4990<h5>Semantics:</h5>
4991
4992<p>
4993This intrinsic does not modify the behavior of the program. In particular,
4994prefetches cannot trap and do not produce a value. On targets that support this
4995intrinsic, the prefetch can provide hints to the processor cache for better
4996performance.
4997</p>
4998
4999</div>
5000
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5001<!-- _______________________________________________________________________ -->
5002<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5003 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5004</div>
5005
5006<div class="doc_text">
5007
5008<h5>Syntax:</h5>
5009<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5010 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5011</pre>
5012
5013<h5>Overview:</h5>
5014
5015
5016<p>
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5017The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5018(PC) in a region of
5019code to simulators and other tools. The method is target specific, but it is
5020expected that the marker will use exported symbols to transmit the PC of the
5021marker.
5022The marker makes no guarantees that it will remain with any specific instruction
5023after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb40261e2006-03-24 07:16:10 +0000[diff] [blame]5024optimizations. The intended use is to be inserted after optimizations to allow
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5025correlations of simulation runs.
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5026</p>
5027
5028<h5>Arguments:</h5>
5029
5030<p>
5031<tt>id</tt> is a numerical id identifying the marker.
5032</p>
5033
5034<h5>Semantics:</h5>
5035
5036<p>
5037This intrinsic does not modify the behavior of the program. Backends that do not
5038support this intrinisic may ignore it.
5039</p>
5040
5041</div>
5042
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5043<!-- _______________________________________________________________________ -->
5044<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5045 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5046</div>
5047
5048<div class="doc_text">
5049
5050<h5>Syntax:</h5>
5051<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5052 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5053</pre>
5054
5055<h5>Overview:</h5>
5056
5057
5058<p>
5059The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5060counter register (or similar low latency, high accuracy clocks) on those targets
5061that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5062As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5063should only be used for small timings.
5064</p>
5065
5066<h5>Semantics:</h5>
5067
5068<p>
5069When directly supported, reading the cycle counter should not modify any memory.
5070Implementations are allowed to either return a application specific value or a
5071system wide value. On backends without support, this is lowered to a constant 0.
5072</p>
5073
5074</div>
5075
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5076<!-- ======================================================================= -->
5077<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5078 <a name="int_libc">Standard C Library Intrinsics</a>
5079</div>
5080
5081<div class="doc_text">
5082<p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5083LLVM provides intrinsics for a few important standard C library functions.
5084These intrinsics allow source-language front-ends to pass information about the
5085alignment of the pointer arguments to the code generator, providing opportunity
5086for more efficient code generation.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5087</p>
5088
5089</div>
5090
5091<!-- _______________________________________________________________________ -->
5092<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5093 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5094</div>
5095
5096<div class="doc_text">
5097
5098<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5099<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
5100width. Not all targets support all bit widths however.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5101<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5102 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5103 i8 &lt;len&gt;, i32 &lt;align&gt;)
5104 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5105 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5106 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5107 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5108 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5109 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5110</pre>
5111
5112<h5>Overview:</h5>
5113
5114<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5115The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5116location to the destination location.
5117</p>
5118
5119<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5120Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5121intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5122</p>
5123
5124<h5>Arguments:</h5>
5125
5126<p>
5127The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5128the source. The third argument is an integer argument
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5129specifying the number of bytes to copy, and the fourth argument is the alignment
5130of the source and destination locations.
5131</p>
5132
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5133<p>
5134If 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]5135the caller guarantees that both the source and destination pointers are aligned
5136to that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5137</p>
5138
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5139<h5>Semantics:</h5>
5140
5141<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5142The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5143location to the destination location, which are not allowed to overlap. It
5144copies "len" bytes of memory over. If the argument is known to be aligned to
5145some boundary, this can be specified as the fourth argument, otherwise it should
5146be set to 0 or 1.
5147</p>
5148</div>
5149
5150
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5151<!-- _______________________________________________________________________ -->
5152<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5153 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5154</div>
5155
5156<div class="doc_text">
5157
5158<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5159<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
5160width. Not all targets support all bit widths however.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5161<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5162 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5163 i8 &lt;len&gt;, i32 &lt;align&gt;)
5164 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5165 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5166 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5167 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5168 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5169 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5170</pre>
5171
5172<h5>Overview:</h5>
5173
5174<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5175The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5176location to the destination location. It is similar to the
Chris Lattnerec564022008-01-06 19:51:52 +0000[diff] [blame]5177'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5178</p>
5179
5180<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5181Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5182intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5183</p>
5184
5185<h5>Arguments:</h5>
5186
5187<p>
5188The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5189the source. The third argument is an integer argument
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5190specifying the number of bytes to copy, and the fourth argument is the alignment
5191of the source and destination locations.
