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gerrit-public.fairphone.software / toolchain / llvm-project / 33a9cef204d1a4ecaed912ad07244a446b6c5ea9 / . / llvm / docs / LangRef.html
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4<head>
5 <title>LLVM Assembly Language Reference Manual</title>
Reid Spencercb84e432004-08-26 20:44:00 +0000[diff] [blame]6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
7 <meta name="author" content="Chris Lattner">
8 <meta name="description"
9 content="LLVM Assembly Language Reference Manual.">
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a></li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]24 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]25 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]26 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]27 <li><a href="#functionstructure">Functions</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]28 <li><a href="#aliasstructure">Aliases</a></li>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]29 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]30 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]31 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]32 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]33 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]34 </ol>
35 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]36 <li><a href="#typesystem">Type System</a>
37 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]38 <li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]39 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]40 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]41 <li><a href="#t_floating">Floating Point Types</a></li>
42 <li><a href="#t_void">Void Type</a></li>
43 <li><a href="#t_label">Label Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]44 </ol>
45 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]46 <li><a href="#t_derived">Derived Types</a>
47 <ol>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]48 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]49 <li><a href="#t_array">Array Type</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]50 <li><a href="#t_function">Function Type</a></li>
51 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]52 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]53 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]54 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]55 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]56 </ol>
57 </li>
58 </ol>
59 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]60 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]61 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]62 <li><a href="#simpleconstants">Simple Constants</a></li>
63 <li><a href="#aggregateconstants">Aggregate Constants</a></li>
64 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
65 <li><a href="#undefvalues">Undefined Values</a></li>
66 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]67 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]68 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]69 <li><a href="#othervalues">Other Values</a>
70 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]71 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]72 </ol>
73 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]74 <li><a href="#instref">Instruction Reference</a>
75 <ol>
76 <li><a href="#terminators">Terminator Instructions</a>
77 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]78 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
79 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]80 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
81 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]82 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]83 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]84 </ol>
85 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]86 <li><a href="#binaryops">Binary Operations</a>
87 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]88 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
89 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
90 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]91 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
92 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
93 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]94 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
95 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
96 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]97 </ol>
98 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]99 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
100 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]101 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
102 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
103 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]104 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]105 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]106 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]107 </ol>
108 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]109 <li><a href="#vectorops">Vector Operations</a>
110 <ol>
111 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
112 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
113 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]114 </ol>
115 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]116 <li><a href="#aggregateops">Aggregate Operations</a>
117 <ol>
118 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
119 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
120 </ol>
121 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]122 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]123 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]124 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
125 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
126 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]127 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
128 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
129 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]130 </ol>
131 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]132 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]133 <ol>
134 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
135 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
136 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
137 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
138 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]139 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
140 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
141 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
142 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]143 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
144 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]145 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]146 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]147 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]148 <li><a href="#otherops">Other Operations</a>
149 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]150 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
151 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]152 <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
153 <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]154 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]155 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]156 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]157 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]158 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]159 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]160 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]161 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]162 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]163 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]164 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
165 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]166 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
167 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
168 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]169 </ol>
170 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]171 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
172 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]173 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
174 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
175 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]176 </ol>
177 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]178 <li><a href="#int_codegen">Code Generator Intrinsics</a>
179 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]180 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
181 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
182 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
183 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
184 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
185 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
186 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]187 </ol>
188 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]189 <li><a href="#int_libc">Standard C Library Intrinsics</a>
190 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]191 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
192 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
193 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
194 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
195 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]196 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
197 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
198 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]199 </ol>
200 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]201 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]202 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]203 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]204 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
205 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
206 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]207 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
208 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]209 </ol>
210 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]211 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]212 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]213 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]214 <ol>
215 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]216 </ol>
217 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]218 <li><a href="#int_atomics">Atomic intrinsics</a>
219 <ol>
220 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
221 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
222 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
223 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
224 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
225 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
226 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
227 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
228 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
229 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
230 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
231 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
232 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
233 </ol>
234 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]235 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]236 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]237 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]238 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]239 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]240 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]241 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]242 '<tt>llvm.trap</tt>' Intrinsic</a></li>
243 <li><a href="#int_stackprotector">
244 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]245 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]246 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]247 </ol>
248 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]249</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]250
251<div class="doc_author">
252 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
253 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]254</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]255
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]256<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]257<div class="doc_section"> <a name="abstract">Abstract </a></div>
258<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]259
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]260<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]261<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling6e03f9a2008-08-05 22:29:16 +0000[diff] [blame]262LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]263type safety, low-level operations, flexibility, and the capability of
264representing 'all' high-level languages cleanly. It is the common code
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]265representation used throughout all phases of the LLVM compilation
266strategy.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]267</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]268
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]269<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]270<div class="doc_section"> <a name="introduction">Introduction</a> </div>
271<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]272
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]273<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]274
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]275<p>The LLVM code representation is designed to be used in three
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]276different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]277representation (suitable for fast loading by a Just-In-Time compiler),
278and as a human readable assembly language representation. This allows
279LLVM to provide a powerful intermediate representation for efficient
280compiler transformations and analysis, while providing a natural means
281to debug and visualize the transformations. The three different forms
282of LLVM are all equivalent. This document describes the human readable
283representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]284
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]285<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]286while being expressive, typed, and extensible at the same time. It
287aims to be a "universal IR" of sorts, by being at a low enough level
288that high-level ideas may be cleanly mapped to it (similar to how
289microprocessors are "universal IR's", allowing many source languages to
290be mapped to them). By providing type information, LLVM can be used as
291the target of optimizations: for example, through pointer analysis, it
292can be proven that a C automatic variable is never accessed outside of
293the current function... allowing it to be promoted to a simple SSA
294value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]295
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]296</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]297
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]298<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]299<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]300
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]301<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]302
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]303<p>It is important to note that this document describes 'well formed'
304LLVM assembly language. There is a difference between what the parser
305accepts and what is considered 'well formed'. For example, the
306following instruction is syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]307
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]308<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]309<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]310%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]311</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]312</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]313
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]314<p>...because the definition of <tt>%x</tt> does not dominate all of
315its uses. The LLVM infrastructure provides a verification pass that may
316be used to verify that an LLVM module is well formed. This pass is
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]317automatically run by the parser after parsing input assembly and by
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]318the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]319by the verifier pass indicate bugs in transformation passes or input to
320the parser.</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]321</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]322
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]323<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]324
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]325<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]326<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]327<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]328
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]329<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]330
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]331 <p>LLVM identifiers come in two basic types: global and local. Global
332 identifiers (functions, global variables) begin with the @ character. Local
333 identifiers (register names, types) begin with the % character. Additionally,
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]334 there are three different formats for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]335
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]336<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]337 <li>Named values are represented as a string of characters with their prefix.
338 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
339 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]340 Identifiers which require other characters in their names can be surrounded
Daniel Dunbar0f8155a2008-10-14 23:51:43 +0000[diff] [blame]341 with quotes. Special characters may be escaped using "\xx" where xx is the
342 ASCII code for the character in hexadecimal. In this way, any character can
343 be used in a name value, even quotes themselves.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]344
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]345 <li>Unnamed values are represented as an unsigned numeric value with their
346 prefix. For example, %12, @2, %44.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]347
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]348 <li>Constants, which are described in a <a href="#constants">section about
349 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]350</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]351
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]352<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]353don't need to worry about name clashes with reserved words, and the set of
354reserved words may be expanded in the future without penalty. Additionally,
355unnamed identifiers allow a compiler to quickly come up with a temporary
356variable without having to avoid symbol table conflicts.</p>
357
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]358<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]359languages. There are keywords for different opcodes
360('<tt><a href="#i_add">add</a></tt>',
361 '<tt><a href="#i_bitcast">bitcast</a></tt>',
362 '<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]363href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]364and others. These reserved words cannot conflict with variable names, because
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]365none of them start with a prefix character ('%' or '@').</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]366
367<p>Here is an example of LLVM code to multiply the integer variable
368'<tt>%X</tt>' by 8:</p>
369
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]370<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]371
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]372<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]373<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]374%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]375</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]376</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]377
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]378<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]379
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]380<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]381<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]382%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]383</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]384</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]385
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]386<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]387
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]388<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]389<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]390<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
391<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
392%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]393</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]394</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]395
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]396<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
397important lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]398
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]399<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]400
401 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
402 line.</li>
403
404 <li>Unnamed temporaries are created when the result of a computation is not
405 assigned to a named value.</li>
406
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]407 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]408
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]409</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]410
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]411<p>...and it also shows a convention that we follow in this document. When
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]412demonstrating instructions, we will follow an instruction with a comment that
413defines the type and name of value produced. Comments are shown in italic
414text.</p>
415
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]416</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]417
418<!-- *********************************************************************** -->
419<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
420<!-- *********************************************************************** -->
421
422<!-- ======================================================================= -->
423<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
424</div>
425
426<div class="doc_text">
427
428<p>LLVM programs are composed of "Module"s, each of which is a
429translation unit of the input programs. Each module consists of
430functions, global variables, and symbol table entries. Modules may be
431combined together with the LLVM linker, which merges function (and
432global variable) definitions, resolves forward declarations, and merges
433symbol table entries. Here is an example of the "hello world" module:</p>
434
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]435<div class="doc_code">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]436<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]437<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
438 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]439
440<i>; External declaration of the puts function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]441<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]442
443<i>; Definition of main function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]444define i32 @main() { <i>; i32()* </i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]445 <i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]446 %cast210 = <a
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]447 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]448
449 <i>; Call puts function to write out the string to stdout...</i>
450 <a
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]451 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]452 <a
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]453 href="#i_ret">ret</a> i32 0<br>}<br>
454</pre>
455</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]456
457<p>This example is made up of a <a href="#globalvars">global variable</a>
458named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
459function, and a <a href="#functionstructure">function definition</a>
460for "<tt>main</tt>".</p>
461
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]462<p>In general, a module is made up of a list of global values,
463where both functions and global variables are global values. Global values are
464represented by a pointer to a memory location (in this case, a pointer to an
465array of char, and a pointer to a function), and have one of the following <a
466href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]467
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]468</div>
469
470<!-- ======================================================================= -->
471<div class="doc_subsection">
472 <a name="linkage">Linkage Types</a>
473</div>
474
475<div class="doc_text">
476
477<p>
478All Global Variables and Functions have one of the following types of linkage:
479</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]480
481<dl>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]482
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]483 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]484
485 <dd>Global values with internal linkage are only directly accessible by
486 objects in the current module. In particular, linking code into a module with
487 an internal global value may cause the internal to be renamed as necessary to
488 avoid collisions. Because the symbol is internal to the module, all
489 references can be updated. This corresponds to the notion of the
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]490 '<tt>static</tt>' keyword in C.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]491 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]492
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]493 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]494
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]495 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
496 the same name when linkage occurs. This is typically used to implement
497 inline functions, templates, or other code which must be generated in each
498 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
499 allowed to be discarded.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]500 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]501
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]502 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
503
504 <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
505 linkage, except that unreferenced <tt>common</tt> globals may not be
506 discarded. This is used for globals that may be emitted in multiple
507 translation units, but that are not guaranteed to be emitted into every
508 translation unit that uses them. One example of this is tentative
509 definitions in C, such as "<tt>int X;</tt>" at global scope.
510 </dd>
511
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]512 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]513
Dale Johannesen4188aad2008-05-23 23:13:41 +0000[diff] [blame]514 <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
515 that some targets may choose to emit different assembly sequences for them
516 for target-dependent reasons. This is used for globals that are declared
517 "weak" in C source code.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]518 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]519
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]520 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]521
522 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
523 pointer to array type. When two global variables with appending linkage are
524 linked together, the two global arrays are appended together. This is the
525 LLVM, typesafe, equivalent of having the system linker append together
526 "sections" with identical names when .o files are linked.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]527 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]528
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]529 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]530 <dd>The semantics of this linkage follow the ELF object file model: the
531 symbol is weak until linked, if not linked, the symbol becomes null instead
532 of being an undefined reference.
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]533 </dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]534
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]535 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]536
537 <dd>If none of the above identifiers are used, the global is externally
538 visible, meaning that it participates in linkage and can be used to resolve
539 external symbol references.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]540 </dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]541</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]542
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]543 <p>
544 The next two types of linkage are targeted for Microsoft Windows platform
545 only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]546 DLLs (Dynamic Link Libraries).
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]547 </p>
548
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]549 <dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]550 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
551
552 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
553 or variable via a global pointer to a pointer that is set up by the DLL
554 exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman33a9cef2009-01-12 21:35:55 +0000[diff] [blame^]555 formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]556 </dd>
557
558 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
559
560 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
561 pointer to a pointer in a DLL, so that it can be referenced with the
562 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman33a9cef2009-01-12 21:35:55 +0000[diff] [blame^]563 name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]564 name.
565 </dd>
566
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]567</dl>
568
Dan Gohman8ef44982008-11-24 17:18:39 +0000[diff] [blame]569<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]570variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
571variable and was linked with this one, one of the two would be renamed,
572preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
573external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer92c671e2007-01-05 00:59:10 +0000[diff] [blame]574outside of the current module.</p>
575<p>It is illegal for a function <i>declaration</i>
576to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]577or <tt>extern_weak</tt>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]578<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]579linkages.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]580</div>
581
582<!-- ======================================================================= -->
583<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]584 <a name="callingconv">Calling Conventions</a>
585</div>
586
587<div class="doc_text">
588
589<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
590and <a href="#i_invoke">invokes</a> can all have an optional calling convention
591specified for the call. The calling convention of any pair of dynamic
592caller/callee must match, or the behavior of the program is undefined. The
593following calling conventions are supported by LLVM, and more may be added in
594the future:</p>
595
596<dl>
597 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
598
599 <dd>This calling convention (the default if no other calling convention is
600 specified) matches the target C calling conventions. This calling convention
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]601 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer72ba4992006-12-31 21:30:18 +0000[diff] [blame]602 prototype and implemented declaration of the function (as does normal C).
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]603 </dd>
604
605 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
606
607 <dd>This calling convention attempts to make calls as fast as possible
608 (e.g. by passing things in registers). This calling convention allows the
609 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]610 without having to conform to an externally specified ABI (Application Binary
611 Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer2c6b8882008-05-14 09:17:12 +0000[diff] [blame]612 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
613 supported. This calling convention does not support varargs and requires the
614 prototype of all callees to exactly match the prototype of the function
615 definition.
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]616 </dd>
617
618 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
619
620 <dd>This calling convention attempts to make code in the caller as efficient
621 as possible under the assumption that the call is not commonly executed. As
622 such, these calls often preserve all registers so that the call does not break
623 any live ranges in the caller side. This calling convention does not support
624 varargs and requires the prototype of all callees to exactly match the
625 prototype of the function definition.
626 </dd>
627
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]628 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]629
630 <dd>Any calling convention may be specified by number, allowing
631 target-specific calling conventions to be used. Target specific calling
632 conventions start at 64.
633 </dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]634</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]635
636<p>More calling conventions can be added/defined on an as-needed basis, to
637support pascal conventions or any other well-known target-independent
638convention.</p>
639
640</div>
641
642<!-- ======================================================================= -->
643<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]644 <a name="visibility">Visibility Styles</a>
645</div>
646
647<div class="doc_text">
648
649<p>
650All Global Variables and Functions have one of the following visibility styles:
651</p>
652
653<dl>
654 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
655
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]656 <dd>On targets that use the ELF object file format, default visibility means
657 that the declaration is visible to other
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]658 modules and, in shared libraries, means that the declared entity may be
659 overridden. On Darwin, default visibility means that the declaration is
660 visible to other modules. Default visibility corresponds to "external
661 linkage" in the language.
662 </dd>
663
664 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
665
666 <dd>Two declarations of an object with hidden visibility refer to the same
667 object if they are in the same shared object. Usually, hidden visibility
668 indicates that the symbol will not be placed into the dynamic symbol table,
669 so no other module (executable or shared library) can reference it
670 directly.
671 </dd>
672
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]673 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
674
675 <dd>On ELF, protected visibility indicates that the symbol will be placed in
676 the dynamic symbol table, but that references within the defining module will
677 bind to the local symbol. That is, the symbol cannot be overridden by another
678 module.
679 </dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]680</dl>
681
682</div>
683
684<!-- ======================================================================= -->
685<div class="doc_subsection">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]686 <a name="namedtypes">Named Types</a>
687</div>
688
689<div class="doc_text">
690
691<p>LLVM IR allows you to specify name aliases for certain types. This can make
692it easier to read the IR and make the IR more condensed (particularly when
693recursive types are involved). An example of a name specification is:
694</p>
695
696<div class="doc_code">
697<pre>
698%mytype = type { %mytype*, i32 }
699</pre>
700</div>
701
702<p>You may give a name to any <a href="#typesystem">type</a> except "<a
703href="t_void">void</a>". Type name aliases may be used anywhere a type is
704expected with the syntax "%mytype".</p>
705
706<p>Note that type names are aliases for the structural type that they indicate,
707and that you can therefore specify multiple names for the same type. This often
708leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
709structural typing, the name is not part of the type. When printing out LLVM IR,
710the printer will pick <em>one name</em> to render all types of a particular
711shape. This means that if you have code where two different source types end up
712having the same LLVM type, that the dumper will sometimes print the "wrong" or
713unexpected type. This is an important design point and isn't going to
714change.</p>
715
716</div>
717
718
719<!-- ======================================================================= -->
720<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]721 <a name="globalvars">Global Variables</a>
722</div>
723
724<div class="doc_text">
725
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]726<p>Global variables define regions of memory allocated at compilation time
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]727instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]728an explicit section to be placed in, and may have an optional explicit alignment
729specified. A variable may be defined as "thread_local", which means that it
730will not be shared by threads (each thread will have a separated copy of the
731variable). A variable may be defined as a global "constant," which indicates
732that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]733optimization, allowing the global data to be placed in the read-only section of
734an executable, etc). Note that variables that need runtime initialization
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]735cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]736
737<p>
738LLVM explicitly allows <em>declarations</em> of global variables to be marked
739constant, even if the final definition of the global is not. This capability
740can be used to enable slightly better optimization of the program, but requires
741the language definition to guarantee that optimizations based on the
742'constantness' are valid for the translation units that do not include the
743definition.
