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gerrit-public.fairphone.software / toolchain / llvm-project / a47634ecb16458898871ff5996756733193f5c6d / . / 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>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]29 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]30 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]31 <li><a href="#datalayout">Data Layout</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]32 </ol>
33 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]34 <li><a href="#typesystem">Type System</a>
35 <ol>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]36 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]37 <ol>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]38 <li><a href="#t_classifications">Type Classifications</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]39 </ol>
40 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]41 <li><a href="#t_derived">Derived Types</a>
42 <ol>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]43 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]44 <li><a href="#t_array">Array Type</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]45 <li><a href="#t_function">Function Type</a></li>
46 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]47 <li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]48 <li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]49 <li><a href="#t_vector">Vector Type</a></li>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]50 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]51 </ol>
52 </li>
53 </ol>
54 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]55 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]56 <ol>
57 <li><a href="#simpleconstants">Simple Constants</a>
58 <li><a href="#aggregateconstants">Aggregate Constants</a>
59 <li><a href="#globalconstants">Global Variable and Function Addresses</a>
60 <li><a href="#undefvalues">Undefined Values</a>
61 <li><a href="#constantexprs">Constant Expressions</a>
62 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]63 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]64 <li><a href="#othervalues">Other Values</a>
65 <ol>
66 <li><a href="#inlineasm">Inline Assembler Expressions</a>
67 </ol>
68 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]69 <li><a href="#instref">Instruction Reference</a>
70 <ol>
71 <li><a href="#terminators">Terminator Instructions</a>
72 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]73 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
74 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]75 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
76 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]77 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]78 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]79 </ol>
80 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]81 <li><a href="#binaryops">Binary Operations</a>
82 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]83 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
84 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
85 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]86 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
87 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
88 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]89 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
90 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
91 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]92 </ol>
93 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]94 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
95 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]96 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
97 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
98 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]99 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]100 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]101 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]102 </ol>
103 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]104 <li><a href="#vectorops">Vector Operations</a>
105 <ol>
106 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
107 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
108 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]109 </ol>
110 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]111 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]112 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]113 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
114 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
115 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]116 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
117 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
118 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]119 </ol>
120 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]121 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]122 <ol>
123 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
124 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
125 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
126 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
127 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]128 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
129 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
130 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
131 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]132 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
133 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]134 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]135 </ol>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]136 <li><a href="#otherops">Other Operations</a>
137 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]138 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
139 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]140 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]141 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]142 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]143 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></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 Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]146 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]147 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]148 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]149 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]150 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
151 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]152 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
153 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
154 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]155 </ol>
156 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]157 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
158 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]159 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
160 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
161 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]162 </ol>
163 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]164 <li><a href="#int_codegen">Code Generator Intrinsics</a>
165 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]166 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
167 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
168 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
169 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
170 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
171 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
172 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]173 </ol>
174 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]175 <li><a href="#int_libc">Standard C Library Intrinsics</a>
176 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]177 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
178 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
179 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
180 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
181 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]182 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
183 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
184 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]185 </ol>
186 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]187 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]188 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]189 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]190 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
191 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
192 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]193 <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
194 <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]195 </ol>
196 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]197 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]198 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]199 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]200 <ol>
201 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]202 </ol>
203 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]204 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]205 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]206 <li><a href="#int_var_annotation">
Tanya Lattner08abc812007-09-22 00:01:26 +0000[diff] [blame]207 <tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]208 </ol>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]209 <ol>
210 <li><a href="#int_annotation">
Tanya Lattner08abc812007-09-22 00:01:26 +0000[diff] [blame]211 <tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]212 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]213 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]214 </ol>
215 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]216</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]217
218<div class="doc_author">
219 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
220 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]221</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]222
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]223<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]224<div class="doc_section"> <a name="abstract">Abstract </a></div>
225<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]226
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]227<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]228<p>This document is a reference manual for the LLVM assembly language.
229LLVM is an SSA based representation that provides type safety,
230low-level operations, flexibility, and the capability of representing
231'all' high-level languages cleanly. It is the common code
232representation used throughout all phases of the LLVM compilation
233strategy.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]234</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]235
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]236<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]237<div class="doc_section"> <a name="introduction">Introduction</a> </div>
238<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]239
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]240<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]241
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]242<p>The LLVM code representation is designed to be used in three
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]243different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]244representation (suitable for fast loading by a Just-In-Time compiler),
245and as a human readable assembly language representation. This allows
246LLVM to provide a powerful intermediate representation for efficient
247compiler transformations and analysis, while providing a natural means
248to debug and visualize the transformations. The three different forms
249of LLVM are all equivalent. This document describes the human readable
250representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]251
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]252<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]253while being expressive, typed, and extensible at the same time. It
254aims to be a "universal IR" of sorts, by being at a low enough level
255that high-level ideas may be cleanly mapped to it (similar to how
256microprocessors are "universal IR's", allowing many source languages to
257be mapped to them). By providing type information, LLVM can be used as
258the target of optimizations: for example, through pointer analysis, it
259can be proven that a C automatic variable is never accessed outside of
260the current function... allowing it to be promoted to a simple SSA
261value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]262
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]263</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]264
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]265<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]266<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]267
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]268<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]269
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]270<p>It is important to note that this document describes 'well formed'
271LLVM assembly language. There is a difference between what the parser
272accepts and what is considered 'well formed'. For example, the
273following instruction is syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]274
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]275<div class="doc_code">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]276<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]277%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]278</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]279</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]280
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]281<p>...because the definition of <tt>%x</tt> does not dominate all of
282its uses. The LLVM infrastructure provides a verification pass that may
283be used to verify that an LLVM module is well formed. This pass is
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]284automatically run by the parser after parsing input assembly and by
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]285the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]286by the verifier pass indicate bugs in transformation passes or input to
287the parser.</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]288</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]289
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]290<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]291
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]292<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]293<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]294<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]295
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]296<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]297
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]298 <p>LLVM identifiers come in two basic types: global and local. Global
299 identifiers (functions, global variables) begin with the @ character. Local
300 identifiers (register names, types) begin with the % character. Additionally,
301 there are three different formats for identifiers, for different purposes:
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]302
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]303<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]304 <li>Named values are represented as a string of characters with their prefix.
305 For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
306 regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]307 Identifiers which require other characters in their names can be surrounded
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]308 with quotes. In this way, anything except a <tt>&quot;</tt> character can
309 be used in a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]310
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]311 <li>Unnamed values are represented as an unsigned numeric value with their
312 prefix. For example, %12, @2, %44.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]313
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]314 <li>Constants, which are described in a <a href="#constants">section about
315 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]316</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]317
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]318<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]319don't need to worry about name clashes with reserved words, and the set of
320reserved words may be expanded in the future without penalty. Additionally,
321unnamed identifiers allow a compiler to quickly come up with a temporary
322variable without having to avoid symbol table conflicts.</p>
323
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]324<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]325languages. There are keywords for different opcodes
326('<tt><a href="#i_add">add</a></tt>',
327 '<tt><a href="#i_bitcast">bitcast</a></tt>',
328 '<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]329href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]330and others. These reserved words cannot conflict with variable names, because
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]331none of them start with a prefix character ('%' or '@').</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]332
333<p>Here is an example of LLVM code to multiply the integer variable
334'<tt>%X</tt>' by 8:</p>
335
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]336<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]337
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]338<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]339<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]340%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]341</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]342</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]343
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]344<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]345
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]346<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]347<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]348%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]349</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]350</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]351
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]352<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]353
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]354<div class="doc_code">
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]355<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]356<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
357<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
358%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]359</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]360</div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]361
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]362<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
363important lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]364
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]365<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]366
367 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
368 line.</li>
369
370 <li>Unnamed temporaries are created when the result of a computation is not
371 assigned to a named value.</li>
372
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]373 <li>Unnamed temporaries are numbered sequentially</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]374
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]375</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]376
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]377<p>...and it also shows a convention that we follow in this document. When
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]378demonstrating instructions, we will follow an instruction with a comment that
379defines the type and name of value produced. Comments are shown in italic
380text.</p>
381
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]382</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]383
384<!-- *********************************************************************** -->
385<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
386<!-- *********************************************************************** -->
387
388<!-- ======================================================================= -->
389<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
390</div>
391
392<div class="doc_text">
393
394<p>LLVM programs are composed of "Module"s, each of which is a
395translation unit of the input programs. Each module consists of
396functions, global variables, and symbol table entries. Modules may be
397combined together with the LLVM linker, which merges function (and
398global variable) definitions, resolves forward declarations, and merges
399symbol table entries. Here is an example of the "hello world" module:</p>
400
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]401<div class="doc_code">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]402<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]403<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
404 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]405
406<i>; External declaration of the puts function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]407<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]408
409<i>; Definition of main function</i>
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]410define i32 @main() { <i>; i32()* </i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]411 <i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]412 %cast210 = <a
Chris Lattner2150cde2007-06-12 17:01:15 +0000[diff] [blame]413 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]414
415 <i>; Call puts function to write out the string to stdout...</i>
416 <a
Chris Lattner2b0bf4f2007-06-12 17:00:26 +0000[diff] [blame]417 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]418 <a
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]419 href="#i_ret">ret</a> i32 0<br>}<br>
420</pre>
421</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]422
423<p>This example is made up of a <a href="#globalvars">global variable</a>
424named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
425function, and a <a href="#functionstructure">function definition</a>
426for "<tt>main</tt>".</p>
427
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]428<p>In general, a module is made up of a list of global values,
429where both functions and global variables are global values. Global values are
430represented by a pointer to a memory location (in this case, a pointer to an
431array of char, and a pointer to a function), and have one of the following <a
432href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]433
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]434</div>
435
436<!-- ======================================================================= -->
437<div class="doc_subsection">
438 <a name="linkage">Linkage Types</a>
439</div>
440
441<div class="doc_text">
442
443<p>
444All Global Variables and Functions have one of the following types of linkage:
445</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]446
447<dl>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]448
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]449 <dt><tt><b><a name="linkage_internal">internal</a></b></tt> </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]450
451 <dd>Global values with internal linkage are only directly accessible by
452 objects in the current module. In particular, linking code into a module with
453 an internal global value may cause the internal to be renamed as necessary to
454 avoid collisions. Because the symbol is internal to the module, all
455 references can be updated. This corresponds to the notion of the
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]456 '<tt>static</tt>' keyword in C.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]457 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]458
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]459 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]460
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]461 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
462 the same name when linkage occurs. This is typically used to implement
463 inline functions, templates, or other code which must be generated in each
464 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
465 allowed to be discarded.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]466 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]467
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]468 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]469
470 <dd>"<tt>weak</tt>" linkage is exactly the same as <tt>linkonce</tt> linkage,
471 except that unreferenced <tt>weak</tt> globals may not be discarded. This is
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]472 used for globals that may be emitted in multiple translation units, but that
473 are not guaranteed to be emitted into every translation unit that uses them.
474 One example of this are common globals in C, such as "<tt>int X;</tt>" at
475 global scope.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]476 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]477
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]478 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]479
480 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
481 pointer to array type. When two global variables with appending linkage are
482 linked together, the two global arrays are appended together. This is the
483 LLVM, typesafe, equivalent of having the system linker append together
484 "sections" with identical names when .o files are linked.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]485 </dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]486
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]487 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
488 <dd>The semantics of this linkage follow the ELF model: the symbol is weak
489 until linked, if not linked, the symbol becomes null instead of being an
490 undefined reference.
491 </dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]492
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]493 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]494
495 <dd>If none of the above identifiers are used, the global is externally
496 visible, meaning that it participates in linkage and can be used to resolve
497 external symbol references.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]498 </dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]499</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]500
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]501 <p>
502 The next two types of linkage are targeted for Microsoft Windows platform
503 only. They are designed to support importing (exporting) symbols from (to)
504 DLLs.
505 </p>
506
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]507 <dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]508 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
509
510 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
511 or variable via a global pointer to a pointer that is set up by the DLL
512 exporting the symbol. On Microsoft Windows targets, the pointer name is
513 formed by combining <code>_imp__</code> and the function or variable name.
514 </dd>
515
516 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
517
518 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
519 pointer to a pointer in a DLL, so that it can be referenced with the
520 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
521 name is formed by combining <code>_imp__</code> and the function or variable
522 name.
523 </dd>
524
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]525</dl>
526
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]527<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]528variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
529variable and was linked with this one, one of the two would be renamed,
530preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
531external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer92c671e2007-01-05 00:59:10 +0000[diff] [blame]532outside of the current module.</p>
533<p>It is illegal for a function <i>declaration</i>
534to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]535or <tt>extern_weak</tt>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]536<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
537linkages.
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]538</div>
539
540<!-- ======================================================================= -->
541<div class="doc_subsection">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]542 <a name="callingconv">Calling Conventions</a>
543</div>
544
545<div class="doc_text">
546
547<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
548and <a href="#i_invoke">invokes</a> can all have an optional calling convention
549specified for the call. The calling convention of any pair of dynamic
550caller/callee must match, or the behavior of the program is undefined. The
551following calling conventions are supported by LLVM, and more may be added in
552the future:</p>
553
554<dl>
555 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
556
557 <dd>This calling convention (the default if no other calling convention is
558 specified) matches the target C calling conventions. This calling convention
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]559 supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer72ba4992006-12-31 21:30:18 +0000[diff] [blame]560 prototype and implemented declaration of the function (as does normal C).
