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gerrit-public.fairphone.software / toolchain / llvm-project / e31cd5b564d48240788dcd6b721236b6adc7e0fe / . / llvm / docs / LangRef.html
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5 <title>LLVM Assembly Language Reference Manual</title>
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7 <meta name="author" content="Chris Lattner">
8 <meta name="description"
9 content="LLVM Assembly Language Reference Manual.">
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11</head>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]14
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]15<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a></li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]24 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]25 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]26 <li><a href="#functionstructure">Functions</a></li>
Anton Korobeynikov546ea7e2007-04-29 18:02:48 +0000[diff] [blame]27 <li><a href="#aliasstructure">Aliases</a>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]28 <li><a href="#paramattrs">Parameter Attributes</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]29 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]30 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]31 </ol>
32 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]33 <li><a href="#typesystem">Type System</a>
34 <ol>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]35 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]36 <ol>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]37 <li><a href="#t_classifications">Type Classifications</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]38 </ol>
39 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]40 <li><a href="#t_derived">Derived Types</a>
41 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]42 <li><a href="#t_array">Array Type</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]43 <li><a href="#t_function">Function Type</a></li>
44 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]45 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]46 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]47 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]48 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]49 </ol>
50 </li>
51 </ol>
52 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]53 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]54 <ol>
55 <li><a href="#simpleconstants">Simple Constants</a>
56 <li><a href="#aggregateconstants">Aggregate Constants</a>
57 <li><a href="#globalconstants">Global Variable and Function Addresses</a>
58 <li><a href="#undefvalues">Undefined Values</a>
59 <li><a href="#constantexprs">Constant Expressions</a>
60 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]61 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]62 <li><a href="#othervalues">Other Values</a>
63 <ol>
64 <li><a href="#inlineasm">Inline Assembler Expressions</a>
65 </ol>
66 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]67 <li><a href="#instref">Instruction Reference</a>
68 <ol>
69 <li><a href="#terminators">Terminator Instructions</a>
70 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]71 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
72 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]73 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
74 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]75 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]76 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]77 </ol>
78 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]79 <li><a href="#binaryops">Binary Operations</a>
80 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]81 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
82 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
83 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]84 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
85 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
86 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]87 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
88 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
89 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]90 </ol>
91 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]92 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
93 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]94 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
95 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
96 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]97 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]98 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]99 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]100 </ol>
101 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]102 <li><a href="#vectorops">Vector Operations</a>
103 <ol>
104 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
105 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
106 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]107 </ol>
108 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]109 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]110 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]111 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
112 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
113 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]114 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
115 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
116 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]117 </ol>
118 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]119 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]120 <ol>
121 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
122 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
123 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
124 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
125 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]126 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
127 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
128 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
129 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]130 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
131 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]132 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]133 </ol>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]134 <li><a href="#otherops">Other Operations</a>
135 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]136 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
137 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]138 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]139 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]140 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]141 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]142 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]143 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]144 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]145 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]146 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]147 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]148 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
149 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]150 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
151 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
152 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]153 </ol>
154 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]155 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
156 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]157 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
158 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
159 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]160 </ol>
161 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]162 <li><a href="#int_codegen">Code Generator Intrinsics</a>
163 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]164 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
165 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
166 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
167 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
168 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
169 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
170 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]171 </ol>
172 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]173 <li><a href="#int_libc">Standard C Library Intrinsics</a>
174 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]175 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
176 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
177 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
178 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
179 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]180 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
181 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
182 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]183 </ol>
184 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]185 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]186 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]187 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]188 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
189 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
190 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]191 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
192 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]193 </ol>
194 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]195 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]196 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]197 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]198 <ol>
199 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]200 </ol>
201 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]202 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]203 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]204 <li><a href="#int_var_annotation">
Tanya Lattner08abc812007-09-22 00:01:26 +0000[diff] [blame]205 <tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]206 </ol>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]207 <ol>
208 <li><a href="#int_annotation">
Tanya Lattner08abc812007-09-22 00:01:26 +0000[diff] [blame]209 <tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]210 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]211 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]212 </ol>
213 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]214</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]215
216<div class="doc_author">
217 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
218 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]219</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]220
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]221<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]222<div class="doc_section"> <a name="abstract">Abstract </a></div>
223<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]224
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]225<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]226<p>This document is a reference manual for the LLVM assembly language.
227LLVM is an SSA based representation that provides type safety,
228low-level operations, flexibility, and the capability of representing
229'all' high-level languages cleanly. It is the common code
230representation used throughout all phases of the LLVM compilation
231strategy.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]232</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]233
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]234<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]235<div class="doc_section"> <a name="introduction">Introduction</a> </div>
236<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]237
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]238<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]239
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]240<p>The LLVM code representation is designed to be used in three
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]241different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]242representation (suitable for fast loading by a Just-In-Time compiler),
243and as a human readable assembly language representation. This allows
244LLVM to provide a powerful intermediate representation for efficient
245compiler transformations and analysis, while providing a natural means
246to debug and visualize the transformations. The three different forms
247of LLVM are all equivalent. This document describes the human readable
248representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]249
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]250<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]251while being expressive, typed, and extensible at the same time. It
252aims to be a "universal IR" of sorts, by being at a low enough level
253that high-level ideas may be cleanly mapped to it (similar to how
254microprocessors are "universal IR's", allowing many source languages to
255be mapped to them). By providing type information, LLVM can be used as
256the target of optimizations: for example, through pointer analysis, it
257can be proven that a C automatic variable is never accessed outside of
258the current function... allowing it to be promoted to a simple SSA
259value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]260
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]261</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]262
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]263<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]264<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]265
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]266<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]267
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]268<p>It is important to note that this document describes 'well formed'
269LLVM assembly language. There is a difference between what the parser
270accepts and what is considered 'well formed'. For example, the
271following instruction is syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]272
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]273<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]274<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]275%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]276</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]277</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]278
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]279<p>...because the definition of <tt>%x</tt> does not dominate all of
280its uses. The LLVM infrastructure provides a verification pass that may
281be used to verify that an LLVM module is well formed. This pass is
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]282automatically run by the parser after parsing input assembly and by
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]283the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]284by the verifier pass indicate bugs in transformation passes or input to
285the parser.</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]286</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]287
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]288<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]289
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]290<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]291<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]292<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]293
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]294<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]295
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]296 <p>LLVM identifiers come in two basic types: global and local. Global
297 identifiers (functions, global variables) begin with the @ character. Local
298 identifiers (register names, types) begin with the % character. Additionally,
299 there are three different formats for identifiers, for different purposes:
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]300
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]301<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]302 <li>Named values are represented as a string of characters with their prefix.
303 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
304 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]305 Identifiers which require other characters in their names can be surrounded
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]306 with quotes. In this way, anything except a <tt>&quot;</tt> character can
307 be used in a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]308
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]309 <li>Unnamed values are represented as an unsigned numeric value with their
310 prefix. For example, %12, @2, %44.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]311
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]312 <li>Constants, which are described in a <a href="#constants">section about
313 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]314</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]315
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]316<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]317don't need to worry about name clashes with reserved words, and the set of
318reserved words may be expanded in the future without penalty. Additionally,
319unnamed identifiers allow a compiler to quickly come up with a temporary
320variable without having to avoid symbol table conflicts.</p>
321
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]322<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]323languages. There are keywords for different opcodes
324('<tt><a href="#i_add">add</a></tt>',
325 '<tt><a href="#i_bitcast">bitcast</a></tt>',
326 '<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]327href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]328and others. These reserved words cannot conflict with variable names, because
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]329none of them start with a prefix character ('%' or '@').</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]330
331<p>Here is an example of LLVM code to multiply the integer variable
332'<tt>%X</tt>' by 8:</p>
333
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]334<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]335
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]336<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]337<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]338%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]339</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]340</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]341
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]342<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]343
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]344<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]345<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]346%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]347</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]348</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]349
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]350<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]351
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]352<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]353<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]354<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
355<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
356%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]357</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]358</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]359
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]360<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
361important lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]362
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]363<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]364
365 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
366 line.</li>
367
368 <li>Unnamed temporaries are created when the result of a computation is not
369 assigned to a named value.</li>
370
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]371 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]372
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]373</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]374
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]375<p>...and it also shows a convention that we follow in this document. When
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]376demonstrating instructions, we will follow an instruction with a comment that
377defines the type and name of value produced. Comments are shown in italic
378text.</p>
379
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]380</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]381
382<!-- *********************************************************************** -->
383<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
384<!-- *********************************************************************** -->
385
386<!-- ======================================================================= -->
387<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
388</div>
389
390<div class="doc_text">
391
392<p>LLVM programs are composed of "Module"s, each of which is a
393translation unit of the input programs. Each module consists of
394functions, global variables, and symbol table entries. Modules may be
395combined together with the LLVM linker, which merges function (and
396global variable) definitions, resolves forward declarations, and merges
397symbol table entries. Here is an example of the "hello world" module:</p>
398
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]399<div class="doc_code">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]400<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]401<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
402 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]403
404<i>; External declaration of the puts function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]405<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]406
407<i>; Definition of main function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]408define i32 @main() { <i>; i32()* </i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]409 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]410 %cast210 = <a
Chris Lattner2150cde2007-06-12 17:01:15 +0000[diff] [blame]411 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]412
413 <i>; Call puts function to write out the string to stdout...</i>
414 <a
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]415 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]416 <a
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]417 href="#i_ret">ret</a> i32 0<br>}<br>
418</pre>
419</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]420
421<p>This example is made up of a <a href="#globalvars">global variable</a>
422named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
423function, and a <a href="#functionstructure">function definition</a>
424for "<tt>main</tt>".</p>
425
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]426<p>In general, a module is made up of a list of global values,
427where both functions and global variables are global values. Global values are
428represented by a pointer to a memory location (in this case, a pointer to an
429array of char, and a pointer to a function), and have one of the following <a
430href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]431
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]432</div>
433
434<!-- ======================================================================= -->
435<div class="doc_subsection">
436 <a name="linkage">Linkage Types</a>
437</div>
438
439<div class="doc_text">
440
441<p>
442All Global Variables and Functions have one of the following types of linkage:
443</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]444
445<dl>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]446
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]447 <dt><tt><b><a name="linkage_internal">internal</a></b></tt> </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]448
449 <dd>Global values with internal linkage are only directly accessible by
450 objects in the current module. In particular, linking code into a module with
451 an internal global value may cause the internal to be renamed as necessary to
452 avoid collisions. Because the symbol is internal to the module, all
453 references can be updated. This corresponds to the notion of the
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]454 '<tt>static</tt>' keyword in C.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]455 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]456
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]457 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]458
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]459 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
460 the same name when linkage occurs. This is typically used to implement
461 inline functions, templates, or other code which must be generated in each
462 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
463 allowed to be discarded.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]464 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]465
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]466 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]467
468 <dd>"<tt>weak</tt>" linkage is exactly the same as <tt>linkonce</tt> linkage,
469 except that unreferenced <tt>weak</tt> globals may not be discarded. This is
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]470 used for globals that may be emitted in multiple translation units, but that
471 are not guaranteed to be emitted into every translation unit that uses them.
472 One example of this are common globals in C, such as "<tt>int X;</tt>" at
473 global scope.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]474 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]475
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]476 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]477
478 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
479 pointer to array type. When two global variables with appending linkage are
480 linked together, the two global arrays are appended together. This is the
481 LLVM, typesafe, equivalent of having the system linker append together
482 "sections" with identical names when .o files are linked.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]483 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]484
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]485 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
486 <dd>The semantics of this linkage follow the ELF model: the symbol is weak
487 until linked, if not linked, the symbol becomes null instead of being an
488 undefined reference.
489 </dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]490
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]491 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]492
493 <dd>If none of the above identifiers are used, the global is externally
494 visible, meaning that it participates in linkage and can be used to resolve
495 external symbol references.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]496 </dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]497</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]498
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]499 <p>
500 The next two types of linkage are targeted for Microsoft Windows platform
501 only. They are designed to support importing (exporting) symbols from (to)
502 DLLs.
503 </p>
504
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]505 <dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]506 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
507
508 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
509 or variable via a global pointer to a pointer that is set up by the DLL
510 exporting the symbol. On Microsoft Windows targets, the pointer name is
511 formed by combining <code>_imp__</code> and the function or variable name.
512 </dd>
513
514 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
515
516 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
517 pointer to a pointer in a DLL, so that it can be referenced with the
518 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
519 name is formed by combining <code>_imp__</code> and the function or variable
520 name.
521 </dd>
522
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]523</dl>
524
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]525<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]526variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
527variable and was linked with this one, one of the two would be renamed,
528preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
529external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer92c671e2007-01-05 00:59:10 +0000[diff] [blame]530outside of the current module.</p>
531<p>It is illegal for a function <i>declaration</i>
532to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]533or <tt>extern_weak</tt>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]534<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
535linkages.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]536</div>
537
538<!-- ======================================================================= -->
539<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]540 <a name="callingconv">Calling Conventions</a>
541</div>
542
543<div class="doc_text">
544
545<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
546and <a href="#i_invoke">invokes</a> can all have an optional calling convention
547specified for the call. The calling convention of any pair of dynamic
548caller/callee must match, or the behavior of the program is undefined. The
549following calling conventions are supported by LLVM, and more may be added in
550the future:</p>
551
552<dl>
553 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
554
555 <dd>This calling convention (the default if no other calling convention is
556 specified) matches the target C calling conventions. This calling convention
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]557 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer72ba4992006-12-31 21:30:18 +0000[diff] [blame]558 prototype and implemented declaration of the function (as does normal C).
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]559 </dd>
560
561 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
562
563 <dd>This calling convention attempts to make calls as fast as possible
564 (e.g. by passing things in registers). This calling convention allows the
565 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattnerc792eb32005-05-06 23:08:23 +0000[diff] [blame]566 without having to conform to an externally specified ABI. Implementations of
567 this convention should allow arbitrary tail call optimization to be supported.
568 This calling convention does not support varargs and requires the prototype of
569 all callees to exactly match the prototype of the function definition.
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]570 </dd>
571
572 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
573
574 <dd>This calling convention attempts to make code in the caller as efficient
575 as possible under the assumption that the call is not commonly executed. As
576 such, these calls often preserve all registers so that the call does not break
577 any live ranges in the caller side. This calling convention does not support
578 varargs and requires the prototype of all callees to exactly match the
579 prototype of the function definition.
580 </dd>
581
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]582 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]583
584 <dd>Any calling convention may be specified by number, allowing
585 target-specific calling conventions to be used. Target specific calling
586 conventions start at 64.
587 </dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]588</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]589
590<p>More calling conventions can be added/defined on an as-needed basis, to
591support pascal conventions or any other well-known target-independent
592convention.</p>
593
594</div>
595
596<!-- ======================================================================= -->
597<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]598 <a name="visibility">Visibility Styles</a>
599</div>
600
601<div class="doc_text">
602
603<p>
604All Global Variables and Functions have one of the following visibility styles:
605</p>
606
607<dl>
608 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
609
610 <dd>On ELF, default visibility means that the declaration is visible to other
611 modules and, in shared libraries, means that the declared entity may be
612 overridden. On Darwin, default visibility means that the declaration is
613 visible to other modules. Default visibility corresponds to "external
614 linkage" in the language.
615 </dd>
616
617 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
618
619 <dd>Two declarations of an object with hidden visibility refer to the same
620 object if they are in the same shared object. Usually, hidden visibility
621 indicates that the symbol will not be placed into the dynamic symbol table,
622 so no other module (executable or shared library) can reference it
623 directly.
624 </dd>
625
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]626 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
627
628 <dd>On ELF, protected visibility indicates that the symbol will be placed in
629 the dynamic symbol table, but that references within the defining module will
630 bind to the local symbol. That is, the symbol cannot be overridden by another
631 module.