744</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]745
746<p>As SSA values, global variables define pointer values that are in
747scope (i.e. they dominate) all basic blocks in the program. Global
748variables always define a pointer to their "content" type because they
749describe a region of memory, and all memory objects in LLVM are
750accessed through pointers.</p>
751
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]752<p>A global variable may be declared to reside in a target-specifc numbered
753address space. For targets that support them, address spaces may affect how
754optimizations are performed and/or what target instructions are used to access
Christopher Lamb25f50762007-12-12 08:44:39 +0000[diff] [blame]755the variable. The default address space is zero. The address space qualifier
756must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]757
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]758<p>LLVM allows an explicit section to be specified for globals. If the target
759supports it, it will emit globals to the section specified.</p>
760
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]761<p>An explicit alignment may be specified for a global. If not present, or if
762the alignment is set to zero, the alignment of the global is set by the target
763to whatever it feels convenient. If an explicit alignment is specified, the
764global is forced to have at least that much alignment. All alignments must be
765a power of 2.</p>
766
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]767<p>For example, the following defines a global in a numbered address space with
768an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]769
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]770<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]771<pre>
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]772@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]773</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]774</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]775
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]776</div>
777
778
779<!-- ======================================================================= -->
780<div class="doc_subsection">
781 <a name="functionstructure">Functions</a>
782</div>
783
784<div class="doc_text">
785
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]786<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
787an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]788<a href="#visibility">visibility style</a>, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]789<a href="#callingconv">calling convention</a>, a return type, an optional
790<a href="#paramattrs">parameter attribute</a> for the return type, a function
791name, a (possibly empty) argument list (each with optional
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]792<a href="#paramattrs">parameter attributes</a>), optional
793<a href="#fnattrs">function attributes</a>, an optional section,
794an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattnercbc4d2a2008-10-04 18:10:21 +0000[diff] [blame]795an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]796
797LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
798optional <a href="#linkage">linkage type</a>, an optional
799<a href="#visibility">visibility style</a>, an optional
800<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]801<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]802name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksendc5cafb2007-12-10 03:30:21 +0000[diff] [blame]803<a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]804
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]805<p>A function definition contains a list of basic blocks, forming the CFG
806(Control Flow Graph) for
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]807the function. Each basic block may optionally start with a label (giving the
808basic block a symbol table entry), contains a list of instructions, and ends
809with a <a href="#terminators">terminator</a> instruction (such as a branch or
810function return).</p>
811
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]812<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]813executed on entrance to the function, and it is not allowed to have predecessor
814basic blocks (i.e. there can not be any branches to the entry block of a
815function). Because the block can have no predecessors, it also cannot have any
816<a href="#i_phi">PHI nodes</a>.</p>
817
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]818<p>LLVM allows an explicit section to be specified for functions. If the target
819supports it, it will emit functions to the section specified.</p>
820
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]821<p>An explicit alignment may be specified for a function. If not present, or if
822the alignment is set to zero, the alignment of the function is set by the target
823to whatever it feels convenient. If an explicit alignment is specified, the
824function is forced to have at least that much alignment. All alignments must be
825a power of 2.</p>
826
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]827 <h5>Syntax:</h5>
828
829<div class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]830<tt>
831define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
832 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
833 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
834 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
835 [<a href="#gc">gc</a>] { ... }
836</tt>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]837</div>
838
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]839</div>
840
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]841
842<!-- ======================================================================= -->
843<div class="doc_subsection">
844 <a name="aliasstructure">Aliases</a>
845</div>
846<div class="doc_text">
847 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov25b2e822008-03-22 08:36:14 +0000[diff] [blame]848 function, global variable, another alias or bitcast of global value). Aliases
849 may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]850 optional <a href="#visibility">visibility style</a>.</p>
851
852 <h5>Syntax:</h5>
853
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]854<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]855<pre>
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]856@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]857</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]858</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]859
860</div>
861
862
863
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]864<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]865<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
866<div class="doc_text">
867 <p>The return type and each parameter of a function type may have a set of
868 <i>parameter attributes</i> associated with them. Parameter attributes are
869 used to communicate additional information about the result or parameters of
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]870 a function. Parameter attributes are considered to be part of the function,
871 not of the function type, so functions with different parameter attributes
872 can have the same function type.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]873
Reid Spencercf7ebf52007-01-15 18:27:39 +0000[diff] [blame]874 <p>Parameter attributes are simple keywords that follow the type specified. If
875 multiple parameter attributes are needed, they are space separated. For
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]876 example:</p>
877
878<div class="doc_code">
879<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]880declare i32 @printf(i8* noalias , ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]881declare i32 @atoi(i8 zeroext)
882declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]883</pre>
884</div>
885
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]886 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
887 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]888
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]889 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]890 <dl>
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]891 <dt><tt>zeroext</tt></dt>
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]892 <dd>This indicates to the code generator that the parameter or return value
893 should be zero-extended to a 32-bit value by the caller (for a parameter)
894 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]895
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]896 <dt><tt>signext</tt></dt>
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]897 <dd>This indicates to the code generator that the parameter or return value
898 should be sign-extended to a 32-bit value by the caller (for a parameter)
899 or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]900
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]901 <dt><tt>inreg</tt></dt>
Dale Johannesenc50ada22008-09-25 20:47:45 +0000[diff] [blame]902 <dd>This indicates that this parameter or return value should be treated
903 in a special target-dependent fashion during while emitting code for a
904 function call or return (usually, by putting it in a register as opposed
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]905 to memory, though some targets use it to distinguish between two different
906 kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]907
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]908 <dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner352ab9b2008-01-15 04:34:22 +0000[diff] [blame]909 <dd>This indicates that the pointer parameter should really be passed by
910 value to the function. The attribute implies that a hidden copy of the
911 pointee is made between the caller and the callee, so the callee is unable
Chris Lattner1ca5c642008-08-05 18:21:08 +0000[diff] [blame]912 to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner352ab9b2008-01-15 04:34:22 +0000[diff] [blame]913 pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]914 value, but is also valid on pointers to scalars. The copy is considered to
915 belong to the caller not the callee (for example,
916 <tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]917 <tt>byval</tt> parameters). This is not a valid attribute for return
918 values. </dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]919
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]920 <dt><tt>sret</tt></dt>
Duncan Sandsfa4b6732008-02-18 04:19:38 +0000[diff] [blame]921 <dd>This indicates that the pointer parameter specifies the address of a
922 structure that is the return value of the function in the source program.
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]923 This pointer must be guaranteed by the caller to be valid: loads and stores
924 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]925 be applied to the first parameter. This is not a valid attribute for
926 return values. </dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]927
Zhou Sheng2444a9a2007-06-05 05:28:26 +0000[diff] [blame]928 <dt><tt>noalias</tt></dt>
Nick Lewyckyf5ffcbc2008-11-24 03:41:24 +0000[diff] [blame]929 <dd>This indicates that the pointer does not alias any global or any other
930 parameter. The caller is responsible for ensuring that this is the
Nick Lewyckyd59572c2008-11-24 05:00:44 +0000[diff] [blame]931 case. On a function return value, <tt>noalias</tt> additionally indicates
932 that the pointer does not alias any other pointers visible to the
Nick Lewycky2abb1082008-12-19 06:39:12 +0000[diff] [blame]933 caller. For further details, please see the discussion of the NoAlias
934 response in
935 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
936 analysis</a>.</dd>
937
938 <dt><tt>nocapture</tt></dt>
939 <dd>This indicates that the callee does not make any copies of the pointer
940 that outlive the callee itself. This is not a valid attribute for return
941 values.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]942
Duncan Sands27e91592007-07-27 19:57:41 +0000[diff] [blame]943 <dt><tt>nest</tt></dt>
Duncan Sands825bde42008-07-08 09:27:25 +0000[diff] [blame]944 <dd>This indicates that the pointer parameter can be excised using the
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]945 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
946 attribute for return values.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]947 </dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]948
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]949</div>
950
951<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]952<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]953 <a name="gc">Garbage Collector Names</a>
954</div>
955
956<div class="doc_text">
957<p>Each function may specify a garbage collector name, which is simply a
958string.</p>
959
960<div class="doc_code"><pre
961>define void @f() gc "name" { ...</pre></div>
962
963<p>The compiler declares the supported values of <i>name</i>. Specifying a
964collector which will cause the compiler to alter its output in order to support
965the named garbage collection algorithm.</p>
966</div>
967
968<!-- ======================================================================= -->
969<div class="doc_subsection">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]970 <a name="fnattrs">Function Attributes</a>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]971</div>
972
973<div class="doc_text">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]974
975<p>Function attributes are set to communicate additional information about
976 a function. Function attributes are considered to be part of the function,
977 not of the function type, so functions with different parameter attributes
978 can have the same function type.</p>
979
980 <p>Function attributes are simple keywords that follow the type specified. If
981 multiple attributes are needed, they are space separated. For
982 example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]983
984<div class="doc_code">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]985<pre>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]986define void @f() noinline { ... }
987define void @f() alwaysinline { ... }
988define void @f() alwaysinline optsize { ... }
989define void @f() optsize
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]990</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]991</div>
992
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]993<dl>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]994<dt><tt>alwaysinline</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]995<dd>This attribute indicates that the inliner should attempt to inline this
996function into callers whenever possible, ignoring any active inlining size
997threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]998
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]999<dt><tt>noinline</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1000<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner0625c282008-10-05 17:14:59 +0000[diff] [blame]1001in any situation. This attribute may not be used together with the
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1002<tt>alwaysinline</tt> attribute.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1003
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1004<dt><tt>optsize</tt></dt>
Devang Patele9743902008-09-29 18:34:44 +0000[diff] [blame]1005<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1006make choices that keep the code size of this function low, and otherwise do
1007optimizations specifically to reduce code size.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1008
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1009<dt><tt>noreturn</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1010<dd>This function attribute indicates that the function never returns normally.
1011This produces undefined behavior at runtime if the function ever does
1012dynamically return.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1013
1014<dt><tt>nounwind</tt></dt>
Chris Lattnerfbf60a42008-10-04 18:23:17 +0000[diff] [blame]1015<dd>This function attribute indicates that the function never returns with an
1016unwind or exceptional control flow. If the function does unwind, its runtime
1017behavior is undefined.</dd>
1018
1019<dt><tt>readnone</tt></dt>
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]1020<dd>This attribute indicates that the function computes its result (or the
1021exception it throws) based strictly on its arguments, without dereferencing any
1022pointer arguments or otherwise accessing any mutable state (e.g. memory, control
1023registers, etc) visible to caller functions. It does not write through any
1024pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
1025never changes any state visible to callers.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1026
Duncan Sands2a1d8ba2008-10-06 08:14:18 +0000[diff] [blame]1027<dt><tt><a name="readonly">readonly</a></tt></dt>
1028<dd>This attribute indicates that the function does not write through any
1029pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
1030or otherwise modify any state (e.g. memory, control registers, etc) visible to
1031caller functions. It may dereference pointer arguments and read state that may
1032be set in the caller. A readonly function always returns the same value (or
1033throws the same exception) when called with the same set of arguments and global
1034state.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1035
1036<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1037<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1038protector. It is in the form of a "canary"&mdash;a random value placed on the
1039stack before the local variables that's checked upon return from the function to
1040see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1041needs stack protectors or not.
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1042
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1043<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
1044that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
1045have an <tt>ssp</tt> attribute.</p></dd>
1046
1047<dt><tt>sspreq</tt></dt>
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1048<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1049stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendling6e41add2008-11-26 19:19:05 +0000[diff] [blame]1050function attribute.
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1051
1052<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
1053function that doesn't have an <tt>sspreq</tt> attribute or which has
1054an <tt>ssp</tt> attribute, then the resulting function will have
1055an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1056</dl>
1057
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1058</div>
1059
1060<!-- ======================================================================= -->
1061<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1062 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1063</div>
1064
1065<div class="doc_text">
1066<p>
1067Modules may contain "module-level inline asm" blocks, which corresponds to the
1068GCC "file scope inline asm" blocks. These blocks are internally concatenated by
1069LLVM and treated as a single unit, but may be separated in the .ll file if
1070desired. The syntax is very simple:
1071</p>
1072
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1073<div class="doc_code">
1074<pre>
1075module asm "inline asm code goes here"
1076module asm "more can go here"
1077</pre>
1078</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1079
1080<p>The strings can contain any character by escaping non-printable characters.
1081 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
1082 for the number.
1083</p>
1084
1085<p>
1086 The inline asm code is simply printed to the machine code .s file when
1087 assembly code is generated.
1088</p>
1089</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1090
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1091<!-- ======================================================================= -->
1092<div class="doc_subsection">
1093 <a name="datalayout">Data Layout</a>
1094</div>
1095
1096<div class="doc_text">
1097<p>A module may specify a target specific data layout string that specifies how
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]1098data is to be laid out in memory. The syntax for the data layout is simply:</p>
1099<pre> target datalayout = "<i>layout specification</i>"</pre>
1100<p>The <i>layout specification</i> consists of a list of specifications
1101separated by the minus sign character ('-'). Each specification starts with a
1102letter and may include other information after the letter to define some
1103aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1104<dl>
1105 <dt><tt>E</tt></dt>
1106 <dd>Specifies that the target lays out data in big-endian form. That is, the
1107 bits with the most significance have the lowest address location.</dd>
1108 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1109 <dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1110 the bits with the least significance have the lowest address location.</dd>
1111 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1112 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
1113 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
1114 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
1115 too.</dd>
1116 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1117 <dd>This specifies the alignment for an integer type of a given bit
1118 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1119 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1120 <dd>This specifies the alignment for a vector type of a given bit
1121 <i>size</i>.</dd>
1122 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1123 <dd>This specifies the alignment for a floating point type of a given bit
1124 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1125 (double).</dd>
1126 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1127 <dd>This specifies the alignment for an aggregate type of a given bit
1128 <i>size</i>.</dd>
1129</dl>
1130<p>When constructing the data layout for a given target, LLVM starts with a
1131default set of specifications which are then (possibly) overriden by the
1132specifications in the <tt>datalayout</tt> keyword. The default specifications
1133are given in this list:</p>
1134<ul>
1135 <li><tt>E</tt> - big endian</li>
1136 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1137 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1138 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1139 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1140 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1141 <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]1142 alignment of 64-bits</li>
1143 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1144 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1145 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1146 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1147 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
1148</ul>
Chris Lattner1ca5c642008-08-05 18:21:08 +0000[diff] [blame]1149<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1150following rules:</p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1151<ol>
1152 <li>If the type sought is an exact match for one of the specifications, that
1153 specification is used.</li>
1154 <li>If no match is found, and the type sought is an integer type, then the
1155 smallest integer type that is larger than the bitwidth of the sought type is
1156 used. If none of the specifications are larger than the bitwidth then the the
1157 largest integer type is used. For example, given the default specifications
1158 above, the i7 type will use the alignment of i8 (next largest) while both
1159 i65 and i256 will use the alignment of i64 (largest specified).</li>
1160 <li>If no match is found, and the type sought is a vector type, then the
1161 largest vector type that is smaller than the sought vector type will be used
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1162 as a fall back. This happens because &lt;128 x double&gt; can be implemented
1163 in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1164</ol>
1165</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1166
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1167<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1168<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1169<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1170
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1171<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1172
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1173<p>The LLVM type system is one of the most important features of the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1174intermediate representation. Being typed enables a number of
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1175optimizations to be performed on the intermediate representation directly,
1176without having to do
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1177extra analyses on the side before the transformation. A strong type
1178system makes it easier to read the generated code and enables novel
1179analyses and transformations that are not feasible to perform on normal
1180three address code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1181
1182</div>
1183
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1184<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1185<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1186Classifications</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1187<div class="doc_text">
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1188<p>The types fall into a few useful
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1189classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1190
1191<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1192 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1193 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1194 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1195 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1196 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1197 </tr>
1198 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1199 <td><a href="#t_floating">floating point</a></td>
1200 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1201 </tr>
1202 <tr>
1203 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1204 <td><a href="#t_integer">integer</a>,
1205 <a href="#t_floating">floating point</a>,
1206 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1207 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1208 <a href="#t_struct">structure</a>,
1209 <a href="#t_array">array</a>,
Dan Gohmanda52d212008-05-23 22:50:26 +0000[diff] [blame]1210 <a href="#t_label">label</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1211 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1212 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1213 <tr>
1214 <td><a href="#t_primitive">primitive</a></td>
1215 <td><a href="#t_label">label</a>,
1216 <a href="#t_void">void</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1217 <a href="#t_floating">floating point</a>.</td>
1218 </tr>
1219 <tr>
1220 <td><a href="#t_derived">derived</a></td>
1221 <td><a href="#t_integer">integer</a>,
1222 <a href="#t_array">array</a>,
1223 <a href="#t_function">function</a>,
1224 <a href="#t_pointer">pointer</a>,
1225 <a href="#t_struct">structure</a>,
1226 <a href="#t_pstruct">packed structure</a>,
1227 <a href="#t_vector">vector</a>,
1228 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1229 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1230 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1231 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1232</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1233
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1234<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1235most important. Values of these types are the only ones which can be
1236produced by instructions, passed as arguments, or used as operands to
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]1237instructions.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1238</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1239
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1240<!-- ======================================================================= -->
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1241<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1242
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1243<div class="doc_text">
1244<p>The primitive types are the fundamental building blocks of the LLVM
1245system.</p>
1246
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1247</div>
1248
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1249<!-- _______________________________________________________________________ -->
1250<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1251
1252<div class="doc_text">
1253 <table>
1254 <tbody>
1255 <tr><th>Type</th><th>Description</th></tr>
1256 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1257 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1258 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1259 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1260 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1261 </tbody>
1262 </table>
1263</div>
1264
1265<!-- _______________________________________________________________________ -->
1266<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1267
1268<div class="doc_text">
1269<h5>Overview:</h5>
1270<p>The void type does not represent any value and has no size.</p>
1271
1272<h5>Syntax:</h5>
1273
1274<pre>
1275 void
1276</pre>
1277</div>
1278
1279<!-- _______________________________________________________________________ -->
1280<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1281
1282<div class="doc_text">
1283<h5>Overview:</h5>
1284<p>The label type represents code labels.</p>
1285
1286<h5>Syntax:</h5>
1287
1288<pre>
1289 label
1290</pre>
1291</div>
1292
1293
1294<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1295<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1296
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1297<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1298
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1299<p>The real power in LLVM comes from the derived types in the system.
1300This is what allows a programmer to represent arrays, functions,
1301pointers, and other useful types. Note that these derived types may be
1302recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1303
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1304</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1305
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1306<!-- _______________________________________________________________________ -->
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1307<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1308
1309<div class="doc_text">
1310
1311<h5>Overview:</h5>
1312<p>The integer type is a very simple derived type that simply specifies an
1313arbitrary bit width for the integer type desired. Any bit width from 1 bit to
13142^23-1 (about 8 million) can be specified.</p>
1315
1316<h5>Syntax:</h5>
1317
1318<pre>
1319 iN
1320</pre>
1321
1322<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1323value.</p>
1324
1325<h5>Examples:</h5>
1326<table class="layout">
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1327 <tbody>
1328 <tr>
1329 <td><tt>i1</tt></td>
1330 <td>a single-bit integer.</td>
1331 </tr><tr>
1332 <td><tt>i32</tt></td>
1333 <td>a 32-bit integer.</td>
1334 </tr><tr>
1335 <td><tt>i1942652</tt></td>
1336 <td>a really big integer of over 1 million bits.</td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1337 </tr>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1338 </tbody>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1339</table>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1340</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1341
1342<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1343<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1344
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1345<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1346
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1347<h5>Overview:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1348
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1349<p>The array type is a very simple derived type that arranges elements
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1350sequentially in memory. The array type requires a size (number of
1351elements) and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1352
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1353<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1354
1355<pre>
1356 [&lt;# elements&gt; x &lt;elementtype&gt;]
1357</pre>
1358
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1359<p>The number of elements is a constant integer value; elementtype may
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1360be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1361
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1362<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1363<table class="layout">
1364 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1365 <td class="left"><tt>[40 x i32]</tt></td>
1366 <td class="left">Array of 40 32-bit integer values.</td>
1367 </tr>
1368 <tr class="layout">
1369 <td class="left"><tt>[41 x i32]</tt></td>
1370 <td class="left">Array of 41 32-bit integer values.</td>
1371 </tr>
1372 <tr class="layout">
1373 <td class="left"><tt>[4 x i8]</tt></td>
1374 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1375 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1376</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1377<p>Here are some examples of multidimensional arrays:</p>
1378<table class="layout">
1379 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1380 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1381 <td class="left">3x4 array of 32-bit integer values.</td>
1382 </tr>
1383 <tr class="layout">
1384 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1385 <td class="left">12x10 array of single precision floating point values.</td>
1386 </tr>
1387 <tr class="layout">
1388 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1389 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1390 </tr>
1391</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1392
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1393<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1394length array. Normally, accesses past the end of an array are undefined in
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1395LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1396As a special case, however, zero length arrays are recognized to be variable
1397length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1398type "{ i32, [0 x float]}", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1399
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1400</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1401
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1402<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1403<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1404<div class="doc_text">
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1405
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1406<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1407
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1408<p>The function type can be thought of as a function signature. It
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1409consists of a return type and a list of formal parameter types. The
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1410return 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]1411If 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]1412class types, and the struct must have at least one element.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1413
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1414<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1415
1416<pre>
1417 &lt;returntype list&gt; (&lt;parameter list&gt;)
1418</pre>
1419
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1420<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]1421specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1422which indicates that the function takes a variable number of arguments.