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]561 </dd>
562
563 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
564
565 <dd>This calling convention attempts to make calls as fast as possible
566 (e.g. by passing things in registers). This calling convention allows the
567 target to use whatever tricks it wants to produce fast code for the target,
Chris Lattnerc792eb32005-05-06 23:08:23 +0000[diff] [blame]568 without having to conform to an externally specified ABI. Implementations of
569 this convention should allow arbitrary tail call optimization to be supported.
570 This calling convention does not support varargs and requires the prototype of
571 all callees to exactly match the prototype of the function definition.
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]572 </dd>
573
574 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
575
576 <dd>This calling convention attempts to make code in the caller as efficient
577 as possible under the assumption that the call is not commonly executed. As
578 such, these calls often preserve all registers so that the call does not break
579 any live ranges in the caller side. This calling convention does not support
580 varargs and requires the prototype of all callees to exactly match the
581 prototype of the function definition.
582 </dd>
583
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]584 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]585
586 <dd>Any calling convention may be specified by number, allowing
587 target-specific calling conventions to be used. Target specific calling
588 conventions start at 64.
589 </dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]590</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]591
592<p>More calling conventions can be added/defined on an as-needed basis, to
593support pascal conventions or any other well-known target-independent
594convention.</p>
595
596</div>
597
598<!-- ======================================================================= -->
599<div class="doc_subsection">
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]600 <a name="visibility">Visibility Styles</a>
601</div>
602
603<div class="doc_text">
604
605<p>
606All Global Variables and Functions have one of the following visibility styles:
607</p>
608
609<dl>
610 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
611
612 <dd>On ELF, default visibility means that the declaration is visible to other
613 modules and, in shared libraries, means that the declared entity may be
614 overridden. On Darwin, default visibility means that the declaration is
615 visible to other modules. Default visibility corresponds to "external
616 linkage" in the language.
617 </dd>
618
619 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
620
621 <dd>Two declarations of an object with hidden visibility refer to the same
622 object if they are in the same shared object. Usually, hidden visibility
623 indicates that the symbol will not be placed into the dynamic symbol table,
624 so no other module (executable or shared library) can reference it
625 directly.
626 </dd>
627
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]628 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
629
630 <dd>On ELF, protected visibility indicates that the symbol will be placed in
631 the dynamic symbol table, but that references within the defining module will
632 bind to the local symbol. That is, the symbol cannot be overridden by another
633 module.
634 </dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]635</dl>
636
637</div>
638
639<!-- ======================================================================= -->
640<div class="doc_subsection">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]641 <a name="globalvars">Global Variables</a>
642</div>
643
644<div class="doc_text">
645
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]646<p>Global variables define regions of memory allocated at compilation time
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]647instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]648an explicit section to be placed in, and may have an optional explicit alignment
649specified. A variable may be defined as "thread_local", which means that it
650will not be shared by threads (each thread will have a separated copy of the
651variable). A variable may be defined as a global "constant," which indicates
652that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]653optimization, allowing the global data to be placed in the read-only section of
654an executable, etc). Note that variables that need runtime initialization
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]655cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]656
657<p>
658LLVM explicitly allows <em>declarations</em> of global variables to be marked
659constant, even if the final definition of the global is not. This capability
660can be used to enable slightly better optimization of the program, but requires
661the language definition to guarantee that optimizations based on the
662'constantness' are valid for the translation units that do not include the
663definition.
664</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]665
666<p>As SSA values, global variables define pointer values that are in
667scope (i.e. they dominate) all basic blocks in the program. Global
668variables always define a pointer to their "content" type because they
669describe a region of memory, and all memory objects in LLVM are
670accessed through pointers.</p>
671
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]672<p>A global variable may be declared to reside in a target-specifc numbered
673address space. For targets that support them, address spaces may affect how
674optimizations are performed and/or what target instructions are used to access
Christopher Lamb25f50762007-12-12 08:44:39 +0000[diff] [blame]675the variable. The default address space is zero. The address space qualifier
676must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]677
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]678<p>LLVM allows an explicit section to be specified for globals. If the target
679supports it, it will emit globals to the section specified.</p>
680
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]681<p>An explicit alignment may be specified for a global. If not present, or if
682the alignment is set to zero, the alignment of the global is set by the target
683to whatever it feels convenient. If an explicit alignment is specified, the
684global is forced to have at least that much alignment. All alignments must be
685a power of 2.</p>
686
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]687<p>For example, the following defines a global in a numbered address space with
688an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]689
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]690<div class="doc_code">
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]691<pre>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]692@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]693</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]694</div>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]695
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]696</div>
697
698
699<!-- ======================================================================= -->
700<div class="doc_subsection">
701 <a name="functionstructure">Functions</a>
702</div>
703
704<div class="doc_text">
705
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]706<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
707an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]708<a href="#visibility">visibility style</a>, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]709<a href="#callingconv">calling convention</a>, a return type, an optional
710<a href="#paramattrs">parameter attribute</a> for the return type, a function
711name, a (possibly empty) argument list (each with optional
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]712<a href="#paramattrs">parameter attributes</a>), an optional section, an
Gordon Henriksendc5cafb2007-12-10 03:30:21 +0000[diff] [blame]713optional alignment, an optional <a href="#gc">garbage collector name</a>, an
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]714opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]715
716LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
717optional <a href="#linkage">linkage type</a>, an optional
718<a href="#visibility">visibility style</a>, an optional
719<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]720<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]721name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksendc5cafb2007-12-10 03:30:21 +0000[diff] [blame]722<a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]723
724<p>A function definition contains a list of basic blocks, forming the CFG for
725the function. Each basic block may optionally start with a label (giving the
726basic block a symbol table entry), contains a list of instructions, and ends
727with a <a href="#terminators">terminator</a> instruction (such as a branch or
728function return).</p>
729
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]730<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]731executed on entrance to the function, and it is not allowed to have predecessor
732basic blocks (i.e. there can not be any branches to the entry block of a
733function). Because the block can have no predecessors, it also cannot have any
734<a href="#i_phi">PHI nodes</a>.</p>
735
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]736<p>LLVM allows an explicit section to be specified for functions. If the target
737supports it, it will emit functions to the section specified.</p>
738
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]739<p>An explicit alignment may be specified for a function. If not present, or if
740the alignment is set to zero, the alignment of the function is set by the target
741to whatever it feels convenient. If an explicit alignment is specified, the
742function is forced to have at least that much alignment. All alignments must be
743a power of 2.</p>
744
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]745</div>
746
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]747
748<!-- ======================================================================= -->
749<div class="doc_subsection">
750 <a name="aliasstructure">Aliases</a>
751</div>
752<div class="doc_text">
753 <p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikovb18f8f82007-04-28 13:45:00 +0000[diff] [blame]754 function or global variable or bitcast of global value). Aliases may have an
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]755 optional <a href="#linkage">linkage type</a>, and an
756 optional <a href="#visibility">visibility style</a>.</p>
757
758 <h5>Syntax:</h5>
759
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]760<div class="doc_code">
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]761<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]762@&lt;Name&gt; = [Linkage] [Visibility] alias &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]763</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]764</div>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]765
766</div>
767
768
769
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]770<!-- ======================================================================= -->
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]771<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
772<div class="doc_text">
773 <p>The return type and each parameter of a function type may have a set of
774 <i>parameter attributes</i> associated with them. Parameter attributes are
775 used to communicate additional information about the result or parameters of
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]776 a function. Parameter attributes are considered to be part of the function,
777 not of the function type, so functions with different parameter attributes
778 can have the same function type.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]779
Reid Spencercf7ebf52007-01-15 18:27:39 +0000[diff] [blame]780 <p>Parameter attributes are simple keywords that follow the type specified. If
781 multiple parameter attributes are needed, they are space separated. For
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]782 example:</p>
783
784<div class="doc_code">
785<pre>
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]786declare i32 @printf(i8* noalias , ...) nounwind
787declare i32 @atoi(i8*) nounwind readonly
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]788</pre>
789</div>
790
Duncan Sandsad0ea2d2007-11-27 13:23:08 +0000[diff] [blame]791 <p>Note that any attributes for the function result (<tt>nounwind</tt>,
792 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]793
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]794 <p>Currently, only the following parameter attributes are defined:</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]795 <dl>
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]796 <dt><tt>zeroext</tt></dt>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]797 <dd>This indicates that the parameter should be zero extended just before
798 a call to this function.</dd>
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]799 <dt><tt>signext</tt></dt>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]800 <dd>This indicates that the parameter should be sign extended just before
801 a call to this function.</dd>
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]802 <dt><tt>inreg</tt></dt>
803 <dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikove93c6e82007-01-28 15:27:21 +0000[diff] [blame]804 possible) during assembling function call. Support for this attribute is
805 target-specific</dd>
Anton Korobeynikove8166852007-01-28 14:30:45 +0000[diff] [blame]806 <dt><tt>sret</tt></dt>
Anton Korobeynikove93c6e82007-01-28 15:27:21 +0000[diff] [blame]807 <dd>This indicates that the parameter specifies the address of a structure
Reid Spencer05dbb9d2007-03-22 02:02:11 +0000[diff] [blame]808 that is the return value of the function in the source program.</dd>
Zhou Sheng2444a9a2007-06-05 05:28:26 +0000[diff] [blame]809 <dt><tt>noalias</tt></dt>
810 <dd>This indicates that the parameter not alias any other object or any
811 other "noalias" objects during the function call.
Reid Spencer9d1700e2007-03-22 02:18:56 +0000[diff] [blame]812 <dt><tt>noreturn</tt></dt>
813 <dd>This function attribute indicates that the function never returns. This
814 indicates to LLVM that every call to this function should be treated as if
815 an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Reid Spencer05dbb9d2007-03-22 02:02:11 +0000[diff] [blame]816 <dt><tt>nounwind</tt></dt>
817 <dd>This function attribute indicates that the function type does not use
818 the unwind instruction and does not allow stack unwinding to propagate
819 through it.</dd>
Duncan Sands27e91592007-07-27 19:57:41 +0000[diff] [blame]820 <dt><tt>nest</tt></dt>
821 <dd>This indicates that the parameter can be excised using the
822 <a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sandsa89a1132007-11-22 20:23:04 +0000[diff] [blame]823 <dt><tt>readonly</tt></dt>
Duncan Sands730a3262007-11-14 21:14:02 +0000[diff] [blame]824 <dd>This function attribute indicates that the function has no side-effects
Duncan Sandsa89a1132007-11-22 20:23:04 +0000[diff] [blame]825 except for producing a return value or throwing an exception. The value
826 returned must only depend on the function arguments and/or global variables.
827 It may use values obtained by dereferencing pointers.</dd>
828 <dt><tt>readnone</tt></dt>
829 <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]830 function, but in addition it is not allowed to dereference any pointer arguments
831 or global variables.
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]832 </dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]833
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]834</div>
835
836<!-- ======================================================================= -->
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]837<div class="doc_subsection">
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]838 <a name="gc">Garbage Collector Names</a>
839</div>
840
841<div class="doc_text">
842<p>Each function may specify a garbage collector name, which is simply a
843string.</p>
844
845<div class="doc_code"><pre
846>define void @f() gc "name" { ...</pre></div>
847
848<p>The compiler declares the supported values of <i>name</i>. Specifying a
849collector which will cause the compiler to alter its output in order to support
850the named garbage collection algorithm.</p>
851</div>
852
853<!-- ======================================================================= -->
854<div class="doc_subsection">
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]855 <a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]856</div>
857
858<div class="doc_text">
859<p>
860Modules may contain "module-level inline asm" blocks, which corresponds to the
861GCC "file scope inline asm" blocks. These blocks are internally concatenated by
862LLVM and treated as a single unit, but may be separated in the .ll file if
863desired. The syntax is very simple:
864</p>
865
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]866<div class="doc_code">
867<pre>
868module asm "inline asm code goes here"
869module asm "more can go here"
870</pre>
871</div>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]872
873<p>The strings can contain any character by escaping non-printable characters.
874 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
875 for the number.
876</p>
877
878<p>
879 The inline asm code is simply printed to the machine code .s file when
880 assembly code is generated.