632 </dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]633</dl>
634
635</div>
636
637<!-- ======================================================================= -->
638<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]639 <a name="globalvars">Global Variables</a>
640</div>
641
642<div class="doc_text">
643
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]644<p>Global variables define regions of memory allocated at compilation time
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]645instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]646an explicit section to be placed in, and may have an optional explicit alignment
647specified. A variable may be defined as "thread_local", which means that it
648will not be shared by threads (each thread will have a separated copy of the
649variable). A variable may be defined as a global "constant," which indicates
650that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]651optimization, allowing the global data to be placed in the read-only section of
652an executable, etc). Note that variables that need runtime initialization
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]653cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]654
655<p>
656LLVM explicitly allows <em>declarations</em> of global variables to be marked
657constant, even if the final definition of the global is not. This capability
658can be used to enable slightly better optimization of the program, but requires
659the language definition to guarantee that optimizations based on the
660'constantness' are valid for the translation units that do not include the
661definition.
662</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]663
664<p>As SSA values, global variables define pointer values that are in
665scope (i.e. they dominate) all basic blocks in the program. Global
666variables always define a pointer to their "content" type because they
667describe a region of memory, and all memory objects in LLVM are
668accessed through pointers.</p>
669
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]670<p>LLVM allows an explicit section to be specified for globals. If the target
671supports it, it will emit globals to the section specified.</p>
672
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]673<p>An explicit alignment may be specified for a global. If not present, or if
674the alignment is set to zero, the alignment of the global is set by the target
675to whatever it feels convenient. If an explicit alignment is specified, the
676global is forced to have at least that much alignment. All alignments must be
677a power of 2.</p>
678
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]679<p>For example, the following defines a global with an initializer, section,
680 and alignment:</p>
681
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]682<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]683<pre>
Chris Lattner0a2d0992007-07-13 20:01:46 +0000[diff] [blame]684@G = constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]685</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]686</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]687
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]688</div>
689
690
691<!-- ======================================================================= -->
692<div class="doc_subsection">
693 <a name="functionstructure">Functions</a>
694</div>
695
696<div class="doc_text">
697
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]698<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
699an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]700<a href="#visibility">visibility style</a>, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]701<a href="#callingconv">calling convention</a>, a return type, an optional
702<a href="#paramattrs">parameter attribute</a> for the return type, a function
703name, a (possibly empty) argument list (each with optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]704<a href="#paramattrs">parameter attributes</a>), an optional section, an
705optional alignment, an opening curly brace, a list of basic blocks, and a
706closing curly brace.
707
708LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
709optional <a href="#linkage">linkage type</a>, an optional
710<a href="#visibility">visibility style</a>, an optional
711<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]712<a href="#paramattrs">parameter attribute</a> for the return type, a function
713name, a possibly empty list of arguments, and an optional alignment.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]714
715<p>A function definition contains a list of basic blocks, forming the CFG for
716the function. Each basic block may optionally start with a label (giving the
717basic block a symbol table entry), contains a list of instructions, and ends
718with a <a href="#terminators">terminator</a> instruction (such as a branch or
719function return).</p>
720
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]721<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]722executed on entrance to the function, and it is not allowed to have predecessor
723basic blocks (i.e. there can not be any branches to the entry block of a
724function). Because the block can have no predecessors, it also cannot have any
725<a href="#i_phi">PHI nodes</a>.</p>
726
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]727<p>LLVM allows an explicit section to be specified for functions. If the target
728supports it, it will emit functions to the section specified.</p>
729
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]730<p>An explicit alignment may be specified for a function. If not present, or if
731the alignment is set to zero, the alignment of the function is set by the target
732to whatever it feels convenient. If an explicit alignment is specified, the
733function is forced to have at least that much alignment. All alignments must be
734a power of 2.</p>
735
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]736</div>
737
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]738
739<!-- ======================================================================= -->
740<div class="doc_subsection">
741 <a name="aliasstructure">Aliases</a>
742</div>
743<div class="doc_text">
744 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikovb18f8f82007-04-28 13:45:00 +0000[diff] [blame]745 function or global variable or bitcast of global value). Aliases may have an
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]746 optional <a href="#linkage">linkage type</a>, and an
747 optional <a href="#visibility">visibility style</a>.</p>
748
749 <h5>Syntax:</h5>
750
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]751<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]752<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]753@&lt;Name&gt; = [Linkage] [Visibility] alias &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]754</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]755</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]756
757</div>
758
759
760
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]761<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]762<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
763<div class="doc_text">
764 <p>The return type and each parameter of a function type may have a set of
765 <i>parameter attributes</i> associated with them. Parameter attributes are
766 used to communicate additional information about the result or parameters of
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]767 a function. Parameter attributes are considered to be part of the function,
768 not of the function type, so functions with different parameter attributes
769 can have the same function type.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]770
Reid Spencercf7ebf52007-01-15 18:27:39 +0000[diff] [blame]771 <p>Parameter attributes are simple keywords that follow the type specified. If
772 multiple parameter attributes are needed, they are space separated. For
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]773 example:</p>
774
775<div class="doc_code">
776<pre>
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]777declare i32 @printf(i8* noalias , ...) nounwind
778declare i32 @atoi(i8*) nounwind readonly
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]779</pre>
780</div>
781
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]782 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
783 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]784
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]785 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]786 <dl>
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]787 <dt><tt>zeroext</tt></dt>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]788 <dd>This indicates that the parameter should be zero extended just before
789 a call to this function.</dd>
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]790 <dt><tt>signext</tt></dt>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]791 <dd>This indicates that the parameter should be sign extended just before
792 a call to this function.</dd>
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]793 <dt><tt>inreg</tt></dt>
794 <dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikove93c6e82007-01-28 15:27:21 +0000[diff] [blame]795 possible) during assembling function call. Support for this attribute is
796 target-specific</dd>
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]797 <dt><tt>sret</tt></dt>
Anton Korobeynikove93c6e82007-01-28 15:27:21 +0000[diff] [blame]798 <dd>This indicates that the parameter specifies the address of a structure
Reid Spencer05dbb9d2007-03-22 02:02:11 +0000[diff] [blame]799 that is the return value of the function in the source program.</dd>
Zhou Sheng2444a9a2007-06-05 05:28:26 +0000[diff] [blame]800 <dt><tt>noalias</tt></dt>
801 <dd>This indicates that the parameter not alias any other object or any
802 other "noalias" objects during the function call.
Reid Spencer9d1700e2007-03-22 02:18:56 +0000[diff] [blame]803 <dt><tt>noreturn</tt></dt>
804 <dd>This function attribute indicates that the function never returns. This
805 indicates to LLVM that every call to this function should be treated as if
806 an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Reid Spencer05dbb9d2007-03-22 02:02:11 +0000[diff] [blame]807 <dt><tt>nounwind</tt></dt>
808 <dd>This function attribute indicates that the function type does not use
809 the unwind instruction and does not allow stack unwinding to propagate
810 through it.</dd>
Duncan Sands27e91592007-07-27 19:57:41 +0000[diff] [blame]811 <dt><tt>nest</tt></dt>
812 <dd>This indicates that the parameter can be excised using the
813 <a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sandsa89a1132007-11-22 20:23:04 +0000[diff] [blame]814 <dt><tt>readonly</tt></dt>
Duncan Sands730a3262007-11-14 21:14:02 +0000[diff] [blame]815 <dd>This function attribute indicates that the function has no side-effects
Duncan Sandsa89a1132007-11-22 20:23:04 +0000[diff] [blame]816 except for producing a return value or throwing an exception. The value
817 returned must only depend on the function arguments and/or global variables.
818 It may use values obtained by dereferencing pointers.</dd>
819 <dt><tt>readnone</tt></dt>
820 <dd>A <tt>readnone</tt> function has the same restrictions as a <tt>readonly</tt>
Duncan Sands730a3262007-11-14 21:14:02 +0000[diff] [blame]821 function, but in addition it is not allowed to dereference any pointer arguments
822 or global variables.
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]823 </dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]824
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]825</div>
826
827<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]828<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]829 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]830</div>
831
832<div class="doc_text">
833<p>
834Modules may contain "module-level inline asm" blocks, which corresponds to the
835GCC "file scope inline asm" blocks. These blocks are internally concatenated by
836LLVM and treated as a single unit, but may be separated in the .ll file if
837desired. The syntax is very simple:
838</p>
839
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]840<div class="doc_code">
841<pre>
842module asm "inline asm code goes here"
843module asm "more can go here"
844</pre>
845</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]846
847<p>The strings can contain any character by escaping non-printable characters.
848 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
849 for the number.
850</p>
851
852<p>
853 The inline asm code is simply printed to the machine code .s file when
854 assembly code is generated.
855</p>
856</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]857
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]858<!-- ======================================================================= -->
859<div class="doc_subsection">
860 <a name="datalayout">Data Layout</a>
861</div>
862
863<div class="doc_text">
864<p>A module may specify a target specific data layout string that specifies how
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]865data is to be laid out in memory. The syntax for the data layout is simply:</p>
866<pre> target datalayout = "<i>layout specification</i>"</pre>
867<p>The <i>layout specification</i> consists of a list of specifications
868separated by the minus sign character ('-'). Each specification starts with a
869letter and may include other information after the letter to define some
870aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]871<dl>
872 <dt><tt>E</tt></dt>
873 <dd>Specifies that the target lays out data in big-endian form. That is, the
874 bits with the most significance have the lowest address location.</dd>
875 <dt><tt>e</tt></dt>
876 <dd>Specifies that hte target lays out data in little-endian form. That is,
877 the bits with the least significance have the lowest address location.</dd>
878 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
879 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
880 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
881 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
882 too.</dd>
883 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
884 <dd>This specifies the alignment for an integer type of a given bit
885 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
886 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
887 <dd>This specifies the alignment for a vector type of a given bit
888 <i>size</i>.</dd>
889 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
890 <dd>This specifies the alignment for a floating point type of a given bit
891 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
892 (double).</dd>
893 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
894 <dd>This specifies the alignment for an aggregate type of a given bit
895 <i>size</i>.</dd>
896</dl>
897<p>When constructing the data layout for a given target, LLVM starts with a
898default set of specifications which are then (possibly) overriden by the
899specifications in the <tt>datalayout</tt> keyword. The default specifications
900are given in this list:</p>
901<ul>
902 <li><tt>E</tt> - big endian</li>
903 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
904 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
905 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
906 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
907 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
908 <li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
909 alignment of 64-bits</li>
910 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
911 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
912 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
913 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
914 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
915</ul>
916<p>When llvm is determining the alignment for a given type, it uses the
917following rules:
918<ol>
919 <li>If the type sought is an exact match for one of the specifications, that
920 specification is used.</li>
921 <li>If no match is found, and the type sought is an integer type, then the
922 smallest integer type that is larger than the bitwidth of the sought type is
923 used. If none of the specifications are larger than the bitwidth then the the
924 largest integer type is used. For example, given the default specifications
925 above, the i7 type will use the alignment of i8 (next largest) while both
926 i65 and i256 will use the alignment of i64 (largest specified).</li>
927 <li>If no match is found, and the type sought is a vector type, then the
928 largest vector type that is smaller than the sought vector type will be used
929 as a fall back. This happens because <128 x double> can be implemented in
930 terms of 64 <2 x double>, for example.</li>
931</ol>
932</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]933
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]934<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]935<div class="doc_section"> <a name="typesystem">Type System</a> </div>
936<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]937
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]938<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]939
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]940<p>The LLVM type system is one of the most important features of the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]941intermediate representation. Being typed enables a number of
942optimizations to be performed on the IR directly, without having to do
943extra analyses on the side before the transformation. A strong type
944system makes it easier to read the generated code and enables novel
945analyses and transformations that are not feasible to perform on normal
946three address code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]947
948</div>
949
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]950<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]951<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]952<div class="doc_text">
John Criswell417228d2004-04-09 16:48:45 +0000[diff] [blame]953<p>The primitive types are the fundamental building blocks of the LLVM
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]954system. The current set of primitive types is as follows:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]955
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]956<table class="layout">
957 <tr class="layout">
958 <td class="left">
959 <table>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]960 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]961 <tr><th>Type</th><th>Description</th></tr>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]962 <tr><td><tt><a name="t_void">void</a></tt></td><td>No value</td></tr>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]963 <tr><td><tt>label</tt></td><td>Branch destination</td></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]964 </tbody>
965 </table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]966 </td>
967 <td class="right">
968 <table>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]969 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]970 <tr><th>Type</th><th>Description</th></tr>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]971 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]972 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]973 </tbody>
974 </table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]975 </td>
976 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]977</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]978</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]979
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]980<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]981<div class="doc_subsubsection"> <a name="t_classifications">Type
982Classifications</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]983<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]984<p>These different primitive types fall into a few useful
985classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]986
987<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]988 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]989 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]990 <tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]991 <td><a name="t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]992 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]993 </tr>
994 <tr>
995 <td><a name="t_floating">floating point</a></td>
996 <td><tt>float, double</tt></td>
997 </tr>
998 <tr>
999 <td><a name="t_firstclass">first class</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1000 <td><tt>i1, ..., float, double, <br/>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1001 <a href="#t_pointer">pointer</a>,<a href="#t_vector">vector</a></tt>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1002 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1003 </tr>
1004 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1005</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1006
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1007<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1008most important. Values of these types are the only ones which can be
1009produced by instructions, passed as arguments, or used as operands to
1010instructions. This means that all structures and arrays must be
1011manipulated either by pointer or by component.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1012</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1013
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1014<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1015<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1016
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1017<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1018
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1019<p>The real power in LLVM comes from the derived types in the system.
1020This is what allows a programmer to represent arrays, functions,
1021pointers, and other useful types. Note that these derived types may be
1022recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1023
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1024</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1025
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1026<!-- _______________________________________________________________________ -->
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1027<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1028
1029<div class="doc_text">
1030
1031<h5>Overview:</h5>
1032<p>The integer type is a very simple derived type that simply specifies an
1033arbitrary bit width for the integer type desired. Any bit width from 1 bit to
10342^23-1 (about 8 million) can be specified.</p>
1035
1036<h5>Syntax:</h5>
1037
1038<pre>
1039 iN
1040</pre>
1041
1042<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1043value.</p>
1044
1045<h5>Examples:</h5>
1046<table class="layout">
1047 <tr class="layout">
1048 <td class="left">
1049 <tt>i1</tt><br/>
1050 <tt>i4</tt><br/>
1051 <tt>i8</tt><br/>
1052 <tt>i16</tt><br/>
1053 <tt>i32</tt><br/>
1054 <tt>i42</tt><br/>
1055 <tt>i64</tt><br/>
1056 <tt>i1942652</tt><br/>
1057 </td>
1058 <td class="left">
1059 A boolean integer of 1 bit<br/>
1060 A nibble sized integer of 4 bits.<br/>
1061 A byte sized integer of 8 bits.<br/>
1062 A half word sized integer of 16 bits.<br/>
1063 A word sized integer of 32 bits.<br/>
1064 An integer whose bit width is the answer. <br/>
1065 A double word sized integer of 64 bits.<br/>
1066 A really big integer of over 1 million bits.<br/>
1067 </td>
1068 </tr>
1069</table>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1070</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1071
1072<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1073<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1074
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1075<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1076
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1077<h5>Overview:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1078
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1079<p>The array type is a very simple derived type that arranges elements
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1080sequentially in memory. The array type requires a size (number of
1081elements) and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1082
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1083<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1084
1085<pre>
1086 [&lt;# elements&gt; x &lt;elementtype&gt;]
1087</pre>
1088
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1089<p>The number of elements is a constant integer value; elementtype may
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1090be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1091
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1092<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1093<table class="layout">
1094 <tr class="layout">
1095 <td class="left">
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1096 <tt>[40 x i32 ]</tt><br/>
1097 <tt>[41 x i32 ]</tt><br/>
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1098 <tt>[40 x i8]</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1099 </td>
1100 <td class="left">
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1101 Array of 40 32-bit integer values.<br/>
1102 Array of 41 32-bit integer values.<br/>
1103 Array of 40 8-bit integer values.<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1104 </td>
1105 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1106</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1107<p>Here are some examples of multidimensional arrays:</p>
1108<table class="layout">
1109 <tr class="layout">
1110 <td class="left">
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1111 <tt>[3 x [4 x i32]]</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1112 <tt>[12 x [10 x float]]</tt><br/>
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1113 <tt>[2 x [3 x [4 x i16]]]</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1114 </td>
1115 <td class="left">
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1116 3x4 array of 32-bit integer values.<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1117 12x10 array of single precision floating point values.<br/>
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1118 2x3x4 array of 16-bit integer values.<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1119 </td>
1120 </tr>
1121</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1122
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1123<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1124length array. Normally, accesses past the end of an array are undefined in
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1125LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1126As a special case, however, zero length arrays are recognized to be variable
1127length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1128type "{ i32, [0 x float]}", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1129
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1130</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1131
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1132<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1133<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1134<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1135<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1136<p>The function type can be thought of as a function signature. It
1137consists of a return type and a list of formal parameter types.