1423Variable argument functions can access their arguments with the <a
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1424 href="#int_varargs">variable argument handling intrinsic</a> functions.
1425'<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1426<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1427
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1428<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1429<table class="layout">
1430 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1431 <td class="left"><tt>i32 (i32)</tt></td>
1432 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1433 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1434 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]1435 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1436 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1437 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1438 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1439 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1440 <tt>float</tt>.
1441 </td>
1442 </tr><tr class="layout">
1443 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1444 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1445 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1446 which returns an integer. This is the signature for <tt>printf</tt> in
1447 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1448 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1449 </tr><tr class="layout">
1450 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanc9813bd2008-11-27 06:41:20 +0000[diff] [blame]1451 <td class="left">A function taking an <tt>i32</tt>, returning two
1452 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1453 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1454 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1455</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1456
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1457</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1458<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1459<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1460<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1461<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1462<p>The structure type is used to represent a collection of data members
1463together in memory. The packing of the field types is defined to match
1464the ABI of the underlying processor. The elements of a structure may
1465be any type that has a size.</p>
1466<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1467and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1468field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1469instruction.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1470<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1471<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1472<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1473<table class="layout">
1474 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1475 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1476 <td class="left">A triple of three <tt>i32</tt> values</td>
1477 </tr><tr class="layout">
1478 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1479 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1480 second element is a <a href="#t_pointer">pointer</a> to a
1481 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1482 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1483 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1484</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1485</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1486
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1487<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1488<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1489</div>
1490<div class="doc_text">
1491<h5>Overview:</h5>
1492<p>The packed structure type is used to represent a collection of data members
1493together in memory. There is no padding between fields. Further, the alignment
1494of a packed structure is 1 byte. The elements of a packed structure may
1495be any type that has a size.</p>
1496<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1497and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1498field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1499instruction.</p>
1500<h5>Syntax:</h5>
1501<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1502<h5>Examples:</h5>
1503<table class="layout">
1504 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1505 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1506 <td class="left">A triple of three <tt>i32</tt> values</td>
1507 </tr><tr class="layout">
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1508 <td class="left">
1509<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1510 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1511 second element is a <a href="#t_pointer">pointer</a> to a
1512 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1513 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1514 </tr>
1515</table>
1516</div>
1517
1518<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1519<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1520<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1521<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1522<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]1523reference to another object, which must live in memory. Pointer types may have
1524an optional address space attribute defining the target-specific numbered
1525address space where the pointed-to object resides. The default address space is
1526zero.</p>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1527<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1528<pre> &lt;type&gt; *<br></pre>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1529<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1530<table class="layout">
1531 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]1532 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1533 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1534 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1535 </tr>
1536 <tr class="layout">
1537 <td class="left"><tt>i32 (i32 *) *</tt></td>
1538 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1539 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1540 <tt>i32</tt>.</td>
1541 </tr>
1542 <tr class="layout">
1543 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1544 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1545 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1546 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1547</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1548</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1549
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1550<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1551<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1552<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1553
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1554<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1555
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1556<p>A vector type is a simple derived type that represents a vector
1557of elements. Vector types are used when multiple primitive data
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1558are operated in parallel using a single instruction (SIMD).
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1559A vector type requires a size (number of
Chris Lattner330ce692005-11-10 01:44:22 +0000[diff] [blame]1560elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1561of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1562considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1563
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1564<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1565
1566<pre>
1567 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1568</pre>
1569
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1570<p>The number of elements is a constant integer value; elementtype may
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1571be any integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1572
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1573<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1574
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1575<table class="layout">
1576 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1577 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1578 <td class="left">Vector of 4 32-bit integer values.</td>
1579 </tr>
1580 <tr class="layout">
1581 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1582 <td class="left">Vector of 8 32-bit floating-point values.</td>
1583 </tr>
1584 <tr class="layout">
1585 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1586 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1587 </tr>
1588</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1589</div>
1590
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1591<!-- _______________________________________________________________________ -->
1592<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1593<div class="doc_text">
1594
1595<h5>Overview:</h5>
1596
1597<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksena699c4d2007-10-14 00:34:53 +0000[diff] [blame]1598corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1599In LLVM, opaque types can eventually be resolved to any type (not just a
1600structure type).</p>
1601
1602<h5>Syntax:</h5>
1603
1604<pre>
1605 opaque
1606</pre>
1607
1608<h5>Examples:</h5>
1609
1610<table class="layout">
1611 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1612 <td class="left"><tt>opaque</tt></td>
1613 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1614 </tr>
1615</table>
1616</div>
1617
1618
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1619<!-- *********************************************************************** -->
1620<div class="doc_section"> <a name="constants">Constants</a> </div>
1621<!-- *********************************************************************** -->
1622
1623<div class="doc_text">
1624
1625<p>LLVM has several different basic types of constants. This section describes
1626them all and their syntax.</p>
1627
1628</div>
1629
1630<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1631<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1632
1633<div class="doc_text">
1634
1635<dl>
1636 <dt><b>Boolean constants</b></dt>
1637
1638 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1639 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1640 </dd>
1641
1642 <dt><b>Integer constants</b></dt>
1643
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1644 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1645 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1646 integer types.
1647 </dd>
1648
1649 <dt><b>Floating point constants</b></dt>
1650
1651 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1652 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]1653 notation (see below). The assembler requires the exact decimal value of
1654 a floating-point constant. For example, the assembler accepts 1.25 but
1655 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1656 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1657
1658 <dt><b>Null pointer constants</b></dt>
1659
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1660 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1661 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1662
1663</dl>
1664
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1665<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1666of floating point constants. For example, the form '<tt>double
16670x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
16684.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1669(and the only time that they are generated by the disassembler) is when a
1670floating point constant must be emitted but it cannot be represented as a
1671decimal floating point number. For example, NaN's, infinities, and other
1672special values are represented in their IEEE hexadecimal format so that
1673assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1674
1675</div>
1676
1677<!-- ======================================================================= -->
1678<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1679</div>
1680
1681<div class="doc_text">
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]1682<p>Aggregate constants arise from aggregation of simple constants
1683and smaller aggregate constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1684
1685<dl>
1686 <dt><b>Structure constants</b></dt>
1687
1688 <dd>Structure constants are represented with notation similar to structure
1689 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattnerbea11172007-12-25 20:34:52 +0000[diff] [blame]1690 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1691 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]1692 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1693 types of elements must match those specified by the type.
1694 </dd>
1695
1696 <dt><b>Array constants</b></dt>
1697
1698 <dd>Array constants are represented with notation similar to array type
1699 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1700 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1701 constants must have <a href="#t_array">array type</a>, and the number and
1702 types of elements must match those specified by the type.
1703 </dd>
1704
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1705 <dt><b>Vector constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1706
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1707 <dd>Vector constants are represented with notation similar to vector type
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1708 definitions (a comma separated list of elements, surrounded by
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1709 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]1710 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1711 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1712 match those specified by the type.
1713 </dd>
1714
1715 <dt><b>Zero initialization</b></dt>
1716
1717 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1718 value to zero of <em>any</em> type, including scalar and aggregate types.
1719 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]1720 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1721 initializers.
1722 </dd>
1723</dl>
1724
1725</div>
1726
1727<!-- ======================================================================= -->
1728<div class="doc_subsection">
1729 <a name="globalconstants">Global Variable and Function Addresses</a>
1730</div>
1731
1732<div class="doc_text">
1733
1734<p>The addresses of <a href="#globalvars">global variables</a> and <a
1735href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1736constants. These constants are explicitly referenced when the <a
1737href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1738href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1739file:</p>
1740
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1741<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1742<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]1743@X = global i32 17
1744@Y = global i32 42
1745@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1746</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1747</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1748
1749</div>
1750
1751<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1752<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1753<div class="doc_text">
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1754 <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]1755 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1756 a constant is permitted.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1757
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1758 <p>Undefined values indicate to the compiler that the program is well defined
1759 no matter what value is used, giving the compiler more freedom to optimize.
1760 </p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1761</div>
1762
1763<!-- ======================================================================= -->
1764<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1765</div>
1766
1767<div class="doc_text">
1768
1769<p>Constant expressions are used to allow expressions involving other constants
1770to be used as constants. Constant expressions may be of any <a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1771href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1772that does not have side effects (e.g. load and call are not supported). The
1773following is the syntax for constant expressions:</p>
1774
1775<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1776 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1777 <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]1778 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1779
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1780 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1781 <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]1782 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]1783
1784 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1785 <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]1786 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]1787
1788 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1789 <dd>Truncate a floating point constant to another floating point type. The
1790 size of CST must be larger than the size of TYPE. Both types must be
1791 floating point.</dd>
1792
1793 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1794 <dd>Floating point extend a constant to another type. The size of CST must be
1795 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1796
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]1797 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1798 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1799 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1800 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1801 of the same number of elements. If the value won't fit in the integer type,
1802 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1803
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1804 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1805 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1806 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1807 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1808 of the same number of elements. If the value won't fit in the integer type,
1809 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1810
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1811 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1812 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1813 constant. TYPE must be a scalar or vector floating point type. CST must be of
1814 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1815 of the same number of elements. If the value won't fit in the floating point
1816 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1817
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1818 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1819 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1820 constant. TYPE must be a scalar or vector floating point type. CST must be of
1821 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1822 of the same number of elements. If the value won't fit in the floating point
1823 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1824
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1825 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1826 <dd>Convert a pointer typed constant to the corresponding integer constant
1827 TYPE must be an integer type. CST must be of pointer type. The CST value is
1828 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1829
1830 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1831 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1832 pointer type. CST must be of integer type. The CST value is zero extended,
1833 truncated, or unchanged to make it fit in a pointer size. This one is
1834 <i>really</i> dangerous!</dd>
1835
1836 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1837 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1838 identical (same number of bits). The conversion is done as if the CST value
1839 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]1840 with this operator, just the type. This can be used for conversion of
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1841 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]1842 pointers it is only valid to cast to another pointer type. It is not valid
1843 to bitcast to or from an aggregate type.
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1844 </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1845
1846 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1847
1848 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1849 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1850 instruction, the index list may have zero or more indexes, which are required
1851 to make sense for the type of "CSTPTR".</dd>
1852
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1853 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1854
1855 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1856 constants.</dd>
1857
1858 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1859 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1860
1861 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1862 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1863
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]1864 <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
1865 <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
1866
1867 <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
1868 <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
1869
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1870 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1871
1872 <dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]1873 operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1874
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1875 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1876
1877 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1878 operation</a> on constants.</dd>
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1879
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1880
1881 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1882
1883 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1884 operation</a> on constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1885
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1886 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1887
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1888 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1889 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1890 binary</a> operations. The constraints on operands are the same as those for
1891 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1892 values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1893</dl>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1894</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]1895
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1896<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1897<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1898<!-- *********************************************************************** -->
1899
1900<!-- ======================================================================= -->
1901<div class="doc_subsection">
1902<a name="inlineasm">Inline Assembler Expressions</a>
1903</div>
1904
1905<div class="doc_text">
1906
1907<p>
1908LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1909Module-Level Inline Assembly</a>) through the use of a special value. This
1910value represents the inline assembler as a string (containing the instructions
1911to emit), a list of operand constraints (stored as a string), and a flag that
1912indicates whether or not the inline asm expression has side effects. An example
1913inline assembler expression is:
1914</p>
1915
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1916<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1917<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1918i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1919</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1920</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1921
1922<p>
1923Inline assembler expressions may <b>only</b> be used as the callee operand of
1924a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1925</p>
1926
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1927<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1928<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1929%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]1930</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1931</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1932
1933<p>
1934Inline asms with side effects not visible in the constraint list must be marked
1935as having side effects. This is done through the use of the
1936'<tt>sideeffect</tt>' keyword, like so:
1937</p>
1938
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1939<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1940<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1941call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1942</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1943</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1944
1945<p>TODO: The format of the asm and constraints string still need to be
1946documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattnerd5528262008-10-04 18:36:02 +0000[diff] [blame]1947need to be documented). This is probably best done by reference to another
1948document that covers inline asm from a holistic perspective.
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1949</p>
1950
1951</div>
1952
1953<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1954<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1955<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1956
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1957<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1958
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1959<p>The LLVM instruction set consists of several different
1960classifications of instructions: <a href="#terminators">terminator
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1961instructions</a>, <a href="#binaryops">binary instructions</a>,
1962<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1963 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1964instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1965
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1966</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1967
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1968<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1969<div class="doc_subsection"> <a name="terminators">Terminator
1970Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1971
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1972<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1973
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1974<p>As mentioned <a href="#functionstructure">previously</a>, every
1975basic block in a program ends with a "Terminator" instruction, which
1976indicates which block should be executed after the current block is
1977finished. These terminator instructions typically yield a '<tt>void</tt>'
1978value: they produce control flow, not values (the one exception being
1979the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1980<p>There are six different terminator instructions: the '<a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1981 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1982instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1983the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1984 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1985 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1986
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1987</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1988
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1989<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1990<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1991Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1992<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1993<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]1994<pre>
1995 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]1996 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1997</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1998
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1999<h5>Overview:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2000
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2001<p>The '<tt>ret</tt>' instruction is used to return control flow (and
2002optionally a value) from a function back to the caller.</p>
John Criswell417228d2004-04-09 16:48:45 +0000[diff] [blame]2003<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2004returns a value and then causes control flow, and one that just causes
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2005control flow to occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2006
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2007<h5>Arguments:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2008
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2009<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
2010the return value. The type of the return value must be a
2011'<a href="#t_firstclass">first class</a>' type.</p>
2012
2013<p>A function is not <a href="#wellformed">well formed</a> if
2014it it has a non-void return type and contains a '<tt>ret</tt>'
2015instruction with no return value or a return value with a type that
2016does not match its type, or if it has a void return type and contains
2017a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2018
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2019<h5>Semantics:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2020
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2021<p>When the '<tt>ret</tt>' instruction is executed, control flow
2022returns back to the calling function's context. If the caller is a "<a
John Criswell40db33f2004-06-25 15:16:57 +0000[diff] [blame]2023 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2024the instruction after the call. If the caller was an "<a
2025 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2026at the beginning of the "normal" destination block. If the instruction
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2027returns a value, that value shall set the call or invoke instruction's
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]2028return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2029
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2030<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2031
2032<pre>
2033 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2034 ret void <i>; Return from a void function</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2035 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]2036</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2037</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2038<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2039<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2040<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2041<h5>Syntax:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2042<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]2043</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2044<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2045<p>The '<tt>br</tt>' instruction is used to cause control flow to
2046transfer to a different basic block in the current function. There are
2047two forms of this instruction, corresponding to a conditional branch
2048and an unconditional branch.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2049<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2050<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2051single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]2052unconditional form of the '<tt>br</tt>' instruction takes a single
2053'<tt>label</tt>' value as a target.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2054<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2055<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2056argument is evaluated. If the value is <tt>true</tt>, control flows
2057to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2058control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2059<h5>Example:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2060<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]2061 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]2062</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2063<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2064<div class="doc_subsubsection">
2065 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2066</div>
2067
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2068<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2069<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2070
2071<pre>
2072 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2073</pre>
2074
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2075<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2076
2077<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
2078several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2079instruction, allowing a branch to occur to one of many possible
2080destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2081
2082
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2083<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2084
2085<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
2086comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
2087an array of pairs of comparison value constants and '<tt>label</tt>'s. The
2088table is not allowed to contain duplicate constant entries.</p>
2089
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2090<h5>Semantics:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2091
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2092<p>The <tt>switch</tt> instruction specifies a table of values and
2093destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]2094table is searched for the given value. If the value is found, control flow is
2095transfered to the corresponding destination; otherwise, control flow is
2096transfered to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2097
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2098<h5>Implementation:</h5>
2099
2100<p>Depending on properties of the target machine and the particular
2101<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]2102ways. For example, it could be generated as a series of chained conditional
2103branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2104
2105<h5>Example:</h5>
2106
2107<pre>
2108 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2109 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2110 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2111
2112 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2113 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2114
2115 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2116 switch i32 %val, label %otherwise [ i32 0, label %onzero
2117 i32 1, label %onone
2118 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2119</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2120</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2121
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2122<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2123<div class="doc_subsubsection">
2124 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2125</div>
2126
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2127<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2128
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2129<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2130
2131<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2132 &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]2133 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2134</pre>
2135
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2136<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2137
2138<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
2139function, with the possibility of control flow transfer to either the
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2140'<tt>normal</tt>' label or the
2141'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2142"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
2143"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]2144href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]2145continued at the dynamically nearest "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2146
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2147<h5>Arguments:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2148
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2149<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2150
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2151<ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2152 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]2153 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2154 convention</a> the call should use. If none is specified, the call defaults
2155 to using C calling conventions.
2156 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2157
2158 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
2159 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
2160 and '<tt>inreg</tt>' attributes are valid here.</li>
2161
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2162 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
2163 function value being invoked. In most cases, this is a direct function
2164 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
2165 an arbitrary pointer to function value.