881</p>
882</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]883
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]884<!-- ======================================================================= -->
885<div class="doc_subsection">
886 <a name="datalayout">Data Layout</a>
887</div>
888
889<div class="doc_text">
890<p>A module may specify a target specific data layout string that specifies how
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]891data is to be laid out in memory. The syntax for the data layout is simply:</p>
892<pre> target datalayout = "<i>layout specification</i>"</pre>
893<p>The <i>layout specification</i> consists of a list of specifications
894separated by the minus sign character ('-'). Each specification starts with a
895letter and may include other information after the letter to define some
896aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]897<dl>
898 <dt><tt>E</tt></dt>
899 <dd>Specifies that the target lays out data in big-endian form. That is, the
900 bits with the most significance have the lowest address location.</dd>
901 <dt><tt>e</tt></dt>
902 <dd>Specifies that hte target lays out data in little-endian form. That is,
903 the bits with the least significance have the lowest address location.</dd>
904 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
905 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
906 <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
907 alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
908 too.</dd>
909 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
910 <dd>This specifies the alignment for an integer type of a given bit
911 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
912 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
913 <dd>This specifies the alignment for a vector type of a given bit
914 <i>size</i>.</dd>
915 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
916 <dd>This specifies the alignment for a floating point type of a given bit
917 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
918 (double).</dd>
919 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
920 <dd>This specifies the alignment for an aggregate type of a given bit
921 <i>size</i>.</dd>
922</dl>
923<p>When constructing the data layout for a given target, LLVM starts with a
924default set of specifications which are then (possibly) overriden by the
925specifications in the <tt>datalayout</tt> keyword. The default specifications
926are given in this list:</p>
927<ul>
928 <li><tt>E</tt> - big endian</li>
929 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
930 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
931 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
932 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
933 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
934 <li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
935 alignment of 64-bits</li>
936 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
937 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
938 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
939 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
940 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
941</ul>
942<p>When llvm is determining the alignment for a given type, it uses the
943following rules:
944<ol>
945 <li>If the type sought is an exact match for one of the specifications, that
946 specification is used.</li>
947 <li>If no match is found, and the type sought is an integer type, then the
948 smallest integer type that is larger than the bitwidth of the sought type is
949 used. If none of the specifications are larger than the bitwidth then the the
950 largest integer type is used. For example, given the default specifications
951 above, the i7 type will use the alignment of i8 (next largest) while both
952 i65 and i256 will use the alignment of i64 (largest specified).</li>
953 <li>If no match is found, and the type sought is a vector type, then the
954 largest vector type that is smaller than the sought vector type will be used
955 as a fall back. This happens because <128 x double> can be implemented in
956 terms of 64 <2 x double>, for example.</li>
957</ol>
958</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]959
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]960<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]961<div class="doc_section"> <a name="typesystem">Type System</a> </div>
962<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]963
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]964<div class="doc_text">
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]965
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]966<p>The LLVM type system is one of the most important features of the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]967intermediate representation. Being typed enables a number of
968optimizations to be performed on the IR directly, without having to do
969extra analyses on the side before the transformation. A strong type
970system makes it easier to read the generated code and enables novel
971analyses and transformations that are not feasible to perform on normal
972three address code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]973
974</div>
975
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]976<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]977<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]978<div class="doc_text">
John Criswell417228d2004-04-09 16:48:45 +0000[diff] [blame]979<p>The primitive types are the fundamental building blocks of the LLVM
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]980system. The current set of primitive types is as follows:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]981
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]982<table class="layout">
983 <tr class="layout">
984 <td class="left">
985 <table>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]986 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]987 <tr><th>Type</th><th>Description</th></tr>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]988 <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]989 <tr><td><tt>label</tt></td><td>Branch destination</td></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]990 </tbody>
991 </table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]992 </td>
993 <td class="right">
994 <table>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]995 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]996 <tr><th>Type</th><th>Description</th></tr>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]997 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]998 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]999 </tbody>
1000 </table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1001 </td>
1002 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1003</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1004</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1005
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1006<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1007<div class="doc_subsubsection"> <a name="t_classifications">Type
1008Classifications</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1009<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1010<p>These different primitive types fall into a few useful
1011classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1012
1013<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1014 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1015 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1016 <tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1017 <td><a name="t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1018 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1019 </tr>
1020 <tr>
1021 <td><a name="t_floating">floating point</a></td>
1022 <td><tt>float, double</tt></td>
1023 </tr>
1024 <tr>
1025 <td><a name="t_firstclass">first class</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1026 <td><tt>i1, ..., float, double, <br/>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1027 <a href="#t_pointer">pointer</a>,<a href="#t_vector">vector</a></tt>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1028 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1029 </tr>
1030 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1031</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1032
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1033<p>The <a href="#t_firstclass">first class</a> types are perhaps the
1034most important. Values of these types are the only ones which can be
1035produced by instructions, passed as arguments, or used as operands to
1036instructions. This means that all structures and arrays must be
1037manipulated either by pointer or by component.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1038</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1039
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1040<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1041<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1042
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1043<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1044
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1045<p>The real power in LLVM comes from the derived types in the system.
1046This is what allows a programmer to represent arrays, functions,
1047pointers, and other useful types. Note that these derived types may be
1048recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1049
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1050</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1051
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1052<!-- _______________________________________________________________________ -->
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1053<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1054
1055<div class="doc_text">
1056
1057<h5>Overview:</h5>
1058<p>The integer type is a very simple derived type that simply specifies an
1059arbitrary bit width for the integer type desired. Any bit width from 1 bit to
10602^23-1 (about 8 million) can be specified.</p>
1061
1062<h5>Syntax:</h5>
1063
1064<pre>
1065 iN
1066</pre>
1067
1068<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1069value.</p>
1070
1071<h5>Examples:</h5>
1072<table class="layout">
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1073 <tbody>
1074 <tr>
1075 <td><tt>i1</tt></td>
1076 <td>a single-bit integer.</td>
1077 </tr><tr>
1078 <td><tt>i32</tt></td>
1079 <td>a 32-bit integer.</td>
1080 </tr><tr>
1081 <td><tt>i1942652</tt></td>
1082 <td>a really big integer of over 1 million bits.</td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1083 </tr>
Chris Lattner9a2e3cb2007-12-18 06:18:21 +0000[diff] [blame]1084 </tbody>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1085</table>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1086</div>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1087
1088<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1089<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1090
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1091<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1092
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1093<h5>Overview:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1094
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1095<p>The array type is a very simple derived type that arranges elements
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1096sequentially in memory. The array type requires a size (number of
1097elements) and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1098
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1099<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1100
1101<pre>
1102 [&lt;# elements&gt; x &lt;elementtype&gt;]
1103</pre>
1104
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1105<p>The number of elements is a constant integer value; elementtype may
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1106be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1107
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1108<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1109<table class="layout">
1110 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1111 <td class="left"><tt>[40 x i32]</tt></td>
1112 <td class="left">Array of 40 32-bit integer values.</td>
1113 </tr>
1114 <tr class="layout">
1115 <td class="left"><tt>[41 x i32]</tt></td>
1116 <td class="left">Array of 41 32-bit integer values.</td>
1117 </tr>
1118 <tr class="layout">
1119 <td class="left"><tt>[4 x i8]</tt></td>
1120 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1121 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1122</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1123<p>Here are some examples of multidimensional arrays:</p>
1124<table class="layout">
1125 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1126 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1127 <td class="left">3x4 array of 32-bit integer values.</td>
1128 </tr>
1129 <tr class="layout">
1130 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1131 <td class="left">12x10 array of single precision floating point values.</td>
1132 </tr>
1133 <tr class="layout">
1134 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1135 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1136 </tr>
1137</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1138
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1139<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1140length array. Normally, accesses past the end of an array are undefined in
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1141LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
1142As a special case, however, zero length arrays are recognized to be variable
1143length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1144type "{ i32, [0 x float]}", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1145
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1146</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1147
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1148<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1149<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1150<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1151<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1152<p>The function type can be thought of as a function signature. It
1153consists of a return type and a list of formal parameter types.
John Criswella0d50d22003-11-25 21:45:46 +0000[diff] [blame]1154Function types are usually used to build virtual function tables
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1155(which are structures of pointers to functions), for indirect function
1156calls, and when defining a function.</p>
John Criswella0d50d22003-11-25 21:45:46 +0000[diff] [blame]1157<p>
1158The return type of a function type cannot be an aggregate type.
1159</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1160<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1161<pre> &lt;returntype&gt; (&lt;parameter list&gt;)<br></pre>
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1162<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]1163specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1164which indicates that the function takes a variable number of arguments.
1165Variable argument functions can access their arguments with the <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1166 href="#int_varargs">variable argument handling intrinsic</a> functions.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1167<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1168<table class="layout">
1169 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1170 <td class="left"><tt>i32 (i32)</tt></td>
1171 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1172 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1173 </tr><tr class="layout">
Reid Spencer314e1cb2007-07-19 23:13:04 +0000[diff] [blame]1174 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1175 </tt></td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1176 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1177 an <tt>i16</tt> that should be sign extended and a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1178 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1179 <tt>float</tt>.
1180 </td>
1181 </tr><tr class="layout">
1182 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1183 <td class="left">A vararg function that takes at least one
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1184 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1185 which returns an integer. This is the signature for <tt>printf</tt> in
1186 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1187 </td>
1188 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1189</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1190
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1191</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1192<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1193<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1194<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1195<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1196<p>The structure type is used to represent a collection of data members
1197together in memory. The packing of the field types is defined to match
1198the ABI of the underlying processor. The elements of a structure may
1199be any type that has a size.</p>
1200<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1201and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1202field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1203instruction.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1204<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1205<pre> { &lt;type list&gt; }<br></pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1206<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1207<table class="layout">
1208 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1209 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1210 <td class="left">A triple of three <tt>i32</tt> values</td>
1211 </tr><tr class="layout">
1212 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1213 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1214 second element is a <a href="#t_pointer">pointer</a> to a
1215 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1216 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1217 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1218</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1219</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1220
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1221<!-- _______________________________________________________________________ -->
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1222<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1223</div>
1224<div class="doc_text">
1225<h5>Overview:</h5>
1226<p>The packed structure type is used to represent a collection of data members
1227together in memory. There is no padding between fields. Further, the alignment
1228of a packed structure is 1 byte. The elements of a packed structure may
1229be any type that has a size.</p>
1230<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
1231and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
1232field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
1233instruction.</p>
1234<h5>Syntax:</h5>
1235<pre> &lt; { &lt;type list&gt; } &gt; <br></pre>
1236<h5>Examples:</h5>
1237<table class="layout">
1238 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1239 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1240 <td class="left">A triple of three <tt>i32</tt> values</td>
1241 </tr><tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1242 <td class="left"><tt>&lt; { float, i32 (i32)* } &gt;</tt></td>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1243 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1244 second element is a <a href="#t_pointer">pointer</a> to a
1245 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1246 an <tt>i32</tt>.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1247 </tr>
1248</table>
1249</div>
1250
1251<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1252<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1253<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1254<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1255<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]1256reference to another object, which must live in memory. Pointer types may have
1257an optional address space attribute defining the target-specific numbered
1258address space where the pointed-to object resides. The default address space is
1259zero.</p>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1260<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1261<pre> &lt;type&gt; *<br></pre>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1262<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1263<table class="layout">
1264 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1265 <td class="left"><tt>[4x i32]*</tt></td>
1266 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1267 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1268 </tr>
1269 <tr class="layout">
1270 <td class="left"><tt>i32 (i32 *) *</tt></td>
1271 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1272 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1273 <tt>i32</tt>.</td>
1274 </tr>
1275 <tr class="layout">
1276 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1277 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1278 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1279 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1280</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1281</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1282
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1283<!-- _______________________________________________________________________ -->
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1284<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1285<div class="doc_text">
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1286
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1287<h5>Overview:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1288
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1289<p>A vector type is a simple derived type that represents a vector
1290of elements. Vector types are used when multiple primitive data
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1291are operated in parallel using a single instruction (SIMD).
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1292A vector type requires a size (number of
Chris Lattner330ce692005-11-10 01:44:22 +0000[diff] [blame]1293elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1294of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1295considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1296
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1297<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1298
1299<pre>
1300 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1301</pre>
1302
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1303<p>The number of elements is a constant integer value; elementtype may
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]1304be any integer or floating point type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1305
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1306<h5>Examples:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1307
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1308<table class="layout">
1309 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1310 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1311 <td class="left">Vector of 4 32-bit integer values.</td>
1312 </tr>
1313 <tr class="layout">
1314 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1315 <td class="left">Vector of 8 32-bit floating-point values.</td>
1316 </tr>
1317 <tr class="layout">
1318 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1319 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1320 </tr>
1321</table>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1322</div>
1323
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1324<!-- _______________________________________________________________________ -->
1325<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1326<div class="doc_text">
1327
1328<h5>Overview:</h5>
1329
1330<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksena699c4d2007-10-14 00:34:53 +0000[diff] [blame]1331corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1332In LLVM, opaque types can eventually be resolved to any type (not just a
1333structure type).</p>
1334
1335<h5>Syntax:</h5>
1336
1337<pre>
1338 opaque
1339</pre>
1340
1341<h5>Examples:</h5>
1342
1343<table class="layout">
1344 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1345 <td class="left"><tt>opaque</tt></td>
1346 <td class="left">An opaque type.</td>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1347 </tr>
1348</table>
1349</div>
1350
1351
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1352<!-- *********************************************************************** -->
1353<div class="doc_section"> <a name="constants">Constants</a> </div>
1354<!-- *********************************************************************** -->
1355
1356<div class="doc_text">
1357
1358<p>LLVM has several different basic types of constants. This section describes
1359them all and their syntax.</p>
1360
1361</div>
1362
1363<!-- ======================================================================= -->
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1364<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1365
1366<div class="doc_text">
1367
1368<dl>
1369 <dt><b>Boolean constants</b></dt>
1370
1371 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1372 constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1373 </dd>
1374
1375 <dt><b>Integer constants</b></dt>
1376
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1377 <dd>Standard integers (such as '4') are constants of the <a
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]1378 href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1379 integer types.