5192</p>
5193
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5194<p>
5195If 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]5196the caller guarantees that the source and destination pointers are aligned to
5197that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5198</p>
5199
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5200<h5>Semantics:</h5>
5201
5202<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5203The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5204location to the destination location, which may overlap. It
5205copies "len" bytes of memory over. If the argument is known to be aligned to
5206some boundary, this can be specified as the fourth argument, otherwise it should
5207be set to 0 or 1.
5208</p>
5209</div>
5210
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5211
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5212<!-- _______________________________________________________________________ -->
5213<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5214 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5215</div>
5216
5217<div class="doc_text">
5218
5219<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5220<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
5221width. Not all targets support all bit widths however.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5222<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5223 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5224 i8 &lt;len&gt;, i32 &lt;align&gt;)
5225 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5226 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5227 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5228 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5229 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5230 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5231</pre>
5232
5233<h5>Overview:</h5>
5234
5235<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5236The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5237byte value.
5238</p>
5239
5240<p>
5241Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5242does not return a value, and takes an extra alignment argument.
5243</p>
5244
5245<h5>Arguments:</h5>
5246
5247<p>
5248The first argument is a pointer to the destination to fill, the second is the
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5249byte value to fill it with, the third argument is an integer
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5250argument specifying the number of bytes to fill, and the fourth argument is the
5251known alignment of destination location.
5252</p>
5253
5254<p>
5255If 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]5256the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5257</p>
5258
5259<h5>Semantics:</h5>
5260
5261<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5262The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5263the
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5264destination location. If the argument is known to be aligned to some boundary,
5265this can be specified as the fourth argument, otherwise it should be set to 0 or
52661.
5267</p>
5268</div>
5269
5270
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5271<!-- _______________________________________________________________________ -->
5272<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5273 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5274</div>
5275
5276<div class="doc_text">
5277
5278<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5279<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]5280floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5281types however.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5282<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5283 declare float @llvm.sqrt.f32(float %Val)
5284 declare double @llvm.sqrt.f64(double %Val)
5285 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5286 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5287 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5288</pre>
5289
5290<h5>Overview:</h5>
5291
5292<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5293The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5294returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5295<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner00d7cb92008-01-29 07:00:44 +0000[diff] [blame]5296negative numbers other than -0.0 (which allows for better optimization, because
5297there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5298defined to return -0.0 like IEEE sqrt.
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5299</p>
5300
5301<h5>Arguments:</h5>
5302
5303<p>
5304The argument and return value are floating point numbers of the same type.
5305</p>
5306
5307<h5>Semantics:</h5>
5308
5309<p>
Dan Gohman33988db2007-07-16 14:37:41 +0000[diff] [blame]5310This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5311floating point number.
5312</p>
5313</div>
5314
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5315<!-- _______________________________________________________________________ -->
5316<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5317 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5318</div>
5319
5320<div class="doc_text">
5321
5322<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5323<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]5324floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5325types however.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5326<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5327 declare float @llvm.powi.f32(float %Val, i32 %power)
5328 declare double @llvm.powi.f64(double %Val, i32 %power)
5329 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5330 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5331 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5332</pre>
5333
5334<h5>Overview:</h5>
5335
5336<p>
5337The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5338specified (positive or negative) power. The order of evaluation of
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5339multiplications is not defined. When a vector of floating point type is
5340used, the second argument remains a scalar integer value.
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5341</p>
5342
5343<h5>Arguments:</h5>
5344
5345<p>
5346The second argument is an integer power, and the first is a value to raise to
5347that power.
5348</p>
5349
5350<h5>Semantics:</h5>
5351
5352<p>
5353This function returns the first value raised to the second power with an
5354unspecified sequence of rounding operations.</p>
5355</div>
5356
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5357<!-- _______________________________________________________________________ -->
5358<div class="doc_subsubsection">
5359 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5360</div>
5361
5362<div class="doc_text">
5363
5364<h5>Syntax:</h5>
5365<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5366floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5367types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5368<pre>
5369 declare float @llvm.sin.f32(float %Val)
5370 declare double @llvm.sin.f64(double %Val)
5371 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5372 declare fp128 @llvm.sin.f128(fp128 %Val)
5373 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5374</pre>
5375
5376<h5>Overview:</h5>
5377
5378<p>
5379The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5380</p>
5381
5382<h5>Arguments:</h5>
5383
5384<p>
5385The argument and return value are floating point numbers of the same type.