John Criswella0d50d22003-11-25 21:45:46 +0000[diff] [blame]1138Function types are usually used to build virtual function tables
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1139(which are structures of pointers to functions), for indirect function
1140calls, and when defining a function.</p>
John Criswella0d50d22003-11-25 21:45:46 +0000[diff] [blame]1141<p>
1142The return type of a function type cannot be an aggregate type.
1143</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1144<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1145<pre> &lt;returntype&gt; (&lt;parameter list&gt;)<br></pre>
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1146<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]1147specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1148which indicates that the function takes a variable number of arguments.
1149Variable argument functions can access their arguments with the <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1150 href="#int_varargs">variable argument handling intrinsic</a> functions.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1151<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1152<table class="layout">
1153 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1154 <td class="left"><tt>i32 (i32)</tt></td>
1155 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1156 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1157 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]1158 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1159 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1160 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1161 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1162 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1163 <tt>float</tt>.
1164 </td>
1165 </tr><tr class="layout">
1166 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1167 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1168 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1169 which returns an integer. This is the signature for <tt>printf</tt> in
1170 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1171 </td>
1172 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1173</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1174
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1175</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1176<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1177<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1178<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1179<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1180<p>The structure type is used to represent a collection of data members
1181together in memory. The packing of the field types is defined to match
1182the ABI of the underlying processor. The elements of a structure may
1183be any type that has a size.</p>
1184<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1185and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1186field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1187instruction.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1188<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1189<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1190<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1191<table class="layout">
1192 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1193 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1194 <td class="left">A triple of three <tt>i32</tt> values</td>
1195 </tr><tr class="layout">
1196 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1197 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1198 second element is a <a href="#t_pointer">pointer</a> to a
1199 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1200 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1201 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1202</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1203</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1204
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1205<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1206<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1207</div>
1208<div class="doc_text">
1209<h5>Overview:</h5>
1210<p>The packed structure type is used to represent a collection of data members
1211together in memory. There is no padding between fields. Further, the alignment
1212of a packed structure is 1 byte. The elements of a packed structure may
1213be any type that has a size.</p>
1214<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1215and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1216field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1217instruction.</p>
1218<h5>Syntax:</h5>
1219<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1220<h5>Examples:</h5>
1221<table class="layout">
1222 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1223 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1224 <td class="left">A triple of three <tt>i32</tt> values</td>
1225 </tr><tr class="layout">
1226 <td class="left"><tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}&nbsp;&gt;</tt></td>
1227 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1228 second element is a <a href="#t_pointer">pointer</a> to a
1229 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1230 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1231 </tr>
1232</table>
1233</div>
1234
1235<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1236<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1237<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1238<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1239<p>As in many languages, the pointer type represents a pointer or
1240reference to another object, which must live in memory.</p>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1241<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1242<pre> &lt;type&gt; *<br></pre>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1243<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1244<table class="layout">
1245 <tr class="layout">
1246 <td class="left">
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1247 <tt>[4x i32]*</tt><br/>
1248 <tt>i32 (i32 *) *</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1249 </td>
1250 <td class="left">
1251 A <a href="#t_pointer">pointer</a> to <a href="#t_array">array</a> of
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1252 four <tt>i32</tt> values<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1253 A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1254 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
1255 <tt>i32</tt>.<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1256 </td>
1257 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1258</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1259</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1260
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1261<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1262<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1263<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1264
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1265<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1266
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1267<p>A vector type is a simple derived type that represents a vector
1268of elements. Vector types are used when multiple primitive data
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1269are operated in parallel using a single instruction (SIMD).
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1270A vector type requires a size (number of
Chris Lattner330ce692005-11-10 01:44:22 +0000[diff] [blame]1271elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1272of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1273considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1274
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1275<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1276
1277<pre>
1278 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1279</pre>
1280
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1281<p>The number of elements is a constant integer value; elementtype may
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1282be any integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1283
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1284<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1285
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1286<table class="layout">
1287 <tr class="layout">
1288 <td class="left">
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1289 <tt>&lt;4 x i32&gt;</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1290 <tt>&lt;8 x float&gt;</tt><br/>
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1291 <tt>&lt;2 x i64&gt;</tt><br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1292 </td>
1293 <td class="left">
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1294 Vector of 4 32-bit integer values.<br/>
1295 Vector of 8 floating-point values.<br/>
1296 Vector of 2 64-bit integer values.<br/>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1297 </td>
1298 </tr>
1299</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1300</div>
1301
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1302<!-- _______________________________________________________________________ -->
1303<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1304<div class="doc_text">
1305
1306<h5>Overview:</h5>
1307
1308<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksena699c4d2007-10-14 00:34:53 +0000[diff] [blame]1309corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1310In LLVM, opaque types can eventually be resolved to any type (not just a
1311structure type).</p>
1312
1313<h5>Syntax:</h5>
1314
1315<pre>
1316 opaque
1317</pre>
1318
1319<h5>Examples:</h5>
1320
1321<table class="layout">
1322 <tr class="layout">
1323 <td class="left">
1324 <tt>opaque</tt>
1325 </td>
1326 <td class="left">
1327 An opaque type.<br/>
1328 </td>
1329 </tr>
1330</table>
1331</div>
1332
1333
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1334<!-- *********************************************************************** -->
1335<div class="doc_section"> <a name="constants">Constants</a> </div>
1336<!-- *********************************************************************** -->
1337
1338<div class="doc_text">
1339
1340<p>LLVM has several different basic types of constants. This section describes
1341them all and their syntax.</p>
1342
1343</div>
1344
1345<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1346<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1347
1348<div class="doc_text">
1349
1350<dl>
1351 <dt><b>Boolean constants</b></dt>
1352
1353 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1354 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1355 </dd>
1356
1357 <dt><b>Integer constants</b></dt>
1358
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1359 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1360 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1361 integer types.
1362 </dd>
1363
1364 <dt><b>Floating point constants</b></dt>
1365
1366 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1367 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1368 notation (see below). Floating point constants must have a <a
1369 href="#t_floating">floating point</a> type. </dd>
1370
1371 <dt><b>Null pointer constants</b></dt>
1372
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1373 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1374 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1375
1376</dl>
1377
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1378<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1379of floating point constants. For example, the form '<tt>double
13800x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
13814.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1382(and the only time that they are generated by the disassembler) is when a
1383floating point constant must be emitted but it cannot be represented as a
1384decimal floating point number. For example, NaN's, infinities, and other
1385special values are represented in their IEEE hexadecimal format so that
1386assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1387
1388</div>
1389
1390<!-- ======================================================================= -->
1391<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1392</div>
1393
1394<div class="doc_text">
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]1395<p>Aggregate constants arise from aggregation of simple constants
1396and smaller aggregate constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1397
1398<dl>
1399 <dt><b>Structure constants</b></dt>
1400
1401 <dd>Structure constants are represented with notation similar to structure
1402 type definitions (a comma separated list of elements, surrounded by braces
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1403 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* %G }</tt>",
Chris Lattner0a2d0992007-07-13 20:01:46 +0000[diff] [blame]1404 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]1405 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1406 types of elements must match those specified by the type.
1407 </dd>
1408
1409 <dt><b>Array constants</b></dt>
1410
1411 <dd>Array constants are represented with notation similar to array type
1412 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1413 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1414 constants must have <a href="#t_array">array type</a>, and the number and
1415 types of elements must match those specified by the type.
1416 </dd>
1417
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1418 <dt><b>Vector constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1419
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1420 <dd>Vector constants are represented with notation similar to vector type
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1421 definitions (a comma separated list of elements, surrounded by
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1422 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]1423 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1424 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1425 match those specified by the type.
1426 </dd>
1427
1428 <dt><b>Zero initialization</b></dt>
1429
1430 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1431 value to zero of <em>any</em> type, including scalar and aggregate types.
1432 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]1433 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1434 initializers.
1435 </dd>
1436</dl>
1437
1438</div>
1439
1440<!-- ======================================================================= -->
1441<div class="doc_subsection">
1442 <a name="globalconstants">Global Variable and Function Addresses</a>
1443</div>
1444
1445<div class="doc_text">
1446
1447<p>The addresses of <a href="#globalvars">global variables</a> and <a
1448href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1449constants. These constants are explicitly referenced when the <a
1450href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1451href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1452file:</p>
1453
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1454<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1455<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]1456@X = global i32 17
1457@Y = global i32 42
1458@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1459</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1460</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1461
1462</div>
1463
1464<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1465<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1466<div class="doc_text">
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1467 <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]1468 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1469 a constant is permitted.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1470
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1471 <p>Undefined values indicate to the compiler that the program is well defined
1472 no matter what value is used, giving the compiler more freedom to optimize.
1473 </p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1474</div>
1475
1476<!-- ======================================================================= -->
1477<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1478</div>
1479
1480<div class="doc_text">
1481
1482<p>Constant expressions are used to allow expressions involving other constants
1483to be used as constants. Constant expressions may be of any <a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1484href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1485that does not have side effects (e.g. load and call are not supported). The
1486following is the syntax for constant expressions:</p>
1487
1488<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1489 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1490 <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]1491 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1492
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1493 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1494 <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]1495 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]1496
1497 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1498 <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]1499 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]1500
1501 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1502 <dd>Truncate a floating point constant to another floating point type. The
1503 size of CST must be larger than the size of TYPE. Both types must be
1504 floating point.</dd>
1505
1506 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1507 <dd>Floating point extend a constant to another type. The size of CST must be
1508 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1509
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]1510 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1511 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1512 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1513 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1514 of the same number of elements. If the value won't fit in the integer type,
1515 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1516
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1517 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1518 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1519 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1520 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1521 of the same number of elements. If the value won't fit in the integer type,
1522 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1523
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1524 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1525 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1526 constant. TYPE must be a scalar or vector floating point type. CST must be of
1527 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1528 of the same number of elements. If the value won't fit in the floating point
1529 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1530
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1531 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1532 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1533 constant. TYPE must be a scalar or vector floating point type. CST must be of
1534 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1535 of the same number of elements. If the value won't fit in the floating point
1536 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1537
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1538 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1539 <dd>Convert a pointer typed constant to the corresponding integer constant
1540 TYPE must be an integer type. CST must be of pointer type. The CST value is
1541 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1542
1543 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1544 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1545 pointer type. CST must be of integer type. The CST value is zero extended,
1546 truncated, or unchanged to make it fit in a pointer size. This one is
1547 <i>really</i> dangerous!</dd>
1548
1549 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1550 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1551 identical (same number of bits). The conversion is done as if the CST value
1552 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]1553 with this operator, just the type. This can be used for conversion of
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1554 vector types to any other type, as long as they have the same bit width. For
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1555 pointers it is only valid to cast to another pointer type.
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1556 </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1557
1558 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1559
1560 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1561 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1562 instruction, the index list may have zero or more indexes, which are required
1563 to make sense for the type of "CSTPTR".</dd>
1564
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1565 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1566
1567 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1568 constants.</dd>
1569
1570 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1571 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1572
1573 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1574 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1575
1576 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1577
1578 <dd>Perform the <a href="#i_extractelement">extractelement
1579 operation</a> on constants.
1580
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1581 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1582
1583 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1584 operation</a> on constants.</dd>
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1585
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1586
1587 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1588
1589 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1590 operation</a> on constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1591
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1592 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1593
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1594 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1595 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1596 binary</a> operations. The constraints on operands are the same as those for
1597 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1598 values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1599</dl>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1600</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]1601
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1602<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1603<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1604<!-- *********************************************************************** -->
1605
1606<!-- ======================================================================= -->
1607<div class="doc_subsection">
1608<a name="inlineasm">Inline Assembler Expressions</a>
1609</div>
1610
1611<div class="doc_text">
1612
1613<p>
1614LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1615Module-Level Inline Assembly</a>) through the use of a special value. This
1616value represents the inline assembler as a string (containing the instructions
1617to emit), a list of operand constraints (stored as a string), and a flag that
1618indicates whether or not the inline asm expression has side effects. An example
1619inline assembler expression is:
1620</p>
1621
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1622<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1623<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1624i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1625</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1626</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1627
1628<p>
1629Inline assembler expressions may <b>only</b> be used as the callee operand of
1630a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1631</p>
1632
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1633<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1634<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1635%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]1636</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1637</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1638
1639<p>
1640Inline asms with side effects not visible in the constraint list must be marked
1641as having side effects. This is done through the use of the
1642'<tt>sideeffect</tt>' keyword, like so:
1643</p>
1644
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1645<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1646<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1647call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1648</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1649</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1650
1651<p>TODO: The format of the asm and constraints string still need to be
1652documented here. Constraints on what can be done (e.g. duplication, moving, etc
1653need to be documented).
1654</p>
1655
1656</div>
1657
1658<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1659<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1660<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1661
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1662<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1663
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1664<p>The LLVM instruction set consists of several different
1665classifications of instructions: <a href="#terminators">terminator
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1666instructions</a>, <a href="#binaryops">binary instructions</a>,
1667<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1668 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1669instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1670
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1671</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1672
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1673<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1674<div class="doc_subsection"> <a name="terminators">Terminator
1675Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1676
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1677<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1678
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1679<p>As mentioned <a href="#functionstructure">previously</a>, every
1680basic block in a program ends with a "Terminator" instruction, which
1681indicates which block should be executed after the current block is
1682finished. These terminator instructions typically yield a '<tt>void</tt>'
1683value: they produce control flow, not values (the one exception being
1684the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1685<p>There are six different terminator instructions: the '<a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1686 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1687instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1688the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1689 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1690 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1691
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1692</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1693
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1694<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1695<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1696Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1697<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1698<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1699<pre> ret &lt;type&gt; &lt;value&gt; <i>; Return a value from a non-void function</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1700 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1701</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1702<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1703<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1704value) from a function back to the caller.</p>
John Criswell417228d2004-04-09 16:48:45 +0000[diff] [blame]1705<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1706returns a value and then causes control flow, and one that just causes
1707control flow to occur.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1708<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1709<p>The '<tt>ret</tt>' instruction may return any '<a
1710 href="#t_firstclass">first class</a>' type. Notice that a function is
1711not <a href="#wellformed">well formed</a> if there exists a '<tt>ret</tt>'
1712instruction inside of the function that returns a value that does not
1713match the return type of the function.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1714<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1715<p>When the '<tt>ret</tt>' instruction is executed, control flow
1716returns back to the calling function's context. If the caller is a "<a
John Criswell40db33f2004-06-25 15:16:57 +0000[diff] [blame]1717 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1718the instruction after the call. If the caller was an "<a
1719 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1720at the beginning of the "normal" destination block. If the instruction
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1721returns a value, that value shall set the call or invoke instruction's
1722return value.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1723<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1724<pre> ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1725 ret void <i>; Return from a void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1726</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1727</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1728<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1729<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1730<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1731<h5>Syntax:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1732<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]1733</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1734<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1735<p>The '<tt>br</tt>' instruction is used to cause control flow to
1736transfer to a different basic block in the current function. There are
1737two forms of this instruction, corresponding to a conditional branch
1738and an unconditional branch.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1739<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1740<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1741single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1742unconditional form of the '<tt>br</tt>' instruction takes a single
1743'<tt>label</tt>' value as a target.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1744<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1745<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1746argument is evaluated. If the value is <tt>true</tt>, control flows
1747to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1748control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1749<h5>Example:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1750<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]1751 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]1752</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1753<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1754<div class="doc_subsubsection">
1755 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1756</div>
1757
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1758<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1759<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1760
1761<pre>
1762 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
1763</pre>
1764
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1765<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1766
1767<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
1768several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1769instruction, allowing a branch to occur to one of many possible
1770destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1771
1772
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1773<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1774
1775<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
1776comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
1777an array of pairs of comparison value constants and '<tt>label</tt>'s. The
1778table is not allowed to contain duplicate constant entries.</p>
1779
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1780<h5>Semantics:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1781
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1782<p>The <tt>switch</tt> instruction specifies a table of values and
1783destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]1784table is searched for the given value. If the value is found, control flow is
1785transfered to the corresponding destination; otherwise, control flow is
1786transfered to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1787
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1788<h5>Implementation:</h5>
1789
1790<p>Depending on properties of the target machine and the particular
1791<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]1792ways. For example, it could be generated as a series of chained conditional
1793branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1794
1795<h5>Example:</h5>
1796
1797<pre>
1798 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1799 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1800 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1801
1802 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1803 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1804
1805 <i>; Implement a jump table:</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1806 switch i32 %val, label %otherwise [ i32 0, label %onzero
1807 i32 1, label %onone
1808 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1809</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1810</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1811
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1812<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1813<div class="doc_subsubsection">
1814 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
1815</div>
1816
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1817<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1818
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1819<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1820
1821<pre>
1822 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] &lt;ptr to function ty&gt; %&lt;function ptr val&gt;(&lt;function args&gt;)
Chris Lattner6b7a0082006-05-14 18:23:06 +0000[diff] [blame]1823 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1824</pre>
1825
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]1826<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1827
1828<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
1829function, with the possibility of control flow transfer to either the
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1830'<tt>normal</tt>' label or the
1831'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1832"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
1833"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1834href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
1835continued at the dynamically nearest "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1836
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1837<h5>Arguments:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1838
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1839<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1840
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1841<ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1842 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]1843 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1844 convention</a> the call should use. If none is specified, the call defaults
1845 to using C calling conventions.