1380 </dd>
1381
1382 <dt><b>Floating point constants</b></dt>
1383
1384 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
1385 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1386 notation (see below). Floating point constants must have a <a
1387 href="#t_floating">floating point</a> type. </dd>
1388
1389 <dt><b>Null pointer constants</b></dt>
1390
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1391 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1392 and must be of <a href="#t_pointer">pointer type</a>.</dd>
1393
1394</dl>
1395
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1396<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1397of floating point constants. For example, the form '<tt>double
13980x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
13994.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]1400(and the only time that they are generated by the disassembler) is when a
1401floating point constant must be emitted but it cannot be represented as a
1402decimal floating point number. For example, NaN's, infinities, and other
1403special values are represented in their IEEE hexadecimal format so that
1404assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1405
1406</div>
1407
1408<!-- ======================================================================= -->
1409<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
1410</div>
1411
1412<div class="doc_text">
Chris Lattner455fc8c2005-03-07 22:13:59 +0000[diff] [blame]1413<p>Aggregate constants arise from aggregation of simple constants
1414and smaller aggregate constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1415
1416<dl>
1417 <dt><b>Structure constants</b></dt>
1418
1419 <dd>Structure constants are represented with notation similar to structure
1420 type definitions (a comma separated list of elements, surrounded by braces
Chris Lattnerbea11172007-12-25 20:34:52 +0000[diff] [blame]1421 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1422 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]1423 must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1424 types of elements must match those specified by the type.
1425 </dd>
1426
1427 <dt><b>Array constants</b></dt>
1428
1429 <dd>Array constants are represented with notation similar to array type
1430 definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1431 (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1432 constants must have <a href="#t_array">array type</a>, and the number and
1433 types of elements must match those specified by the type.
1434 </dd>
1435
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1436 <dt><b>Vector constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1437
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1438 <dd>Vector constants are represented with notation similar to vector type
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1439 definitions (a comma separated list of elements, surrounded by
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1440 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]1441 i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must have <a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1442 href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1443 match those specified by the type.
1444 </dd>
1445
1446 <dt><b>Zero initialization</b></dt>
1447
1448 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
1449 value to zero of <em>any</em> type, including scalar and aggregate types.
1450 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]1451 large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1452 initializers.
1453 </dd>
1454</dl>
1455
1456</div>
1457
1458<!-- ======================================================================= -->
1459<div class="doc_subsection">
1460 <a name="globalconstants">Global Variable and Function Addresses</a>
1461</div>
1462
1463<div class="doc_text">
1464
1465<p>The addresses of <a href="#globalvars">global variables</a> and <a
1466href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1467constants. These constants are explicitly referenced when the <a
1468href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1469href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
1470file:</p>
1471
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1472<div class="doc_code">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1473<pre>
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]1474@X = global i32 17
1475@Y = global i32 42
1476@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1477</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1478</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1479
1480</div>
1481
1482<!-- ======================================================================= -->
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1483<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1484<div class="doc_text">
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1485 <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]1486 no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1487 a constant is permitted.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1488
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1489 <p>Undefined values indicate to the compiler that the program is well defined
1490 no matter what value is used, giving the compiler more freedom to optimize.
1491 </p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1492</div>
1493
1494<!-- ======================================================================= -->
1495<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
1496</div>
1497
1498<div class="doc_text">
1499
1500<p>Constant expressions are used to allow expressions involving other constants
1501to be used as constants. Constant expressions may be of any <a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1502href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1503that does not have side effects (e.g. load and call are not supported). The
1504following is the syntax for constant expressions:</p>
1505
1506<dl>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1507 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
1508 <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]1509 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1510
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1511 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
1512 <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]1513 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]1514
1515 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
1516 <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]1517 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]1518
1519 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
1520 <dd>Truncate a floating point constant to another floating point type. The
1521 size of CST must be larger than the size of TYPE. Both types must be
1522 floating point.</dd>
1523
1524 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
1525 <dd>Floating point extend a constant to another type. The size of CST must be
1526 smaller or equal to the size of TYPE. Both types must be floating point.</dd>
1527
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]1528 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1529 <dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1530 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1531 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1532 of the same number of elements. If the value won't fit in the integer type,
1533 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1534
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1535 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1536 <dd>Convert a floating point constant to the corresponding signed integer
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1537 constant. TYPE must be a scalar or vector integer type. CST must be of scalar
1538 or vector floating point type. Both CST and TYPE must be scalars, or vectors
1539 of the same number of elements. If the value won't fit in the integer type,
1540 the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1541
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1542 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1543 <dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1544 constant. TYPE must be a scalar or vector floating point type. CST must be of
1545 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1546 of the same number of elements. If the value won't fit in the floating point
1547 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1548
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]1549 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1550 <dd>Convert a signed integer constant to the corresponding floating point
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]1551 constant. TYPE must be a scalar or vector floating point type. CST must be of
1552 scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
1553 of the same number of elements. If the value won't fit in the floating point
1554 type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1555
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]1556 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
1557 <dd>Convert a pointer typed constant to the corresponding integer constant
1558 TYPE must be an integer type. CST must be of pointer type. The CST value is
1559 zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
1560
1561 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
1562 <dd>Convert a integer constant to a pointer constant. TYPE must be a
1563 pointer type. CST must be of integer type. The CST value is zero extended,
1564 truncated, or unchanged to make it fit in a pointer size. This one is
1565 <i>really</i> dangerous!</dd>
1566
1567 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1568 <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
1569 identical (same number of bits). The conversion is done as if the CST value
1570 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]1571 with this operator, just the type. This can be used for conversion of
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1572 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]1573 pointers it is only valid to cast to another pointer type.
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]1574 </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1575
1576 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
1577
1578 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
1579 constants. As with the <a href="#i_getelementptr">getelementptr</a>
1580 instruction, the index list may have zero or more indexes, which are required
1581 to make sense for the type of "CSTPTR".</dd>
1582
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1583 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
1584
1585 <dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1586 constants.</dd>
1587
1588 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
1589 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
1590
1591 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
1592 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]1593
1594 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
1595
1596 <dd>Perform the <a href="#i_extractelement">extractelement
1597 operation</a> on constants.
1598
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1599 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
1600
1601 <dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1602 operation</a> on constants.</dd>
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]1603
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1604
1605 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
1606
1607 <dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]1608 operation</a> on constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]1609
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1610 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
1611
Reid Spencer641f5c92004-12-09 18:13:12 +0000[diff] [blame]1612 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
1613 be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1614 binary</a> operations. The constraints on operands are the same as those for
1615 the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1616 values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1617</dl>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1618</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]1619
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1620<!-- *********************************************************************** -->
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1621<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
1622<!-- *********************************************************************** -->
1623
1624<!-- ======================================================================= -->
1625<div class="doc_subsection">
1626<a name="inlineasm">Inline Assembler Expressions</a>
1627</div>
1628
1629<div class="doc_text">
1630
1631<p>
1632LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
1633Module-Level Inline Assembly</a>) through the use of a special value. This
1634value represents the inline assembler as a string (containing the instructions
1635to emit), a list of operand constraints (stored as a string), and a flag that
1636indicates whether or not the inline asm expression has side effects. An example
1637inline assembler expression is:
1638</p>
1639
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1640<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1641<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1642i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1643</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1644</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1645
1646<p>
1647Inline assembler expressions may <b>only</b> be used as the callee operand of
1648a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
1649</p>
1650
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1651<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1652<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1653%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]1654</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1655</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1656
1657<p>
1658Inline asms with side effects not visible in the constraint list must be marked
1659as having side effects. This is done through the use of the
1660'<tt>sideeffect</tt>' keyword, like so:
1661</p>
1662
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1663<div class="doc_code">
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1664<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1665call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1666</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1667</div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]1668
1669<p>TODO: The format of the asm and constraints string still need to be
1670documented here. Constraints on what can be done (e.g. duplication, moving, etc
1671need to be documented).
1672</p>
1673
1674</div>
1675
1676<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1677<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
1678<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1679
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1680<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1681
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1682<p>The LLVM instruction set consists of several different
1683classifications of instructions: <a href="#terminators">terminator
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1684instructions</a>, <a href="#binaryops">binary instructions</a>,
1685<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1686 href="#memoryops">memory instructions</a>, and <a href="#otherops">other
1687instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1688
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1689</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1690
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1691<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1692<div class="doc_subsection"> <a name="terminators">Terminator
1693Instructions</a> </div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1694
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1695<div class="doc_text">
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1696
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1697<p>As mentioned <a href="#functionstructure">previously</a>, every
1698basic block in a program ends with a "Terminator" instruction, which
1699indicates which block should be executed after the current block is
1700finished. These terminator instructions typically yield a '<tt>void</tt>'
1701value: they produce control flow, not values (the one exception being
1702the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1703<p>There are six different terminator instructions: the '<a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1704 href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
1705instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1706the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
1707 href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
1708 href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1709
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1710</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1711
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1712<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1713<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
1714Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1715<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1716<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1717<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]1718 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1719</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1720<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1721<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]1722value) from a function back to the caller.</p>
John Criswell417228d2004-04-09 16:48:45 +0000[diff] [blame]1723<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1724returns a value and then causes control flow, and one that just causes
1725control flow to occur.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1726<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1727<p>The '<tt>ret</tt>' instruction may return any '<a
1728 href="#t_firstclass">first class</a>' type. Notice that a function is
1729not <a href="#wellformed">well formed</a> if there exists a '<tt>ret</tt>'
1730instruction inside of the function that returns a value that does not
1731match the return type of the function.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1732<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1733<p>When the '<tt>ret</tt>' instruction is executed, control flow
1734returns back to the calling function's context. If the caller is a "<a
John Criswell40db33f2004-06-25 15:16:57 +0000[diff] [blame]1735 href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1736the instruction after the call. If the caller was an "<a
1737 href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1738at the beginning of the "normal" destination block. If the instruction
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1739returns a value, that value shall set the call or invoke instruction's
1740return value.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1741<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1742<pre> ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1743 ret void <i>; Return from a void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1744</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1745</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1746<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1747<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1748<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1749<h5>Syntax:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1750<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]1751</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1752<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1753<p>The '<tt>br</tt>' instruction is used to cause control flow to
1754transfer to a different basic block in the current function. There are
1755two forms of this instruction, corresponding to a conditional branch
1756and an unconditional branch.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1757<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1758<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1759single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1760unconditional form of the '<tt>br</tt>' instruction takes a single
1761'<tt>label</tt>' value as a target.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1762<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1763<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1764argument is evaluated. If the value is <tt>true</tt>, control flows
1765to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
1766control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1767<h5>Example:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1768<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]1769 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]1770</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1771<!-- _______________________________________________________________________ -->
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1772<div class="doc_subsubsection">
1773 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
1774</div>
1775
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1776<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1777<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1778
1779<pre>
1780 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
1781</pre>
1782
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1783<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1784
1785<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
1786several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1787instruction, allowing a branch to occur to one of many possible
1788destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1789
1790
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1791<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1792
1793<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
1794comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
1795an array of pairs of comparison value constants and '<tt>label</tt>'s. The
1796table is not allowed to contain duplicate constant entries.</p>
1797
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1798<h5>Semantics:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1799
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1800<p>The <tt>switch</tt> instruction specifies a table of values and
1801destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]1802table is searched for the given value. If the value is found, control flow is
1803transfered to the corresponding destination; otherwise, control flow is
1804transfered to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1805
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1806<h5>Implementation:</h5>
1807
1808<p>Depending on properties of the target machine and the particular
1809<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswellbcbb18c2004-06-25 16:05:06 +0000[diff] [blame]1810ways. For example, it could be generated as a series of chained conditional
1811branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1812
1813<h5>Example:</h5>
1814
1815<pre>
1816 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]1817 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1818 switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1819
1820 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1821 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]1822
1823 <i>; Implement a jump table:</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1824 switch i32 %val, label %otherwise [ i32 0, label %onzero
1825 i32 1, label %onone
1826 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1827</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1828</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1829
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1830<!-- _______________________________________________________________________ -->
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1831<div class="doc_subsubsection">
1832 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
1833</div>
1834
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1835<div class="doc_text">
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1836
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1837<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1838
1839<pre>
1840 &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]1841 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1842</pre>
1843
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]1844<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1845
1846<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
1847function, with the possibility of control flow transfer to either the
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1848'<tt>normal</tt>' label or the
1849'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1850"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
1851"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell02fdc6f2005-05-12 16:52:32 +0000[diff] [blame]1852href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
1853continued at the dynamically nearest "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1854
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1855<h5>Arguments:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1856
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1857<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1858
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1859<ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1860 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]1861 The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1862 convention</a> the call should use. If none is specified, the call defaults
1863 to using C calling conventions.