5386</p>
5387
5388<h5>Semantics:</h5>
5389
5390<p>
5391This function returns the sine of the specified operand, returning the
5392same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5393conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5394</div>
5395
5396<!-- _______________________________________________________________________ -->
5397<div class="doc_subsubsection">
5398 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5399</div>
5400
5401<div class="doc_text">
5402
5403<h5>Syntax:</h5>
5404<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5405floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5406types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5407<pre>
5408 declare float @llvm.cos.f32(float %Val)
5409 declare double @llvm.cos.f64(double %Val)
5410 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5411 declare fp128 @llvm.cos.f128(fp128 %Val)
5412 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5413</pre>
5414
5415<h5>Overview:</h5>
5416
5417<p>
5418The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5419</p>
5420
5421<h5>Arguments:</h5>
5422
5423<p>
5424The argument and return value are floating point numbers of the same type.
5425</p>
5426
5427<h5>Semantics:</h5>
5428
5429<p>
5430This function returns the cosine of the specified operand, returning the
5431same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5432conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5433</div>
5434
5435<!-- _______________________________________________________________________ -->
5436<div class="doc_subsubsection">
5437 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5438</div>
5439
5440<div class="doc_text">
5441
5442<h5>Syntax:</h5>
5443<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5444floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5445types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5446<pre>
5447 declare float @llvm.pow.f32(float %Val, float %Power)
5448 declare double @llvm.pow.f64(double %Val, double %Power)
5449 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5450 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5451 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5452</pre>
5453
5454<h5>Overview:</h5>
5455
5456<p>
5457The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5458specified (positive or negative) power.
5459</p>
5460
5461<h5>Arguments:</h5>
5462
5463<p>
5464The second argument is a floating point power, and the first is a value to
5465raise to that power.
5466</p>
5467
5468<h5>Semantics:</h5>
5469
5470<p>
5471This function returns the first value raised to the second power,
5472returning the
5473same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5474conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5475</div>
5476
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5477
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5478<!-- ======================================================================= -->
5479<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5480 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5481</div>
5482
5483<div class="doc_text">
5484<p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5485LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5486These allow efficient code generation for some algorithms.
5487</p>
5488
5489</div>
5490
5491<!-- _______________________________________________________________________ -->
5492<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5493 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5494</div>
5495
5496<div class="doc_text">
5497
5498<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5499<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5500type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5501<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5502 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5503 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5504 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5505</pre>
5506
5507<h5>Overview:</h5>
5508
5509<p>
Reid Spencerf361c4f2007-04-02 02:25:19 +0000[diff] [blame]5510The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5511values with an even number of bytes (positive multiple of 16 bits). These are
5512useful for performing operations on data that is not in the target's native
5513byte order.
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5514</p>
5515
5516<h5>Semantics:</h5>
5517
5518<p>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5519The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5520and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5521intrinsic returns an i32 value that has the four bytes of the input i32
5522swapped, 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]5523i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5524<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5525additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5526</p>
5527
5528</div>
5529
5530<!-- _______________________________________________________________________ -->
5531<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5532 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5533</div>
5534
5535<div class="doc_text">
5536
5537<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5538<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5539width. Not all targets support all bit widths however.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5540<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5541 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
5542 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5543 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5544 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5545 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5546</pre>
5547
5548<h5>Overview:</h5>
5549
5550<p>
Chris Lattner069b5bd2006-01-16 22:38:59 +0000[diff] [blame]5551The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5552value.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5553</p>
5554
5555<h5>Arguments:</h5>
5556
5557<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5558The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5559integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5560</p>
5561
5562<h5>Semantics:</h5>
5563
5564<p>
5565The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5566</p>
5567</div>
5568
5569<!-- _______________________________________________________________________ -->
5570<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5571 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5572</div>
5573
5574<div class="doc_text">
5575
5576<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5577<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5578integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5579<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5580 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5581 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5582 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5583 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5584 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5585</pre>
5586
5587<h5>Overview:</h5>
5588
5589<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5590The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5591leading zeros in a variable.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5592</p>
5593
5594<h5>Arguments:</h5>
5595
5596<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5597The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5598integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5599</p>
5600
5601<h5>Semantics:</h5>
5602
5603<p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5604The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5605in 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]5606of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5607</p>
5608</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5609
5610
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5611
5612<!-- _______________________________________________________________________ -->
5613<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5614 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5615</div>