1846 </li>
1847 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
1848 function value being invoked. In most cases, this is a direct function
1849 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
1850 an arbitrary pointer to function value.
1851 </li>
1852
1853 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
1854 function to be invoked. </li>
1855
1856 <li>'<tt>function args</tt>': argument list whose types match the function
1857 signature argument types. If the function signature indicates the function
1858 accepts a variable number of arguments, the extra arguments can be
1859 specified. </li>
1860
1861 <li>'<tt>normal label</tt>': the label reached when the called function
1862 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
1863
1864 <li>'<tt>exception label</tt>': the label reached when a callee returns with
1865 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
1866
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1867</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1868
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1869<h5>Semantics:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1870
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1871<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1872href="#i_call">call</a></tt>' instruction in most regards. The primary
1873difference is that it establishes an association with a label, which is used by
1874the runtime library to unwind the stack.</p>
1875
1876<p>This instruction is used in languages with destructors to ensure that proper
1877cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
1878exception. Additionally, this is important for implementation of
1879'<tt>catch</tt>' clauses in high-level languages that support them.</p>
1880
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1881<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1882<pre>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1883 %retval = invoke i32 %Test(i32 15) to label %Continue
1884 unwind label %TestCleanup <i>; {i32}:retval set</i>
1885 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Test(i32 15) to label %Continue
1886 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1887</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1888</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1889
1890
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1891<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1892
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1893<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
1894Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1895
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1896<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1897
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1898<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1899<pre>
1900 unwind
1901</pre>
1902
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1903<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1904
1905<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
1906at the first callee in the dynamic call stack which used an <a
1907href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
1908primarily used to implement exception handling.</p>
1909
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1910<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1911
1912<p>The '<tt>unwind</tt>' intrinsic causes execution of the current function to
1913immediately halt. The dynamic call stack is then searched for the first <a
1914href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
1915execution continues at the "exceptional" destination block specified by the
1916<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
1917dynamic call chain, undefined behavior results.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1918</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1919
1920<!-- _______________________________________________________________________ -->
1921
1922<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
1923Instruction</a> </div>
1924
1925<div class="doc_text">
1926
1927<h5>Syntax:</h5>
1928<pre>
1929 unreachable
1930</pre>
1931
1932<h5>Overview:</h5>
1933
1934<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
1935instruction is used to inform the optimizer that a particular portion of the
1936code is not reachable. This can be used to indicate that the code after a
1937no-return function cannot be reached, and other facts.</p>
1938
1939<h5>Semantics:</h5>
1940
1941<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
1942</div>
1943
1944
1945
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1946<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1947<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1948<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1949<p>Binary operators are used to do most of the computation in a
1950program. They require two operands, execute an operation on them, and
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1951produce a single value. The operands might represent
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1952multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1953The result value of a binary operator is not
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1954necessarily the same type as its operands.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1955<p>There are several different binary operators:</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1956</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1957<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1958<div class="doc_subsubsection"> <a name="i_add">'<tt>add</tt>'
1959Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1960<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1961<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1962<pre> &lt;result&gt; = add &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1963</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1964<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1965<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1966<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1967<p>The two arguments to the '<tt>add</tt>' instruction must be either <a
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1968 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a> values.
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1969 This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1970Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1971<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1972<p>The value produced is the integer or floating point sum of the two
1973operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1974<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1975<pre> &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1976</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1977</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1978<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1979<div class="doc_subsubsection"> <a name="i_sub">'<tt>sub</tt>'
1980Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1981<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1982<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1983<pre> &lt;result&gt; = sub &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1984</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1985<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1986<p>The '<tt>sub</tt>' instruction returns the difference of its two
1987operands.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1988<p>Note that the '<tt>sub</tt>' instruction is used to represent the '<tt>neg</tt>'
1989instruction present in most other intermediate representations.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1990<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1991<p>The two arguments to the '<tt>sub</tt>' instruction must be either <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1992 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1993values.
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1994This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1995Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1996<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1997<p>The value produced is the integer or floating point difference of
1998the two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1999<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2000<pre>
2001 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2002 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2003</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2004</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2005<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2006<div class="doc_subsubsection"> <a name="i_mul">'<tt>mul</tt>'
2007Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2008<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2009<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2010<pre> &lt;result&gt; = mul &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2011</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2012<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2013<p>The '<tt>mul</tt>' instruction returns the product of its two
2014operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2015<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2016<p>The two arguments to the '<tt>mul</tt>' instruction must be either <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2017 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2018values.
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2019This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2020Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2021<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2022<p>The value produced is the integer or floating point product of the
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2023two operands.</p>
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]2024<p>Because the operands are the same width, the result of an integer
2025multiplication is the same whether the operands should be deemed unsigned or
2026signed.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2027<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2028<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]2029</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2030</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2031<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2032<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2033</a></div>
2034<div class="doc_text">
2035<h5>Syntax:</h5>
2036<pre> &lt;result&gt; = udiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2037</pre>
2038<h5>Overview:</h5>
2039<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2040operands.</p>
2041<h5>Arguments:</h5>
2042<p>The two arguments to the '<tt>udiv</tt>' instruction must be
2043<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2044types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2045of the values in which case the elements must be integers.</p>
2046<h5>Semantics:</h5>
2047<p>The value produced is the unsigned integer quotient of the two operands. This
2048instruction always performs an unsigned division operation, regardless of
2049whether the arguments are unsigned or not.</p>
2050<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2051<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]2052</pre>
2053</div>
2054<!-- _______________________________________________________________________ -->
2055<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2056</a> </div>
2057<div class="doc_text">
2058<h5>Syntax:</h5>
2059<pre> &lt;result&gt; = sdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2060</pre>
2061<h5>Overview:</h5>
2062<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2063operands.</p>
2064<h5>Arguments:</h5>
2065<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2066<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2067types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2068of the values in which case the elements must be integers.</p>
2069<h5>Semantics:</h5>
2070<p>The value produced is the signed integer quotient of the two operands. This
2071instruction always performs a signed division operation, regardless of whether
2072the arguments are signed or not.</p>
2073<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2074<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]2075</pre>
2076</div>
2077<!-- _______________________________________________________________________ -->
2078<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2079Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2080<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2081<h5>Syntax:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2082<pre> &lt;result&gt; = fdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2083</pre>
2084<h5>Overview:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2085<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2086operands.</p>
2087<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2088<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2089<a href="#t_floating">floating point</a> values. Both arguments must have
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2090identical types. This instruction can also take <a href="#t_vector">vector</a>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2091versions of floating point values.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2092<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2093<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2094<h5>Example:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2095<pre> &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]2096</pre>
2097</div>
2098<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2099<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2100</div>
2101<div class="doc_text">
2102<h5>Syntax:</h5>
2103<pre> &lt;result&gt; = urem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2104</pre>
2105<h5>Overview:</h5>
2106<p>The '<tt>urem</tt>' instruction returns the remainder from the
2107unsigned division of its two arguments.</p>
2108<h5>Arguments:</h5>
2109<p>The two arguments to the '<tt>urem</tt>' instruction must be
2110<a href="#t_integer">integer</a> values. Both arguments must have identical
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame]2111types. This instruction can also take <a href="#t_vector">vector</a> versions
2112of the values in which case the elements must be integers.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2113<h5>Semantics:</h5>
2114<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
2115This instruction always performs an unsigned division to get the remainder,
2116regardless of whether the arguments are unsigned or not.</p>
2117<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2118<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]2119</pre>
2120
2121</div>
2122<!-- _______________________________________________________________________ -->
2123<div class="doc_subsubsection"> <a name="i_srem">'<tt>srem</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2124Instruction</a> </div>
2125<div class="doc_text">
2126<h5>Syntax:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2127<pre> &lt;result&gt; = srem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2128</pre>
2129<h5>Overview:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2130<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame]2131signed division of its two operands. This instruction can also take
2132<a href="#t_vector">vector</a> versions of the values in which case
2133the elements must be integers.</p>
2134</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2135<h5>Arguments:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2136<p>The two arguments to the '<tt>srem</tt>' instruction must be
2137<a href="#t_integer">integer</a> values. Both arguments must have identical
2138types.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2139<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2140<p>This instruction returns the <i>remainder</i> of a division (where the result
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2141has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
2142operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
2143a value. For more information about the difference, see <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2144 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2145Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencerdb3b93b2007-03-24 22:40:44 +0000[diff] [blame]2146please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2147Wikipedia: modulo operation</a>.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2148<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2149<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]2150</pre>
2151
2152</div>
2153<!-- _______________________________________________________________________ -->
2154<div class="doc_subsubsection"> <a name="i_frem">'<tt>frem</tt>'
2155Instruction</a> </div>
2156<div class="doc_text">
2157<h5>Syntax:</h5>
2158<pre> &lt;result&gt; = frem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2159</pre>
2160<h5>Overview:</h5>
2161<p>The '<tt>frem</tt>' instruction returns the remainder from the
2162division of its two operands.</p>
2163<h5>Arguments:</h5>
2164<p>The two arguments to the '<tt>frem</tt>' instruction must be
2165<a href="#t_floating">floating point</a> values. Both arguments must have
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame]2166identical types. This instruction can also take <a href="#t_vector">vector</a>
2167versions of floating point values.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2168<h5>Semantics:</h5>
2169<p>This instruction returns the <i>remainder</i> of a division.</p>
2170<h5>Example:</h5>
2171<pre> &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]2172</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2173</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]2174
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2175<!-- ======================================================================= -->
2176<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2177Operations</a> </div>
2178<div class="doc_text">
2179<p>Bitwise binary operators are used to do various forms of
2180bit-twiddling in a program. They are generally very efficient
2181instructions and can commonly be strength reduced from other
2182instructions. They require two operands, execute an operation on them,
2183and produce a single value. The resulting value of the bitwise binary
2184operators is always the same type as its first operand.</p>
2185</div>
2186
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2187<!-- _______________________________________________________________________ -->
2188<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2189Instruction</a> </div>
2190<div class="doc_text">
2191<h5>Syntax:</h5>
2192<pre> &lt;result&gt; = shl &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2193</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2194
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2195<h5>Overview:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2196
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2197<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2198the left a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2199
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2200<h5>Arguments:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2201
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2202<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
2203 href="#t_integer">integer</a> type.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2204
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2205<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2206
2207<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup>. If
2208<tt>var2</tt> is (statically or dynamically) equal to or larger than the number
2209of bits in <tt>var1</tt>, the result is undefined.</p>
2210
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2211<h5>Example:</h5><pre>
2212 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2213 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2214 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2215 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2216</pre>
2217</div>
2218<!-- _______________________________________________________________________ -->
2219<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2220Instruction</a> </div>
2221<div class="doc_text">
2222<h5>Syntax:</h5>
2223<pre> &lt;result&gt; = lshr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2224</pre>
2225
2226<h5>Overview:</h5>
2227<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2228operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2229
2230<h5>Arguments:</h5>
2231<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
2232<a href="#t_integer">integer</a> type.</p>
2233
2234<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2235
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2236<p>This instruction always performs a logical shift right operation. The most
2237significant bits of the result will be filled with zero bits after the
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2238shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
2239the number of bits in <tt>var1</tt>, the result is undefined.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2240
2241<h5>Example:</h5>
2242<pre>
2243 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2244 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2245 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2246 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2247 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2248</pre>
2249</div>
2250
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2251<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2252<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2253Instruction</a> </div>
2254<div class="doc_text">
2255
2256<h5>Syntax:</h5>
2257<pre> &lt;result&gt; = ashr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2258</pre>
2259
2260<h5>Overview:</h5>
2261<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2262operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2263
2264<h5>Arguments:</h5>
2265<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
2266<a href="#t_integer">integer</a> type.</p>
2267
2268<h5>Semantics:</h5>
2269<p>This instruction always performs an arithmetic shift right operation,
2270The most significant bits of the result will be filled with the sign bit
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2271of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
2272larger than the number of bits in <tt>var1</tt>, the result is undefined.
2273</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2274
2275<h5>Example:</h5>
2276<pre>
2277 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2278 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2279 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2280 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2281 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2282</pre>
2283</div>
2284
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2285<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2286<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2287Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2288<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2289<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2290<pre> &lt;result&gt; = and &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2291</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2292<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2293<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2294its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2295<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2296<p>The two arguments to the '<tt>and</tt>' instruction must be <a
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]2297 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2298identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2299<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2300<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2301<p> </p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2302<div style="align: center">
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2303<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2304 <tbody>
2305 <tr>
2306 <td>In0</td>
2307 <td>In1</td>
2308 <td>Out</td>
2309 </tr>
2310 <tr>
2311 <td>0</td>
2312 <td>0</td>
2313 <td>0</td>
2314 </tr>
2315 <tr>
2316 <td>0</td>
2317 <td>1</td>
2318 <td>0</td>
2319 </tr>
2320 <tr>
2321 <td>1</td>
2322 <td>0</td>
2323 <td>0</td>
2324 </tr>
2325 <tr>
2326 <td>1</td>
2327 <td>1</td>
2328 <td>1</td>
2329 </tr>
2330 </tbody>
2331</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2332</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2333<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2334<pre> &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
2335 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2336 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2337</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2338</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2339<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2340<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2341<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2342<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2343<pre> &lt;result&gt; = or &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2344</pre>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2345<h5>Overview:</h5>
2346<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2347or of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2348<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2349<p>The two arguments to the '<tt>or</tt>' instruction must be <a
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]2350 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2351identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2352<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2353<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2354<p> </p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2355<div style="align: center">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2356<table border="1" cellspacing="0" cellpadding="4">
2357 <tbody>
2358 <tr>
2359 <td>In0</td>
2360 <td>In1</td>
2361 <td>Out</td>
2362 </tr>
2363 <tr>
2364 <td>0</td>
2365 <td>0</td>
2366 <td>0</td>
2367 </tr>
2368 <tr>
2369 <td>0</td>
2370 <td>1</td>
2371 <td>1</td>
2372 </tr>
2373 <tr>
2374 <td>1</td>
2375 <td>0</td>
2376 <td>1</td>
2377 </tr>
2378 <tr>
2379 <td>1</td>
2380 <td>1</td>
2381 <td>1</td>
2382 </tr>
2383 </tbody>
2384</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2385</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2386<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2387<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2388 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2389 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2390</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2391</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2392<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2393<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2394Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2395<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2396<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2397<pre> &lt;result&gt; = xor &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2398</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2399<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2400<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2401or of its two operands. The <tt>xor</tt> is used to implement the
2402"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2403<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2404<p>The two arguments to the '<tt>xor</tt>' instruction must be <a
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]2405 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2406identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2407<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2408<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2409<p> </p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2410<div style="align: center">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2411<table border="1" cellspacing="0" cellpadding="4">
2412 <tbody>
2413 <tr>
2414 <td>In0</td>
2415 <td>In1</td>
2416 <td>Out</td>
2417 </tr>
2418 <tr>
2419 <td>0</td>
2420 <td>0</td>
2421 <td>0</td>
2422 </tr>
2423 <tr>
2424 <td>0</td>
2425 <td>1</td>
2426 <td>1</td>
2427 </tr>
2428 <tr>
2429 <td>1</td>
2430 <td>0</td>
2431 <td>1</td>
2432 </tr>
2433 <tr>
2434 <td>1</td>
2435 <td>1</td>
2436 <td>0</td>
2437 </tr>
2438 </tbody>
2439</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2440</div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2441<p> </p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2442<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2443<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2444 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2445 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2446 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2447</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2448</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2449
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2450<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2451<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2452 <a name="vectorops">Vector Operations</a>
2453</div>
2454
2455<div class="doc_text">
2456
2457<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2458target-independent manner. These instructions cover the element-access and
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2459vector-specific operations needed to process vectors effectively. While LLVM
2460does directly support these vector operations, many sophisticated algorithms
2461will want to use target-specific intrinsics to take full advantage of a specific
2462target.</p>
2463
2464</div>
2465
2466<!-- _______________________________________________________________________ -->
2467<div class="doc_subsubsection">
2468 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2469</div>
2470
2471<div class="doc_text">
2472
2473<h5>Syntax:</h5>
2474
2475<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2476 &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]2477</pre>
2478
2479<h5>Overview:</h5>
2480
2481<p>
2482The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2483element from a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2484</p>
2485
2486
2487<h5>Arguments:</h5>
2488
2489<p>
2490The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2491value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2492an index indicating the position from which to extract the element.