1864 </li>
1865 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
1866 function value being invoked. In most cases, this is a direct function
1867 invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
1868 an arbitrary pointer to function value.
1869 </li>
1870
1871 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
1872 function to be invoked. </li>
1873
1874 <li>'<tt>function args</tt>': argument list whose types match the function
1875 signature argument types. If the function signature indicates the function
1876 accepts a variable number of arguments, the extra arguments can be
1877 specified. </li>
1878
1879 <li>'<tt>normal label</tt>': the label reached when the called function
1880 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
1881
1882 <li>'<tt>exception label</tt>': the label reached when a callee returns with
1883 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
1884
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1885</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1886
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1887<h5>Semantics:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1888
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1889<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1890href="#i_call">call</a></tt>' instruction in most regards. The primary
1891difference is that it establishes an association with a label, which is used by
1892the runtime library to unwind the stack.</p>
1893
1894<p>This instruction is used in languages with destructors to ensure that proper
1895cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
1896exception. Additionally, this is important for implementation of
1897'<tt>catch</tt>' clauses in high-level languages that support them.</p>
1898
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1899<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]1900<pre>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1901 %retval = invoke i32 %Test(i32 15) to label %Continue
1902 unwind label %TestCleanup <i>; {i32}:retval set</i>
1903 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Test(i32 15) to label %Continue
1904 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1905</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1906</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1907
1908
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1909<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1910
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1911<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
1912Instruction</a> </div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1913
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1914<div class="doc_text">
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1915
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1916<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1917<pre>
1918 unwind
1919</pre>
1920
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1921<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1922
1923<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
1924at the first callee in the dynamic call stack which used an <a
1925href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
1926primarily used to implement exception handling.</p>
1927
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]1928<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1929
1930<p>The '<tt>unwind</tt>' intrinsic causes execution of the current function to
1931immediately halt. The dynamic call stack is then searched for the first <a
1932href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
1933execution continues at the "exceptional" destination block specified by the
1934<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
1935dynamic call chain, undefined behavior results.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1936</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]1937
1938<!-- _______________________________________________________________________ -->
1939
1940<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
1941Instruction</a> </div>
1942
1943<div class="doc_text">
1944
1945<h5>Syntax:</h5>
1946<pre>
1947 unreachable
1948</pre>
1949
1950<h5>Overview:</h5>
1951
1952<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
1953instruction is used to inform the optimizer that a particular portion of the
1954code is not reachable. This can be used to indicate that the code after a
1955no-return function cannot be reached, and other facts.</p>
1956
1957<h5>Semantics:</h5>
1958
1959<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
1960</div>
1961
1962
1963
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1964<!-- ======================================================================= -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1965<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1966<div class="doc_text">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1967<p>Binary operators are used to do most of the computation in a
1968program. They require two operands, execute an operation on them, and
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]1969produce a single value. The operands might represent
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1970multiple 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]1971The result value of a binary operator is not
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1972necessarily the same type as its operands.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1973<p>There are several different binary operators:</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1974</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1975<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1976<div class="doc_subsubsection"> <a name="i_add">'<tt>add</tt>'
1977Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1978<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1979<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1980<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]1981</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1982<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1983<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1984<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1985<p>The two arguments to the '<tt>add</tt>' instruction must be either <a
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1986 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a> values.
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]1987 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]1988Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1989<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1990<p>The value produced is the integer or floating point sum of the two
1991operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1992<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1993<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]1994</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1995</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1996<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1997<div class="doc_subsubsection"> <a name="i_sub">'<tt>sub</tt>'
1998Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1999<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2000<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2001<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]2002</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2003<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2004<p>The '<tt>sub</tt>' instruction returns the difference of its two
2005operands.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2006<p>Note that the '<tt>sub</tt>' instruction is used to represent the '<tt>neg</tt>'
2007instruction present in most other intermediate representations.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2008<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2009<p>The two arguments to the '<tt>sub</tt>' instruction must be either <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2010 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2011values.
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2012This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2013Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2014<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2015<p>The value produced is the integer or floating point difference of
2016the two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2017<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2018<pre>
2019 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2020 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2021</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2022</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2023<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2024<div class="doc_subsubsection"> <a name="i_mul">'<tt>mul</tt>'
2025Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2026<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2027<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2028<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]2029</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2030<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2031<p>The '<tt>mul</tt>' instruction returns the product of its two
2032operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2033<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2034<p>The two arguments to the '<tt>mul</tt>' instruction must be either <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2035 href="#t_integer">integer</a> or <a href="#t_floating">floating point</a>
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2036values.
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2037This instruction can also take <a href="#t_vector">vector</a> versions of the values.
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]2038Both arguments must have identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2039<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2040<p>The value produced is the integer or floating point product of the
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2041two operands.</p>
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]2042<p>Because the operands are the same width, the result of an integer
2043multiplication is the same whether the operands should be deemed unsigned or
2044signed.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2045<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2046<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]2047</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2048</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2049<!-- _______________________________________________________________________ -->
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2050<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2051</a></div>
2052<div class="doc_text">
2053<h5>Syntax:</h5>
2054<pre> &lt;result&gt; = udiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2055</pre>
2056<h5>Overview:</h5>
2057<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
2058operands.</p>
2059<h5>Arguments:</h5>
2060<p>The two arguments to the '<tt>udiv</tt>' instruction must be
2061<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2062types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2063of the values in which case the elements must be integers.</p>
2064<h5>Semantics:</h5>
2065<p>The value produced is the unsigned integer quotient of the two operands. This
2066instruction always performs an unsigned division operation, regardless of
2067whether the arguments are unsigned or not.</p>
2068<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2069<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]2070</pre>
2071</div>
2072<!-- _______________________________________________________________________ -->
2073<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2074</a> </div>
2075<div class="doc_text">
2076<h5>Syntax:</h5>
2077<pre> &lt;result&gt; = sdiv &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2078</pre>
2079<h5>Overview:</h5>
2080<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
2081operands.</p>
2082<h5>Arguments:</h5>
2083<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
2084<a href="#t_integer">integer</a> values. Both arguments must have identical
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2085types. This instruction can also take <a href="#t_vector">vector</a> versions
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2086of the values in which case the elements must be integers.</p>
2087<h5>Semantics:</h5>
2088<p>The value produced is the signed integer quotient of the two operands. This
2089instruction always performs a signed division operation, regardless of whether
2090the arguments are signed or not.</p>
2091<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2092<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]2093</pre>
2094</div>
2095<!-- _______________________________________________________________________ -->
2096<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2097Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2098<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2099<h5>Syntax:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2100<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]2101</pre>
2102<h5>Overview:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2103<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2104operands.</p>
2105<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2106<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2107<a href="#t_floating">floating point</a> values. Both arguments must have
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2108identical types. This instruction can also take <a href="#t_vector">vector</a>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2109versions of floating point values.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2110<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2111<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2112<h5>Example:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]2113<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]2114</pre>
2115</div>
2116<!-- _______________________________________________________________________ -->
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2117<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
2118</div>
2119<div class="doc_text">
2120<h5>Syntax:</h5>
2121<pre> &lt;result&gt; = urem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2122</pre>
2123<h5>Overview:</h5>
2124<p>The '<tt>urem</tt>' instruction returns the remainder from the
2125unsigned division of its two arguments.</p>
2126<h5>Arguments:</h5>
2127<p>The two arguments to the '<tt>urem</tt>' instruction must be
2128<a href="#t_integer">integer</a> values. Both arguments must have identical
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame]2129types. This instruction can also take <a href="#t_vector">vector</a> versions
2130of the values in which case the elements must be integers.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2131<h5>Semantics:</h5>
2132<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
2133This instruction always performs an unsigned division to get the remainder,
2134regardless of whether the arguments are unsigned or not.</p>
2135<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2136<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]2137</pre>
2138
2139</div>
2140<!-- _______________________________________________________________________ -->
2141<div class="doc_subsubsection"> <a name="i_srem">'<tt>srem</tt>'
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2142Instruction</a> </div>
2143<div class="doc_text">
2144<h5>Syntax:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2145<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]2146</pre>
2147<h5>Overview:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2148<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame]2149signed division of its two operands. This instruction can also take
2150<a href="#t_vector">vector</a> versions of the values in which case
2151the elements must be integers.</p>
2152</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2153<h5>Arguments:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2154<p>The two arguments to the '<tt>srem</tt>' instruction must be
2155<a href="#t_integer">integer</a> values. Both arguments must have identical
2156types.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2157<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2158<p>This instruction returns the <i>remainder</i> of a division (where the result
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2159has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
2160operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
2161a value. For more information about the difference, see <a
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2162 href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2163Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencerdb3b93b2007-03-24 22:40:44 +0000[diff] [blame]2164please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer806ad6a2007-03-24 22:23:39 +0000[diff] [blame]2165Wikipedia: modulo operation</a>.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2166<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2167<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]2168</pre>
2169
2170</div>
2171<!-- _______________________________________________________________________ -->
2172<div class="doc_subsubsection"> <a name="i_frem">'<tt>frem</tt>'
2173Instruction</a> </div>
2174<div class="doc_text">
2175<h5>Syntax:</h5>
2176<pre> &lt;result&gt; = frem &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2177</pre>
2178<h5>Overview:</h5>
2179<p>The '<tt>frem</tt>' instruction returns the remainder from the
2180division of its two operands.</p>
2181<h5>Arguments:</h5>
2182<p>The two arguments to the '<tt>frem</tt>' instruction must be
2183<a href="#t_floating">floating point</a> values. Both arguments must have
Dan Gohman08143e32007-11-05 23:35:22 +0000[diff] [blame]2184identical types. This instruction can also take <a href="#t_vector">vector</a>
2185versions of floating point values.</p>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]2186<h5>Semantics:</h5>
2187<p>This instruction returns the <i>remainder</i> of a division.</p>
2188<h5>Example:</h5>
2189<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]2190</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2191</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]2192
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2193<!-- ======================================================================= -->
2194<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
2195Operations</a> </div>
2196<div class="doc_text">
2197<p>Bitwise binary operators are used to do various forms of
2198bit-twiddling in a program. They are generally very efficient
2199instructions and can commonly be strength reduced from other
2200instructions. They require two operands, execute an operation on them,
2201and produce a single value. The resulting value of the bitwise binary
2202operators is always the same type as its first operand.</p>
2203</div>
2204
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2205<!-- _______________________________________________________________________ -->
2206<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
2207Instruction</a> </div>
2208<div class="doc_text">
2209<h5>Syntax:</h5>
2210<pre> &lt;result&gt; = shl &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2211</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2212
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2213<h5>Overview:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2214
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2215<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
2216the left a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2217
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2218<h5>Arguments:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2219
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2220<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
2221 href="#t_integer">integer</a> type.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2222
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2223<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2224
2225<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup>. If
2226<tt>var2</tt> is (statically or dynamically) equal to or larger than the number
2227of bits in <tt>var1</tt>, the result is undefined.</p>
2228
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2229<h5>Example:</h5><pre>
2230 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
2231 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
2232 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2233 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2234</pre>
2235</div>
2236<!-- _______________________________________________________________________ -->
2237<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
2238Instruction</a> </div>
2239<div class="doc_text">
2240<h5>Syntax:</h5>
2241<pre> &lt;result&gt; = lshr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2242</pre>
2243
2244<h5>Overview:</h5>
2245<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2246operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2247
2248<h5>Arguments:</h5>
2249<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
2250<a href="#t_integer">integer</a> type.</p>
2251
2252<h5>Semantics:</h5>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2253
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2254<p>This instruction always performs a logical shift right operation. The most
2255significant bits of the result will be filled with zero bits after the
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2256shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
2257the number of bits in <tt>var1</tt>, the result is undefined.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2258
2259<h5>Example:</h5>
2260<pre>
2261 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
2262 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
2263 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
2264 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2265 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2266</pre>
2267</div>
2268
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]2269<!-- _______________________________________________________________________ -->
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2270<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
2271Instruction</a> </div>
2272<div class="doc_text">
2273
2274<h5>Syntax:</h5>
2275<pre> &lt;result&gt; = ashr &lt;ty&gt; &lt;var1&gt;, &lt;var2&gt; <i>; yields {ty}:result</i>
2276</pre>
2277
2278<h5>Overview:</h5>
2279<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2280operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2281
2282<h5>Arguments:</h5>
2283<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
2284<a href="#t_integer">integer</a> type.</p>
2285
2286<h5>Semantics:</h5>
2287<p>This instruction always performs an arithmetic shift right operation,
2288The most significant bits of the result will be filled with the sign bit
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2289of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
2290larger than the number of bits in <tt>var1</tt>, the result is undefined.