2166 </li>
2167
2168 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
2169 function to be invoked. </li>
2170
2171 <li>'<tt>function args</tt>': argument list whose types match the function
2172 signature argument types. If the function signature indicates the function
2173 accepts a variable number of arguments, the extra arguments can be
2174 specified. </li>
2175
2176 <li>'<tt>normal label</tt>': the label reached when the called function
2177 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
2178
2179 <li>'<tt>exception label</tt>': the label reached when a callee returns with
2180 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
2181
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]2182 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]2183 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2184 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2185</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2186
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2187<h5>Semantics:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2188
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2189<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2190href="#i_call">call</a></tt>' instruction in most regards. The primary
2191difference is that it establishes an association with a label, which is used by
2192the runtime library to unwind the stack.</p>
2193
2194<p>This instruction is used in languages with destructors to ensure that proper
2195cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2196exception. Additionally, this is important for implementation of
2197'<tt>catch</tt>' clauses in high-level languages that support them.</p>
2198
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2199<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]2200<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2201 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2202 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]2203 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2204 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2205</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2206</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2207
2208
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2209<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2210
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2211<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2212Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2213
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2214<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2215
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2216<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2217<pre>
2218 unwind
2219</pre>
2220
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2221<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2222
2223<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
2224at the first callee in the dynamic call stack which used an <a
2225href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
2226primarily used to implement exception handling.</p>
2227
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]2228<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2229
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]2230<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2231immediately halt. The dynamic call stack is then searched for the first <a
2232href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
2233execution continues at the "exceptional" destination block specified by the
2234<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
2235dynamic call chain, undefined behavior results.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2236</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]2237
2238<!-- _______________________________________________________________________ -->
2239
2240<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2241Instruction</a> </div>
2242
2243<div class="doc_text">
2244
2245<h5>Syntax:</h5>
2246<pre>
2247 unreachable
2248</pre>
2249
2250<h5>Overview:</h5>
2251
2252<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
2253instruction is used to inform the optimizer that a particular portion of the
2254code is not reachable. This can be used to indicate that the code after a
2255no-return function cannot be reached, and other facts.</p>
2256
2257<h5>Semantics:</h5>
2258
2259<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
2260</div>
2261
2262
2263
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2264<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2265<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2266<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2267<p>Binary operators are used to do most of the computation in a
Chris Lattner81f92972008-04-01 18:47:32 +0000[diff] [blame]2268program. They require two operands of the same type, execute an operation on them, and
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2269produce a single value. The operands might represent
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2270multiple 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]2271The result value has the same type as its operands.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2272<p>There are several different binary operators:</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2273</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2274<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2275<div class="doc_subsubsection">
2276 <a name="i_add">'<tt>add</tt>' Instruction</a>
2277</div>
2278
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2279<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2280
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2281<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2282
2283<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2284 &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]2285</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2286
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2287<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2288
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2289<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2290
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2291<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2292
2293<p>The two arguments to the '<tt>add</tt>' instruction must be <a
2294 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
2295 <a href="#t_vector">vector</a> values. Both arguments must have identical
2296 types.</p>
2297
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2298<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2299
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2300<p>The value produced is the integer or floating point sum of the two
2301operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2302
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2303<p>If an integer sum has unsigned overflow, the result returned is the
2304mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2305the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2306
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2307<p>Because LLVM integers use a two's complement representation, this
2308instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2309
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2310<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2311
2312<pre>
2313 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2314</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2315</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2316<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2317<div class="doc_subsubsection">
2318 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2319</div>
2320
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2321<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2322
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2323<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2324
2325<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2326 &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]2327</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2328
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2329<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2330
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2331<p>The '<tt>sub</tt>' instruction returns the difference of its two
2332operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2333
2334<p>Note that the '<tt>sub</tt>' instruction is used to represent the
2335'<tt>neg</tt>' instruction present in most other intermediate
2336representations.</p>
2337
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2338<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2339
2340<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
2341 href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2342 or <a href="#t_vector">vector</a> values. Both arguments must have identical
2343 types.</p>
2344
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2345<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2346
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2347<p>The value produced is the integer or floating point difference of
2348the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2349
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2350<p>If an integer difference has unsigned overflow, the result returned is the
2351mathematical result modulo 2<sup>n</sup>, where n is the bit width of
2352the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2353
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2354<p>Because LLVM integers use a two's complement representation, this
2355instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2356
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2357<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2358<pre>
2359 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2360 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2361</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2362</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2363
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2364<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2365<div class="doc_subsubsection">
2366 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2367</div>
2368
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2369<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2370
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2371<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2372<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]2373</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2374<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2375<p>The '<tt>mul</tt>' instruction returns the product of its two
2376operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2377
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2378<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2379
2380<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
2381href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
2382or <a href="#t_vector">vector</a> values. Both arguments must have identical
2383types.</p>
2384
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2385<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2386
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2387<p>The value produced is the integer or floating point product of the
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2388two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2389
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2390<p>If the result of an integer multiplication has unsigned overflow,
2391the result returned is the mathematical result modulo
23922<sup>n</sup>, where n is the bit width of the result.</p>
2393<p>Because LLVM integers use a two's complement representation, and the
2394result is the same width as the operands, this instruction returns the
2395correct result for both signed and unsigned integers. If a full product
2396(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
2397should be sign-extended or zero-extended as appropriate to the
2398width of the full product.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2399<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2400<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]2401</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2402</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2403
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2404<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2405<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2406</a></div>
2407<div class="doc_text">
2408<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2409<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]2410</pre>
2411<h5>Overview:</h5>
2412<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2413operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2414
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2415<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2416
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2417<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2418<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2419values. Both arguments must have identical types.</p>
2420
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2421<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2422
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2423<p>The value produced is the unsigned integer quotient of the two operands.</p>
2424<p>Note that unsigned integer division and signed integer division are distinct
2425operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2426<p>Division by zero leads to undefined behavior.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2427<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2428<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]2429</pre>
2430</div>
2431<!-- _______________________________________________________________________ -->
2432<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2433</a> </div>
2434<div class="doc_text">
2435<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2436<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2437 &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]2438</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2439
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2440<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2441
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2442<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2443operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2444
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2445<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2446
2447<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2448<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2449values. Both arguments must have identical types.</p>
2450
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2451<h5>Semantics:</h5>
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2452<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]2453<p>Note that signed integer division and unsigned integer division are distinct
2454operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2455<p>Division by zero leads to undefined behavior. Overflow also leads to
2456undefined behavior; this is a rare case, but can occur, for example,
2457by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2458<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2459<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]2460</pre>
2461</div>
2462<!-- _______________________________________________________________________ -->
2463<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2464Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2465<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2466<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2467<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2468 &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]2469</pre>
2470<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2471
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2472<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2473operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2474
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2475<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2476
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2477<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2478<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2479of floating point values. Both arguments must have identical types.</p>
2480
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2481<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2482
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2483<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2484
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2485<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2486
2487<pre>
2488 &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]2489</pre>
2490</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2491
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2492<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2493<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2494</div>
2495<div class="doc_text">
2496<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2497<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]2498</pre>
2499<h5>Overview:</h5>
2500<p>The '<tt>urem</tt>' instruction returns the remainder from the
2501unsigned division of its two arguments.</p>
2502<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2503<p>The two arguments to the '<tt>urem</tt>' instruction must be
2504<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2505values. Both arguments must have identical types.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2506<h5>Semantics:</h5>
2507<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2508This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2509<p>Note that unsigned integer remainder and signed integer remainder are
2510distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
2511<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2512<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2513<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]2514</pre>
2515
2516</div>
2517<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2518<div class="doc_subsubsection">
2519 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
2520</div>
2521
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2522<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2523
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2524<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2525
2526<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2527 &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]2528</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2529
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2530<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2531
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2532<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame]2533signed division of its two operands. This instruction can also take
2534<a href="#t_vector">vector</a> versions of the values in which case
2535the elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]2536
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2537<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2538
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2539<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2540<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2541values. Both arguments must have identical types.</p>
2542
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2543<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2544
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2545<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2546has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
2547operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2548a value. For more information about the difference, see <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2549 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2550Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencerdb3b93b2007-03-24 22:40:44 +0000[diff] [blame]2551please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2552Wikipedia: modulo operation</a>.</p>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]2553<p>Note that signed integer remainder and unsigned integer remainder are
2554distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
2555<p>Taking the remainder of a division by zero leads to undefined behavior.
2556Overflow also leads to undefined behavior; this is a rare case, but can occur,
2557for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
2558(The remainder doesn't actually overflow, but this rule lets srem be
2559implemented using instructions that return both the result of the division
2560and the remainder.)</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2561<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2562<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]2563</pre>
2564
2565</div>
2566<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2567<div class="doc_subsubsection">
2568 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
2569
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2570<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2571
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2572<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2573<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]2574</pre>
2575<h5>Overview:</h5>
2576<p>The '<tt>frem</tt>' instruction returns the remainder from the
2577division of its two operands.</p>
2578<h5>Arguments:</h5>
2579<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2580<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
2581of floating point values. Both arguments must have identical types.</p>
2582
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2583<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2584
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2585<p>This instruction returns the <i>remainder</i> of a division.
2586The remainder has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2587
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2588<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2589
2590<pre>
2591 &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]2592</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2593</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]2594
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2595<!-- ======================================================================= -->
2596<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2597Operations</a> </div>
2598<div class="doc_text">
2599<p>Bitwise binary operators are used to do various forms of
2600bit-twiddling in a program. They are generally very efficient
2601instructions and can commonly be strength reduced from other
Chris Lattner1429e6f2008-04-01 18:45:27 +0000[diff] [blame]2602instructions. They require two operands of the same type, execute an operation on them,
2603and 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]2604</div>
2605
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2606<!-- _______________________________________________________________________ -->
2607<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2608Instruction</a> </div>
2609<div class="doc_text">
2610<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2611<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]2612</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2613
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2614<h5>Overview:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2615
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2616<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2617the left a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2618
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2619<h5>Arguments:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2620
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2621<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2622 href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2623type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2624
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2625<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2626
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2627<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
2628where 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]2629equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
2630If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2631corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2632
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2633<h5>Example:</h5><pre>
2634 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2635 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2636 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2637 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]2638 &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]2639</pre>
2640</div>
2641<!-- _______________________________________________________________________ -->
2642<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2643Instruction</a> </div>
2644<div class="doc_text">
2645<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2646<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]2647</pre>
2648
2649<h5>Overview:</h5>
2650<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2651operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2652
2653<h5>Arguments:</h5>
2654<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2655<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]2656type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2657
2658<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2659
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2660<p>This instruction always performs a logical shift right operation. The most
2661significant bits of the result will be filled with zero bits after the
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2662shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang68d4eee2008-12-10 08:55:09 +0000[diff] [blame]2663the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
2664vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
2665amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2666
2667<h5>Example:</h5>
2668<pre>
2669 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2670 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2671 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2672 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2673 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]2674 &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]2675</pre>
2676</div>
2677
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2678<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2679<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2680Instruction</a> </div>
2681<div class="doc_text">
2682
2683<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2684<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]2685</pre>
2686
2687<h5>Overview:</h5>
2688<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2689operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2690
2691<h5>Arguments:</h5>
2692<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begemanfecbc8c2008-07-29 15:49:41 +0000[diff] [blame]2693<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]2694type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2695
2696<h5>Semantics:</h5>
2697<p>This instruction always performs an arithmetic shift right operation,
2698The most significant bits of the result will be filled with the sign bit
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2699of <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]2700larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
2701arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
2702corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2703
2704<h5>Example:</h5>
2705<pre>
2706 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2707 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2708 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2709 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2710 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]2711 &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]2712</pre>
2713</div>
2714
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2715<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2716<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2717Instruction</a> </div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2718
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2719<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2720
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2721<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2722
2723<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2724 &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]2725</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2726
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2727<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2728
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2729<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2730its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2731
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2732<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2733
2734<p>The two arguments to the '<tt>and</tt>' instruction must be
2735<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2736values. Both arguments must have identical types.</p>
2737
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2738<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2739<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2740<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2741<div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2742<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2743 <tbody>
2744 <tr>
2745 <td>In0</td>
2746 <td>In1</td>
2747 <td>Out</td>
2748 </tr>
2749 <tr>
2750 <td>0</td>
2751 <td>0</td>
2752 <td>0</td>
2753 </tr>
2754 <tr>
2755 <td>0</td>
2756 <td>1</td>
2757 <td>0</td>
2758 </tr>
2759 <tr>
2760 <td>1</td>
2761 <td>0</td>
2762 <td>0</td>
2763 </tr>
2764 <tr>
2765 <td>1</td>
2766 <td>1</td>
2767 <td>1</td>
2768 </tr>
2769 </tbody>
2770</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2771</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2772<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2773<pre>
2774 &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]2775 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2776 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2777</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2778</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2779<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2780<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2781<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2782<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2783<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]2784</pre>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2785<h5>Overview:</h5>
2786<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2787or of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2788<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2789
2790<p>The two arguments to the '<tt>or</tt>' instruction must be
2791<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2792values. Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2793<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2794<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2795<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2796<div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2797<table border="1" cellspacing="0" cellpadding="4">
2798 <tbody>
2799 <tr>
2800 <td>In0</td>
2801 <td>In1</td>
2802 <td>Out</td>
2803 </tr>
2804 <tr>
2805 <td>0</td>
2806 <td>0</td>
2807 <td>0</td>
2808 </tr>
2809 <tr>
2810 <td>0</td>
2811 <td>1</td>
2812 <td>1</td>
2813 </tr>
2814 <tr>
2815 <td>1</td>
2816 <td>0</td>
2817 <td>1</td>
2818 </tr>
2819 <tr>
2820 <td>1</td>
2821 <td>1</td>
2822 <td>1</td>
2823 </tr>
2824 </tbody>
2825</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2826</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2827<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2828<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2829 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2830 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2831</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2832</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2833<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2834<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2835Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2836<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2837<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]2838<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]2839</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2840<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2841<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2842or of its two operands. The <tt>xor</tt> is used to implement the
2843"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2844<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2845<p>The two arguments to the '<tt>xor</tt>' instruction must be
2846<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2847values. Both arguments must have identical types.</p>
2848
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2849<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]2850
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2851<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2852<p> </p>
Bill Wendling5703c6e2008-09-07 10:29:20 +0000[diff] [blame]2853<div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2854<table border="1" cellspacing="0" cellpadding="4">
2855 <tbody>
2856 <tr>
2857 <td>In0</td>
2858 <td>In1</td>
2859 <td>Out</td>
2860 </tr>
2861 <tr>
2862 <td>0</td>
2863 <td>0</td>
2864 <td>0</td>
2865 </tr>
2866 <tr>
2867 <td>0</td>
2868 <td>1</td>
2869 <td>1</td>
2870 </tr>
2871 <tr>
2872 <td>1</td>
2873 <td>0</td>
2874 <td>1</td>
2875 </tr>
2876 <tr>
2877 <td>1</td>
2878 <td>1</td>
2879 <td>0</td>
2880 </tr>
2881 </tbody>
2882</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2883</div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2884<p> </p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2885<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2886<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2887 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2888 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2889 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2890</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2891</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2892
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2893<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2894<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2895 <a name="vectorops">Vector Operations</a>
2896</div>
2897
2898<div class="doc_text">
2899
2900<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2901target-independent manner. These instructions cover the element-access and
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2902vector-specific operations needed to process vectors effectively. While LLVM
2903does directly support these vector operations, many sophisticated algorithms
2904will want to use target-specific intrinsics to take full advantage of a specific
2905target.</p>
2906
2907</div>
2908
2909<!-- _______________________________________________________________________ -->
2910<div class="doc_subsubsection">
2911 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2912</div>
2913
2914<div class="doc_text">
2915
2916<h5>Syntax:</h5>
2917
2918<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2919 &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]2920</pre>
2921
2922<h5>Overview:</h5>
2923
2924<p>
2925The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2926element from a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2927</p>
2928
2929
2930<h5>Arguments:</h5>
2931
2932<p>
2933The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2934value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2935an index indicating the position from which to extract the element.
2936The index may be a variable.</p>
2937
2938<h5>Semantics:</h5>
2939
2940<p>
2941The result is a scalar of the same type as the element type of
2942<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2943<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2944results are undefined.
2945</p>
2946
2947<h5>Example:</h5>
2948
2949<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2950 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2951</pre>
2952</div>
2953
2954
2955<!-- _______________________________________________________________________ -->
2956<div class="doc_subsubsection">
2957 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2958</div>
2959
2960<div class="doc_text">
2961
2962<h5>Syntax:</h5>
2963
2964<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]2965 &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]2966</pre>
2967
2968<h5>Overview:</h5>
2969
2970<p>
2971The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2972element into a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2973</p>
2974
2975
2976<h5>Arguments:</h5>
2977
2978<p>
2979The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2980value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2981scalar value whose type must equal the element type of the first
2982operand. The third operand is an index indicating the position at
2983which to insert the value. The index may be a variable.</p>
2984
2985<h5>Semantics:</h5>
2986
2987<p>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2988The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2989element values are those of <tt>val</tt> except at position
2990<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2991exceeds the length of <tt>val</tt>, the results are undefined.
2992</p>
2993
2994<h5>Example:</h5>
2995
2996<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2997 %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]2998</pre>
2999</div>
3000
3001<!-- _______________________________________________________________________ -->
3002<div class="doc_subsubsection">
3003 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3004</div>
3005
3006<div class="doc_text">
3007
3008<h5>Syntax:</h5>
3009
3010<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3011 &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]3012</pre>
3013
3014<h5>Overview:</h5>
3015
3016<p>
3017The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3018from two input vectors, returning a vector with the same element type as
3019the input and length that is the same as the shuffle mask.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3020</p>
3021
3022<h5>Arguments:</h5>
3023
3024<p>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3025The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3026with types that match each other. The third argument is a shuffle mask whose
3027element type is always 'i32'. The result of the instruction is a vector whose
3028length is the same as the shuffle mask and whose element type is the same as
3029the element type of the first two operands.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3030</p>
3031
3032<p>
3033The shuffle mask operand is required to be a constant vector with either
3034constant integer or undef values.
3035</p>
3036
3037<h5>Semantics:</h5>
3038
3039<p>
3040The elements of the two input vectors are numbered from left to right across
3041both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]3042the result vector, which element of the two input vectors the result element
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3043gets. The element selector may be undef (meaning "don't care") and the second
3044operand may be undef if performing a shuffle from only one vector.
3045</p>
3046
3047<h5>Example:</h5>
3048
3049<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3050 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3051 &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]3052 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3053 &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]3054 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3055 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3056 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3057 &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]3058</pre>
3059</div>
3060
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]3061
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]3062<!-- ======================================================================= -->
3063<div class="doc_subsection">
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3064 <a name="aggregateops">Aggregate Operations</a>
3065</div>
3066
3067<div class="doc_text">
3068
3069<p>LLVM supports several instructions for working with aggregate values.
3070</p>
3071
3072</div>
3073
3074<!-- _______________________________________________________________________ -->
3075<div class="doc_subsubsection">
3076 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3077</div>
3078
3079<div class="doc_text">
3080
3081<h5>Syntax:</h5>
3082
3083<pre>
3084 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3085</pre>
3086
3087<h5>Overview:</h5>
3088
3089<p>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3090The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3091or array element from an aggregate value.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3092</p>
3093
3094
3095<h5>Arguments:</h5>
3096
3097<p>
3098The first operand of an '<tt>extractvalue</tt>' instruction is a
3099value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3100type. The operands are constant indices to specify which value to extract
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3101in a similar manner as indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3102'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3103</p>
3104
3105<h5>Semantics:</h5>
3106
3107<p>
3108The result is the value at the position in the aggregate specified by
3109the index operands.
3110</p>
3111
3112<h5>Example:</h5>
3113
3114<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3115 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3116</pre>
3117</div>
3118
3119
3120<!-- _______________________________________________________________________ -->
3121<div class="doc_subsubsection">
3122 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3123</div>
3124
3125<div class="doc_text">
3126
3127<h5>Syntax:</h5>
3128
3129<pre>
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3130 &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]3131</pre>
3132
3133<h5>Overview:</h5>
3134
3135<p>
3136The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3137into a struct field or array element in an aggregate.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3138</p>
3139
3140
3141<h5>Arguments:</h5>
3142
3143<p>
3144The first operand of an '<tt>insertvalue</tt>' instruction is a
3145value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
3146The second operand is a first-class value to insert.
Dan Gohman34d1c0d2008-05-23 21:53:15 +0000[diff] [blame]3147The following operands are constant indices
Dan Gohman1ecaf452008-05-31 00:58:22 +0000[diff] [blame]3148indicating the position at which to insert the value in a similar manner as
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3149indices in a
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3150'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
3151The value to insert must have the same type as the value identified
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3152by the indices.
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3153</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3154
3155<h5>Semantics:</h5>
3156
3157<p>
3158The result is an aggregate of the same type as <tt>val</tt>. Its
3159value is that of <tt>val</tt> except that the value at the position
Dan Gohman35a835c2008-05-13 18:16:06 +0000[diff] [blame]3160specified by the indices is that of <tt>elt</tt>.