5616
5617<div class="doc_text">
5618
5619<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5620<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5621integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5622<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5623 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5624 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5625 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5626 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5627 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5628</pre>
5629
5630<h5>Overview:</h5>
5631
5632<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5633The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5634trailing zeros.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5635</p>
5636
5637<h5>Arguments:</h5>
5638
5639<p>
5640The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5641integer type. The return type must match the argument type.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5642</p>
5643
5644<h5>Semantics:</h5>
5645
5646<p>
5647The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5648in a variable. If the src == 0 then the result is the size in bits of the type
5649of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5650</p>
5651</div>
5652
Reid Spencer8a5799f2007-04-01 08:27:01 +0000[diff] [blame]5653<!-- _______________________________________________________________________ -->
5654<div class="doc_subsubsection">
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5655 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5656</div>
5657
5658<div class="doc_text">
5659
5660<h5>Syntax:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5661<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5662on any integer bit width.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5663<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5664 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5665 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5666</pre>
5667
5668<h5>Overview:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5669<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5670range of bits from an integer value and returns them in the same bit width as
5671the original value.</p>
5672
5673<h5>Arguments:</h5>
5674<p>The first argument, <tt>%val</tt> and the result may be integer types of
5675any bit width but they must have the same bit width. The second and third
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5676arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5677
5678<h5>Semantics:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5679<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5680of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5681<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5682operates in forward mode.</p>
5683<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5684right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5685only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5686<ol>
5687 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5688 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5689 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5690 to determine the number of bits to retain.</li>
5691 <li>A mask of the retained bits is created by shifting a -1 value.</li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5692 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5693</ol>
Reid Spencer70845c02007-05-14 16:14:57 +0000[diff] [blame]5694<p>In reverse mode, a similar computation is made except that the bits are
5695returned in the reverse order. So, for example, if <tt>X</tt> has the value
5696<tt>i16 0x0ACF (101011001111)</tt> and we apply
5697<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5698<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5699</div>
5700
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5701<div class="doc_subsubsection">
5702 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5703</div>
5704
5705<div class="doc_text">
5706
5707<h5>Syntax:</h5>
5708<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5709on any integer bit width.</p>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5710<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5711 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5712 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]5713</pre>
5714
5715<h5>Overview:</h5>
5716<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5717of bits in an integer value with another integer value. It returns the integer
5718with the replaced bits.</p>
5719
5720<h5>Arguments:</h5>
5721<p>The first argument, <tt>%val</tt> and the result may be integer types of
5722any bit width but they must have the same bit width. <tt>%val</tt> is the value
5723whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5724integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5725type since they specify only a bit index.</p>
5726
5727<h5>Semantics:</h5>
5728<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5729of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5730<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5731operates in forward mode.</p>
5732<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5733truncating it down to the size of the replacement area or zero extending it
5734up to that size.</p>
5735<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5736are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5737in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5738to the <tt>%hi</tt>th bit.</p>
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5739<p>In reverse mode, a similar computation is made except that the bits are
5740reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5741<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5742<h5>Examples:</h5>
5743<pre>
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5744 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5745 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5746 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5747 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5748 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]5749</pre>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5750</div>
5751
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5752<!-- ======================================================================= -->
5753<div class="doc_subsection">
5754 <a name="int_debugger">Debugger Intrinsics</a>
5755</div>
5756
5757<div class="doc_text">
5758<p>
5759The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5760are described in the <a
5761href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5762Debugging</a> document.
5763</p>
5764</div>
5765
5766
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]5767<!-- ======================================================================= -->
5768<div class="doc_subsection">
5769 <a name="int_eh">Exception Handling Intrinsics</a>
5770</div>
5771
5772<div class="doc_text">
5773<p> The LLVM exception handling intrinsics (which all start with
5774<tt>llvm.eh.</tt> prefix), are described in the <a
5775href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5776Handling</a> document. </p>
5777</div>
5778
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]5779<!-- ======================================================================= -->
5780<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5781 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5782</div>
5783
5784<div class="doc_text">
5785<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5786 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5787 the <tt>nest</tt> attribute, from a function. The result is a callable
5788 function pointer lacking the nest parameter - the caller does not need
5789 to provide a value for it. Instead, the value to use is stored in
5790 advance in a "trampoline", a block of memory usually allocated
5791 on the stack, which also contains code to splice the nest value into the
5792 argument list. This is used to implement the GCC nested function address
5793 extension.