2291</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2292
2293<h5>Example:</h5>
2294<pre>
2295 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
2296 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
2297 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
2298 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]2299 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]2300</pre>
2301</div>
2302
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2303<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2304<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
2305Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2306<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2307<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2308<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]2309</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2310<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2311<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
2312its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2313<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2314<p>The two arguments to the '<tt>and</tt>' instruction must be <a
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]2315 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2316identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2317<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2318<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2319<p> </p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2320<div style="align: center">
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2321<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2322 <tbody>
2323 <tr>
2324 <td>In0</td>
2325 <td>In1</td>
2326 <td>Out</td>
2327 </tr>
2328 <tr>
2329 <td>0</td>
2330 <td>0</td>
2331 <td>0</td>
2332 </tr>
2333 <tr>
2334 <td>0</td>
2335 <td>1</td>
2336 <td>0</td>
2337 </tr>
2338 <tr>
2339 <td>1</td>
2340 <td>0</td>
2341 <td>0</td>
2342 </tr>
2343 <tr>
2344 <td>1</td>
2345 <td>1</td>
2346 <td>1</td>
2347 </tr>
2348 </tbody>
2349</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2350</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2351<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2352<pre> &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
2353 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
2354 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2355</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2356</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2357<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2358<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2359<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2360<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2361<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]2362</pre>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2363<h5>Overview:</h5>
2364<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
2365or of its two operands.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2366<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2367<p>The two arguments to the '<tt>or</tt>' instruction must be <a
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]2368 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2369identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2370<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2371<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2372<p> </p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2373<div style="align: center">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2374<table border="1" cellspacing="0" cellpadding="4">
2375 <tbody>
2376 <tr>
2377 <td>In0</td>
2378 <td>In1</td>
2379 <td>Out</td>
2380 </tr>
2381 <tr>
2382 <td>0</td>
2383 <td>0</td>
2384 <td>0</td>
2385 </tr>
2386 <tr>
2387 <td>0</td>
2388 <td>1</td>
2389 <td>1</td>
2390 </tr>
2391 <tr>
2392 <td>1</td>
2393 <td>0</td>
2394 <td>1</td>
2395 </tr>
2396 <tr>
2397 <td>1</td>
2398 <td>1</td>
2399 <td>1</td>
2400 </tr>
2401 </tbody>
2402</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2403</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2404<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2405<pre> &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
2406 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
2407 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2408</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2409</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2410<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2411<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
2412Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2413<div class="doc_text">
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2414<h5>Syntax:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2415<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]2416</pre>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2417<h5>Overview:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2418<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
2419or of its two operands. The <tt>xor</tt> is used to implement the
2420"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2421<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2422<p>The two arguments to the '<tt>xor</tt>' instruction must be <a
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]2423 href="#t_integer">integer</a> values. Both arguments must have
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2424identical types.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2425<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2426<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2427<p> </p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2428<div style="align: center">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2429<table border="1" cellspacing="0" cellpadding="4">
2430 <tbody>
2431 <tr>
2432 <td>In0</td>
2433 <td>In1</td>
2434 <td>Out</td>
2435 </tr>
2436 <tr>
2437 <td>0</td>
2438 <td>0</td>
2439 <td>0</td>
2440 </tr>
2441 <tr>
2442 <td>0</td>
2443 <td>1</td>
2444 <td>1</td>
2445 </tr>
2446 <tr>
2447 <td>1</td>
2448 <td>0</td>
2449 <td>1</td>
2450 </tr>
2451 <tr>
2452 <td>1</td>
2453 <td>1</td>
2454 <td>0</td>
2455 </tr>
2456 </tbody>
2457</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]2458</div>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2459<p> </p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2460<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2461<pre> &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
2462 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
2463 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
2464 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2465</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2466</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2467
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2468<!-- ======================================================================= -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2469<div class="doc_subsection">
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2470 <a name="vectorops">Vector Operations</a>
2471</div>
2472
2473<div class="doc_text">
2474
2475<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2476target-independent manner. These instructions cover the element-access and
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2477vector-specific operations needed to process vectors effectively. While LLVM
2478does directly support these vector operations, many sophisticated algorithms
2479will want to use target-specific intrinsics to take full advantage of a specific
2480target.</p>
2481
2482</div>
2483
2484<!-- _______________________________________________________________________ -->
2485<div class="doc_subsubsection">
2486 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
2487</div>
2488
2489<div class="doc_text">
2490
2491<h5>Syntax:</h5>
2492
2493<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2494 &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]2495</pre>
2496
2497<h5>Overview:</h5>
2498
2499<p>
2500The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2501element from a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2502</p>
2503
2504
2505<h5>Arguments:</h5>
2506
2507<p>
2508The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2509value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2510an index indicating the position from which to extract the element.
2511The index may be a variable.</p>
2512
2513<h5>Semantics:</h5>
2514
2515<p>
2516The result is a scalar of the same type as the element type of
2517<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
2518<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
2519results are undefined.
2520</p>
2521
2522<h5>Example:</h5>
2523
2524<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2525 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2526</pre>
2527</div>
2528
2529
2530<!-- _______________________________________________________________________ -->
2531<div class="doc_subsubsection">
2532 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
2533</div>
2534
2535<div class="doc_text">
2536
2537<h5>Syntax:</h5>
2538
2539<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2540 &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]2541</pre>
2542
2543<h5>Overview:</h5>
2544
2545<p>
2546The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2547element into a vector at a specified index.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2548</p>
2549
2550
2551<h5>Arguments:</h5>
2552
2553<p>
2554The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2555value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2556scalar value whose type must equal the element type of the first
2557operand. The third operand is an index indicating the position at
2558which to insert the value. The index may be a variable.</p>
2559
2560<h5>Semantics:</h5>
2561
2562<p>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2563The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2564element values are those of <tt>val</tt> except at position
2565<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
2566exceeds the length of <tt>val</tt>, the results are undefined.
2567</p>
2568
2569<h5>Example:</h5>
2570
2571<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2572 %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]2573</pre>
2574</div>
2575
2576<!-- _______________________________________________________________________ -->
2577<div class="doc_subsubsection">
2578 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
2579</div>
2580
2581<div class="doc_text">
2582
2583<h5>Syntax:</h5>
2584
2585<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2586 &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]2587</pre>
2588
2589<h5>Overview:</h5>
2590
2591<p>
2592The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
2593from two input vectors, returning a vector of the same type.
2594</p>
2595
2596<h5>Arguments:</h5>
2597
2598<p>
2599The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
2600with types that match each other and types that match the result of the
2601instruction. The third argument is a shuffle mask, which has the same number
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2602of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2603</p>
2604
2605<p>
2606The shuffle mask operand is required to be a constant vector with either
2607constant integer or undef values.
2608</p>
2609
2610<h5>Semantics:</h5>
2611
2612<p>
2613The elements of the two input vectors are numbered from left to right across
2614both of the vectors. The shuffle mask operand specifies, for each element of
2615the result vector, which element of the two input registers the result element
2616gets. The element selector may be undef (meaning "don't care") and the second
2617operand may be undef if performing a shuffle from only one vector.
2618</p>
2619
2620<h5>Example:</h5>
2621
2622<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2623 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2624 &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]2625 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
2626 &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]2627</pre>
2628</div>
2629
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]2630
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]2631<!-- ======================================================================= -->
2632<div class="doc_subsection">
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]2633 <a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2634</div>
2635
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2636<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2637
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2638<p>A key design point of an SSA-based representation is how it
2639represents memory. In LLVM, no memory locations are in SSA form, which
2640makes things very simple. This section describes how to read, write,
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2641allocate, and free memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2642
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2643</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2644
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2645<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2646<div class="doc_subsubsection">
2647 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
2648</div>
2649
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2650<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2651
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2652<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2653
2654<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2655 &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]2656</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2657
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2658<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2659
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2660<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]2661heap and returns a pointer to it. The object is always allocated in the generic
2662address space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2663
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2664<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2665
2666<p>The '<tt>malloc</tt>' instruction allocates
2667<tt>sizeof(&lt;type&gt;)*NumElements</tt>
John Criswella92e5862004-02-24 16:13:56 +0000[diff] [blame]2668bytes of memory from the operating system and returns a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2669appropriate type to the program. If "NumElements" is specified, it is the
2670number of elements allocated. If an alignment is specified, the value result
2671of the allocation is guaranteed to be aligned to at least that boundary. If
2672not specified, or if zero, the target can choose to align the allocation on any
2673convenient boundary.</p>
2674
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2675<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2676
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2677<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2678
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2679<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
2680a pointer is returned.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2681
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2682<h5>Example:</h5>
2683
2684<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2685 %array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2686
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]2687 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
2688 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
2689 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
2690 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
2691 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2692</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2693</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2694
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2695<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2696<div class="doc_subsubsection">
2697 <a name="i_free">'<tt>free</tt>' Instruction</a>
2698</div>
2699
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2700<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2701
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2702<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2703
2704<pre>
2705 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2706</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2707
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2708<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2709
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2710<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2711memory heap to be reallocated in the future.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2712
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2713<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2714
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2715<p>'<tt>value</tt>' shall be a pointer value that points to a value
2716that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
2717instruction.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2718
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2719<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2720
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2721<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2722after this instruction executes.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2723
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2724<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2725
2726<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2727 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
2728 free [4 x i8]* %array
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2729</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2730</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2731
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2732<!-- _______________________________________________________________________ -->
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2733<div class="doc_subsubsection">
2734 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
2735</div>
2736
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2737<div class="doc_text">
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2738
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2739<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2740
2741<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2742 &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]2743</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2744
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2745<h5>Overview:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2746
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2747<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
2748currently executing function, to be automatically released when this function
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]2749returns to its caller. The object is always allocated in the generic address
2750space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2751
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2752<h5>Arguments:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2753
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2754<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2755bytes of memory on the runtime stack, returning a pointer of the
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2756appropriate type to the program. If "NumElements" is specified, it is the
2757number of elements allocated. If an alignment is specified, the value result
2758of the allocation is guaranteed to be aligned to at least that boundary. If
2759not specified, or if zero, the target can choose to align the allocation on any
2760convenient boundary.</p>
2761
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2762<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2763
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2764<h5>Semantics:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2765
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2766<p>Memory is allocated; a pointer is returned. '<tt>alloca</tt>'d
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2767memory is automatically released when the function returns. The '<tt>alloca</tt>'
2768instruction is commonly used to represent automatic variables that must
2769have an address available. When the function returns (either with the <tt><a
John Criswellc932bef2005-05-12 16:55:34 +0000[diff] [blame]2770 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]2771instructions), the memory is reclaimed.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2772
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2773<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2774
2775<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2776 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2777 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
2778 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2779 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2780</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2781</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]2782
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2783<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2784<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
2785Instruction</a> </div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2786<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2787<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]2788<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]2789<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2790<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2791<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2792<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]2793address from which to load. The pointer must point to a <a
Chris Lattner10ee9652004-06-03 22:57:15 +0000[diff] [blame]2794 href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]2795marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2796the number or order of execution of this <tt>load</tt> with other
2797volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
2798instructions. </p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2799<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2800<p>The location of memory pointed to is loaded.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2801<h5>Examples:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2802<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2803 <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2804 href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
2805 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2806</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2807</div>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2808<!-- _______________________________________________________________________ -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2809<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
2810Instruction</a> </div>
Reid Spencera89fb182006-11-09 21:18:01 +0000[diff] [blame]2811<div class="doc_text">
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2812<h5>Syntax:</h5>
Christopher Lambbff50202007-04-21 08:16:25 +0000[diff] [blame]2813<pre> store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
2814 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]2815</pre>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2816<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2817<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2818<h5>Arguments:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2819<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2820to 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]2821operand must be a pointer to the type of the '<tt>&lt;value&gt;</tt>'
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2822operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2823optimizer is not allowed to modify the number or order of execution of
2824this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
2825 href="#i_store">store</a></tt> instructions.</p>
2826<h5>Semantics:</h5>
2827<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>'
2828at the location specified by the '<tt>&lt;pointer&gt;</tt>' operand.</p>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2829<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2830<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]2831 store i32 3, i32* %ptr <i>; yields {void}</i>
2832 %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]2833</pre>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]2834</div>
2835
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]2836<!-- _______________________________________________________________________ -->
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2837<div class="doc_subsubsection">
2838 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
2839</div>
2840
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2841<div class="doc_text">
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2842<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2843<pre>
2844 &lt;result&gt; = getelementptr &lt;ty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
2845</pre>
2846
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2847<h5>Overview:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2848
2849<p>
2850The '<tt>getelementptr</tt>' instruction is used to get the address of a
2851subelement of an aggregate data structure.</p>
2852
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2853<h5>Arguments:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2854
Reid Spencercee005c2006-12-04 21:29:24 +0000[diff] [blame]2855<p>This instruction takes a list of integer operands that indicate what
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2856elements of the aggregate object to index to. The actual types of the arguments
2857provided depend on the type of the first pointer argument. The
2858'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]2859levels 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]2860structure, only <tt>i32</tt> integer constants are allowed. When indexing
Reid Spencercee005c2006-12-04 21:29:24 +0000[diff] [blame]2861into an array or pointer, only integers of 32 or 64 bits are allowed, and will
2862be sign extended to 64-bit values.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2863
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2864<p>For example, let's consider a C code fragment and how it gets
2865compiled to LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2866
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2867<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2868<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2869struct RT {
2870 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]2871 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2872 char C;
2873};
2874struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]2875 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2876 double Y;
2877 struct RT Z;
2878};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2879
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]2880int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2881 return &amp;s[1].Z.B[5][13];
2882}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2883</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2884</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2885
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2886<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2887
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2888<div class="doc_code">
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2889<pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2890%RT = type { i8 , [10 x [20 x i32]], i8 }
2891%ST = type { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2892
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2893define i32* %foo(%ST* %s) {
2894entry:
2895 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
2896 ret i32* %reg
2897}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2898</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2899</div>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2900
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2901<h5>Semantics:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2902
2903<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell4a3327e2005-05-13 22:25:59 +0000[diff] [blame]2904on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencercee005c2006-12-04 21:29:24 +0000[diff] [blame]2905and <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]2906<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]2907to 64-bits. <a href="#t_struct">Structure</a> types require <tt>i32</tt>
Reid Spencerc0312692006-12-03 16:53:48 +0000[diff] [blame]2908<b>constants</b>.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2909
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2910<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]2911type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2912}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2913the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
2914i8 }</tt>' type, another structure. The third index indexes into the second
2915element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2916array. The two dimensions of the array are subscripted into, yielding an
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2917'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
2918to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2919
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2920<p>Note that it is perfectly legal to index partially through a
2921structure, returning a pointer to an inner element. Because of this,
2922the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2923
2924<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2925 define i32* %foo(%ST* %s) {
2926 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]2927 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
2928 %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]2929 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
2930 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
2931 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2932 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2933</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]2934
2935<p>Note that it is undefined to access an array out of bounds: array and
2936pointer indexes must always be within the defined bounds of the array type.