2493The index may be a variable.</p>
2494
2495<h5>Semantics:</h5>
2496
2497<p>
2498The result is a scalar of the same type as the element type of
2499<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2500<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2501results are undefined.
2502</p>
2503
2504<h5>Example:</h5>
2505
2506<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2507 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2508</pre>
2509</div>
2510
2511
2512<!-- _______________________________________________________________________ -->
2513<div class="doc_subsubsection">
2514 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2515</div>
2516
2517<div class="doc_text">
2518
2519<h5>Syntax:</h5>
2520
2521<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2522 &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]2523</pre>
2524
2525<h5>Overview:</h5>
2526
2527<p>
2528The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2529element into a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2530</p>
2531
2532
2533<h5>Arguments:</h5>
2534
2535<p>
2536The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2537value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2538scalar value whose type must equal the element type of the first
2539operand. The third operand is an index indicating the position at
2540which to insert the value. The index may be a variable.</p>
2541
2542<h5>Semantics:</h5>
2543
2544<p>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2545The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2546element values are those of <tt>val</tt> except at position
2547<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2548exceeds the length of <tt>val</tt>, the results are undefined.
2549</p>
2550
2551<h5>Example:</h5>
2552
2553<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2554 %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]2555</pre>
2556</div>
2557
2558<!-- _______________________________________________________________________ -->
2559<div class="doc_subsubsection">
2560 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2561</div>
2562
2563<div class="doc_text">
2564
2565<h5>Syntax:</h5>
2566
2567<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2568 &lt;result&gt; = shufflevector &lt;n x &lt;ty&gt;&gt; &lt;v1&gt;, &lt;n x &lt;ty&gt;&gt; &lt;v2&gt;, &lt;n x i32&gt; &lt;mask&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2569</pre>
2570
2571<h5>Overview:</h5>
2572
2573<p>
2574The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2575from two input vectors, returning a vector of the same type.
2576</p>
2577
2578<h5>Arguments:</h5>
2579
2580<p>
2581The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2582with types that match each other and types that match the result of the
2583instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2584of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2585</p>
2586
2587<p>
2588The shuffle mask operand is required to be a constant vector with either
2589constant integer or undef values.
2590</p>
2591
2592<h5>Semantics:</h5>
2593
2594<p>
2595The elements of the two input vectors are numbered from left to right across
2596both of the vectors. The shuffle mask operand specifies, for each element of
2597the result vector, which element of the two input registers the result element
2598gets. The element selector may be undef (meaning "don't care") and the second
2599operand may be undef if performing a shuffle from only one vector.
2600</p>
2601
2602<h5>Example:</h5>
2603
2604<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2605 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2606 &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]2607 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2608 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i> - Identity shuffle.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2609</pre>
2610</div>
2611
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]2612
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2613<!-- ======================================================================= -->
2614<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]2615 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2616</div>
2617
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2618<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2619
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2620<p>A key design point of an SSA-based representation is how it
2621represents memory. In LLVM, no memory locations are in SSA form, which
2622makes things very simple. This section describes how to read, write,
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2623allocate, and free memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2624
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2625</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2626
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2627<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2628<div class="doc_subsubsection">
2629 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
2630</div>
2631
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2632<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2633
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2634<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2635
2636<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2637 &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]2638</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2639
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2640<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2641
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2642<p>The '<tt>malloc</tt>' instruction allocates memory from the system
2643heap and returns a pointer to it.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2644
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2645<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2646
2647<p>The '<tt>malloc</tt>' instruction allocates
2648<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswella92e5862004-02-24 16:13:56 +0000[diff] [blame]2649bytes of memory from the operating system and returns a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2650appropriate type to the program. If "NumElements" is specified, it is the
2651number of elements allocated. If an alignment is specified, the value result
2652of the allocation is guaranteed to be aligned to at least that boundary. If
2653not specified, or if zero, the target can choose to align the allocation on any
2654convenient boundary.</p>
2655
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2656<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2657
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2658<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2659
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2660<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
2661a pointer is returned.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2662
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2663<h5>Example:</h5>
2664
2665<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2666 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2667
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2668 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
2669 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
2670 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
2671 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
2672 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2673</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2674</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2675
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2676<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2677<div class="doc_subsubsection">
2678 <a name="i_free">'<tt>free</tt>' Instruction</a>
2679</div>
2680
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2681<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2682
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2683<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2684
2685<pre>
2686 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2687</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2688
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2689<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2690
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2691<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2692memory heap to be reallocated in the future.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2693
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2694<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2695
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2696<p>'<tt>value</tt>' shall be a pointer value that points to a value
2697that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
2698instruction.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2699
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2700<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2701
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2702<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2703after this instruction executes.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2704
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2705<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2706
2707<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2708 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
2709 free [4 x i8]* %array
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2710</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2711</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2712
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2713<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2714<div class="doc_subsubsection">
2715 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
2716</div>
2717
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2718<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2719
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2720<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2721
2722<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2723 &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]2724</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2725
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2726<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2727
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2728<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
2729currently executing function, to be automatically released when this function
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2730returns to its caller.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2731
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2732<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2733
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2734<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2735bytes of memory on the runtime stack, returning a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2736appropriate type to the program. If "NumElements" is specified, it is the
2737number of elements allocated. If an alignment is specified, the value result
2738of the allocation is guaranteed to be aligned to at least that boundary. If
2739not specified, or if zero, the target can choose to align the allocation on any
2740convenient boundary.</p>
2741
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2742<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2743
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2744<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2745
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2746<p>Memory is allocated; a pointer is returned. '<tt>alloca</tt>'d
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2747memory is automatically released when the function returns. The '<tt>alloca</tt>'
2748instruction is commonly used to represent automatic variables that must
2749have an address available. When the function returns (either with the <tt><a
John Criswellc932bef2005-05-12 16:55:34 +0000[diff] [blame]2750 href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2751instructions), the memory is reclaimed.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2752
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2753<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2754
2755<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2756 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2757 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
2758 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2759 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2760</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2761</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2762
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2763<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2764<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
2765Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2766<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2767<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]2768<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]2769<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2770<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2771<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2772<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]2773address from which to load. The pointer must point to a <a
Chris Lattner10ee9652004-06-03 22:57:15 +0000[diff] [blame]2774 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]2775marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2776the number or order of execution of this <tt>load</tt> with other
2777volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
2778instructions. </p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2779<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2780<p>The location of memory pointed to is loaded.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2781<h5>Examples:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2782<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2783 <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2784 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
2785 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2786</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2787</div>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2788<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2789<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
2790Instruction</a> </div>
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]2791<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2792<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]2793<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
2794 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]2795</pre>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2796<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2797<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2798<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2799<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2800to store and an address at which to store it. The type of the '<tt>&lt;pointer&gt;</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2801operand must be a pointer to the type of the '<tt>&lt;value&gt;</tt>'
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2802operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2803optimizer is not allowed to modify the number or order of execution of
2804this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
2805 href="#i_store">store</a></tt> instructions.</p>
2806<h5>Semantics:</h5>
2807<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
2808at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2809<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2810<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]2811 store i32 3, i32* %ptr <i>; yields {void}</i>
2812 %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]2813</pre>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]2814</div>
2815
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2816<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2817<div class="doc_subsubsection">
2818 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
2819</div>
2820
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2821<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2822<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2823<pre>
2824 &lt;result&gt; = getelementptr &lt;ty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
2825</pre>
2826
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2827<h5>Overview:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2828
2829<p>
2830The '<tt>getelementptr</tt>' instruction is used to get the address of a
2831subelement of an aggregate data structure.</p>
2832
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2833<h5>Arguments:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2834
Reid Spencercee005c2006-12-04 21:29:24 +0000[diff] [blame]2835<p>This instruction takes a list of integer operands that indicate what
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2836elements of the aggregate object to index to. The actual types of the arguments
2837provided depend on the type of the first pointer argument. The
2838'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]2839levels of a structure or to a specific index in an array. When indexing into a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2840structure, only <tt>i32</tt> integer constants are allowed. When indexing
Reid Spencercee005c2006-12-04 21:29:24 +0000[diff] [blame]2841into an array or pointer, only integers of 32 or 64 bits are allowed, and will
2842be sign extended to 64-bit values.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2843
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2844<p>For example, let's consider a C code fragment and how it gets
2845compiled to LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2846
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2847<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2848<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2849struct RT {
2850 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]2851 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2852 char C;
2853};
2854struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]2855 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2856 double Y;
2857 struct RT Z;
2858};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2859
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]2860int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2861 return &amp;s[1].Z.B[5][13];
2862}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2863</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2864</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2865
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2866<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2867
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2868<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2869<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2870%RT = type { i8 , [10 x [20 x i32]], i8 }
2871%ST = type { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2872
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2873define i32* %foo(%ST* %s) {
2874entry:
2875 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
2876 ret i32* %reg
2877}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2878</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2879</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2880
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2881<h5>Semantics:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2882
2883<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2884on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencercee005c2006-12-04 21:29:24 +0000[diff] [blame]2885and <a href="#t_array">array</a> types can use a 32-bit or 64-bit
Reid Spencerc0312692006-12-03 16:53:48 +0000[diff] [blame]2886<a href="#t_integer">integer</a> type but the value will always be sign extended
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2887to 64-bits. <a href="#t_struct">Structure</a> types require <tt>i32</tt>
Reid Spencerc0312692006-12-03 16:53:48 +0000[diff] [blame]2888<b>constants</b>.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2889
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2890<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]2891type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2892}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2893the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
2894i8 }</tt>' type, another structure. The third index indexes into the second
2895element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2896array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2897'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
2898to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2899
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2900<p>Note that it is perfectly legal to index partially through a
2901structure, returning a pointer to an inner element. Because of this,
2902the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2903
2904<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2905 define i32* %foo(%ST* %s) {
2906 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2907 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
2908 %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]2909 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
2910 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
2911 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2912 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2913</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]2914
2915<p>Note that it is undefined to access an array out of bounds: array and
2916pointer indexes must always be within the defined bounds of the array type.
2917The one exception for this rules is zero length arrays. These arrays are
2918defined to be accessible as variable length arrays, which requires access
2919beyond the zero'th element.</p>
2920
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]2921<p>The getelementptr instruction is often confusing. For some more insight
2922into how it works, see <a href="GetElementPtr.html">the getelementptr
2923FAQ</a>.</p>
2924
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2925<h5>Example:</h5>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]2926
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2927<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2928 <i>; yields [12 x i8]*:aptr</i>
2929 %aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2930</pre>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2931</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]2932
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2933<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]2934<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2935</div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2936<div class="doc_text">
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]2937<p>The instructions in this category are the conversion instructions (casting)
2938which all take a single operand and a type. They perform various bit conversions
2939on the operand.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2940</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]2941
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2942<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]2943<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2944 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
2945</div>
2946<div class="doc_text">
2947
2948<h5>Syntax:</h5>
2949<pre>
2950 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2951</pre>
2952
2953<h5>Overview:</h5>
2954<p>
2955The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
2956</p>
2957
2958<h5>Arguments:</h5>
2959<p>
2960The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
2961be 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]2962and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2963type. The bit size of <tt>value</tt> must be larger than the bit size of
2964<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2965
2966<h5>Semantics:</h5>
2967<p>
2968The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2969and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
2970larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
2971It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2972
2973<h5>Example:</h5>
2974<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2975 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2976 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
2977 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2978</pre>
2979</div>
2980
2981<!-- _______________________________________________________________________ -->
2982<div class="doc_subsubsection">
2983 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
2984</div>
2985<div class="doc_text">
2986
2987<h5>Syntax:</h5>
2988<pre>
2989 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2990</pre>
2991
2992<h5>Overview:</h5>
2993<p>The '<tt>zext</tt>' instruction zero extends its operand to type
2994<tt>ty2</tt>.</p>
2995
2996
2997<h5>Arguments:</h5>
2998<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]2999<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3000also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3001<tt>value</tt> must be smaller than the bit size of the destination type,
3002<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3003
3004<h5>Semantics:</h5>
3005<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]3006bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3007
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]3008<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]3009
3010<h5>Example:</h5>
3011<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3012 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3013 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3014</pre>
3015</div>
3016
3017<!-- _______________________________________________________________________ -->
3018<div class="doc_subsubsection">
3019 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3020</div>
3021<div class="doc_text">
3022
3023<h5>Syntax:</h5>
3024<pre>
3025 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3026</pre>
3027
3028<h5>Overview:</h5>
3029<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3030
3031<h5>Arguments:</h5>
3032<p>
3033The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3034<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3035also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3036<tt>value</tt> must be smaller than the bit size of the destination type,
3037<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3038
3039<h5>Semantics:</h5>
3040<p>
3041The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3042bit (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]3043the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3044
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3045<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]3046
3047<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3048<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3049 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3050 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3051</pre>
3052</div>
3053
3054<!-- _______________________________________________________________________ -->
3055<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3056 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3057</div>
3058
3059<div class="doc_text">
3060
3061<h5>Syntax:</h5>
3062
3063<pre>
3064 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3065</pre>
3066
3067<h5>Overview:</h5>
3068<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3069<tt>ty2</tt>.</p>
3070
3071
3072<h5>Arguments:</h5>
3073<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3074 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3075cast it to. The size of <tt>value</tt> must be larger than the size of
3076<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3077<i>no-op cast</i>.</p>
3078
3079<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3080<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3081<a href="#t_floating">floating point</a> type to a smaller
3082<a href="#t_floating">floating point</a> type. If the value cannot fit within
3083the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3084
3085<h5>Example:</h5>
3086<pre>
3087 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3088 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3089</pre>
3090</div>
3091
3092<!-- _______________________________________________________________________ -->
3093<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3094 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3095</div>
3096<div class="doc_text">
3097
3098<h5>Syntax:</h5>
3099<pre>
3100 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3101</pre>
3102
3103<h5>Overview:</h5>
3104<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3105floating point value.</p>
3106
3107<h5>Arguments:</h5>
3108<p>The '<tt>fpext</tt>' instruction takes a
3109<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3110and a <a href="#t_floating">floating point</a> type to cast it to. The source
3111type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3112
3113<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3114<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3115<a href="#t_floating">floating point</a> type to a larger
3116<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3117used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3118<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]3119
3120<h5>Example:</h5>
3121<pre>
3122 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3123 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3124</pre>
3125</div>
3126
3127<!-- _______________________________________________________________________ -->
3128<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]3129 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3130</div>
3131<div class="doc_text">
3132
3133<h5>Syntax:</h5>
3134<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3135 &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]3136</pre>
3137
3138<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3139<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3140unsigned integer equivalent of type <tt>ty2</tt>.