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3161</p>
3162
3163<h5>Example:</h5>
3164
3165<pre>
Dan Gohman88ce1a52008-06-23 15:26:37 +0000[diff] [blame]3166 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]3167</pre>
3168</div>
3169
3170
3171<!-- ======================================================================= -->
3172<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3173 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3174</div>
3175
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3176<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3177
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3178<p>A key design point of an SSA-based representation is how it
3179represents memory. In LLVM, no memory locations are in SSA form, which
3180makes things very simple. This section describes how to read, write,
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3181allocate, and free memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3182
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3183</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3184
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3185<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3186<div class="doc_subsubsection">
3187 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3188</div>
3189
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3190<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3191
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3192<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3193
3194<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3195 &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]3196</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3197
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3198<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3199
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3200<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3201heap and returns a pointer to it. The object is always allocated in the generic
3202address space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3203
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3204<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3205
3206<p>The '<tt>malloc</tt>' instruction allocates
3207<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswella92e5862004-02-24 16:13:56 +0000[diff] [blame]3208bytes of memory from the operating system and returns a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3209appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3210number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3211If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3212be aligned to at least that boundary. If not specified, or if zero, the target can
3213choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3214
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3215<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3216
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3217<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3218
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3219<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewyckyf5ffcbc2008-11-24 03:41:24 +0000[diff] [blame]3220a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3221result is null if there is insufficient memory available.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3222
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3223<h5>Example:</h5>
3224
3225<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3226 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3227
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3228 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3229 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3230 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3231 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3232 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3233</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3234</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3235
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3236<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3237<div class="doc_subsubsection">
3238 <a name="i_free">'<tt>free</tt>' Instruction</a>
3239</div>
3240
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3241<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3242
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3243<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3244
3245<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3246 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3247</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3248
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3249<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3250
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3251<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3252memory heap to be reallocated in the future.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3253
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3254<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3255
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3256<p>'<tt>value</tt>' shall be a pointer value that points to a value
3257that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
3258instruction.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3259
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3260<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3261
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3262<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner0f103e12008-04-19 22:41:32 +0000[diff] [blame]3263after this instruction executes. If the pointer is null, the operation
3264is a noop.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3265
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3266<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3267
3268<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3269 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3270 free [4 x i8]* %array
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3271</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3272</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3273
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3274<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3275<div class="doc_subsubsection">
3276 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3277</div>
3278
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3279<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3280
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3281<h5>Syntax:</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 &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]3285</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3286
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3287<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3288
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3289<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
3290currently executing function, to be automatically released when this function
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3291returns to its caller. The object is always allocated in the generic address
3292space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3293
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3294<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3295
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3296<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3297bytes of memory on the runtime stack, returning a pointer of the
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3298appropriate type to the program. If "NumElements" is specified, it is the
3299number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3300If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greifdd1fc982008-02-09 22:24:34 +0000[diff] [blame]3301to be aligned to at least that boundary. If not specified, or if zero, the target
3302can choose to align the allocation on any convenient boundary.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3303
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3304<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3305
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3306<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3307
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3308<p>Memory is allocated; a pointer is returned. The operation is undefiend if
3309there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3310memory is automatically released when the function returns. The '<tt>alloca</tt>'
3311instruction is commonly used to represent automatic variables that must
3312have an address available. When the function returns (either with the <tt><a
John Criswellc932bef2005-05-12 16:55:34 +0000[diff] [blame]3313 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]3314instructions), the memory is reclaimed. Allocating zero bytes
3315is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3316
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3317<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3318
3319<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]3320 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3321 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3322 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3323 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3324</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3325</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]3326
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3327<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3328<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3329Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3330<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3331<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3332<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]3333<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3334<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3335<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3336<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3337address from which to load. The pointer must point to a <a
Chris Lattner10ee9652004-06-03 22:57:15 +0000[diff] [blame]3338 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]3339marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3340the number or order of execution of this <tt>load</tt> with other
3341volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3342instructions. </p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3343<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3344The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3345(that is, the alignment of the memory address). A value of 0 or an
3346omitted "align" argument means that the operation has the preferential
3347alignment for the target. It is the responsibility of the code emitter
3348to ensure that the alignment information is correct. Overestimating
3349the alignment results in an undefined behavior. Underestimating the
3350alignment may produce less efficient code. An alignment of 1 is always
3351safe.
3352</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3353<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3354<p>The location of memory pointed to is loaded.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3355<h5>Examples:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3356<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3357 <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3358 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
3359 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3360</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3361</div>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3362<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3363<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3364Instruction</a> </div>
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]3365<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3366<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]3367<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3368 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]3369</pre>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3370<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3371<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3372<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3373<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3374to 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]3375operand must be a pointer to the <a href="#t_firstclass">first class</a> type
3376of the '<tt>&lt;value&gt;</tt>'
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]3377operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3378optimizer is not allowed to modify the number or order of execution of
3379this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
3380 href="#i_store">store</a></tt> instructions.</p>
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3381<p>
Chris Lattner1f17cce2008-04-02 00:38:26 +0000[diff] [blame]3382The optional constant "align" argument specifies the alignment of the operation
Chris Lattner2a1993f2008-01-06 21:04:43 +0000[diff] [blame]3383(that is, the alignment of the memory address). A value of 0 or an
3384omitted "align" argument means that the operation has the preferential
3385alignment for the target. It is the responsibility of the code emitter
3386to ensure that the alignment information is correct. Overestimating
3387the alignment results in an undefined behavior. Underestimating the
3388alignment may produce less efficient code. An alignment of 1 is always
3389safe.
3390</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3391<h5>Semantics:</h5>
3392<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
3393at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3394<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3395<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]3396 store i32 3, i32* %ptr <i>; yields {void}</i>
3397 %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]3398</pre>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3399</div>
3400
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]3401<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3402<div class="doc_subsubsection">
3403 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3404</div>
3405
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3406<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3407<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3408<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3409 &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]3410</pre>
3411
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3412<h5>Overview:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3413
3414<p>
3415The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3416subelement of an aggregate data structure. It performs address calculation only
3417and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3418
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3419<h5>Arguments:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3420
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3421<p>The first argument is always a pointer, and forms the basis of the
3422calculation. The remaining arguments are indices, that indicate which of the
3423elements of the aggregate object are indexed. The interpretation of each index
3424is dependent on the type being indexed into. The first index always indexes the
3425pointer value given as the first argument, the second index indexes a value of
3426the type pointed to (not necessarily the value directly pointed to, since the
3427first index can be non-zero), etc. The first type indexed into must be a pointer
3428value, subsequent types can be arrays, vectors and structs. Note that subsequent
3429types being indexed into can never be pointers, since that would require loading
3430the pointer before continuing calculation.</p>
3431
3432<p>The type of each index argument depends on the type it is indexing into.
3433When indexing into a (packed) structure, only <tt>i32</tt> integer
3434<b>constants</b> are allowed. When indexing into an array, pointer or vector,
3435only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
3436will be sign extended to 64-bits if required.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3437
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3438<p>For example, let's consider a C code fragment and how it gets
3439compiled to LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3440
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3441<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3442<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3443struct RT {
3444 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3445 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3446 char C;
3447};
3448struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3449 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3450 double Y;
3451 struct RT Z;
3452};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3453
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]3454int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3455 return &amp;s[1].Z.B[5][13];
3456}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3457</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3458</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3459
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3460<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3461
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3462<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3463<pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]3464%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3465%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3466
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3467define i32* %foo(%ST* %s) {
3468entry:
3469 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3470 ret i32* %reg
3471}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3472</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3473</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3474
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3475<h5>Semantics:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3476
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3477<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]3478type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3479}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3480the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3481i8 }</tt>' type, another structure. The third index indexes into the second
3482element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3483array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3484'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
3485to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3486
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3487<p>Note that it is perfectly legal to index partially through a
3488structure, returning a pointer to an inner element. Because of this,
3489the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3490
3491<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3492 define i32* %foo(%ST* %s) {
3493 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3494 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
3495 %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]3496 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
3497 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
3498 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3499 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3500</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3501
3502<p>Note that it is undefined to access an array out of bounds: array and
3503pointer indexes must always be within the defined bounds of the array type.
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]3504The one exception for this rule is zero length arrays. These arrays are
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3505defined to be accessible as variable length arrays, which requires access
3506beyond the zero'th element.</p>
3507
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]3508<p>The getelementptr instruction is often confusing. For some more insight
3509into how it works, see <a href="GetElementPtr.html">the getelementptr
3510FAQ</a>.</p>
3511
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]3512<h5>Example:</h5>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]3513
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3514<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3515 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]3516 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
3517 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3518 %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]3519 <i>; yields i8*:eptr</i>
3520 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3521</pre>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]3522</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]3523
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3524<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3525<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3526</div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3527<div class="doc_text">
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3528<p>The instructions in this category are the conversion instructions (casting)
3529which all take a single operand and a type. They perform various bit conversions
3530on the operand.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3531</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3532
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3533<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3534<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3535 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
3536</div>
3537<div class="doc_text">
3538
3539<h5>Syntax:</h5>
3540<pre>
3541 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3542</pre>
3543
3544<h5>Overview:</h5>
3545<p>
3546The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
3547</p>
3548
3549<h5>Arguments:</h5>
3550<p>
3551The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
3552be 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]3553and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3554type. The bit size of <tt>value</tt> must be larger than the bit size of
3555<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3556
3557<h5>Semantics:</h5>
3558<p>
3559The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3560and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
3561larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
3562It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3563
3564<h5>Example:</h5>
3565<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3566 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3567 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
3568 %Y = trunc i32 122 to i1 <i>; yields i1:false</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_zext">'<tt>zext .. to</tt>' Instruction</a>
3575</div>
3576<div class="doc_text">
3577
3578<h5>Syntax:</h5>
3579<pre>
3580 &lt;result&gt; = zext &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>zext</tt>' instruction zero extends its operand to type
3585<tt>ty2</tt>.</p>
3586
3587
3588<h5>Arguments:</h5>
3589<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]3590<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3591also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3592<tt>value</tt> must be smaller than the bit size of the destination type,
3593<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3594
3595<h5>Semantics:</h5>
3596<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]3597bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3598
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]3599<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]3600
3601<h5>Example:</h5>
3602<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3603 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3604 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3605</pre>
3606</div>
3607
3608<!-- _______________________________________________________________________ -->
3609<div class="doc_subsubsection">
3610 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3611</div>
3612<div class="doc_text">
3613
3614<h5>Syntax:</h5>
3615<pre>
3616 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3617</pre>
3618
3619<h5>Overview:</h5>
3620<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3621
3622<h5>Arguments:</h5>
3623<p>
3624The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3625<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3626also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3627<tt>value</tt> must be smaller than the bit size of the destination type,
3628<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3629
3630<h5>Semantics:</h5>
3631<p>
3632The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3633bit (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]3634the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3635
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3636<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]3637
3638<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3639<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3640 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3641 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3642</pre>
3643</div>
3644
3645<!-- _______________________________________________________________________ -->
3646<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3647 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3648</div>
3649
3650<div class="doc_text">
3651
3652<h5>Syntax:</h5>
3653
3654<pre>
3655 &lt;result&gt; = fptrunc &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>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3660<tt>ty2</tt>.</p>
3661
3662
3663<h5>Arguments:</h5>
3664<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3665 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3666cast it to. The size of <tt>value</tt> must be larger than the size of
3667<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3668<i>no-op cast</i>.</p>
3669
3670<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3671<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3672<a href="#t_floating">floating point</a> type to a smaller
3673<a href="#t_floating">floating point</a> type. If the value cannot fit within
3674the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3675
3676<h5>Example:</h5>
3677<pre>
3678 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3679 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3680</pre>
3681</div>
3682
3683<!-- _______________________________________________________________________ -->
3684<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3685 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3686</div>
3687<div class="doc_text">
3688
3689<h5>Syntax:</h5>
3690<pre>
3691 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3692</pre>
3693
3694<h5>Overview:</h5>
3695<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3696floating point value.</p>
3697
3698<h5>Arguments:</h5>
3699<p>The '<tt>fpext</tt>' instruction takes a
3700<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3701and a <a href="#t_floating">floating point</a> type to cast it to. The source
3702type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3703
3704<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3705<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3706<a href="#t_floating">floating point</a> type to a larger
3707<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3708used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3709<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]3710
3711<h5>Example:</h5>
3712<pre>
3713 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3714 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3715</pre>
3716</div>
3717
3718<!-- _______________________________________________________________________ -->
3719<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]3720 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3721</div>
3722<div class="doc_text">
3723
3724<h5>Syntax:</h5>
3725<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3726 &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]3727</pre>
3728
3729<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3730<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3731unsigned integer equivalent of type <tt>ty2</tt>.
3732</p>
3733
3734<h5>Arguments:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3735<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]3736scalar or vector <a href="#t_floating">floating point</a> value, and a type
3737to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3738type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3739vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3740
3741<h5>Semantics:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3742<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3743<a href="#t_floating">floating point</a> operand into the nearest (rounding
3744towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3745the results are undefined.</p>
3746
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3747<h5>Example:</h5>
3748<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3749 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3750 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3751 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3752</pre>
3753</div>
3754
3755<!-- _______________________________________________________________________ -->
3756<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3757 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3758</div>
3759<div class="doc_text">
3760
3761<h5>Syntax:</h5>
3762<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3763 &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]3764</pre>
3765
3766<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3767<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3768<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]3769</p>
3770
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3771<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3772<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]3773scalar or vector <a href="#t_floating">floating point</a> value, and a type
3774to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3775type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3776vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3777
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3778<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3779<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3780<a href="#t_floating">floating point</a> operand into the nearest (rounding
3781towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3782the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3783
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3784<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3785<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3786 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3787 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3788 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3789</pre>
3790</div>
3791
3792<!-- _______________________________________________________________________ -->
3793<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3794 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3795</div>
3796<div class="doc_text">
3797
3798<h5>Syntax:</h5>
3799<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3800 &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]3801</pre>
3802
3803<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3804<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3805integer and converts that value to the <tt>ty2</tt> type.</p>
3806
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3807<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3808<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3809scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3810to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3811type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3812floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3813
3814<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3815<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3816integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3817the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3818
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3819<h5>Example:</h5>
3820<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3821 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3822 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3823</pre>
3824</div>
3825
3826<!-- _______________________________________________________________________ -->
3827<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3828 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3829</div>
3830<div class="doc_text">
3831
3832<h5>Syntax:</h5>
3833<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3834 &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]3835</pre>
3836
3837<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3838<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3839integer and converts that value to the <tt>ty2</tt> type.</p>
3840
3841<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3842<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3843scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3844to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3845type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3846floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3847
3848<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3849<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3850integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3851the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3852
3853<h5>Example:</h5>
3854<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3855 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3856 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3857</pre>
3858</div>
3859
3860<!-- _______________________________________________________________________ -->
3861<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3862 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3863</div>
3864<div class="doc_text">
3865
3866<h5>Syntax:</h5>
3867<pre>
3868 &lt;result&gt; = ptrtoint &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>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3873the integer type <tt>ty2</tt>.</p>
3874
3875<h5>Arguments:</h5>
3876<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3877must 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]3878<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]3879
3880<h5>Semantics:</h5>
3881<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3882<tt>ty2</tt> by interpreting the pointer value as an integer and either
3883truncating or zero extending that value to the size of the integer type. If
3884<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3885<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]3886are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3887change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3888
3889<h5>Example:</h5>
3890<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3891 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3892 %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]3893</pre>
3894</div>
3895
3896<!-- _______________________________________________________________________ -->
3897<div class="doc_subsubsection">
3898 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3899</div>
3900<div class="doc_text">
3901
3902<h5>Syntax:</h5>
3903<pre>
3904 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3905</pre>
3906
3907<h5>Overview:</h5>
3908<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3909a pointer type, <tt>ty2</tt>.</p>
3910
3911<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3912<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3913value to cast, and a type to cast it to, which must be a
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3914<a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3915
3916<h5>Semantics:</h5>
3917<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3918<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3919the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3920size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3921the size of a pointer then a zero extension is done. If they are the same size,
3922nothing is done (<i>no-op cast</i>).</p>
3923
3924<h5>Example:</h5>
3925<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3926 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3927 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3928 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3929</pre>
3930</div>
3931
3932<!-- _______________________________________________________________________ -->
3933<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3934 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3935</div>
3936<div class="doc_text">
3937
3938<h5>Syntax:</h5>
3939<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3940 &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]3941</pre>
3942
3943<h5>Overview:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3944
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3945<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3946<tt>ty2</tt> without changing any bits.</p>
3947
3948<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3949
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3950<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohmanc05dca92008-09-08 16:45:59 +0000[diff] [blame]3951a non-aggregate first class value, and a type to cast it to, which must also be
3952a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
3953<tt>value</tt>
Reid Spencere3db84c2007-01-09 20:08:58 +0000[diff] [blame]3954and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3955type is a pointer, the destination type must also be a pointer. This
3956instruction supports bitwise conversion of vectors to integers and to vectors
3957of other types (as long as they have the same size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3958
3959<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3960<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3961<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3962this conversion. The conversion is done as if the <tt>value</tt> had been
3963stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3964converted to other pointer types with this instruction. To convert pointers to
3965other types, use the <a href="#i_inttoptr">inttoptr</a> or
3966<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3967
3968<h5>Example:</h5>
3969<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3970 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3971 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3972 %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]3973</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3974</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3975
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3976<!-- ======================================================================= -->
3977<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3978<div class="doc_text">
3979<p>The instructions in this category are the "miscellaneous"
3980instructions, which defy better classification.</p>
3981</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3982
3983<!-- _______________________________________________________________________ -->
3984<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3985</div>
3986<div class="doc_text">
3987<h5>Syntax:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3988<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]3989</pre>
3990<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]3991<p>The '<tt>icmp</tt>' instruction returns a boolean value or
3992a vector of boolean values based on comparison
3993of its two integer, integer vector, or pointer operands.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3994<h5>Arguments:</h5>
3995<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3996the condition code indicating the kind of comparison to perform. It is not
3997a value, just a keyword. The possible condition code are:
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]3998</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3999<ol>
4000 <li><tt>eq</tt>: equal</li>
4001 <li><tt>ne</tt>: not equal </li>
4002 <li><tt>ugt</tt>: unsigned greater than</li>
4003 <li><tt>uge</tt>: unsigned greater or equal</li>
4004 <li><tt>ult</tt>: unsigned less than</li>
4005 <li><tt>ule</tt>: unsigned less or equal</li>
4006 <li><tt>sgt</tt>: signed greater than</li>
4007 <li><tt>sge</tt>: signed greater or equal</li>
4008 <li><tt>slt</tt>: signed less than</li>
4009 <li><tt>sle</tt>: signed less or equal</li>
4010</ol>
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]4011<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4012<a href="#t_pointer">pointer</a>
4013or integer <a href="#t_vector">vector</a> typed.
4014They must also be identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4015<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4016<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]4017the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4018yields 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]4019</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4020<ol>
4021 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
4022 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
4023 </li>
4024 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4025 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4026 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4027 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4028 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4029 <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]4030 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4031 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4032 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4033 <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]4034 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4035 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4036 <li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4037 <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]4038 <li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4039 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4040 <li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4041 <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]4042</ol>
4043<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4044values are compared as if they were integers.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4045<p>If the operands are integer vectors, then they are compared
4046element by element. The result is an <tt>i1</tt> vector with
4047the same number of elements as the values being compared.
4048Otherwise, the result is an <tt>i1</tt>.
4049</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4050
4051<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4052<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
4053 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4054 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4055 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4056 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4057 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4058</pre>
4059</div>
4060
4061<!-- _______________________________________________________________________ -->
4062<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4063</div>
4064<div class="doc_text">
4065<h5>Syntax:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4066<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]4067</pre>
4068<h5>Overview:</h5>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4069<p>The '<tt>fcmp</tt>' instruction returns a boolean value
4070or vector of boolean values based on comparison
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4071of its operands.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4072<p>
4073If the operands are floating point scalars, then the result
4074type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
4075</p>
4076<p>If the operands are floating point vectors, then the result type
4077is a vector of boolean with the same number of elements as the
4078operands being compared.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4079<h5>Arguments:</h5>
4080<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4081the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4082a value, just a keyword. The possible condition code are:</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4083<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4084 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4085 <li><tt>oeq</tt>: ordered and equal</li>
4086 <li><tt>ogt</tt>: ordered and greater than </li>
4087 <li><tt>oge</tt>: ordered and greater than or equal</li>
4088 <li><tt>olt</tt>: ordered and less than </li>
4089 <li><tt>ole</tt>: ordered and less than or equal</li>
4090 <li><tt>one</tt>: ordered and not equal</li>
4091 <li><tt>ord</tt>: ordered (no nans)</li>
4092 <li><tt>ueq</tt>: unordered or equal</li>
4093 <li><tt>ugt</tt>: unordered or greater than </li>
4094 <li><tt>uge</tt>: unordered or greater than or equal</li>
4095 <li><tt>ult</tt>: unordered or less than </li>
4096 <li><tt>ule</tt>: unordered or less than or equal</li>
4097 <li><tt>une</tt>: unordered or not equal</li>
4098 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4099 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4100</ol>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4101<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer02e0d1d2006-12-06 07:08:07 +0000[diff] [blame]4102<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4103<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
4104either a <a href="#t_floating">floating point</a> type
4105or a <a href="#t_vector">vector</a> of floating point type.