2937The one exception for this rules is zero length arrays. These arrays are
2938defined to be accessible as variable length arrays, which requires access
2939beyond the zero'th element.</p>
2940
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]2941<p>The getelementptr instruction is often confusing. For some more insight
2942into how it works, see <a href="GetElementPtr.html">the getelementptr
2943FAQ</a>.</p>
2944
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2945<h5>Example:</h5>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]2946
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2947<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2948 <i>; yields [12 x i8]*:aptr</i>
2949 %aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2950</pre>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]2951</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]2952
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2953<!-- ======================================================================= -->
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]2954<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2955</div>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2956<div class="doc_text">
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]2957<p>The instructions in this category are the conversion instructions (casting)
2958which all take a single operand and a type. They perform various bit conversions
2959on the operand.</p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2960</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]2961
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]2962<!-- _______________________________________________________________________ -->
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]2963<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2964 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
2965</div>
2966<div class="doc_text">
2967
2968<h5>Syntax:</h5>
2969<pre>
2970 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
2971</pre>
2972
2973<h5>Overview:</h5>
2974<p>
2975The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
2976</p>
2977
2978<h5>Arguments:</h5>
2979<p>
2980The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
2981be 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]2982and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2983type. The bit size of <tt>value</tt> must be larger than the bit size of
2984<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2985
2986<h5>Semantics:</h5>
2987<p>
2988The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]2989and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
2990larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
2991It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2992
2993<h5>Example:</h5>
2994<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2995 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2996 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
2997 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2998</pre>
2999</div>
3000
3001<!-- _______________________________________________________________________ -->
3002<div class="doc_subsubsection">
3003 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
3004</div>
3005<div class="doc_text">
3006
3007<h5>Syntax:</h5>
3008<pre>
3009 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3010</pre>
3011
3012<h5>Overview:</h5>
3013<p>The '<tt>zext</tt>' instruction zero extends its operand to type
3014<tt>ty2</tt>.</p>
3015
3016
3017<h5>Arguments:</h5>
3018<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]3019<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3020also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3021<tt>value</tt> must be smaller than the bit size of the destination type,
3022<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3023
3024<h5>Semantics:</h5>
3025<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]3026bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3027
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]3028<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]3029
3030<h5>Example:</h5>
3031<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3032 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3033 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3034</pre>
3035</div>
3036
3037<!-- _______________________________________________________________________ -->
3038<div class="doc_subsubsection">
3039 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
3040</div>
3041<div class="doc_text">
3042
3043<h5>Syntax:</h5>
3044<pre>
3045 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3046</pre>
3047
3048<h5>Overview:</h5>
3049<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
3050
3051<h5>Arguments:</h5>
3052<p>
3053The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3054<a href="#t_integer">integer</a> type, and a type to cast it to, which must
3055also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3056<tt>value</tt> must be smaller than the bit size of the destination type,
3057<tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3058
3059<h5>Semantics:</h5>
3060<p>
3061The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
3062bit (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]3063the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3064
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3065<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]3066
3067<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3068<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3069 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3070 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3071</pre>
3072</div>
3073
3074<!-- _______________________________________________________________________ -->
3075<div class="doc_subsubsection">
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3076 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
3077</div>
3078
3079<div class="doc_text">
3080
3081<h5>Syntax:</h5>
3082
3083<pre>
3084 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3085</pre>
3086
3087<h5>Overview:</h5>
3088<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
3089<tt>ty2</tt>.</p>
3090
3091
3092<h5>Arguments:</h5>
3093<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
3094 point</a> value to cast and a <a href="#t_floating">floating point</a> type to
3095cast it to. The size of <tt>value</tt> must be larger than the size of
3096<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
3097<i>no-op cast</i>.</p>
3098
3099<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3100<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
3101<a href="#t_floating">floating point</a> type to a smaller
3102<a href="#t_floating">floating point</a> type. If the value cannot fit within
3103the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]3104
3105<h5>Example:</h5>
3106<pre>
3107 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
3108 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
3109</pre>
3110</div>
3111
3112<!-- _______________________________________________________________________ -->
3113<div class="doc_subsubsection">
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3114 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
3115</div>
3116<div class="doc_text">
3117
3118<h5>Syntax:</h5>
3119<pre>
3120 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3121</pre>
3122
3123<h5>Overview:</h5>
3124<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
3125floating point value.</p>
3126
3127<h5>Arguments:</h5>
3128<p>The '<tt>fpext</tt>' instruction takes a
3129<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3130and a <a href="#t_floating">floating point</a> type to cast it to. The source
3131type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3132
3133<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3134<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3135<a href="#t_floating">floating point</a> type to a larger
3136<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3137used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3138<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]3139
3140<h5>Example:</h5>
3141<pre>
3142 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
3143 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
3144</pre>
3145</div>
3146
3147<!-- _______________________________________________________________________ -->
3148<div class="doc_subsubsection">
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]3149 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3150</div>
3151<div class="doc_text">
3152
3153<h5>Syntax:</h5>
3154<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3155 &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]3156</pre>
3157
3158<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3159<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3160unsigned integer equivalent of type <tt>ty2</tt>.
3161</p>
3162
3163<h5>Arguments:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3164<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]3165scalar or vector <a href="#t_floating">floating point</a> value, and a type
3166to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3167type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3168vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3169
3170<h5>Semantics:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3171<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3172<a href="#t_floating">floating point</a> operand into the nearest (rounding
3173towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
3174the results are undefined.</p>
3175
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3176<h5>Example:</h5>
3177<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3178 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3179 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]3180 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3181</pre>
3182</div>
3183
3184<!-- _______________________________________________________________________ -->
3185<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3186 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3187</div>
3188<div class="doc_text">
3189
3190<h5>Syntax:</h5>
3191<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3192 &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]3193</pre>
3194
3195<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3196<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3197<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]3198</p>
3199
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3200<h5>Arguments:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3201<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]3202scalar or vector <a href="#t_floating">floating point</a> value, and a type
3203to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
3204type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
3205vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3206
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3207<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3208<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3209<a href="#t_floating">floating point</a> operand into the nearest (rounding
3210towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
3211the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3212
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3213<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3214<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3215 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]3216 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3217 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3218</pre>
3219</div>
3220
3221<!-- _______________________________________________________________________ -->
3222<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3223 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3224</div>
3225<div class="doc_text">
3226
3227<h5>Syntax:</h5>
3228<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3229 &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]3230</pre>
3231
3232<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3233<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3234integer and converts that value to the <tt>ty2</tt> type.</p>
3235
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3236<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3237<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
3238scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3239to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3240type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3241floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3242
3243<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3244<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3245integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3246the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3247
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3248<h5>Example:</h5>
3249<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3250 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3251 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3252</pre>
3253</div>
3254
3255<!-- _______________________________________________________________________ -->
3256<div class="doc_subsubsection">
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3257 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3258</div>
3259<div class="doc_text">
3260
3261<h5>Syntax:</h5>
3262<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3263 &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]3264</pre>
3265
3266<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3267<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3268integer and converts that value to the <tt>ty2</tt> type.</p>
3269
3270<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]3271<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
3272scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
3273to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
3274type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
3275floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3276
3277<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]3278<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3279integer quantity and converts it to the corresponding floating point value. If
Jeff Cohenbeccb742007-04-22 14:56:37 +0000[diff] [blame]3280the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3281
3282<h5>Example:</h5>
3283<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3284 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3285 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3286</pre>
3287</div>
3288
3289<!-- _______________________________________________________________________ -->
3290<div class="doc_subsubsection">
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3291 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
3292</div>
3293<div class="doc_text">
3294
3295<h5>Syntax:</h5>
3296<pre>
3297 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3298</pre>
3299
3300<h5>Overview:</h5>
3301<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
3302the integer type <tt>ty2</tt>.</p>
3303
3304<h5>Arguments:</h5>
3305<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3306must 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]3307<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
3308
3309<h5>Semantics:</h5>
3310<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
3311<tt>ty2</tt> by interpreting the pointer value as an integer and either
3312truncating or zero extending that value to the size of the integer type. If
3313<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
3314<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]3315are the same size, then nothing is done (<i>no-op cast</i>) other than a type
3316change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3317
3318<h5>Example:</h5>
3319<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3320 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
3321 %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]3322</pre>
3323</div>
3324
3325<!-- _______________________________________________________________________ -->
3326<div class="doc_subsubsection">
3327 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
3328</div>
3329<div class="doc_text">
3330
3331<h5>Syntax:</h5>
3332<pre>
3333 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
3334</pre>
3335
3336<h5>Overview:</h5>
3337<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
3338a pointer type, <tt>ty2</tt>.</p>
3339
3340<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3341<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3342value to cast, and a type to cast it to, which must be a
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]3343<a href="#t_pointer">pointer</a> type.
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3344
3345<h5>Semantics:</h5>
3346<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
3347<tt>ty2</tt> by applying either a zero extension or a truncation depending on
3348the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
3349size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
3350the size of a pointer then a zero extension is done. If they are the same size,
3351nothing is done (<i>no-op cast</i>).</p>
3352
3353<h5>Example:</h5>
3354<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3355 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
3356 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
3357 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3358</pre>
3359</div>
3360
3361<!-- _______________________________________________________________________ -->
3362<div class="doc_subsubsection">
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3363 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3364</div>
3365<div class="doc_text">
3366
3367<h5>Syntax:</h5>
3368<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3369 &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]3370</pre>
3371
3372<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3373<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3374<tt>ty2</tt> without changing any bits.</p>
3375
3376<h5>Arguments:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3377<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3378a first class value, and a type to cast it to, which must also be a <a
3379 href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
Reid Spencere3db84c2007-01-09 20:08:58 +0000[diff] [blame]3380and the destination type, <tt>ty2</tt>, must be identical. If the source
3381type is a pointer, the destination type must also be a pointer.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3382
3383<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]3384<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]3385<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
3386this conversion. The conversion is done as if the <tt>value</tt> had been
3387stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
3388converted to other pointer types with this instruction. To convert pointers to
3389other types, use the <a href="#i_inttoptr">inttoptr</a> or
3390<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]3391
3392<h5>Example:</h5>
3393<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3394 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3395 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
3396 %Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]3397</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3398</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3399
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3400<!-- ======================================================================= -->
3401<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
3402<div class="doc_text">
3403<p>The instructions in this category are the "miscellaneous"
3404instructions, which defy better classification.</p>
3405</div>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3406
3407<!-- _______________________________________________________________________ -->
3408<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
3409</div>
3410<div class="doc_text">
3411<h5>Syntax:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3412<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]3413</pre>
3414<h5>Overview:</h5>
3415<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
3416of its two integer operands.</p>
3417<h5>Arguments:</h5>
3418<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3419the condition code indicating the kind of comparison to perform. It is not
3420a value, just a keyword. The possible condition code are:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3421<ol>
3422 <li><tt>eq</tt>: equal</li>
3423 <li><tt>ne</tt>: not equal </li>
3424 <li><tt>ugt</tt>: unsigned greater than</li>
3425 <li><tt>uge</tt>: unsigned greater or equal</li>
3426 <li><tt>ult</tt>: unsigned less than</li>
3427 <li><tt>ule</tt>: unsigned less or equal</li>
3428 <li><tt>sgt</tt>: signed greater than</li>
3429 <li><tt>sge</tt>: signed greater or equal</li>
3430 <li><tt>slt</tt>: signed less than</li>
3431 <li><tt>sle</tt>: signed less or equal</li>
3432</ol>
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]3433<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Reid Spencer784ef792007-01-04 05:19:58 +0000[diff] [blame]3434<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3435<h5>Semantics:</h5>
3436<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3437the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3438yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3439<ol>
3440 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
3441 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3442 </li>
3443 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
3444 <tt>false</tt> otherwise. No sign interpretation is necessary or performed.