3141</p>
3142
3143<h5>Arguments:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3144<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]3145scalar or vector <a href="#t_floating">floating point</a> value, and a type
3146to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3147type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3148vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3149
3150<h5>Semantics:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3151<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3152<a href="#t_floating">floating point</a> operand into the nearest (rounding
3153towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3154the results are undefined.</p>
3155
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3156<h5>Example:</h5>
3157<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3158 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3159 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3160 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3161</pre>
3162</div>
3163
3164<!-- _______________________________________________________________________ -->
3165<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3166 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3167</div>
3168<div class="doc_text">
3169
3170<h5>Syntax:</h5>
3171<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3172 &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]3173</pre>
3174
3175<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3176<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3177<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]3178</p>
3179
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3180<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3181<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]3182scalar or vector <a href="#t_floating">floating point</a> value, and a type
3183to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3184type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3185vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3186
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3187<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3188<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3189<a href="#t_floating">floating point</a> operand into the nearest (rounding
3190towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3191the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3192
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3193<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3194<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3195 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3196 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3197 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3198</pre>
3199</div>
3200
3201<!-- _______________________________________________________________________ -->
3202<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3203 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3204</div>
3205<div class="doc_text">
3206
3207<h5>Syntax:</h5>
3208<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3209 &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]3210</pre>
3211
3212<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3213<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3214integer and converts that value to the <tt>ty2</tt> type.</p>
3215
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3216<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3217<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3218scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3219to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3220type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3221floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3222
3223<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3224<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3225integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3226the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3227
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3228<h5>Example:</h5>
3229<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3230 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3231 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3232</pre>
3233</div>
3234
3235<!-- _______________________________________________________________________ -->
3236<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3237 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3238</div>
3239<div class="doc_text">
3240
3241<h5>Syntax:</h5>
3242<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3243 &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]3244</pre>
3245
3246<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3247<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3248integer and converts that value to the <tt>ty2</tt> type.</p>
3249
3250<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3251<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3252scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3253to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3254type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3255floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3256
3257<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3258<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3259integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3260the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3261
3262<h5>Example:</h5>
3263<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3264 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3265 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3266</pre>
3267</div>
3268
3269<!-- _______________________________________________________________________ -->
3270<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3271 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3272</div>
3273<div class="doc_text">
3274
3275<h5>Syntax:</h5>
3276<pre>
3277 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3278</pre>
3279
3280<h5>Overview:</h5>
3281<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3282the integer type <tt>ty2</tt>.</p>
3283
3284<h5>Arguments:</h5>
3285<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3286must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3287<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
3288
3289<h5>Semantics:</h5>
3290<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3291<tt>ty2</tt> by interpreting the pointer value as an integer and either
3292truncating or zero extending that value to the size of the integer type. If
3293<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3294<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]3295are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3296change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3297
3298<h5>Example:</h5>
3299<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3300 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3301 %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]3302</pre>
3303</div>
3304
3305<!-- _______________________________________________________________________ -->
3306<div class="doc_subsubsection">
3307 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3308</div>
3309<div class="doc_text">
3310
3311<h5>Syntax:</h5>
3312<pre>
3313 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3314</pre>
3315
3316<h5>Overview:</h5>
3317<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3318a pointer type, <tt>ty2</tt>.</p>
3319
3320<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3321<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3322value to cast, and a type to cast it to, which must be a
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]3323<a href="#t_pointer">pointer</a> type.
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3324
3325<h5>Semantics:</h5>
3326<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3327<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3328the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3329size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3330the size of a pointer then a zero extension is done. If they are the same size,
3331nothing is done (<i>no-op cast</i>).</p>
3332
3333<h5>Example:</h5>
3334<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3335 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3336 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3337 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3338</pre>
3339</div>
3340
3341<!-- _______________________________________________________________________ -->
3342<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3343 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3344</div>
3345<div class="doc_text">
3346
3347<h5>Syntax:</h5>
3348<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3349 &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]3350</pre>
3351
3352<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3353<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3354<tt>ty2</tt> without changing any bits.</p>
3355
3356<h5>Arguments:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3357<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3358a first class value, and a type to cast it to, which must also be a <a
3359 href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
Reid Spencere3db84c2007-01-09 20:08:58 +0000[diff] [blame]3360and the destination type, <tt>ty2</tt>, must be identical. If the source
3361type is a pointer, the destination type must also be a pointer.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3362
3363<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3364<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3365<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3366this conversion. The conversion is done as if the <tt>value</tt> had been
3367stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3368converted to other pointer types with this instruction. To convert pointers to
3369other types, use the <a href="#i_inttoptr">inttoptr</a> or
3370<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3371
3372<h5>Example:</h5>
3373<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3374 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3375 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
3376 %Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3377</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3378</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3379
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3380<!-- ======================================================================= -->
3381<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3382<div class="doc_text">
3383<p>The instructions in this category are the "miscellaneous"
3384instructions, which defy better classification.</p>
3385</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3386
3387<!-- _______________________________________________________________________ -->
3388<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3389</div>
3390<div class="doc_text">
3391<h5>Syntax:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3392<pre> &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {i1}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3393</pre>
3394<h5>Overview:</h5>
3395<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
3396of its two integer operands.</p>
3397<h5>Arguments:</h5>
3398<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3399the condition code indicating the kind of comparison to perform. It is not
3400a value, just a keyword. The possible condition code are:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3401<ol>
3402 <li><tt>eq</tt>: equal</li>
3403 <li><tt>ne</tt>: not equal </li>
3404 <li><tt>ugt</tt>: unsigned greater than</li>
3405 <li><tt>uge</tt>: unsigned greater or equal</li>
3406 <li><tt>ult</tt>: unsigned less than</li>
3407 <li><tt>ule</tt>: unsigned less or equal</li>
3408 <li><tt>sgt</tt>: signed greater than</li>
3409 <li><tt>sge</tt>: signed greater or equal</li>
3410 <li><tt>slt</tt>: signed less than</li>
3411 <li><tt>sle</tt>: signed less or equal</li>
3412</ol>
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3413<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Reid Spencer784ef792007-01-04 05:19:58 +0000[diff] [blame]3414<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3415<h5>Semantics:</h5>
3416<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3417the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3418yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3419<ol>
3420 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3421 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3422 </li>
3423 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
3424 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3425 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
3426 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3427 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
3428 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3429 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
3430 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3431 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
3432 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
3433 <li><tt>sgt</tt>: interprets the operands as signed values and yields
3434 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3435 <li><tt>sge</tt>: interprets the operands as signed values and yields
3436 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3437 <li><tt>slt</tt>: interprets the operands as signed values and yields
3438 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3439 <li><tt>sle</tt>: interprets the operands as signed values and yields
3440 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3441</ol>
3442<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3443values are compared as if they were integers.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3444
3445<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3446<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3447 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3448 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3449 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3450 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3451 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3452</pre>
3453</div>
3454
3455<!-- _______________________________________________________________________ -->
3456<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3457</div>
3458<div class="doc_text">
3459<h5>Syntax:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3460<pre> &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {i1}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3461</pre>
3462<h5>Overview:</h5>
3463<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
3464of its floating point operands.</p>
3465<h5>Arguments:</h5>
3466<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3467the condition code indicating the kind of comparison to perform. It is not
3468a value, just a keyword. The possible condition code are:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3469<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3470 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3471 <li><tt>oeq</tt>: ordered and equal</li>
3472 <li><tt>ogt</tt>: ordered and greater than </li>
3473 <li><tt>oge</tt>: ordered and greater than or equal</li>
3474 <li><tt>olt</tt>: ordered and less than </li>
3475 <li><tt>ole</tt>: ordered and less than or equal</li>
3476 <li><tt>one</tt>: ordered and not equal</li>
3477 <li><tt>ord</tt>: ordered (no nans)</li>
3478 <li><tt>ueq</tt>: unordered or equal</li>
3479 <li><tt>ugt</tt>: unordered or greater than </li>
3480 <li><tt>uge</tt>: unordered or greater than or equal</li>
3481 <li><tt>ult</tt>: unordered or less than </li>
3482 <li><tt>ule</tt>: unordered or less than or equal</li>
3483 <li><tt>une</tt>: unordered or not equal</li>
3484 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3485 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3486</ol>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3487<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer02e0d1d2006-12-06 07:08:07 +0000[diff] [blame]3488<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer784ef792007-01-04 05:19:58 +0000[diff] [blame]3489<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
3490<a href="#t_floating">floating point</a> typed. They must have identical
3491types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3492<h5>Semantics:</h5>
3493<p>The '<tt>fcmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3494the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3495yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3496<ol>
3497 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3498 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3499 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3500 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3501 <tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3502 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3503 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3504 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3505 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3506 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3507 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3508 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3509 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3510 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
3511 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3512 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3513 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3514 <tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3515 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3516 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3517 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3518 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3519 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3520 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3521 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3522 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3523 <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]3524 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
3525</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3526
3527<h5>Example:</h5>
3528<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
3529 &lt;result&gt; = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
3530 &lt;result&gt; = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
3531 &lt;result&gt; = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
3532</pre>
3533</div>
3534
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3535<!-- _______________________________________________________________________ -->
3536<div class="doc_subsubsection"> <a name="i_phi">'<tt>phi</tt>'
3537Instruction</a> </div>
3538<div class="doc_text">
3539<h5>Syntax:</h5>
3540<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
3541<h5>Overview:</h5>
3542<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
3543the SSA graph representing the function.</p>
3544<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3545<p>The type of the incoming values is specified with the first type
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3546field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
3547as arguments, with one pair for each predecessor basic block of the
3548current block. Only values of <a href="#t_firstclass">first class</a>
3549type may be used as the value arguments to the PHI node. Only labels
3550may be used as the label arguments.</p>
3551<p>There must be no non-phi instructions between the start of a basic
3552block and the PHI instructions: i.e. PHI instructions must be first in
3553a basic block.</p>
3554<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3555<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
3556specified by the pair corresponding to the predecessor basic block that executed
3557just prior to the current block.</p>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3558<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3559<pre>Loop: ; Infinite loop that counts from 0 on up...<br> %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]<br> %nextindvar = add i32 %indvar, 1<br> br label %Loop<br></pre>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3560</div>
3561
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3562<!-- _______________________________________________________________________ -->
3563<div class="doc_subsubsection">
3564 <a name="i_select">'<tt>select</tt>' Instruction</a>
3565</div>
3566
3567<div class="doc_text">
3568
3569<h5>Syntax:</h5>
3570
3571<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3572 &lt;result&gt; = select i1 &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3573</pre>
3574
3575<h5>Overview:</h5>
3576
3577<p>
3578The '<tt>select</tt>' instruction is used to choose one value based on a
3579condition, without branching.
3580</p>
3581
3582
3583<h5>Arguments:</h5>
3584
3585<p>
3586The '<tt>select</tt>' instruction requires a boolean value indicating the condition, and two values of the same <a href="#t_firstclass">first class</a> type.
3587</p>
3588
3589<h5>Semantics:</h5>
3590
3591<p>
3592If the boolean condition evaluates to true, the instruction returns the first
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3593value argument; otherwise, it returns the second value argument.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3594</p>
3595
3596<h5>Example:</h5>
3597
3598<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3599 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3600</pre>
3601</div>
3602
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]3603
3604<!-- _______________________________________________________________________ -->
3605<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3606 <a name="i_call">'<tt>call</tt>' Instruction</a>
3607</div>
3608
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3609<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3610
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3611<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3612<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]3613 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;param list&gt;)
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3614</pre>
3615
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3616<h5>Overview:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3617
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3618<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3619
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3620<h5>Arguments:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3621
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3622<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3623
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3624<ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3625 <li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3626 <p>The optional "tail" marker indicates whether the callee function accesses
3627 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3628 function call is eligible for tail call optimization. Note that calls may
3629 be marked "tail" even if they do not occur before a <a
3630 href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3631 </li>
3632 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3633 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3634 convention</a> the call should use. If none is specified, the call defaults
3635 to using C calling conventions.
3636 </li>
3637 <li>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]3638 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
3639 the type of the return value. Functions that return no value are marked
3640 <tt><a href="#t_void">void</a></tt>.</p>
3641 </li>
3642 <li>
3643 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
3644 value being invoked. The argument types must match the types implied by
3645 this signature. This type can be omitted if the function is not varargs
3646 and if the function type does not return a pointer to a function.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3647 </li>
3648 <li>
3649 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
3650 be invoked. In most cases, this is a direct function invocation, but
3651 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3652 to function value.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3653 </li>
3654 <li>
3655 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencerd845d162005-05-01 22:22:57 +0000[diff] [blame]3656 function signature argument types. All arguments must be of
3657 <a href="#t_firstclass">first class</a> type. If the function signature
3658 indicates the function accepts a variable number of arguments, the extra
3659 arguments can be specified.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3660 </li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3661</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3662
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3663<h5>Semantics:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3664
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3665<p>The '<tt>call</tt>' instruction is used to cause control flow to
3666transfer to a specified function, with its incoming arguments bound to
3667the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
3668instruction in the called function, control flow continues with the
3669instruction after the function call, and the return value of the
3670function is bound to the result argument. This is a simpler case of
3671the <a href="#i_invoke">invoke</a> instruction.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3672
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3673<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3674
3675<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]3676 %retval = call i32 @test(i32 %argc)
3677 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42);
3678 %X = tail call i32 @foo()
3679 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo()
3680 %Z = call void %foo(i8 97 signext)
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3681</pre>
3682
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3683</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3684
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3685<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3686<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]3687 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3688</div>
3689
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3690<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3691
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3692<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3693
3694<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3695 &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]3696</pre>
3697
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3698<h5>Overview:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3699
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3700<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3701the "variable argument" area of a function call. It is used to implement the
3702<tt>va_arg</tt> macro in C.</p>
3703
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3704<h5>Arguments:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3705
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3706<p>This instruction takes a <tt>va_list*</tt> value and the type of
3707the argument. It returns a value of the specified argument type and
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3708increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3709actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3710
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3711<h5>Semantics:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3712
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3713<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
3714type from the specified <tt>va_list</tt> and causes the
3715<tt>va_list</tt> to point to the next argument. For more information,
3716see the variable argument handling <a href="#int_varargs">Intrinsic
3717Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3718
3719<p>It is legal for this instruction to be called in a function which does not
3720take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3721function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3722
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3723<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3724href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3725argument.</p>
3726
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3727<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3728
3729<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
3730
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3731</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3732
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3733<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3734<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
3735<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3736
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3737<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3738
3739<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]3740well known names and semantics and are required to follow certain restrictions.