5794</p>
5795<p>
5796 For example, if the function is
5797 <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]5798 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]5799<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5800 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5801 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5802 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5803 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5804</pre>
Bill Wendling252570f2007-09-22 09:23:55 +0000[diff] [blame]5805 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5806 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5807</div>
5808
5809<!-- _______________________________________________________________________ -->
5810<div class="doc_subsubsection">
5811 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5812</div>
5813<div class="doc_text">
5814<h5>Syntax:</h5>
5815<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5816declare 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]5817</pre>
5818<h5>Overview:</h5>
5819<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5820 This fills the memory pointed to by <tt>tramp</tt> with code
5821 and returns a function pointer suitable for executing it.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5822</p>
5823<h5>Arguments:</h5>
5824<p>
5825 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5826 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5827 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsf2bcd372007-08-22 23:39:54 +0000[diff] [blame]5828 intrinsic. Note that the size and the alignment are target-specific - LLVM
5829 currently provides no portable way of determining them, so a front-end that
5830 generates this intrinsic needs to have some target-specific knowledge.
5831 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]5832</p>
5833<h5>Semantics:</h5>
5834<p>
5835 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5836 dependent code, turning it into a function. A pointer to this function is
5837 returned, but needs to be bitcast to an
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5838 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5839 before being called. The new function's signature is the same as that of
5840 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5841 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5842 of pointer type. Calling the new function is equivalent to calling
5843 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5844 missing <tt>nest</tt> argument. If, after calling
5845 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5846 modified, then the effect of any later call to the returned function pointer is
5847 undefined.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5848</p>
5849</div>
5850
5851<!-- ======================================================================= -->
5852<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5853 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
5854</div>
5855
5856<div class="doc_text">
5857<p>
5858 These intrinsic functions expand the "universal IR" of LLVM to represent
5859 hardware constructs for atomic operations and memory synchronization. This
5860 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5861 is aimed at a low enough level to allow any programming models or APIs
5862 (Application Programming Interfaces) which
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5863 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
5864 hardware behavior. Just as hardware provides a "universal IR" for source
5865 languages, it also provides a starting point for developing a "universal"
5866 atomic operation and synchronization IR.
5867</p>
5868<p>
5869 These do <em>not</em> form an API such as high-level threading libraries,
5870 software transaction memory systems, atomic primitives, and intrinsic
5871 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
5872 application libraries. The hardware interface provided by LLVM should allow
5873 a clean implementation of all of these APIs and parallel programming models.
5874 No one model or paradigm should be selected above others unless the hardware
5875 itself ubiquitously does so.
5876
5877</p>
5878</div>
5879
5880<!-- _______________________________________________________________________ -->
5881<div class="doc_subsubsection">
5882 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
5883</div>
5884<div class="doc_text">
5885<h5>Syntax:</h5>
5886<pre>
5887declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
5888i1 &lt;device&gt; )
5889
5890</pre>
5891<h5>Overview:</h5>
5892<p>
5893 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
5894 specific pairs of memory access types.
5895</p>
5896<h5>Arguments:</h5>
5897<p>
5898 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
5899 The first four arguments enables a specific barrier as listed below. The fith
5900 argument specifies that the barrier applies to io or device or uncached memory.
5901
5902</p>
5903 <ul>
5904 <li><tt>ll</tt>: load-load barrier</li>
5905 <li><tt>ls</tt>: load-store barrier</li>
5906 <li><tt>sl</tt>: store-load barrier</li>
5907 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5908 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5909 </ul>
5910<h5>Semantics:</h5>
5911<p>
5912 This intrinsic causes the system to enforce some ordering constraints upon
5913 the loads and stores of the program. This barrier does not indicate
5914 <em>when</em> any events will occur, it only enforces an <em>order</em> in
5915 which they occur. For any of the specified pairs of load and store operations
5916 (f.ex. load-load, or store-load), all of the first operations preceding the
5917 barrier will complete before any of the second operations succeeding the
5918 barrier begin. Specifically the semantics for each pairing is as follows:
5919</p>
5920 <ul>
5921 <li><tt>ll</tt>: All loads before the barrier must complete before any load
5922 after the barrier begins.</li>
5923
5924 <li><tt>ls</tt>: All loads before the barrier must complete before any
5925 store after the barrier begins.</li>
5926 <li><tt>ss</tt>: All stores before the barrier must complete before any
5927 store after the barrier begins.</li>
5928 <li><tt>sl</tt>: All stores before the barrier must complete before any
5929 load after the barrier begins.</li>
5930 </ul>
5931<p>
5932 These semantics are applied with a logical "and" behavior when more than one
5933 is enabled in a single memory barrier intrinsic.