4106They must have identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4107<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4108<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4109according to the condition code given as <tt>cond</tt>.
4110If the operands are vectors, then the vectors are compared
4111element by element.
4112Each comparison performed
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4113always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4114<ol>
4115 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4116 <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]4117 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4118 <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]4119 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4120 <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]4121 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4122 <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]4123 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4124 <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]4125 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4126 <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]4127 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4128 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
4129 <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]4130 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4131 <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]4132 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4133 <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]4134 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4135 <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]4136 <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4137 <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]4138 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4139 <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]4140 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]4141 <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]4142 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4143</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]4144
4145<h5>Example:</h5>
4146<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]4147 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4148 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4149 &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]4150</pre>
4151</div>
4152
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4153<!-- _______________________________________________________________________ -->
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4154<div class="doc_subsubsection">
4155 <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
4156</div>
4157<div class="doc_text">
4158<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4159<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]4160</pre>
4161<h5>Overview:</h5>
4162<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
4163element-wise comparison of its two integer vector operands.</p>
4164<h5>Arguments:</h5>
4165<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
4166the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4167a value, just a keyword. The possible condition code are:</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4168<ol>
4169 <li><tt>eq</tt>: equal</li>
4170 <li><tt>ne</tt>: not equal </li>
4171 <li><tt>ugt</tt>: unsigned greater than</li>
4172 <li><tt>uge</tt>: unsigned greater or equal</li>
4173 <li><tt>ult</tt>: unsigned less than</li>
4174 <li><tt>ule</tt>: unsigned less or equal</li>
4175 <li><tt>sgt</tt>: signed greater than</li>
4176 <li><tt>sge</tt>: signed greater or equal</li>
4177 <li><tt>slt</tt>: signed less than</li>
4178 <li><tt>sle</tt>: signed less or equal</li>
4179</ol>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4180<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4181<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
4182<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4183<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4184according to the condition code given as <tt>cond</tt>. The comparison yields a
4185<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
4186identical type as the values being compared. The most significant bit in each
4187element is 1 if the element-wise comparison evaluates to true, and is 0
4188otherwise. All other bits of the result are undefined. The condition codes
4189are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4190instruction</a>.</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4191
4192<h5>Example:</h5>
4193<pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4194 &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>
4195 &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]4196</pre>
4197</div>
4198
4199<!-- _______________________________________________________________________ -->
4200<div class="doc_subsubsection">
4201 <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
4202</div>
4203<div class="doc_text">
4204<h5>Syntax:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4205<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]4206<h5>Overview:</h5>
4207<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
4208element-wise comparison of its two floating point vector operands. The output
4209elements have the same width as the input elements.</p>
4210<h5>Arguments:</h5>
4211<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
4212the condition code indicating the kind of comparison to perform. It is not
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4213a value, just a keyword. The possible condition code are:</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4214<ol>
4215 <li><tt>false</tt>: no comparison, always returns false</li>
4216 <li><tt>oeq</tt>: ordered and equal</li>
4217 <li><tt>ogt</tt>: ordered and greater than </li>
4218 <li><tt>oge</tt>: ordered and greater than or equal</li>
4219 <li><tt>olt</tt>: ordered and less than </li>
4220 <li><tt>ole</tt>: ordered and less than or equal</li>
4221 <li><tt>one</tt>: ordered and not equal</li>
4222 <li><tt>ord</tt>: ordered (no nans)</li>
4223 <li><tt>ueq</tt>: unordered or equal</li>
4224 <li><tt>ugt</tt>: unordered or greater than </li>
4225 <li><tt>uge</tt>: unordered or greater than or equal</li>
4226 <li><tt>ult</tt>: unordered or less than </li>
4227 <li><tt>ule</tt>: unordered or less than or equal</li>
4228 <li><tt>une</tt>: unordered or not equal</li>
4229 <li><tt>uno</tt>: unordered (either nans)</li>
4230 <li><tt>true</tt>: no comparison, always returns true</li>
4231</ol>
4232<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
4233<a href="#t_floating">floating point</a> typed. They must also be identical
4234types.</p>
4235<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]4236<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4237according to the condition code given as <tt>cond</tt>. The comparison yields a
4238<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
4239an identical number of elements as the values being compared, and each element
4240having identical with to the width of the floating point elements. The most
4241significant bit in each element is 1 if the element-wise comparison evaluates to
4242true, and is 0 otherwise. All other bits of the result are undefined. The
4243condition codes are evaluated identically to the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4244<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begemand2195702008-05-12 19:01:56 +0000[diff] [blame]4245
4246<h5>Example:</h5>
4247<pre>
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]4248 <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0, i32 -1 &gt;</i>
4249 &lt;result&gt; = vfcmp oeq &lt;2 x float&gt; &lt; float 4, float 0 &gt;, &lt; float 5, float 0 &gt;
4250
4251 <i>; yields: result=&lt;2 x i64&gt; &lt; i64 -1, i64 0 &gt;</i>
4252 &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]4253</pre>
4254</div>
4255
4256<!-- _______________________________________________________________________ -->
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4257<div class="doc_subsubsection">
4258 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4259</div>
4260
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4261<div class="doc_text">
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4262
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4263<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4264
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4265<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
4266<h5>Overview:</h5>
4267<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
4268the SSA graph representing the function.</p>
4269<h5>Arguments:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4270
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4271<p>The type of the incoming values is specified with the first type
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4272field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
4273as arguments, with one pair for each predecessor basic block of the
4274current block. Only values of <a href="#t_firstclass">first class</a>
4275type may be used as the value arguments to the PHI node. Only labels
4276may be used as the label arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4277
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4278<p>There must be no non-phi instructions between the start of a basic
4279block and the PHI instructions: i.e. PHI instructions must be first in
4280a basic block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4281
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4282<h5>Semantics:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4283
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4284<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
4285specified by the pair corresponding to the predecessor basic block that executed
4286just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4287
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4288<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4289<pre>
4290Loop: ; Infinite loop that counts from 0 on up...
4291 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4292 %nextindvar = add i32 %indvar, 1
4293 br label %Loop
4294</pre>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4295</div>
4296
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4297<!-- _______________________________________________________________________ -->
4298<div class="doc_subsubsection">
4299 <a name="i_select">'<tt>select</tt>' Instruction</a>
4300</div>
4301
4302<div class="doc_text">
4303
4304<h5>Syntax:</h5>
4305
4306<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4307 &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>
4308
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4309 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4310</pre>
4311
4312<h5>Overview:</h5>
4313
4314<p>
4315The '<tt>select</tt>' instruction is used to choose one value based on a
4316condition, without branching.
4317</p>
4318
4319
4320<h5>Arguments:</h5>
4321
4322<p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4323The '<tt>select</tt>' instruction requires an 'i1' value or
4324a vector of 'i1' values indicating the
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4325condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4326type. If the val1/val2 are vectors and
4327the condition is a scalar, then entire vectors are selected, not
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]4328individual elements.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4329</p>
4330
4331<h5>Semantics:</h5>
4332
4333<p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4334If 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]4335value argument; otherwise, it returns the second value argument.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4336</p>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]4337<p>
4338If the condition is a vector of i1, then the value arguments must
4339be vectors of the same size, and the selection is done element
4340by element.
4341</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4342
4343<h5>Example:</h5>
4344
4345<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4346 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4347</pre>
4348</div>
4349
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]4350
4351<!-- _______________________________________________________________________ -->
4352<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4353 <a name="i_call">'<tt>call</tt>' Instruction</a>
4354</div>
4355
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4356<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4357
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4358<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4359<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4360 &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]4361</pre>
4362
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4363<h5>Overview:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4364
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4365<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4366
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4367<h5>Arguments:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4368
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4369<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4370
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4371<ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4372 <li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4373 <p>The optional "tail" marker indicates whether the callee function accesses
4374 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4375 function call is eligible for tail call optimization. Note that calls may
4376 be marked "tail" even if they do not occur before a <a
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4377 href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4378 </li>
4379 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]4380 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4381 convention</a> the call should use. If none is specified, the call defaults
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4382 to using C calling conventions.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4383 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4384
4385 <li>
4386 <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4387 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
4388 and '<tt>inreg</tt>' attributes are valid here.</p>
4389 </li>
4390
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]4391 <li>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4392 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
4393 the type of the return value. Functions that return no value are marked
4394 <tt><a href="#t_void">void</a></tt>.</p>
4395 </li>
4396 <li>
4397 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
4398 value being invoked. The argument types must match the types implied by
4399 this signature. This type can be omitted if the function is not varargs
4400 and if the function type does not return a pointer to a function.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4401 </li>
4402 <li>
4403 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4404 be invoked. In most cases, this is a direct function invocation, but
4405 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4406 to function value.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4407 </li>
4408 <li>
4409 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencerd845d162005-05-01 22:22:57 +0000[diff] [blame]4410 function signature argument types. All arguments must be of
4411 <a href="#t_firstclass">first class</a> type. If the function signature
4412 indicates the function accepts a variable number of arguments, the extra
4413 arguments can be specified.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4414 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4415 <li>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]4416 <p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4417 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4418 '<tt>readnone</tt>' attributes are valid here.</p>
4419 </li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4420</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4421
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4422<h5>Semantics:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4423
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4424<p>The '<tt>call</tt>' instruction is used to cause control flow to
4425transfer to a specified function, with its incoming arguments bound to
4426the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
4427instruction in the called function, control flow continues with the
4428instruction after the function call, and the return value of the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4429function is bound to the result argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4430
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4431<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4432
4433<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]4434 %retval = call i32 @test(i32 %argc)
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]4435 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4436 %X = tail call i32 @foo() <i>; yields i32</i>
4437 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4438 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]4439
4440 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]4441 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]4442 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4443 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]4444 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]4445 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]4446</pre>
4447
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4448</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4449
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4450<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4451<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4452 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4453</div>
4454
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4455<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4456
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4457<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4458
4459<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4460 &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]4461</pre>
4462
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4463<h5>Overview:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4464
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4465<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4466the "variable argument" area of a function call. It is used to implement the
4467<tt>va_arg</tt> macro in C.</p>
4468
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4469<h5>Arguments:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4470
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4471<p>This instruction takes a <tt>va_list*</tt> value and the type of
4472the argument. It returns a value of the specified argument type and
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4473increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4474actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4475
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4476<h5>Semantics:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4477
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4478<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
4479type from the specified <tt>va_list</tt> and causes the
4480<tt>va_list</tt> to point to the next argument. For more information,
4481see the variable argument handling <a href="#int_varargs">Intrinsic
4482Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4483
4484<p>It is legal for this instruction to be called in a function which does not
4485take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4486function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4487
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4488<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4489href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4490argument.</p>
4491
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]4492<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]4493
4494<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4495
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4496</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4497
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4498<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4499<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4500<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4501
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4502<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4503
4504<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4505well known names and semantics and are required to follow certain restrictions.
4506Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4507language that does not require changing all of the transformations in LLVM when
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]4508adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4509
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4510<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4511prefix is reserved in LLVM for intrinsic names; thus, function names may not
4512begin with this prefix. Intrinsic functions must always be external functions:
4513you cannot define the body of intrinsic functions. Intrinsic functions may
4514only be used in call or invoke instructions: it is illegal to take the address
4515of an intrinsic function. Additionally, because intrinsic functions are part
4516of the LLVM language, it is required if any are added that they be documented
4517here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4518
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4519<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
4520a family of functions that perform the same operation but on different data
4521types. Because LLVM can represent over 8 million different integer types,
4522overloading is used commonly to allow an intrinsic function to operate on any
4523integer type. One or more of the argument types or the result type can be
4524overloaded to accept any integer type. Argument types may also be defined as
4525exactly matching a previous argument's type or the result type. This allows an
4526intrinsic function which accepts multiple arguments, but needs all of them to
4527be of the same type, to only be overloaded with respect to a single argument or
4528the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4529
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4530<p>Overloaded intrinsics will have the names of its overloaded argument types
4531encoded into its function name, each preceded by a period. Only those types
4532which are overloaded result in a name suffix. Arguments whose type is matched
4533against another type do not. For example, the <tt>llvm.ctpop</tt> function can
4534take an integer of any width and returns an integer of exactly the same integer
4535width. This leads to a family of functions such as
4536<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
4537Only one type, the return type, is overloaded, and only one type suffix is
4538required. Because the argument's type is matched against the return type, it
4539does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4540
4541<p>To learn how to add an intrinsic function, please see the
4542<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4543</p>
4544
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4545</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4546
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4547<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4548<div class="doc_subsection">
4549 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
4550</div>
4551
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4552<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4553
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4554<p>Variable argument support is defined in LLVM with the <a
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]4555 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4556intrinsic functions. These functions are related to the similarly
4557named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4558
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4559<p>All of these functions operate on arguments that use a
4560target-specific value type "<tt>va_list</tt>". The LLVM assembly
4561language reference manual does not define what this type is, so all
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4562transformations should be prepared to handle these functions regardless of
4563the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4564
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]4565<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]4566instruction and the variable argument handling intrinsic functions are
4567used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4568
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4569<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4570<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4571define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4572 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4573 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4574 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4575 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4576
4577 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4578 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4579
4580 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4581 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4582 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4583 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4584 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4585
4586 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4587 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4588 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4589}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]4590
4591declare void @llvm.va_start(i8*)
4592declare void @llvm.va_copy(i8*, i8*)
4593declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4594</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4595</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4596
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4597</div>
4598
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4599<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4600<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4601 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4602</div>
4603
4604
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4605<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4606<h5>Syntax:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4607<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4608<h5>Overview:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4609<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4610<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
4611href="#i_va_arg">va_arg</a></tt>.</p>
4612
4613<h5>Arguments:</h5>
4614
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4615<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]4616
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4617<h5>Semantics:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4618
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4619<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]4620macro available in C. In a target-dependent way, it initializes the
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4621<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]4622<tt>va_arg</tt> will produce the first variable argument passed to the function.
4623Unlike 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]4624last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4625
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4626</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4627
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4628<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4629<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4630 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4631</div>
4632
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4633<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4634<h5>Syntax:</h5>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4635<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4636<h5>Overview:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4637
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4638<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4639which 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]4640or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4641
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4642<h5>Arguments:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4643
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4644<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]4645
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4646<h5>Semantics:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4647
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4648<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]4649macro available in C. In a target-dependent way, it destroys the
4650<tt>va_list</tt> element to which the argument points. Calls to <a
4651href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
4652<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
4653<tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]4654
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4655</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4656
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4657<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4658<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4659 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4660</div>
4661
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4662<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4663
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4664<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4665
4666<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4667 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4668</pre>
4669
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4670<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4671
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4672<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
4673from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4674
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4675<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4676
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]4677<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]4678The 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]4679
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4680
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]4681<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4682
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4683<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
4684macro available in C. In a target-dependent way, it copies the source
4685<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
4686intrinsic is necessary because the <tt><a href="#int_va_start">
4687llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
4688example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4689
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4690</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4691
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4692<!-- ======================================================================= -->
4693<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4694 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
4695</div>
4696
4697<div class="doc_text">
4698
4699<p>
4700LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]4701Collection</a> (GC) requires the implementation and generation of these
4702intrinsics.
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4703These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4704stack</a>, as well as garbage collector implementations that require <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4705href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4706Front-ends for type-safe garbage collected languages should generate these
4707intrinsics to make use of the LLVM garbage collectors. For more details, see <a
4708href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
4709</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]4710
4711<p>The garbage collection intrinsics only operate on objects in the generic
4712 address space (address space zero).</p>
4713
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4714</div>
4715
4716<!-- _______________________________________________________________________ -->
4717<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4718 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4719</div>
4720
4721<div class="doc_text">
4722
4723<h5>Syntax:</h5>
4724
4725<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4726 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4727</pre>
4728
4729<h5>Overview:</h5>
4730
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]4731<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]4732the code generator, and allows some metadata to be associated with it.</p>
4733
4734<h5>Arguments:</h5>
4735
4736<p>The first argument specifies the address of a stack object that contains the
4737root pointer. The second pointer (which must be either a constant or a global
4738value address) contains the meta-data to be associated with the root.</p>
4739
4740<h5>Semantics:</h5>
4741
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]4742<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]4743location. At compile-time, the code generator generates information to allow
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4744the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
4745intrinsic may only be used in a function which <a href="#gc">specifies a GC
4746algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4747
4748</div>
4749
4750
4751<!-- _______________________________________________________________________ -->
4752<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4753 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4754</div>
4755
4756<div class="doc_text">
4757
4758<h5>Syntax:</h5>
4759
4760<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4761 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4762</pre>
4763
4764<h5>Overview:</h5>
4765
4766<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4767locations, allowing garbage collector implementations that require read
4768barriers.</p>
4769
4770<h5>Arguments:</h5>
4771
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4772<p>The second argument is the address to read from, which should be an address
4773allocated from the garbage collector. The first object is a pointer to the
4774start of the referenced object, if needed by the language runtime (otherwise
4775null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4776
4777<h5>Semantics:</h5>
4778
4779<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4780instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4781garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4782may only be used in a function which <a href="#gc">specifies a GC
4783algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4784
4785</div>
4786
4787
4788<!-- _______________________________________________________________________ -->
4789<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4790 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4791</div>
4792
4793<div class="doc_text">
4794
4795<h5>Syntax:</h5>
4796
4797<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4798 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4799</pre>
4800
4801<h5>Overview:</h5>
4802
4803<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4804locations, allowing garbage collector implementations that require write
4805barriers (such as generational or reference counting collectors).</p>
4806
4807<h5>Arguments:</h5>
4808
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4809<p>The first argument is the reference to store, the second is the start of the
4810object to store it to, and the third is the address of the field of Obj to
4811store to. If the runtime does not require a pointer to the object, Obj may be
4812null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4813
4814<h5>Semantics:</h5>
4815
4816<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4817instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4818garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4819may only be used in a function which <a href="#gc">specifies a GC
4820algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4821
4822</div>
4823
4824
4825
4826<!-- ======================================================================= -->
4827<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4828 <a name="int_codegen">Code Generator Intrinsics</a>
4829</div>
4830
4831<div class="doc_text">
4832<p>
4833These intrinsics are provided by LLVM to expose special features that may only
4834be implemented with code generator support.
4835</p>
4836
4837</div>
4838
4839<!-- _______________________________________________________________________ -->
4840<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4841 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4842</div>
4843
4844<div class="doc_text">
4845
4846<h5>Syntax:</h5>
4847<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4848 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4849</pre>
4850
4851<h5>Overview:</h5>
4852
4853<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4854The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4855target-specific value indicating the return address of the current function
4856or one of its callers.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4857</p>
4858
4859<h5>Arguments:</h5>
4860
4861<p>
4862The argument to this intrinsic indicates which function to return the address
4863for. Zero indicates the calling function, one indicates its caller, etc. The
4864argument is <b>required</b> to be a constant integer value.