3741Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3742language that does not require changing all of the transformations in LLVM when
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]3743adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3744
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3745<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3746prefix is reserved in LLVM for intrinsic names; thus, function names may not
3747begin with this prefix. Intrinsic functions must always be external functions:
3748you cannot define the body of intrinsic functions. Intrinsic functions may
3749only be used in call or invoke instructions: it is illegal to take the address
3750of an intrinsic function. Additionally, because intrinsic functions are part
3751of the LLVM language, it is required if any are added that they be documented
3752here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3753
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]3754<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
3755a family of functions that perform the same operation but on different data
3756types. Because LLVM can represent over 8 million different integer types,
3757overloading is used commonly to allow an intrinsic function to operate on any
3758integer type. One or more of the argument types or the result type can be
3759overloaded to accept any integer type. Argument types may also be defined as
3760exactly matching a previous argument's type or the result type. This allows an
3761intrinsic function which accepts multiple arguments, but needs all of them to
3762be of the same type, to only be overloaded with respect to a single argument or
3763the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3764
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]3765<p>Overloaded intrinsics will have the names of its overloaded argument types
3766encoded into its function name, each preceded by a period. Only those types
3767which are overloaded result in a name suffix. Arguments whose type is matched
3768against another type do not. For example, the <tt>llvm.ctpop</tt> function can
3769take an integer of any width and returns an integer of exactly the same integer
3770width. This leads to a family of functions such as
3771<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
3772Only one type, the return type, is overloaded, and only one type suffix is
3773required. Because the argument's type is matched against the return type, it
3774does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]3775
3776<p>To learn how to add an intrinsic function, please see the
3777<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3778</p>
3779
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3780</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3781
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3782<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3783<div class="doc_subsection">
3784 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
3785</div>
3786
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3787<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3788
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3789<p>Variable argument support is defined in LLVM with the <a
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]3790 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3791intrinsic functions. These functions are related to the similarly
3792named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3793
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3794<p>All of these functions operate on arguments that use a
3795target-specific value type "<tt>va_list</tt>". The LLVM assembly
3796language reference manual does not define what this type is, so all
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3797transformations should be prepared to handle these functions regardless of
3798the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3799
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]3800<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]3801instruction and the variable argument handling intrinsic functions are
3802used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3803
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3804<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3805<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3806define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3807 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3808 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3809 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3810 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3811
3812 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3813 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3814
3815 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3816 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3817 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3818 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3819 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3820
3821 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3822 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3823 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3824}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3825
3826declare void @llvm.va_start(i8*)
3827declare void @llvm.va_copy(i8*, i8*)
3828declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3829</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3830</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3831
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3832</div>
3833
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3834<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3835<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3836 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3837</div>
3838
3839
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3840<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3841<h5>Syntax:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3842<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3843<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3844<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
3845<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
3846href="#i_va_arg">va_arg</a></tt>.</p>
3847
3848<h5>Arguments:</h5>
3849
3850<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
3851
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3852<h5>Semantics:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3853
3854<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
3855macro available in C. In a target-dependent way, it initializes the
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3856<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]3857<tt>va_arg</tt> will produce the first variable argument passed to the function.
3858Unlike 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]3859last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3860
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3861</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3862
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3863<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3864<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3865 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3866</div>
3867
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3868<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3869<h5>Syntax:</h5>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]3870<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3871<h5>Overview:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3872
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3873<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3874which 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]3875or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3876
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3877<h5>Arguments:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3878
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3879<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]3880
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3881<h5>Semantics:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3882
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3883<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]3884macro available in C. In a target-dependent way, it destroys the
3885<tt>va_list</tt> element to which the argument points. Calls to <a
3886href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
3887<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
3888<tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3889
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3890</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3891
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3892<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3893<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3894 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3895</div>
3896
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3897<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3898
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3899<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3900
3901<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]3902 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3903</pre>
3904
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3905<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3906
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3907<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
3908from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3909
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3910<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3911
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3912<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]3913The 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]3914
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3915
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3916<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3917
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3918<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
3919macro available in C. In a target-dependent way, it copies the source
3920<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
3921intrinsic is necessary because the <tt><a href="#int_va_start">
3922llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
3923example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3924
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3925</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3926
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3927<!-- ======================================================================= -->
3928<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3929 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
3930</div>
3931
3932<div class="doc_text">
3933
3934<p>
3935LLVM support for <a href="GarbageCollection.html">Accurate Garbage
3936Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3937These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3938stack</a>, as well as garbage collector implementations that require <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3939href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3940Front-ends for type-safe garbage collected languages should generate these
3941intrinsics to make use of the LLVM garbage collectors. For more details, see <a
3942href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
3943</p>
3944</div>
3945
3946<!-- _______________________________________________________________________ -->
3947<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3948 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3949</div>
3950
3951<div class="doc_text">
3952
3953<h5>Syntax:</h5>
3954
3955<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]3956 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3957</pre>
3958
3959<h5>Overview:</h5>
3960
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3961<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]3962the code generator, and allows some metadata to be associated with it.</p>
3963
3964<h5>Arguments:</h5>
3965
3966<p>The first argument specifies the address of a stack object that contains the
3967root pointer. The second pointer (which must be either a constant or a global
3968value address) contains the meta-data to be associated with the root.</p>
3969
3970<h5>Semantics:</h5>
3971
3972<p>At runtime, a call to this intrinsics stores a null pointer into the "ptrloc"
3973location. At compile-time, the code generator generates information to allow
3974the runtime to find the pointer at GC safe points.
3975</p>
3976
3977</div>
3978
3979
3980<!-- _______________________________________________________________________ -->
3981<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3982 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3983</div>
3984
3985<div class="doc_text">
3986
3987<h5>Syntax:</h5>
3988
3989<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]3990 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3991</pre>
3992
3993<h5>Overview:</h5>
3994
3995<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
3996locations, allowing garbage collector implementations that require read
3997barriers.</p>
3998
3999<h5>Arguments:</h5>
4000
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4001<p>The second argument is the address to read from, which should be an address
4002allocated from the garbage collector. The first object is a pointer to the
4003start of the referenced object, if needed by the language runtime (otherwise
4004null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4005
4006<h5>Semantics:</h5>
4007
4008<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4009instruction, but may be replaced with substantially more complex code by the
4010garbage collector runtime, as needed.</p>
4011
4012</div>
4013
4014
4015<!-- _______________________________________________________________________ -->
4016<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4017 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4018</div>
4019
4020<div class="doc_text">
4021
4022<h5>Syntax:</h5>
4023
4024<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4025 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4026</pre>
4027
4028<h5>Overview:</h5>
4029
4030<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4031locations, allowing garbage collector implementations that require write
4032barriers (such as generational or reference counting collectors).</p>
4033
4034<h5>Arguments:</h5>
4035
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4036<p>The first argument is the reference to store, the second is the start of the
4037object to store it to, and the third is the address of the field of Obj to
4038store to. If the runtime does not require a pointer to the object, Obj may be
4039null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4040
4041<h5>Semantics:</h5>
4042
4043<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4044instruction, but may be replaced with substantially more complex code by the
4045garbage collector runtime, as needed.</p>
4046
4047</div>
4048
4049
4050
4051<!-- ======================================================================= -->
4052<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4053 <a name="int_codegen">Code Generator Intrinsics</a>
4054</div>
4055
4056<div class="doc_text">
4057<p>
4058These intrinsics are provided by LLVM to expose special features that may only
4059be implemented with code generator support.
4060</p>
4061
4062</div>
4063
4064<!-- _______________________________________________________________________ -->
4065<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4066 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4067</div>
4068
4069<div class="doc_text">
4070
4071<h5>Syntax:</h5>
4072<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4073 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4074</pre>
4075
4076<h5>Overview:</h5>
4077
4078<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4079The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4080target-specific value indicating the return address of the current function
4081or one of its callers.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4082</p>
4083
4084<h5>Arguments:</h5>
4085
4086<p>
4087The argument to this intrinsic indicates which function to return the address
4088for. Zero indicates the calling function, one indicates its caller, etc. The
4089argument is <b>required</b> to be a constant integer value.
4090</p>
4091
4092<h5>Semantics:</h5>
4093
4094<p>
4095The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4096the return address of the specified call frame, or zero if it cannot be
4097identified. The value returned by this intrinsic is likely to be incorrect or 0
4098for arguments other than zero, so it should only be used for debugging purposes.
4099</p>
4100
4101<p>
4102Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4103aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4104source-language caller.
4105</p>
4106</div>
4107
4108
4109<!-- _______________________________________________________________________ -->
4110<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4111 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4112</div>
4113
4114<div class="doc_text">
4115
4116<h5>Syntax:</h5>
4117<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4118 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4119</pre>
4120
4121<h5>Overview:</h5>
4122
4123<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4124The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4125target-specific frame pointer value for the specified stack frame.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4126</p>
4127
4128<h5>Arguments:</h5>
4129
4130<p>
4131The argument to this intrinsic indicates which function to return the frame
4132pointer for. Zero indicates the calling function, one indicates its caller,
4133etc. The argument is <b>required</b> to be a constant integer value.
4134</p>
4135
4136<h5>Semantics:</h5>
4137
4138<p>
4139The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4140the frame address of the specified call frame, or zero if it cannot be
4141identified. The value returned by this intrinsic is likely to be incorrect or 0
4142for arguments other than zero, so it should only be used for debugging purposes.
4143</p>
4144
4145<p>
4146Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4147aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4148source-language caller.
4149</p>
4150</div>
4151
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4152<!-- _______________________________________________________________________ -->
4153<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4154 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4155</div>
4156
4157<div class="doc_text">
4158
4159<h5>Syntax:</h5>
4160<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4161 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4162</pre>
4163
4164<h5>Overview:</h5>
4165
4166<p>
4167The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4168the function stack, for use with <a href="#int_stackrestore">
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4169<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4170features like scoped automatic variable sized arrays in C99.
4171</p>
4172
4173<h5>Semantics:</h5>
4174
4175<p>
4176This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4177href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4178<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4179<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4180state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4181practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4182that were allocated after the <tt>llvm.stacksave</tt> was executed.
4183</p>
4184
4185</div>
4186
4187<!-- _______________________________________________________________________ -->
4188<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4189 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4190</div>
4191
4192<div class="doc_text">
4193
4194<h5>Syntax:</h5>
4195<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4196 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4197</pre>
4198
4199<h5>Overview:</h5>
4200
4201<p>
4202The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4203the function stack to the state it was in when the corresponding <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4204href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4205useful for implementing language features like scoped automatic variable sized
4206arrays in C99.
4207</p>
4208
4209<h5>Semantics:</h5>
4210
4211<p>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4212See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4213</p>
4214
4215</div>
4216
4217
4218<!-- _______________________________________________________________________ -->
4219<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4220 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4221</div>
4222
4223<div class="doc_text">
4224
4225<h5>Syntax:</h5>
4226<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4227 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]4228</pre>
4229
4230<h5>Overview:</h5>
4231
4232
4233<p>
4234The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4235a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4236no
4237effect on the behavior of the program but can change its performance
Chris Lattnerff851072005-02-28 19:47:14 +0000[diff] [blame]4238characteristics.
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4239</p>
4240
4241<h5>Arguments:</h5>
4242
4243<p>
4244<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4245determining if the fetch should be for a read (0) or write (1), and
4246<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattnerd3e641c2005-03-07 20:31:38 +0000[diff] [blame]4247locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4248<tt>locality</tt> arguments must be constant integers.
4249</p>
4250
4251<h5>Semantics:</h5>
4252
4253<p>
4254This intrinsic does not modify the behavior of the program. In particular,
4255prefetches cannot trap and do not produce a value. On targets that support this
4256intrinsic, the prefetch can provide hints to the processor cache for better
4257performance.
4258</p>
4259
4260</div>
4261
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4262<!-- _______________________________________________________________________ -->
4263<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4264 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4265</div>
4266
4267<div class="doc_text">
4268
4269<h5>Syntax:</h5>
4270<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4271 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4272</pre>
4273
4274<h5>Overview:</h5>
4275
4276
4277<p>
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4278The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
4279(PC) in a region of
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4280code to simulators and other tools. The method is target specific, but it is
4281expected that the marker will use exported symbols to transmit the PC of the marker.
Jeff Cohendc6bfea2005-11-11 02:15:27 +0000[diff] [blame]4282The marker makes no guarantees that it will remain with any specific instruction
Chris Lattnere64d41d2005-11-15 06:07:55 +0000[diff] [blame]4283after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb40261e2006-03-24 07:16:10 +0000[diff] [blame]4284optimizations. The intended use is to be inserted after optimizations to allow
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4285correlations of simulation runs.
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4286</p>
4287
4288<h5>Arguments:</h5>
4289
4290<p>
4291<tt>id</tt> is a numerical id identifying the marker.
4292</p>
4293
4294<h5>Semantics:</h5>
4295
4296<p>
4297This intrinsic does not modify the behavior of the program. Backends that do not
4298support this intrinisic may ignore it.
4299</p>
4300
4301</div>
4302
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]4303<!-- _______________________________________________________________________ -->
4304<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4305 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]4306</div>
4307
4308<div class="doc_text">
4309
4310<h5>Syntax:</h5>
4311<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4312 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]4313</pre>
4314
4315<h5>Overview:</h5>
4316
4317
4318<p>
4319The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
4320counter register (or similar low latency, high accuracy clocks) on those targets
4321that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
4322As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
4323should only be used for small timings.
4324</p>
4325
4326<h5>Semantics:</h5>
4327
4328<p>
4329When directly supported, reading the cycle counter should not modify any memory.
4330Implementations are allowed to either return a application specific value or a
4331system wide value. On backends without support, this is lowered to a constant 0.
4332</p>
4333
4334</div>
4335
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4336<!-- ======================================================================= -->
4337<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4338 <a name="int_libc">Standard C Library Intrinsics</a>
4339</div>
4340
4341<div class="doc_text">
4342<p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4343LLVM provides intrinsics for a few important standard C library functions.
4344These intrinsics allow source-language front-ends to pass information about the
4345alignment of the pointer arguments to the code generator, providing opportunity
4346for more efficient code generation.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4347</p>
4348
4349</div>
4350
4351<!-- _______________________________________________________________________ -->
4352<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4353 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4354</div>
4355
4356<div class="doc_text">
4357
4358<h5>Syntax:</h5>
4359<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4360 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4361 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4362 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4363 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4364</pre>
4365
4366<h5>Overview:</h5>
4367
4368<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4369The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4370location to the destination location.
4371</p>
4372
4373<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4374Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
4375intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4376</p>
4377
4378<h5>Arguments:</h5>
4379
4380<p>
4381The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4382the source. The third argument is an integer argument
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4383specifying the number of bytes to copy, and the fourth argument is the alignment
4384of the source and destination locations.
4385</p>
4386
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4387<p>
4388If 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]4389the caller guarantees that both the source and destination pointers are aligned
4390to that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4391</p>
4392
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4393<h5>Semantics:</h5>
4394
4395<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4396The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4397location to the destination location, which are not allowed to overlap. It
4398copies "len" bytes of memory over. If the argument is known to be aligned to
4399some boundary, this can be specified as the fourth argument, otherwise it should
4400be set to 0 or 1.
4401</p>
4402</div>
4403
4404
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4405<!-- _______________________________________________________________________ -->
4406<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4407 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4408</div>
4409
4410<div class="doc_text">
4411
4412<h5>Syntax:</h5>
4413<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4414 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4415 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4416 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4417 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4418</pre>
4419
4420<h5>Overview:</h5>
4421
4422<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4423The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
4424location to the destination location. It is similar to the
4425'<tt>llvm.memcmp</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4426</p>
4427
4428<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4429Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
4430intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4431</p>
4432
4433<h5>Arguments:</h5>
4434
4435<p>
4436The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4437the source. The third argument is an integer argument
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4438specifying the number of bytes to copy, and the fourth argument is the alignment
4439of the source and destination locations.
4440</p>
4441
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4442<p>
4443If 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]4444the caller guarantees that the source and destination pointers are aligned to
4445that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4446</p>
4447
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4448<h5>Semantics:</h5>
4449
4450<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4451The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4452location to the destination location, which may overlap. It
4453copies "len" bytes of memory over. If the argument is known to be aligned to
4454some boundary, this can be specified as the fourth argument, otherwise it should
4455be set to 0 or 1.
4456</p>
4457</div>
4458
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4459
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4460<!-- _______________________________________________________________________ -->
4461<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4462 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4463</div>
4464
4465<div class="doc_text">
4466
4467<h5>Syntax:</h5>
4468<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4469 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4470 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4471 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4472 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4473</pre>
4474
4475<h5>Overview:</h5>
4476
4477<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4478The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4479byte value.
4480</p>
4481
4482<p>
4483Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
4484does not return a value, and takes an extra alignment argument.
4485</p>
4486
4487<h5>Arguments:</h5>
4488
4489<p>
4490The first argument is a pointer to the destination to fill, the second is the
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4491byte value to fill it with, the third argument is an integer
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4492argument specifying the number of bytes to fill, and the fourth argument is the
4493known alignment of destination location.