5934</p>
5935<p>
5936 Backends may implement stronger barriers than those requested when they do not
5937 support as fine grained a barrier as requested. Some architectures do not
5938 need all types of barriers and on such architectures, these become noops.
5939</p>
5940<h5>Example:</h5>
5941<pre>
5942%ptr = malloc i32
5943 store i32 4, %ptr
5944
5945%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
5946 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
5947 <i>; guarantee the above finishes</i>
5948 store i32 8, %ptr <i>; before this begins</i>
5949</pre>
5950</div>
5951
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5952<!-- _______________________________________________________________________ -->
5953<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5954 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5955</div>
5956<div class="doc_text">
5957<h5>Syntax:</h5>
5958<p>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5959 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
5960 any integer bit width and for different address spaces. Not all targets
5961 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5962
5963<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5964declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
5965declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
5966declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
5967declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5968
5969</pre>
5970<h5>Overview:</h5>
5971<p>
5972 This loads a value in memory and compares it to a given value. If they are
5973 equal, it stores a new value into the memory.
5974</p>
5975<h5>Arguments:</h5>
5976<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5977 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5978 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
5979 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
5980 this integer type. While any bit width integer may be used, targets may only
5981 lower representations they support in hardware.
5982
5983</p>
5984<h5>Semantics:</h5>
5985<p>
5986 This entire intrinsic must be executed atomically. It first loads the value
5987 in memory pointed to by <tt>ptr</tt> and compares it with the value
5988 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
5989 loaded value is yielded in all cases. This provides the equivalent of an
5990 atomic compare-and-swap operation within the SSA framework.
5991</p>
5992<h5>Examples:</h5>
5993
5994<pre>
5995%ptr = malloc i32
5996 store i32 4, %ptr
5997
5998%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5999%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6000 <i>; yields {i32}:result1 = 4</i>
6001%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6002%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6003
6004%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6005%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6006 <i>; yields {i32}:result2 = 8</i>
6007%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6008
6009%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6010</pre>
6011</div>
6012
6013<!-- _______________________________________________________________________ -->
6014<div class="doc_subsubsection">
6015 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6016</div>
6017<div class="doc_text">
6018<h5>Syntax:</h5>
6019
6020<p>
6021 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6022 integer bit width. Not all targets support all bit widths however.</p>
6023<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6024declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6025declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6026declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6027declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6028
6029</pre>
6030<h5>Overview:</h5>
6031<p>
6032 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6033 the value from memory. It then stores the value in <tt>val</tt> in the memory
6034 at <tt>ptr</tt>.
6035</p>
6036<h5>Arguments:</h5>
6037
6038<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6039 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6040 <tt>val</tt> argument and the result must be integers of the same bit width.
6041 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6042 integer type. The targets may only lower integer representations they
6043 support.
6044</p>
6045<h5>Semantics:</h5>
6046<p>
6047 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6048 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6049 equivalent of an atomic swap operation within the SSA framework.
6050
6051</p>
6052<h5>Examples:</h5>
6053<pre>
6054%ptr = malloc i32
6055 store i32 4, %ptr
6056
6057%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6058%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6059 <i>; yields {i32}:result1 = 4</i>
6060%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6061%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6062
6063%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6064%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6065 <i>; yields {i32}:result2 = 8</i>
6066
6067%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6068%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6069</pre>
6070</div>
6071
6072<!-- _______________________________________________________________________ -->
6073<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6074 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6075
6076</div>
6077<div class="doc_text">
6078<h5>Syntax:</h5>
6079<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6080 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]6081 integer bit width. Not all targets support all bit widths however.</p>
6082<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6083declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6084declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6085declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6086declare i64 @llvm.atomic.load.add.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6087
6088</pre>
6089<h5>Overview:</h5>
6090<p>
6091 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6092 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6093</p>
6094<h5>Arguments:</h5>
6095<p>
6096
6097 The intrinsic takes two arguments, the first a pointer to an integer value
6098 and the second an integer value. The result is also an integer value. These
6099 integer types can have any bit width, but they must all have the same bit
6100 width. The targets may only lower integer representations they support.