4865</p>
4866
4867<h5>Semantics:</h5>
4868
4869<p>
4870The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4871the return address of the specified call frame, or zero if it cannot be
4872identified. The value returned by this intrinsic is likely to be incorrect or 0
4873for arguments other than zero, so it should only be used for debugging purposes.
4874</p>
4875
4876<p>
4877Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4878aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4879source-language caller.
4880</p>
4881</div>
4882
4883
4884<!-- _______________________________________________________________________ -->
4885<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4886 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4887</div>
4888
4889<div class="doc_text">
4890
4891<h5>Syntax:</h5>
4892<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4893 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4894</pre>
4895
4896<h5>Overview:</h5>
4897
4898<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4899The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4900target-specific frame pointer value for the specified stack frame.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4901</p>
4902
4903<h5>Arguments:</h5>
4904
4905<p>
4906The argument to this intrinsic indicates which function to return the frame
4907pointer for. Zero indicates the calling function, one indicates its caller,
4908etc. The argument is <b>required</b> to be a constant integer value.
4909</p>
4910
4911<h5>Semantics:</h5>
4912
4913<p>
4914The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4915the frame address of the specified call frame, or zero if it cannot be
4916identified. The value returned by this intrinsic is likely to be incorrect or 0
4917for arguments other than zero, so it should only be used for debugging purposes.
4918</p>
4919
4920<p>
4921Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4922aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4923source-language caller.
4924</p>
4925</div>
4926
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4927<!-- _______________________________________________________________________ -->
4928<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4929 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4930</div>
4931
4932<div class="doc_text">
4933
4934<h5>Syntax:</h5>
4935<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4936 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4937</pre>
4938
4939<h5>Overview:</h5>
4940
4941<p>
4942The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4943the function stack, for use with <a href="#int_stackrestore">
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4944<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4945features like scoped automatic variable sized arrays in C99.
4946</p>
4947
4948<h5>Semantics:</h5>
4949
4950<p>
4951This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4952href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4953<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4954<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4955state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4956practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4957that were allocated after the <tt>llvm.stacksave</tt> was executed.
4958</p>
4959
4960</div>
4961
4962<!-- _______________________________________________________________________ -->
4963<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4964 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4965</div>
4966
4967<div class="doc_text">
4968
4969<h5>Syntax:</h5>
4970<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4971 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4972</pre>
4973
4974<h5>Overview:</h5>
4975
4976<p>
4977The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4978the function stack to the state it was in when the corresponding <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4979href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4980useful for implementing language features like scoped automatic variable sized
4981arrays in C99.
4982</p>
4983
4984<h5>Semantics:</h5>
4985
4986<p>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4987See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4988</p>
4989
4990</div>
4991
4992
4993<!-- _______________________________________________________________________ -->
4994<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4995 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4996</div>
4997
4998<div class="doc_text">
4999
5000<h5>Syntax:</h5>
5001<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5002 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]5003</pre>
5004
5005<h5>Overview:</h5>
5006
5007
5008<p>
5009The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5010a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
5011no
5012effect on the behavior of the program but can change its performance
Chris Lattnerff851072005-02-28 19:47:14 +0000[diff] [blame]5013characteristics.
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5014</p>
5015
5016<h5>Arguments:</h5>
5017
5018<p>
5019<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
5020determining if the fetch should be for a read (0) or write (1), and
5021<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattnerd3e641c2005-03-07 20:31:38 +0000[diff] [blame]5022locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5023<tt>locality</tt> arguments must be constant integers.
5024</p>
5025
5026<h5>Semantics:</h5>
5027
5028<p>
5029This intrinsic does not modify the behavior of the program. In particular,
5030prefetches cannot trap and do not produce a value. On targets that support this
5031intrinsic, the prefetch can provide hints to the processor cache for better
5032performance.
5033</p>
5034
5035</div>
5036
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5037<!-- _______________________________________________________________________ -->
5038<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5039 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5040</div>
5041
5042<div class="doc_text">
5043
5044<h5>Syntax:</h5>
5045<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5046 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5047</pre>
5048
5049<h5>Overview:</h5>
5050
5051
5052<p>
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5053The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5054(PC) in a region of
5055code to simulators and other tools. The method is target specific, but it is
5056expected that the marker will use exported symbols to transmit the PC of the
5057marker.
5058The marker makes no guarantees that it will remain with any specific instruction
5059after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb40261e2006-03-24 07:16:10 +0000[diff] [blame]5060optimizations. The intended use is to be inserted after optimizations to allow
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5061correlations of simulation runs.
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]5062</p>
5063
5064<h5>Arguments:</h5>
5065
5066<p>
5067<tt>id</tt> is a numerical id identifying the marker.
5068</p>
5069
5070<h5>Semantics:</h5>
5071
5072<p>
5073This intrinsic does not modify the behavior of the program. Backends that do not
5074support this intrinisic may ignore it.
5075</p>
5076
5077</div>
5078
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5079<!-- _______________________________________________________________________ -->
5080<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5081 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5082</div>
5083
5084<div class="doc_text">
5085
5086<h5>Syntax:</h5>
5087<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5088 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]5089</pre>
5090
5091<h5>Overview:</h5>
5092
5093
5094<p>
5095The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5096counter register (or similar low latency, high accuracy clocks) on those targets
5097that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
5098As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
5099should only be used for small timings.
5100</p>
5101
5102<h5>Semantics:</h5>
5103
5104<p>
5105When directly supported, reading the cycle counter should not modify any memory.
5106Implementations are allowed to either return a application specific value or a
5107system wide value. On backends without support, this is lowered to a constant 0.
5108</p>
5109
5110</div>
5111
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5112<!-- ======================================================================= -->
5113<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5114 <a name="int_libc">Standard C Library Intrinsics</a>
5115</div>
5116
5117<div class="doc_text">
5118<p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5119LLVM provides intrinsics for a few important standard C library functions.
5120These intrinsics allow source-language front-ends to pass information about the
5121alignment of the pointer arguments to the code generator, providing opportunity
5122for more efficient code generation.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5123</p>
5124
5125</div>
5126
5127<!-- _______________________________________________________________________ -->
5128<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5129 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5130</div>
5131
5132<div class="doc_text">
5133
5134<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5135<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
5136width. Not all targets support all bit widths however.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5137<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5138 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5139 i8 &lt;len&gt;, i32 &lt;align&gt;)
5140 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5141 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5142 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5143 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5144 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5145 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5146</pre>
5147
5148<h5>Overview:</h5>
5149
5150<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5151The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5152location to the destination location.
5153</p>
5154
5155<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5156Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5157intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5158</p>
5159
5160<h5>Arguments:</h5>
5161
5162<p>
5163The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5164the source. The third argument is an integer argument
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5165specifying the number of bytes to copy, and the fourth argument is the alignment
5166of the source and destination locations.
5167</p>
5168
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5169<p>
5170If 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]5171the caller guarantees that both the source and destination pointers are aligned
5172to that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5173</p>
5174
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5175<h5>Semantics:</h5>
5176
5177<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5178The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5179location to the destination location, which are not allowed to overlap. It
5180copies "len" bytes of memory over. If the argument is known to be aligned to
5181some boundary, this can be specified as the fourth argument, otherwise it should
5182be set to 0 or 1.
5183</p>
5184</div>
5185
5186
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5187<!-- _______________________________________________________________________ -->
5188<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5189 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5190</div>
5191
5192<div class="doc_text">
5193
5194<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5195<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
5196width. Not all targets support all bit widths however.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5197<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5198 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5199 i8 &lt;len&gt;, i32 &lt;align&gt;)
5200 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5201 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5202 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5203 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5204 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5205 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5206</pre>
5207
5208<h5>Overview:</h5>
5209
5210<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5211The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
5212location to the destination location. It is similar to the
Chris Lattnerec564022008-01-06 19:51:52 +0000[diff] [blame]5213'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5214</p>
5215
5216<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5217Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5218intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5219</p>
5220
5221<h5>Arguments:</h5>
5222
5223<p>
5224The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5225the source. The third argument is an integer argument
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5226specifying the number of bytes to copy, and the fourth argument is the alignment
5227of the source and destination locations.
5228</p>
5229
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5230<p>
5231If 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]5232the caller guarantees that the source and destination pointers are aligned to
5233that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]5234</p>
5235
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5236<h5>Semantics:</h5>
5237
5238<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5239The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]5240location to the destination location, which may overlap. It
5241copies "len" bytes of memory over. If the argument is known to be aligned to
5242some boundary, this can be specified as the fourth argument, otherwise it should
5243be set to 0 or 1.
5244</p>
5245</div>
5246
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5247
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5248<!-- _______________________________________________________________________ -->
5249<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5250 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5251</div>
5252
5253<div class="doc_text">
5254
5255<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5256<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
5257width. Not all targets support all bit widths however.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5258<pre>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]5259 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5260 i8 &lt;len&gt;, i32 &lt;align&gt;)
5261 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5262 i16 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5263 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5264 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5265 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5266 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5267</pre>
5268
5269<h5>Overview:</h5>
5270
5271<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5272The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5273byte value.
5274</p>
5275
5276<p>
5277Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
5278does not return a value, and takes an extra alignment argument.
5279</p>
5280
5281<h5>Arguments:</h5>
5282
5283<p>
5284The first argument is a pointer to the destination to fill, the second is the
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5285byte value to fill it with, the third argument is an integer
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5286argument specifying the number of bytes to fill, and the fourth argument is the
5287known alignment of destination location.
5288</p>
5289
5290<p>
5291If 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]5292the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5293</p>
5294
5295<h5>Semantics:</h5>
5296
5297<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]5298The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
5299the
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5300destination location. If the argument is known to be aligned to some boundary,
5301this can be specified as the fourth argument, otherwise it should be set to 0 or
53021.
5303</p>
5304</div>
5305
5306
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5307<!-- _______________________________________________________________________ -->
5308<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5309 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5310</div>
5311
5312<div class="doc_text">
5313
5314<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5315<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]5316floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5317types however.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5318<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5319 declare float @llvm.sqrt.f32(float %Val)
5320 declare double @llvm.sqrt.f64(double %Val)
5321 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5322 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5323 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5324</pre>
5325
5326<h5>Overview:</h5>
5327
5328<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5329The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5330returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5331<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner00d7cb92008-01-29 07:00:44 +0000[diff] [blame]5332negative numbers other than -0.0 (which allows for better optimization, because
5333there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
5334defined to return -0.0 like IEEE sqrt.
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5335</p>
5336
5337<h5>Arguments:</h5>
5338
5339<p>
5340The argument and return value are floating point numbers of the same type.
5341</p>
5342
5343<h5>Semantics:</h5>
5344
5345<p>
Dan Gohman33988db2007-07-16 14:37:41 +0000[diff] [blame]5346This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]5347floating point number.
5348</p>
5349</div>
5350
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5351<!-- _______________________________________________________________________ -->
5352<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5353 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5354</div>
5355
5356<div class="doc_text">
5357
5358<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5359<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]5360floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5361types however.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5362<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]5363 declare float @llvm.powi.f32(float %Val, i32 %power)
5364 declare double @llvm.powi.f64(double %Val, i32 %power)
5365 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5366 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5367 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5368</pre>
5369
5370<h5>Overview:</h5>
5371
5372<p>
5373The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5374specified (positive or negative) power. The order of evaluation of
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5375multiplications is not defined. When a vector of floating point type is
5376used, the second argument remains a scalar integer value.
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5377</p>
5378
5379<h5>Arguments:</h5>
5380
5381<p>
5382The second argument is an integer power, and the first is a value to raise to
5383that power.
5384</p>
5385
5386<h5>Semantics:</h5>
5387
5388<p>
5389This function returns the first value raised to the second power with an
5390unspecified sequence of rounding operations.</p>
5391</div>
5392
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5393<!-- _______________________________________________________________________ -->
5394<div class="doc_subsubsection">
5395 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5396</div>
5397
5398<div class="doc_text">
5399
5400<h5>Syntax:</h5>
5401<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5402floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5403types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5404<pre>
5405 declare float @llvm.sin.f32(float %Val)
5406 declare double @llvm.sin.f64(double %Val)
5407 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5408 declare fp128 @llvm.sin.f128(fp128 %Val)
5409 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5410</pre>
5411
5412<h5>Overview:</h5>
5413
5414<p>
5415The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
5416</p>
5417
5418<h5>Arguments:</h5>
5419
5420<p>
5421The argument and return value are floating point numbers of the same type.
5422</p>
5423
5424<h5>Semantics:</h5>
5425
5426<p>
5427This function returns the sine of the specified operand, returning the
5428same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5429conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5430</div>
5431
5432<!-- _______________________________________________________________________ -->
5433<div class="doc_subsubsection">
5434 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5435</div>
5436
5437<div class="doc_text">
5438
5439<h5>Syntax:</h5>
5440<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5441floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5442types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5443<pre>
5444 declare float @llvm.cos.f32(float %Val)
5445 declare double @llvm.cos.f64(double %Val)
5446 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5447 declare fp128 @llvm.cos.f128(fp128 %Val)
5448 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5449</pre>
5450
5451<h5>Overview:</h5>
5452
5453<p>
5454The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
5455</p>
5456
5457<h5>Arguments:</h5>
5458
5459<p>
5460The argument and return value are floating point numbers of the same type.
5461</p>
5462
5463<h5>Semantics:</h5>
5464
5465<p>
5466This function returns the cosine of the specified operand, returning the
5467same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5468conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5469</div>
5470
5471<!-- _______________________________________________________________________ -->
5472<div class="doc_subsubsection">
5473 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5474</div>
5475
5476<div class="doc_text">
5477
5478<h5>Syntax:</h5>
5479<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5480floating point or vector of floating point type. Not all targets support all
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5481types however.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5482<pre>
5483 declare float @llvm.pow.f32(float %Val, float %Power)
5484 declare double @llvm.pow.f64(double %Val, double %Power)
5485 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5486 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5487 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5488</pre>
5489
5490<h5>Overview:</h5>
5491
5492<p>
5493The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5494specified (positive or negative) power.
5495</p>
5496
5497<h5>Arguments:</h5>
5498
5499<p>
5500The second argument is a floating point power, and the first is a value to
5501raise to that power.
5502</p>
5503
5504<h5>Semantics:</h5>
5505
5506<p>
5507This function returns the first value raised to the second power,
5508returning the
5509same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]5510conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]5511</div>
5512
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]5513
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5514<!-- ======================================================================= -->
5515<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5516 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5517</div>
5518
5519<div class="doc_text">
5520<p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5521LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5522These allow efficient code generation for some algorithms.
5523</p>
5524
5525</div>
5526
5527<!-- _______________________________________________________________________ -->
5528<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5529 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5530</div>
5531
5532<div class="doc_text">
5533
5534<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5535<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5536type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5537<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5538 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5539 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5540 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5541</pre>
5542
5543<h5>Overview:</h5>
5544
5545<p>
Reid Spencerf361c4f2007-04-02 02:25:19 +0000[diff] [blame]5546The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5547values with an even number of bytes (positive multiple of 16 bits). These are
5548useful for performing operations on data that is not in the target's native
5549byte order.
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5550</p>
5551
5552<h5>Semantics:</h5>
5553
5554<p>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5555The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5556and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
5557intrinsic returns an i32 value that has the four bytes of the input i32
5558swapped, 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]5559i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
5560<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5561additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]5562</p>
5563
5564</div>
5565
5566<!-- _______________________________________________________________________ -->
5567<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5568 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5569</div>
5570
5571<div class="doc_text">
5572
5573<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5574<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]5575width. Not all targets support all bit widths however.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5576<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5577 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
5578 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5579 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5580 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5581 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5582</pre>
5583
5584<h5>Overview:</h5>
5585
5586<p>
Chris Lattner069b5bd2006-01-16 22:38:59 +0000[diff] [blame]5587The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
5588value.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5589</p>
5590
5591<h5>Arguments:</h5>
5592
5593<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5594The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5595integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5596</p>
5597
5598<h5>Semantics:</h5>
5599
5600<p>
5601The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
5602</p>
5603</div>
5604
5605<!-- _______________________________________________________________________ -->
5606<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5607 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5608</div>
5609
5610<div class="doc_text">
5611
5612<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5613<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]5614integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5615<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5616 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5617 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5618 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5619 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5620 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5621</pre>
5622
5623<h5>Overview:</h5>
5624
5625<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5626The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5627leading zeros in a variable.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5628</p>
5629
5630<h5>Arguments:</h5>
5631
5632<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]5633The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5634integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5635</p>
5636
5637<h5>Semantics:</h5>
5638
5639<p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5640The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
5641in 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]5642of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]5643</p>
5644</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]5645
5646
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5647
5648<!-- _______________________________________________________________________ -->
5649<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]5650 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5651</div>
5652
5653<div class="doc_text">
5654
5655<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5656<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]5657integer bit width. Not all targets support all bit widths however.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5658<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5659 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5660 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5661 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5662 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5663 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5664</pre>
5665
5666<h5>Overview:</h5>
5667
5668<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]5669The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5670trailing zeros.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5671</p>
5672
5673<h5>Arguments:</h5>
5674
5675<p>
5676The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]5677integer type. The return type must match the argument type.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]5678</p>
5679
5680<h5>Semantics:</h5>
5681
5682<p>
5683The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
5684in a variable. If the src == 0 then the result is the size in bits of the type
5685of src. For example, <tt>llvm.cttz(2) = 1</tt>.
5686</p>
5687</div>
5688
Reid Spencer8a5799f2007-04-01 08:27:01 +0000[diff] [blame]5689<!-- _______________________________________________________________________ -->
5690<div class="doc_subsubsection">
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5691 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5692</div>
5693
5694<div class="doc_text">
5695
5696<h5>Syntax:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5697<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5698on any integer bit width.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5699<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5700 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
5701 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5702</pre>
5703
5704<h5>Overview:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5705<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5706range of bits from an integer value and returns them in the same bit width as
5707the original value.</p>
5708
5709<h5>Arguments:</h5>
5710<p>The first argument, <tt>%val</tt> and the result may be integer types of
5711any bit width but they must have the same bit width. The second and third
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5712arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5713
5714<h5>Semantics:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]5715<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5716of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
5717<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
5718operates in forward mode.</p>
5719<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
5720right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5721only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
5722<ol>
5723 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
5724 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
5725 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
5726 to determine the number of bits to retain.</li>
5727 <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]5728 <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5729</ol>
Reid Spencer70845c02007-05-14 16:14:57 +0000[diff] [blame]5730<p>In reverse mode, a similar computation is made except that the bits are
5731returned in the reverse order. So, for example, if <tt>X</tt> has the value
5732<tt>i16 0x0ACF (101011001111)</tt> and we apply
5733<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
5734<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]5735</div>
5736
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5737<div class="doc_subsubsection">
5738 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
5739</div>
5740
5741<div class="doc_text">
5742
5743<h5>Syntax:</h5>
5744<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5745on any integer bit width.</p>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5746<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]5747 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
5748 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]5749</pre>
5750
5751<h5>Overview:</h5>
5752<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
5753of bits in an integer value with another integer value. It returns the integer
5754with the replaced bits.</p>
5755
5756<h5>Arguments:</h5>
5757<p>The first argument, <tt>%val</tt> and the result may be integer types of
5758any bit width but they must have the same bit width. <tt>%val</tt> is the value
5759whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
5760integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
5761type since they specify only a bit index.</p>
5762
5763<h5>Semantics:</h5>
5764<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
5765of operation: forwards and reverse. If <tt>%lo</tt> is greater than
5766<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5767operates in forward mode.</p>
5768<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5769truncating it down to the size of the replacement area or zero extending it
5770up to that size.</p>
5771<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5772are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5773in <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]5774to the <tt>%hi</tt>th bit.</p>
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5775<p>In reverse mode, a similar computation is made except that the bits are
5776reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5777<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]5778<h5>Examples:</h5>
5779<pre>
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5780 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5781 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5782 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5783 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5784 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]5785</pre>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5786</div>
5787
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5788<!-- ======================================================================= -->
5789<div class="doc_subsection">
5790 <a name="int_debugger">Debugger Intrinsics</a>
5791</div>
5792
5793<div class="doc_text">
5794<p>
5795The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5796are described in the <a
5797href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5798Debugging</a> document.