4494</p>
4495
4496<p>
4497If 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]4498the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4499</p>
4500
4501<h5>Semantics:</h5>
4502
4503<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4504The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
4505the
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4506destination location. If the argument is known to be aligned to some boundary,
4507this can be specified as the fourth argument, otherwise it should be set to 0 or
45081.
4509</p>
4510</div>
4511
4512
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]4513<!-- _______________________________________________________________________ -->
4514<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4515 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4516</div>
4517
4518<div class="doc_text">
4519
4520<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]4521<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]4522floating point or vector of floating point type. Not all targets support all
4523types however.
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4524<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]4525 declare float @llvm.sqrt.f32(float %Val)
4526 declare double @llvm.sqrt.f64(double %Val)
4527 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
4528 declare fp128 @llvm.sqrt.f128(fp128 %Val)
4529 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4530</pre>
4531
4532<h5>Overview:</h5>
4533
4534<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]4535The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4536returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4537<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
4538negative numbers (which allows for better optimization).
4539</p>
4540
4541<h5>Arguments:</h5>
4542
4543<p>
4544The argument and return value are floating point numbers of the same type.
4545</p>
4546
4547<h5>Semantics:</h5>
4548
4549<p>
Dan Gohman33988db2007-07-16 14:37:41 +0000[diff] [blame]4550This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4551floating point number.
4552</p>
4553</div>
4554
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4555<!-- _______________________________________________________________________ -->
4556<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4557 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4558</div>
4559
4560<div class="doc_text">
4561
4562<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]4563<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]4564floating point or vector of floating point type. Not all targets support all
4565types however.
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4566<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]4567 declare float @llvm.powi.f32(float %Val, i32 %power)
4568 declare double @llvm.powi.f64(double %Val, i32 %power)
4569 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
4570 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
4571 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4572</pre>
4573
4574<h5>Overview:</h5>
4575
4576<p>
4577The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
4578specified (positive or negative) power. The order of evaluation of
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4579multiplications is not defined. When a vector of floating point type is
4580used, the second argument remains a scalar integer value.
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4581</p>
4582
4583<h5>Arguments:</h5>
4584
4585<p>
4586The second argument is an integer power, and the first is a value to raise to
4587that power.
4588</p>
4589
4590<h5>Semantics:</h5>
4591
4592<p>
4593This function returns the first value raised to the second power with an
4594unspecified sequence of rounding operations.</p>
4595</div>
4596
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4597<!-- _______________________________________________________________________ -->
4598<div class="doc_subsubsection">
4599 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
4600</div>
4601
4602<div class="doc_text">
4603
4604<h5>Syntax:</h5>
4605<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
4606floating point or vector of floating point type. Not all targets support all
4607types however.
4608<pre>
4609 declare float @llvm.sin.f32(float %Val)
4610 declare double @llvm.sin.f64(double %Val)
4611 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
4612 declare fp128 @llvm.sin.f128(fp128 %Val)
4613 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
4614</pre>
4615
4616<h5>Overview:</h5>
4617
4618<p>
4619The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
4620</p>
4621
4622<h5>Arguments:</h5>
4623
4624<p>
4625The argument and return value are floating point numbers of the same type.
4626</p>
4627
4628<h5>Semantics:</h5>
4629
4630<p>
4631This function returns the sine of the specified operand, returning the
4632same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]4633conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4634</div>
4635
4636<!-- _______________________________________________________________________ -->
4637<div class="doc_subsubsection">
4638 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
4639</div>
4640
4641<div class="doc_text">
4642
4643<h5>Syntax:</h5>
4644<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
4645floating point or vector of floating point type. Not all targets support all
4646types however.
4647<pre>
4648 declare float @llvm.cos.f32(float %Val)
4649 declare double @llvm.cos.f64(double %Val)
4650 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
4651 declare fp128 @llvm.cos.f128(fp128 %Val)
4652 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
4653</pre>
4654
4655<h5>Overview:</h5>
4656
4657<p>
4658The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
4659</p>
4660
4661<h5>Arguments:</h5>
4662
4663<p>
4664The argument and return value are floating point numbers of the same type.
4665</p>
4666
4667<h5>Semantics:</h5>
4668
4669<p>
4670This function returns the cosine of the specified operand, returning the
4671same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]4672conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4673</div>
4674
4675<!-- _______________________________________________________________________ -->
4676<div class="doc_subsubsection">
4677 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
4678</div>
4679
4680<div class="doc_text">
4681
4682<h5>Syntax:</h5>
4683<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
4684floating point or vector of floating point type. Not all targets support all
4685types however.
4686<pre>
4687 declare float @llvm.pow.f32(float %Val, float %Power)
4688 declare double @llvm.pow.f64(double %Val, double %Power)
4689 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
4690 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
4691 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
4692</pre>
4693
4694<h5>Overview:</h5>
4695
4696<p>
4697The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
4698specified (positive or negative) power.
4699</p>
4700
4701<h5>Arguments:</h5>
4702
4703<p>
4704The second argument is a floating point power, and the first is a value to
4705raise to that power.
4706</p>
4707
4708<h5>Semantics:</h5>
4709
4710<p>
4711This function returns the first value raised to the second power,
4712returning the
4713same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]4714conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4715</div>
4716
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4717
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4718<!-- ======================================================================= -->
4719<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4720 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4721</div>
4722
4723<div class="doc_text">
4724<p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4725LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4726These allow efficient code generation for some algorithms.
4727</p>
4728
4729</div>
4730
4731<!-- _______________________________________________________________________ -->
4732<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4733 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4734</div>
4735
4736<div class="doc_text">
4737
4738<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4739<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4740type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4741<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4742 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
4743 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
4744 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4745</pre>
4746
4747<h5>Overview:</h5>
4748
4749<p>
Reid Spencerf361c4f2007-04-02 02:25:19 +0000[diff] [blame]4750The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4751values with an even number of bytes (positive multiple of 16 bits). These are
4752useful for performing operations on data that is not in the target's native
4753byte order.
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4754</p>
4755
4756<h5>Semantics:</h5>
4757
4758<p>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4759The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4760and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
4761intrinsic returns an i32 value that has the four bytes of the input i32
4762swapped, 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]4763i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
4764<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4765additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4766</p>
4767
4768</div>
4769
4770<!-- _______________________________________________________________________ -->
4771<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]4772 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4773</div>
4774
4775<div class="doc_text">
4776
4777<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4778<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
4779width. Not all targets support all bit widths however.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4780<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4781 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
4782 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4783 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4784 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
4785 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4786</pre>
4787
4788<h5>Overview:</h5>
4789
4790<p>
Chris Lattner069b5bd2006-01-16 22:38:59 +0000[diff] [blame]4791The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
4792value.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4793</p>
4794
4795<h5>Arguments:</h5>
4796
4797<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]4798The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]4799integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4800</p>
4801
4802<h5>Semantics:</h5>
4803
4804<p>
4805The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
4806</p>
4807</div>
4808
4809<!-- _______________________________________________________________________ -->
4810<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]4811 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4812</div>
4813
4814<div class="doc_text">
4815
4816<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4817<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
4818integer bit width. Not all targets support all bit widths however.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4819<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4820 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
4821 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4822 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4823 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
4824 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4825</pre>
4826
4827<h5>Overview:</h5>
4828
4829<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]4830The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
4831leading zeros in a variable.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4832</p>
4833
4834<h5>Arguments:</h5>
4835
4836<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]4837The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]4838integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4839</p>
4840
4841<h5>Semantics:</h5>
4842
4843<p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4844The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
4845in 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]4846of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4847</p>
4848</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]4849
4850
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4851
4852<!-- _______________________________________________________________________ -->
4853<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]4854 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4855</div>
4856
4857<div class="doc_text">
4858
4859<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4860<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
4861integer bit width. Not all targets support all bit widths however.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4862<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4863 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
4864 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4865 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4866 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
4867 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4868</pre>
4869
4870<h5>Overview:</h5>
4871
4872<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]4873The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
4874trailing zeros.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4875</p>
4876
4877<h5>Arguments:</h5>
4878
4879<p>
4880The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]4881integer type. The return type must match the argument type.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4882</p>
4883
4884<h5>Semantics:</h5>
4885
4886<p>
4887The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
4888in a variable. If the src == 0 then the result is the size in bits of the type
4889of src. For example, <tt>llvm.cttz(2) = 1</tt>.
4890</p>
4891</div>
4892
Reid Spencer8a5799f2007-04-01 08:27:01 +0000[diff] [blame]4893<!-- _______________________________________________________________________ -->
4894<div class="doc_subsubsection">
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]4895 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4896</div>
4897
4898<div class="doc_text">
4899
4900<h5>Syntax:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]4901<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4902on any integer bit width.
4903<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4904 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
4905 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4906</pre>
4907
4908<h5>Overview:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]4909<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4910range of bits from an integer value and returns them in the same bit width as
4911the original value.</p>
4912
4913<h5>Arguments:</h5>
4914<p>The first argument, <tt>%val</tt> and the result may be integer types of
4915any bit width but they must have the same bit width. The second and third
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4916arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4917
4918<h5>Semantics:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]4919<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4920of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
4921<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
4922operates in forward mode.</p>
4923<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
4924right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4925only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
4926<ol>
4927 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
4928 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
4929 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
4930 to determine the number of bits to retain.</li>
4931 <li>A mask of the retained bits is created by shifting a -1 value.</li>
4932 <li>The mask is ANDed with <tt>%val</tt> to produce the result.
4933</ol>
Reid Spencer70845c02007-05-14 16:14:57 +0000[diff] [blame]4934<p>In reverse mode, a similar computation is made except that the bits are
4935returned in the reverse order. So, for example, if <tt>X</tt> has the value
4936<tt>i16 0x0ACF (101011001111)</tt> and we apply
4937<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
4938<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4939</div>
4940
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]4941<div class="doc_subsubsection">
4942 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
4943</div>
4944
4945<div class="doc_text">
4946
4947<h5>Syntax:</h5>
4948<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
4949on any integer bit width.
4950<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4951 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
4952 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]4953</pre>
4954
4955<h5>Overview:</h5>
4956<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
4957of bits in an integer value with another integer value. It returns the integer
4958with the replaced bits.</p>
4959
4960<h5>Arguments:</h5>
4961<p>The first argument, <tt>%val</tt> and the result may be integer types of
4962any bit width but they must have the same bit width. <tt>%val</tt> is the value
4963whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
4964integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
4965type since they specify only a bit index.</p>
4966
4967<h5>Semantics:</h5>
4968<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
4969of operation: forwards and reverse. If <tt>%lo</tt> is greater than
4970<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
4971operates in forward mode.</p>
4972<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
4973truncating it down to the size of the replacement area or zero extending it
4974up to that size.</p>
4975<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
4976are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
4977in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
4978to the <tt>%hi</tt>th bit.
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]4979<p>In reverse mode, a similar computation is made except that the bits are
4980reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
4981<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]4982<h5>Examples:</h5>
4983<pre>
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]4984 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]4985 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
4986 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
4987 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]4988 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]4989</pre>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]4990</div>
4991
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4992<!-- ======================================================================= -->
4993<div class="doc_subsection">
4994 <a name="int_debugger">Debugger Intrinsics</a>
4995</div>
4996
4997<div class="doc_text">
4998<p>
4999The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5000are described in the <a
5001href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5002Debugging</a> document.
5003</p>
5004</div>
5005
5006
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]5007<!-- ======================================================================= -->
5008<div class="doc_subsection">
5009 <a name="int_eh">Exception Handling Intrinsics</a>
5010</div>
5011
5012<div class="doc_text">
5013<p> The LLVM exception handling intrinsics (which all start with
5014<tt>llvm.eh.</tt> prefix), are described in the <a
5015href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5016Handling</a> document. </p>
5017</div>
5018
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]5019<!-- ======================================================================= -->
5020<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5021 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5022</div>
5023
5024<div class="doc_text">
5025<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5026 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5027 the <tt>nest</tt> attribute, from a function. The result is a callable
5028 function pointer lacking the nest parameter - the caller does not need
5029 to provide a value for it. Instead, the value to use is stored in
5030 advance in a "trampoline", a block of memory usually allocated
5031 on the stack, which also contains code to splice the nest value into the
5032 argument list. This is used to implement the GCC nested function address
5033 extension.
5034</p>
5035<p>
5036 For example, if the function is
5037 <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]5038 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]5039<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5040 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5041 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5042 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5043 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5044</pre>
Bill Wendling252570f2007-09-22 09:23:55 +0000[diff] [blame]5045 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5046 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5047</div>
5048
5049<!-- _______________________________________________________________________ -->
5050<div class="doc_subsubsection">
5051 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5052</div>
5053<div class="doc_text">
5054<h5>Syntax:</h5>
5055<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5056declare 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]5057</pre>
5058<h5>Overview:</h5>
5059<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5060 This fills the memory pointed to by <tt>tramp</tt> with code
5061 and returns a function pointer suitable for executing it.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5062</p>
5063<h5>Arguments:</h5>
5064<p>
5065 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5066 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5067 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsf2bcd372007-08-22 23:39:54 +0000[diff] [blame]5068 intrinsic. Note that the size and the alignment are target-specific - LLVM
5069 currently provides no portable way of determining them, so a front-end that
5070 generates this intrinsic needs to have some target-specific knowledge.
5071 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]5072</p>
5073<h5>Semantics:</h5>
5074<p>
5075 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5076 dependent code, turning it into a function. A pointer to this function is
5077 returned, but needs to be bitcast to an
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5078 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5079 before being called. The new function's signature is the same as that of
5080 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5081 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5082 of pointer type. Calling the new function is equivalent to calling
5083 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5084 missing <tt>nest</tt> argument. If, after calling
5085 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5086 modified, then the effect of any later call to the returned function pointer is
5087 undefined.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5088</p>
5089</div>
5090
5091<!-- ======================================================================= -->
5092<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]5093 <a name="int_general">General Intrinsics</a>
5094</div>
5095
5096<div class="doc_text">
5097<p> This class of intrinsics is designed to be generic and has
5098no specific purpose. </p>
5099</div>
5100
5101<!-- _______________________________________________________________________ -->
5102<div class="doc_subsubsection">
5103 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
5104</div>
5105
5106<div class="doc_text">
5107
5108<h5>Syntax:</h5>
5109<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]5110 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]5111</pre>
5112
5113<h5>Overview:</h5>
5114
5115<p>
5116The '<tt>llvm.var.annotation</tt>' intrinsic
5117</p>
5118
5119<h5>Arguments:</h5>
5120
5121<p>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]5122The first argument is a pointer to a value, the second is a pointer to a
5123global string, the third is a pointer to a global string which is the source
5124file name, and the last argument is the line number.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]5125</p>
5126
5127<h5>Semantics:</h5>
5128
5129<p>
5130This intrinsic allows annotation of local variables with arbitrary strings.
5131This can be useful for special purpose optimizations that want to look for these
5132 annotations. These have no other defined use, they are ignored by code
5133 generation and optimization.
5134</div>
5135
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]5136<!-- _______________________________________________________________________ -->
5137<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]5138 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]5139</div>
5140
5141<div class="doc_text">
5142
5143<h5>Syntax:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]5144<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
5145any integer bit width.
5146</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]5147<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]5148 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5149 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5150 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5151 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5152 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]5153</pre>
5154
5155<h5>Overview:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]5156
5157<p>
5158The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]5159</p>
5160
5161<h5>Arguments:</h5>
5162
5163<p>
5164The first argument is an integer value (result of some expression),
5165the second is a pointer to a global string, the third is a pointer to a global
5166string which is the source file name, and the last argument is the line number.
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]5167It returns the value of the first argument.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]5168</p>
5169
5170<h5>Semantics:</h5>
5171
5172<p>
5173This intrinsic allows annotations to be put on arbitrary expressions
5174with arbitrary strings. This can be useful for special purpose optimizations
5175that want to look for these annotations. These have no other defined use, they
5176are ignored by code generation and optimization.
5177</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]5178
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5179<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5180<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]5181<address>
5182 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
5183 src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
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5186
5187 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]5188 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]5189 Last modified: $Date$
5190</address>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5191</body>
5192</html>