6101</p>
6102<h5>Semantics:</h5>
6103<p>
6104 This intrinsic does a series of operations atomically. It first loads the
6105 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6106 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6107</p>
6108
6109<h5>Examples:</h5>
6110<pre>
6111%ptr = malloc i32
6112 store i32 4, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6113%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6114 <i>; yields {i32}:result1 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6115%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6116 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6117%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6118 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6119%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6120</pre>
6121</div>
6122
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6123<!-- _______________________________________________________________________ -->
6124<div class="doc_subsubsection">
6125 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6126
6127</div>
6128<div class="doc_text">
6129<h5>Syntax:</h5>
6130<p>
6131 This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6132 any integer bit width and for different address spaces. Not all targets
6133 support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6134<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6135declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6136declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6137declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6138declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6139
6140</pre>
6141<h5>Overview:</h5>
6142<p>
6143 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6144 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6145</p>
6146<h5>Arguments:</h5>
6147<p>
6148
6149 The intrinsic takes two arguments, the first a pointer to an integer value
6150 and the second an integer value. The result is also an integer value. These
6151 integer types can have any bit width, but they must all have the same bit
6152 width. The targets may only lower integer representations they support.
6153</p>
6154<h5>Semantics:</h5>
6155<p>
6156 This intrinsic does a series of operations atomically. It first loads the
6157 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6158 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6159</p>
6160
6161<h5>Examples:</h5>
6162<pre>
6163%ptr = malloc i32
6164 store i32 8, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6165%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6166 <i>; yields {i32}:result1 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6167%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6168 <i>; yields {i32}:result2 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6169%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6170 <i>; yields {i32}:result3 = 2</i>
6171%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6172</pre>
6173</div>
6174
6175<!-- _______________________________________________________________________ -->
6176<div class="doc_subsubsection">
6177 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6178 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6179 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6180 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6181
6182</div>
6183<div class="doc_text">
6184<h5>Syntax:</h5>
6185<p>
6186 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6187 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6188 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6189 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6190<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6191declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6192declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6193declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6194declare i64 @llvm.atomic.load.and.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6195
6196</pre>
6197
6198<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6199declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6200declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6201declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6202declare i64 @llvm.atomic.load.or.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6203
6204</pre>
6205
6206<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6207declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6208declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6209declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6210declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6211
6212</pre>
6213
6214<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6215declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6216declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6217declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6218declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6219
6220</pre>
6221<h5>Overview:</h5>
6222<p>
6223 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6224 the value stored in memory at <tt>ptr</tt>. It yields the original value
6225 at <tt>ptr</tt>.
6226</p>
6227<h5>Arguments:</h5>
6228<p>
6229
6230 These intrinsics take two arguments, the first a pointer to an integer value
6231 and the second an integer value. The result is also an integer value. These
6232 integer types can have any bit width, but they must all have the same bit
6233 width. The targets may only lower integer representations they support.
6234</p>
6235<h5>Semantics:</h5>
6236<p>
6237 These intrinsics does a series of operations atomically. They first load the
6238 value stored at <tt>ptr</tt>. They then do the bitwise operation
6239 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6240 value stored at <tt>ptr</tt>.
6241</p>
6242
6243<h5>Examples:</h5>
6244<pre>
6245%ptr = malloc i32
6246 store i32 0x0F0F, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6247%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6248 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6249%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6250 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6251%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6252 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6253%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6254 <i>; yields {i32}:result3 = FF</i>
6255%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6256</pre>
6257</div>
6258
6259
6260<!-- _______________________________________________________________________ -->
6261<div class="doc_subsubsection">
6262 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6263 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6264 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6265 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6266
6267</div>
6268<div class="doc_text">
6269<h5>Syntax:</h5>
6270<p>
6271 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6272 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6273 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6274 address spaces. Not all targets
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6275 support all bit widths however.</p>
6276<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6277declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6278declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6279declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6280declare i64 @llvm.atomic.load.max.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6281
6282</pre>
6283
6284<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6285declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6286declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6287declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6288declare i64 @llvm.atomic.load.min.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6289
6290</pre>
6291
6292<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6293declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6294declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6295declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6296declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6297
6298</pre>
6299
6300<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6301declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6302declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6303declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6304declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6305
6306</pre>
6307<h5>Overview:</h5>
6308<p>
6309 These intrinsics takes the signed or unsigned minimum or maximum of
6310 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6311 original value at <tt>ptr</tt>.
6312</p>
6313<h5>Arguments:</h5>
6314<p>
6315
6316 These intrinsics take two arguments, the first a pointer to an integer value
6317 and the second an integer value. The result is also an integer value. These
6318 integer types can have any bit width, but they must all have the same bit
6319 width. The targets may only lower integer representations they support.
6320</p>
6321<h5>Semantics:</h5>
6322<p>
6323 These intrinsics does a series of operations atomically. They first load the
6324 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6325 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6326 the original value stored at <tt>ptr</tt>.