5799</p>
5800</div>
5801
5802
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]5803<!-- ======================================================================= -->
5804<div class="doc_subsection">
5805 <a name="int_eh">Exception Handling Intrinsics</a>
5806</div>
5807
5808<div class="doc_text">
5809<p> The LLVM exception handling intrinsics (which all start with
5810<tt>llvm.eh.</tt> prefix), are described in the <a
5811href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5812Handling</a> document. </p>
5813</div>
5814
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]5815<!-- ======================================================================= -->
5816<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5817 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5818</div>
5819
5820<div class="doc_text">
5821<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5822 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5823 the <tt>nest</tt> attribute, from a function. The result is a callable
5824 function pointer lacking the nest parameter - the caller does not need
5825 to provide a value for it. Instead, the value to use is stored in
5826 advance in a "trampoline", a block of memory usually allocated
5827 on the stack, which also contains code to splice the nest value into the
5828 argument list. This is used to implement the GCC nested function address
5829 extension.
5830</p>
5831<p>
5832 For example, if the function is
5833 <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]5834 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]5835<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5836 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5837 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5838 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5839 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5840</pre>
Bill Wendling252570f2007-09-22 09:23:55 +0000[diff] [blame]5841 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5842 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5843</div>
5844
5845<!-- _______________________________________________________________________ -->
5846<div class="doc_subsubsection">
5847 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5848</div>
5849<div class="doc_text">
5850<h5>Syntax:</h5>
5851<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5852declare 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]5853</pre>
5854<h5>Overview:</h5>
5855<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5856 This fills the memory pointed to by <tt>tramp</tt> with code
5857 and returns a function pointer suitable for executing it.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5858</p>
5859<h5>Arguments:</h5>
5860<p>
5861 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5862 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5863 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsf2bcd372007-08-22 23:39:54 +0000[diff] [blame]5864 intrinsic. Note that the size and the alignment are target-specific - LLVM
5865 currently provides no portable way of determining them, so a front-end that
5866 generates this intrinsic needs to have some target-specific knowledge.
5867 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]5868</p>
5869<h5>Semantics:</h5>
5870<p>
5871 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5872 dependent code, turning it into a function. A pointer to this function is
5873 returned, but needs to be bitcast to an
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5874 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5875 before being called. The new function's signature is the same as that of
5876 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5877 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5878 of pointer type. Calling the new function is equivalent to calling
5879 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5880 missing <tt>nest</tt> argument. If, after calling
5881 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5882 modified, then the effect of any later call to the returned function pointer is
5883 undefined.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5884</p>
5885</div>
5886
5887<!-- ======================================================================= -->
5888<div class="doc_subsection">
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5889 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
5890</div>
5891
5892<div class="doc_text">
5893<p>
5894 These intrinsic functions expand the "universal IR" of LLVM to represent
5895 hardware constructs for atomic operations and memory synchronization. This
5896 provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5897 is aimed at a low enough level to allow any programming models or APIs
5898 (Application Programming Interfaces) which
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5899 need atomic behaviors to map cleanly onto it. It is also modeled primarily on
5900 hardware behavior. Just as hardware provides a "universal IR" for source
5901 languages, it also provides a starting point for developing a "universal"
5902 atomic operation and synchronization IR.
5903</p>
5904<p>
5905 These do <em>not</em> form an API such as high-level threading libraries,
5906 software transaction memory systems, atomic primitives, and intrinsic
5907 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
5908 application libraries. The hardware interface provided by LLVM should allow
5909 a clean implementation of all of these APIs and parallel programming models.
5910 No one model or paradigm should be selected above others unless the hardware
5911 itself ubiquitously does so.
5912
5913</p>
5914</div>
5915
5916<!-- _______________________________________________________________________ -->
5917<div class="doc_subsubsection">
5918 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
5919</div>
5920<div class="doc_text">
5921<h5>Syntax:</h5>
5922<pre>
5923declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;,
5924i1 &lt;device&gt; )
5925
5926</pre>
5927<h5>Overview:</h5>
5928<p>
5929 The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
5930 specific pairs of memory access types.
5931</p>
5932<h5>Arguments:</h5>
5933<p>
5934 The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
5935 The first four arguments enables a specific barrier as listed below. The fith
5936 argument specifies that the barrier applies to io or device or uncached memory.
5937
5938</p>
5939 <ul>
5940 <li><tt>ll</tt>: load-load barrier</li>
5941 <li><tt>ls</tt>: load-store barrier</li>
5942 <li><tt>sl</tt>: store-load barrier</li>
5943 <li><tt>ss</tt>: store-store barrier</li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5944 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]5945 </ul>
5946<h5>Semantics:</h5>
5947<p>
5948 This intrinsic causes the system to enforce some ordering constraints upon
5949 the loads and stores of the program. This barrier does not indicate
5950 <em>when</em> any events will occur, it only enforces an <em>order</em> in
5951 which they occur. For any of the specified pairs of load and store operations
5952 (f.ex. load-load, or store-load), all of the first operations preceding the
5953 barrier will complete before any of the second operations succeeding the
5954 barrier begin. Specifically the semantics for each pairing is as follows:
5955</p>
5956 <ul>
5957 <li><tt>ll</tt>: All loads before the barrier must complete before any load
5958 after the barrier begins.</li>
5959
5960 <li><tt>ls</tt>: All loads before the barrier must complete before any
5961 store after the barrier begins.</li>
5962 <li><tt>ss</tt>: All stores before the barrier must complete before any
5963 store after the barrier begins.</li>
5964 <li><tt>sl</tt>: All stores before the barrier must complete before any
5965 load after the barrier begins.</li>
5966 </ul>
5967<p>
5968 These semantics are applied with a logical "and" behavior when more than one
5969 is enabled in a single memory barrier intrinsic.
5970</p>
5971<p>
5972 Backends may implement stronger barriers than those requested when they do not
5973 support as fine grained a barrier as requested. Some architectures do not
5974 need all types of barriers and on such architectures, these become noops.
5975</p>
5976<h5>Example:</h5>
5977<pre>
5978%ptr = malloc i32
5979 store i32 4, %ptr
5980
5981%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
5982 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
5983 <i>; guarantee the above finishes</i>
5984 store i32 8, %ptr <i>; before this begins</i>
5985</pre>
5986</div>
5987
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5988<!-- _______________________________________________________________________ -->
5989<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]5990 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5991</div>
5992<div class="doc_text">
5993<h5>Syntax:</h5>
5994<p>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]5995 This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
5996 any integer bit width and for different address spaces. Not all targets
5997 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]5998
5999<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6000declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6001declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6002declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6003declare 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]6004
6005</pre>
6006<h5>Overview:</h5>
6007<p>
6008 This loads a value in memory and compares it to a given value. If they are
6009 equal, it stores a new value into the memory.
6010</p>
6011<h5>Arguments:</h5>
6012<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6013 The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6014 well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6015 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6016 this integer type. While any bit width integer may be used, targets may only
6017 lower representations they support in hardware.
6018
6019</p>
6020<h5>Semantics:</h5>
6021<p>
6022 This entire intrinsic must be executed atomically. It first loads the value
6023 in memory pointed to by <tt>ptr</tt> and compares it with the value
6024 <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
6025 loaded value is yielded in all cases. This provides the equivalent of an
6026 atomic compare-and-swap operation within the SSA framework.
6027</p>
6028<h5>Examples:</h5>
6029
6030<pre>
6031%ptr = malloc i32
6032 store i32 4, %ptr
6033
6034%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6035%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6036 <i>; yields {i32}:result1 = 4</i>
6037%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6038%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6039
6040%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6041%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6042 <i>; yields {i32}:result2 = 8</i>
6043%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6044
6045%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6046</pre>
6047</div>
6048
6049<!-- _______________________________________________________________________ -->
6050<div class="doc_subsubsection">
6051 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6052</div>
6053<div class="doc_text">
6054<h5>Syntax:</h5>
6055
6056<p>
6057 This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6058 integer bit width. Not all targets support all bit widths however.</p>
6059<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6060declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6061declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6062declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6063declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6064
6065</pre>
6066<h5>Overview:</h5>
6067<p>
6068 This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6069 the value from memory. It then stores the value in <tt>val</tt> in the memory
6070 at <tt>ptr</tt>.
6071</p>
6072<h5>Arguments:</h5>
6073
6074<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6075 The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6076 <tt>val</tt> argument and the result must be integers of the same bit width.
6077 The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6078 integer type. The targets may only lower integer representations they
6079 support.
6080</p>
6081<h5>Semantics:</h5>
6082<p>
6083 This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6084 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6085 equivalent of an atomic swap operation within the SSA framework.
6086
6087</p>
6088<h5>Examples:</h5>
6089<pre>
6090%ptr = malloc i32
6091 store i32 4, %ptr
6092
6093%val1 = add i32 4, 4
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6094%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6095 <i>; yields {i32}:result1 = 4</i>
6096%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6097%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6098
6099%val2 = add i32 1, 1
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6100%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6101 <i>; yields {i32}:result2 = 8</i>
6102
6103%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6104%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6105</pre>
6106</div>
6107
6108<!-- _______________________________________________________________________ -->
6109<div class="doc_subsubsection">
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6110 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6111
6112</div>
6113<div class="doc_text">
6114<h5>Syntax:</h5>
6115<p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6116 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]6117 integer bit width. Not all targets support all bit widths however.</p>
6118<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6119declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6120declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6121declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6122declare 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]6123
6124</pre>
6125<h5>Overview:</h5>
6126<p>
6127 This intrinsic adds <tt>delta</tt> to the value stored in memory at
6128 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6129</p>
6130<h5>Arguments:</h5>
6131<p>
6132
6133 The intrinsic takes two arguments, the first a pointer to an integer value
6134 and the second an integer value. The result is also an integer value. These
6135 integer types can have any bit width, but they must all have the same bit
6136 width. The targets may only lower integer representations they support.
6137</p>
6138<h5>Semantics:</h5>
6139<p>
6140 This intrinsic does a series of operations atomically. It first loads the
6141 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6142 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6143</p>
6144
6145<h5>Examples:</h5>
6146<pre>
6147%ptr = malloc i32
6148 store i32 4, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6149%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6150 <i>; yields {i32}:result1 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6151%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6152 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6153%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6154 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6155%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]6156</pre>
6157</div>
6158
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6159<!-- _______________________________________________________________________ -->
6160<div class="doc_subsubsection">
6161 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6162
6163</div>
6164<div class="doc_text">
6165<h5>Syntax:</h5>
6166<p>
6167 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]6168 any integer bit width and for different address spaces. Not all targets
6169 support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6170<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6171declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6172declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6173declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6174declare 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]6175
6176</pre>
6177<h5>Overview:</h5>
6178<p>
6179 This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6180 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
6181</p>
6182<h5>Arguments:</h5>
6183<p>
6184
6185 The intrinsic takes two arguments, the first a pointer to an integer value
6186 and the second an integer value. The result is also an integer value. These
6187 integer types can have any bit width, but they must all have the same bit
6188 width. The targets may only lower integer representations they support.
6189</p>
6190<h5>Semantics:</h5>
6191<p>
6192 This intrinsic does a series of operations atomically. It first loads the
6193 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6194 result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
6195</p>
6196
6197<h5>Examples:</h5>
6198<pre>
6199%ptr = malloc i32
6200 store i32 8, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6201%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6202 <i>; yields {i32}:result1 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6203%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6204 <i>; yields {i32}:result2 = 4</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6205%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6206 <i>; yields {i32}:result3 = 2</i>
6207%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6208</pre>
6209</div>
6210
6211<!-- _______________________________________________________________________ -->
6212<div class="doc_subsubsection">
6213 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6214 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6215 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6216 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
6217
6218</div>
6219<div class="doc_text">
6220<h5>Syntax:</h5>
6221<p>
6222 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
6223 <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6224 <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
6225 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6226<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6227declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6228declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6229declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6230declare 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]6231
6232</pre>
6233
6234<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6235declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6236declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6237declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6238declare 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]6239
6240</pre>
6241
6242<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6243declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6244declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6245declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6246declare 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]6247
6248</pre>
6249
6250<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6251declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6252declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6253declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6254declare 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]6255
6256</pre>
6257<h5>Overview:</h5>
6258<p>
6259 These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6260 the value stored in memory at <tt>ptr</tt>. It yields the original value
6261 at <tt>ptr</tt>.
6262</p>
6263<h5>Arguments:</h5>
6264<p>
6265
6266 These intrinsics take two arguments, the first a pointer to an integer value
6267 and the second an integer value. The result is also an integer value. These
6268 integer types can have any bit width, but they must all have the same bit
6269 width. The targets may only lower integer representations they support.
6270</p>
6271<h5>Semantics:</h5>
6272<p>
6273 These intrinsics does a series of operations atomically. They first load the
6274 value stored at <tt>ptr</tt>. They then do the bitwise operation
6275 <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
6276 value stored at <tt>ptr</tt>.
6277</p>
6278
6279<h5>Examples:</h5>
6280<pre>
6281%ptr = malloc i32
6282 store i32 0x0F0F, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6283%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6284 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6285%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6286 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6287%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6288 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6289%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6290 <i>; yields {i32}:result3 = FF</i>
6291%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6292</pre>
6293</div>
6294
6295
6296<!-- _______________________________________________________________________ -->
6297<div class="doc_subsubsection">
6298 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6299 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6300 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6301 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
6302
6303</div>
6304<div class="doc_text">
6305<h5>Syntax:</h5>
6306<p>
6307 These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6308 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6309 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6310 address spaces. Not all targets
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6311 support all bit widths however.</p>
6312<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6313declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6314declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6315declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6316declare 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]6317
6318</pre>
6319
6320<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6321declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6322declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6323declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6324declare 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]6325
6326</pre>
6327
6328<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6329declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6330declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6331declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6332declare 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]6333
6334</pre>
6335
6336<pre>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6337declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6338declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6339declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6340declare 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]6341
6342</pre>
6343<h5>Overview:</h5>
6344<p>
6345 These intrinsics takes the signed or unsigned minimum or maximum of
6346 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6347 original value at <tt>ptr</tt>.
6348</p>
6349<h5>Arguments:</h5>
6350<p>
6351
6352 These intrinsics take two arguments, the first a pointer to an integer value
6353 and the second an integer value. The result is also an integer value. These
6354 integer types can have any bit width, but they must all have the same bit
6355 width. The targets may only lower integer representations they support.
6356</p>
6357<h5>Semantics:</h5>
6358<p>
6359 These intrinsics does a series of operations atomically. They first load the
6360 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
6361 <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
6362 the original value stored at <tt>ptr</tt>.
6363</p>
6364
6365<h5>Examples:</h5>
6366<pre>
6367%ptr = malloc i32
6368 store i32 7, %ptr
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6369%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6370 <i>; yields {i32}:result0 = 7</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6371%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6372 <i>; yields {i32}:result1 = -2</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6373%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6374 <i>; yields {i32}:result2 = 8</i>
Mon P Wang2c839d42008-07-30 04:36:53 +0000[diff] [blame]6375%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]6376 <i>; yields {i32}:result3 = 8</i>
6377%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6378</pre>
6379</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]6380
6381<!-- ======================================================================= -->
6382<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6383 <a name="int_general">General Intrinsics</a>
6384</div>
6385
6386<div class="doc_text">
6387<p> This class of intrinsics is designed to be generic and has
6388no specific purpose. </p>
6389</div>
6390
6391<!-- _______________________________________________________________________ -->
6392<div class="doc_subsubsection">
6393 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6394</div>
6395
6396<div class="doc_text">
6397
6398<h5>Syntax:</h5>
6399<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6400 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]6401</pre>
6402
6403<h5>Overview:</h5>
6404
6405<p>
6406The '<tt>llvm.var.annotation</tt>' intrinsic
6407</p>
6408
6409<h5>Arguments:</h5>
6410
6411<p>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]6412The first argument is a pointer to a value, the second is a pointer to a
6413global string, the third is a pointer to a global string which is the source
6414file name, and the last argument is the line number.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6415</p>
6416
6417<h5>Semantics:</h5>
6418
6419<p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6420This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6421This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6422annotations. These have no other defined use, they are ignored by code
6423generation and optimization.
6424</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]6425</div>
6426
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6427<!-- _______________________________________________________________________ -->
6428<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]6429 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6430</div>
6431
6432<div class="doc_text">
6433
6434<h5>Syntax:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6435<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6436any integer bit width.
6437</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6438<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]6439 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6440 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6441 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6442 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6443 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]6444</pre>
6445
6446<h5>Overview:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6447
6448<p>
6449The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6450</p>
6451
6452<h5>Arguments:</h5>
6453
6454<p>
6455The first argument is an integer value (result of some expression),
6456the second is a pointer to a global string, the third is a pointer to a global
6457string which is the source file name, and the last argument is the line number.
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]6458It returns the value of the first argument.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6459</p>
6460
6461<h5>Semantics:</h5>
6462
6463<p>
6464This intrinsic allows annotations to be put on arbitrary expressions
6465with arbitrary strings. This can be useful for special purpose optimizations
6466that want to look for these annotations. These have no other defined use, they
6467are ignored by code generation and optimization.
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]6468</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]6469</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]6470
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]6471<!-- _______________________________________________________________________ -->
6472<div class="doc_subsubsection">
6473 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6474</div>
6475
6476<div class="doc_text">
6477
6478<h5>Syntax:</h5>
6479<pre>
6480 declare void @llvm.trap()
6481</pre>
6482
6483<h5>Overview:</h5>
6484
6485<p>
6486The '<tt>llvm.trap</tt>' intrinsic
6487</p>
6488
6489<h5>Arguments:</h5>
6490
6491<p>
6492None
6493</p>
6494
6495<h5>Semantics:</h5>
6496
6497<p>
6498This intrinsics is lowered to the target dependent trap instruction. If the
6499target does not have a trap instruction, this intrinsic will be lowered to the
6500call of the abort() function.
6501</p>
6502</div>
6503
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6504<!-- _______________________________________________________________________ -->
6505<div class="doc_subsubsection">
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]6506 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]6507</div>
6508<div class="doc_text">
6509<h5>Syntax:</h5>
6510<pre>
6511declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
6512
6513</pre>
6514<h5>Overview:</h5>
6515<p>
6516 The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
6517 it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
6518 it is placed on the stack before local variables.
6519</p>
6520<h5>Arguments:</h5>
6521<p>
6522 The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
6523 first argument is the value loaded from the stack guard
6524 <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
6525 has enough space to hold the value of the guard.
6526</p>
6527<h5>Semantics:</h5>
6528<p>
6529 This intrinsic causes the prologue/epilogue inserter to force the position of
6530 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6531 stack. This is to ensure that if a local variable on the stack is overwritten,
6532 it will destroy the value of the guard. When the function exits, the guard on
6533 the stack is checked against the original guard. If they're different, then
6534 the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
6535</p>
6536</div>
6537
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6538<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]6539<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6540<address>
6541 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]6542 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6543 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]6544 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]6545
6546 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]6547 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]6548 Last modified: $Date$
6549</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]6550
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]6551</body>
6552</html>