6327</p>
6328
6329<h5>Examples:</h5>
6330<pre>
6331%ptr = malloc i32
6332 store i32 7, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6333%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6334 <i>; yields {i32}:result0 = 7</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6335%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6336 <i>; yields {i32}:result1 = -2</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6337%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6338 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6339%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6340 <i>; yields {i32}:result3 = 8</i>
6341%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6342</pre>
6343</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6344
6345<!-- ======================================================================= -->
6346<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6347 <a name="int_general">General Intrinsics</a>
6348</div>
6349
6350<div class="doc_text">
6351<p> This class of intrinsics is designed to be generic and has
6352no specific purpose. </p>
6353</div>
6354
6355<!-- _______________________________________________________________________ -->
6356<div class="doc_subsubsection">
6357 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6358</div>
6359
6360<div class="doc_text">
6361
6362<h5>Syntax:</h5>
6363<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6364 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]6365</pre>
6366
6367<h5>Overview:</h5>
6368
6369<p>
6370The '<tt>llvm.var.annotation</tt>' intrinsic
6371</p>
6372
6373<h5>Arguments:</h5>
6374
6375<p>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6376The first argument is a pointer to a value, the second is a pointer to a
6377global string, the third is a pointer to a global string which is the source
6378file name, and the last argument is the line number.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6379</p>
6380
6381<h5>Semantics:</h5>
6382
6383<p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6384This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6385This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6386annotations. These have no other defined use, they are ignored by code
6387generation and optimization.
6388</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6389</div>
6390
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6391<!-- _______________________________________________________________________ -->
6392<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]6393 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6394</div>
6395
6396<div class="doc_text">
6397
6398<h5>Syntax:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6399<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6400any integer bit width.
6401</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6402<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]6403 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6404 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6405 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6406 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6407 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]6408</pre>
6409
6410<h5>Overview:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6411
6412<p>
6413The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6414</p>
6415
6416<h5>Arguments:</h5>
6417
6418<p>
6419The first argument is an integer value (result of some expression),
6420the second is a pointer to a global string, the third is a pointer to a global
6421string which is the source file name, and the last argument is the line number.
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6422It returns the value of the first argument.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6423</p>
6424
6425<h5>Semantics:</h5>
6426
6427<p>
6428This intrinsic allows annotations to be put on arbitrary expressions
6429with arbitrary strings. This can be useful for special purpose optimizations
6430that want to look for these annotations. These have no other defined use, they
6431are ignored by code generation and optimization.
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6432</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6433</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6434
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6435<!-- _______________________________________________________________________ -->
6436<div class="doc_subsubsection">
6437 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6438</div>
6439
6440<div class="doc_text">
6441
6442<h5>Syntax:</h5>
6443<pre>
6444 declare void @llvm.trap()
6445</pre>
6446
6447<h5>Overview:</h5>
6448
6449<p>
6450The '<tt>llvm.trap</tt>' intrinsic
6451</p>
6452
6453<h5>Arguments:</h5>
6454
6455<p>
6456None
6457</p>
6458
6459<h5>Semantics:</h5>
6460
6461<p>
6462This intrinsics is lowered to the target dependent trap instruction. If the
6463target does not have a trap instruction, this intrinsic will be lowered to the
6464call of the abort() function.
6465</p>
6466</div>
6467
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6468<!-- _______________________________________________________________________ -->
6469<div class="doc_subsubsection">
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]6470 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6471</div>
6472<div class="doc_text">
6473<h5>Syntax:</h5>
6474<pre>
6475declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
6476
6477</pre>
6478<h5>Overview:</h5>
6479<p>
6480 The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
6481 it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
6482 it is placed on the stack before local variables.
6483</p>
6484<h5>Arguments:</h5>
6485<p>
6486 The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
6487 first argument is the value loaded from the stack guard
6488 <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
6489 has enough space to hold the value of the guard.
6490</p>
6491<h5>Semantics:</h5>
6492<p>
6493 This intrinsic causes the prologue/epilogue inserter to force the position of
6494 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6495 stack. This is to ensure that if a local variable on the stack is overwritten,
6496 it will destroy the value of the guard. When the function exits, the guard on
6497 the stack is checked against the original guard. If they're different, then
6498 the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
6499</p>
6500</div>
6501
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6502<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6503<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6504<address>
6505 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]6506 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6507 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]6508 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6509
6510 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]6511 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6512 Last modified: $Date$
6513</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]6514
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6515</body>
6516</html>