3445 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
3446 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3447 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
3448 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3449 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
3450 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3451 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
3452 <tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
3453 <li><tt>sgt</tt>: interprets the operands as signed values and yields
3454 <tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
3455 <li><tt>sge</tt>: interprets the operands as signed values and yields
3456 <tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
3457 <li><tt>slt</tt>: interprets the operands as signed values and yields
3458 <tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
3459 <li><tt>sle</tt>: interprets the operands as signed values and yields
3460 <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]3461</ol>
3462<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3463values are compared as if they were integers.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3464
3465<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3466<pre> &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
3467 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
3468 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
3469 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
3470 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
3471 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3472</pre>
3473</div>
3474
3475<!-- _______________________________________________________________________ -->
3476<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
3477</div>
3478<div class="doc_text">
3479<h5>Syntax:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3480<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]3481</pre>
3482<h5>Overview:</h5>
3483<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
3484of its floating point operands.</p>
3485<h5>Arguments:</h5>
3486<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3487the condition code indicating the kind of comparison to perform. It is not
3488a value, just a keyword. The possible condition code are:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3489<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3490 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3491 <li><tt>oeq</tt>: ordered and equal</li>
3492 <li><tt>ogt</tt>: ordered and greater than </li>
3493 <li><tt>oge</tt>: ordered and greater than or equal</li>
3494 <li><tt>olt</tt>: ordered and less than </li>
3495 <li><tt>ole</tt>: ordered and less than or equal</li>
3496 <li><tt>one</tt>: ordered and not equal</li>
3497 <li><tt>ord</tt>: ordered (no nans)</li>
3498 <li><tt>ueq</tt>: unordered or equal</li>
3499 <li><tt>ugt</tt>: unordered or greater than </li>
3500 <li><tt>uge</tt>: unordered or greater than or equal</li>
3501 <li><tt>ult</tt>: unordered or less than </li>
3502 <li><tt>ule</tt>: unordered or less than or equal</li>
3503 <li><tt>une</tt>: unordered or not equal</li>
3504 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3505 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3506</ol>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3507<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer02e0d1d2006-12-06 07:08:07 +0000[diff] [blame]3508<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer784ef792007-01-04 05:19:58 +0000[diff] [blame]3509<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
3510<a href="#t_floating">floating point</a> typed. They must have identical
3511types.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3512<h5>Semantics:</h5>
3513<p>The '<tt>fcmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
3514the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3515yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3516<ol>
3517 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3518 <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]3519 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3520 <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]3521 <tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3522 <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]3523 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3524 <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]3525 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3526 <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]3527 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3528 <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]3529 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3530 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
3531 <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]3532 <tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3533 <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]3534 <tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3535 <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]3536 <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3537 <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]3538 <tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3539 <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]3540 <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3541 <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]3542 <tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]3543 <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]3544 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
3545</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]3546
3547<h5>Example:</h5>
3548<pre> &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
3549 &lt;result&gt; = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
3550 &lt;result&gt; = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
3551 &lt;result&gt; = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
3552</pre>
3553</div>
3554
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3555<!-- _______________________________________________________________________ -->
3556<div class="doc_subsubsection"> <a name="i_phi">'<tt>phi</tt>'
3557Instruction</a> </div>
3558<div class="doc_text">
3559<h5>Syntax:</h5>
3560<pre> &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...<br></pre>
3561<h5>Overview:</h5>
3562<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in
3563the SSA graph representing the function.</p>
3564<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3565<p>The type of the incoming values is specified with the first type
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3566field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
3567as arguments, with one pair for each predecessor basic block of the
3568current block. Only values of <a href="#t_firstclass">first class</a>
3569type may be used as the value arguments to the PHI node. Only labels
3570may be used as the label arguments.</p>
3571<p>There must be no non-phi instructions between the start of a basic
3572block and the PHI instructions: i.e. PHI instructions must be first in
3573a basic block.</p>
3574<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3575<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
3576specified by the pair corresponding to the predecessor basic block that executed
3577just prior to the current block.</p>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]3578<h5>Example:</h5>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3579<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]3580</div>
3581
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3582<!-- _______________________________________________________________________ -->
3583<div class="doc_subsubsection">
3584 <a name="i_select">'<tt>select</tt>' Instruction</a>
3585</div>
3586
3587<div class="doc_text">
3588
3589<h5>Syntax:</h5>
3590
3591<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3592 &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]3593</pre>
3594
3595<h5>Overview:</h5>
3596
3597<p>
3598The '<tt>select</tt>' instruction is used to choose one value based on a
3599condition, without branching.
3600</p>
3601
3602
3603<h5>Arguments:</h5>
3604
3605<p>
3606The '<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.
3607</p>
3608
3609<h5>Semantics:</h5>
3610
3611<p>
3612If the boolean condition evaluates to true, the instruction returns the first
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3613value argument; otherwise, it returns the second value argument.
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3614</p>
3615
3616<h5>Example:</h5>
3617
3618<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]3619 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]3620</pre>
3621</div>
3622
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]3623
3624<!-- _______________________________________________________________________ -->
3625<div class="doc_subsubsection">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3626 <a name="i_call">'<tt>call</tt>' Instruction</a>
3627</div>
3628
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3629<div class="doc_text">
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3630
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3631<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3632<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]3633 &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]3634</pre>
3635
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3636<h5>Overview:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3637
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3638<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3639
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3640<h5>Arguments:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3641
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3642<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3643
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3644<ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3645 <li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3646 <p>The optional "tail" marker indicates whether the callee function accesses
3647 any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3648 function call is eligible for tail call optimization. Note that calls may
3649 be marked "tail" even if they do not occur before a <a
3650 href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3651 </li>
3652 <li>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]3653 <p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3654 convention</a> the call should use. If none is specified, the call defaults
3655 to using C calling conventions.
3656 </li>
3657 <li>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]3658 <p>'<tt>ty</tt>': the type of the call instruction itself which is also
3659 the type of the return value. Functions that return no value are marked
3660 <tt><a href="#t_void">void</a></tt>.</p>
3661 </li>
3662 <li>
3663 <p>'<tt>fnty</tt>': shall be the signature of the pointer to function
3664 value being invoked. The argument types must match the types implied by
3665 this signature. This type can be omitted if the function is not varargs
3666 and if the function type does not return a pointer to a function.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3667 </li>
3668 <li>
3669 <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
3670 be invoked. In most cases, this is a direct function invocation, but
3671 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3672 to function value.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3673 </li>
3674 <li>
3675 <p>'<tt>function args</tt>': argument list whose types match the
Reid Spencerd845d162005-05-01 22:22:57 +0000[diff] [blame]3676 function signature argument types. All arguments must be of
3677 <a href="#t_firstclass">first class</a> type. If the function signature
3678 indicates the function accepts a variable number of arguments, the extra
3679 arguments can be specified.</p>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3680 </li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3681</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3682
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3683<h5>Semantics:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3684
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3685<p>The '<tt>call</tt>' instruction is used to cause control flow to
3686transfer to a specified function, with its incoming arguments bound to
3687the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
3688instruction in the called function, control flow continues with the
3689instruction after the function call, and the return value of the
3690function is bound to the result argument. This is a simpler case of
3691the <a href="#i_invoke">invoke</a> instruction.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3692
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3693<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3694
3695<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]3696 %retval = call i32 @test(i32 %argc)
3697 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42);
3698 %X = tail call i32 @foo()
3699 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo()
3700 %Z = call void %foo(i8 97 signext)
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]3701</pre>
3702
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3703</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3704
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3705<!-- _______________________________________________________________________ -->
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3706<div class="doc_subsubsection">
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]3707 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3708</div>
3709
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3710<div class="doc_text">
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3711
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3712<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3713
3714<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3715 &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]3716</pre>
3717
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3718<h5>Overview:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3719
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3720<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3721the "variable argument" area of a function call. It is used to implement the
3722<tt>va_arg</tt> macro in C.</p>
3723
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3724<h5>Arguments:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3725
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3726<p>This instruction takes a <tt>va_list*</tt> value and the type of
3727the argument. It returns a value of the specified argument type and
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3728increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3729actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3730
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3731<h5>Semantics:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3732
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3733<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
3734type from the specified <tt>va_list</tt> and causes the
3735<tt>va_list</tt> to point to the next argument. For more information,
3736see the variable argument handling <a href="#int_varargs">Intrinsic
3737Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3738
3739<p>It is legal for this instruction to be called in a function which does not
3740take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3741function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3742
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3743<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3744href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3745argument.</p>
3746
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]3747<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]3748
3749<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
3750
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3751</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3752
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3753<!-- *********************************************************************** -->
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3754<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
3755<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3756
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3757<div class="doc_text">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3758
3759<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]3760well known names and semantics and are required to follow certain restrictions.
3761Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3762language that does not require changing all of the transformations in LLVM when
Gabor Greifa54634a2007-07-06 22:07:22 +0000[diff] [blame]3763adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3764
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]3765<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3766prefix is reserved in LLVM for intrinsic names; thus, function names may not
3767begin with this prefix. Intrinsic functions must always be external functions:
3768you cannot define the body of intrinsic functions. Intrinsic functions may
3769only be used in call or invoke instructions: it is illegal to take the address
3770of an intrinsic function. Additionally, because intrinsic functions are part
3771of the LLVM language, it is required if any are added that they be documented
3772here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3773
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]3774<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
3775a family of functions that perform the same operation but on different data
3776types. Because LLVM can represent over 8 million different integer types,
3777overloading is used commonly to allow an intrinsic function to operate on any
3778integer type. One or more of the argument types or the result type can be
3779overloaded to accept any integer type. Argument types may also be defined as
3780exactly matching a previous argument's type or the result type. This allows an
3781intrinsic function which accepts multiple arguments, but needs all of them to
3782be of the same type, to only be overloaded with respect to a single argument or
3783the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3784
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]3785<p>Overloaded intrinsics will have the names of its overloaded argument types
3786encoded into its function name, each preceded by a period. Only those types
3787which are overloaded result in a name suffix. Arguments whose type is matched
3788against another type do not. For example, the <tt>llvm.ctpop</tt> function can
3789take an integer of any width and returns an integer of exactly the same integer
3790width. This leads to a family of functions such as
3791<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
3792Only one type, the return type, is overloaded, and only one type suffix is
3793required. Because the argument's type is matched against the return type, it
3794does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]3795
3796<p>To learn how to add an intrinsic function, please see the
3797<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3798</p>
3799
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3800</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3801
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3802<!-- ======================================================================= -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3803<div class="doc_subsection">
3804 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
3805</div>
3806
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3807<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3808
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3809<p>Variable argument support is defined in LLVM with the <a
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]3810 href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3811intrinsic functions. These functions are related to the similarly
3812named macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3813
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3814<p>All of these functions operate on arguments that use a
3815target-specific value type "<tt>va_list</tt>". The LLVM assembly
3816language reference manual does not define what this type is, so all
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3817transformations should be prepared to handle these functions regardless of
3818the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3819
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]3820<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]3821instruction and the variable argument handling intrinsic functions are
3822used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3823
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3824<div class="doc_code">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3825<pre>
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3826define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3827 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3828 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3829 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3830 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3831
3832 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3833 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3834
3835 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3836 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3837 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3838 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3839 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3840
3841 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3842 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3843 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3844}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]3845
3846declare void @llvm.va_start(i8*)
3847declare void @llvm.va_copy(i8*, i8*)
3848declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3849</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3850</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3851
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]3852</div>
3853
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3854<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3855<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3856 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3857</div>
3858
3859
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3860<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3861<h5>Syntax:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3862<pre> declare void %llvm.va_start(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3863<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3864<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
3865<tt>*&lt;arglist&gt;</tt> for subsequent use by <tt><a
3866href="#i_va_arg">va_arg</a></tt>.</p>
3867
3868<h5>Arguments:</h5>
3869
3870<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
3871
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3872<h5>Semantics:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3873
3874<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
3875macro available in C. In a target-dependent way, it initializes the
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3876<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]3877<tt>va_arg</tt> will produce the first variable argument passed to the function.
3878Unlike 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]3879last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3880
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3881</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3882
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3883<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3884<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3885 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3886</div>
3887
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3888<div class="doc_text">
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3889<h5>Syntax:</h5>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]3890<pre> declare void @llvm.va_end(i8* &lt;arglist&gt;)<br></pre>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3891<h5>Overview:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3892
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3893<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3894which 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]3895or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3896
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3897<h5>Arguments:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3898
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3899<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]3900
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3901<h5>Semantics:</h5>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3902
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3903<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]3904macro available in C. In a target-dependent way, it destroys the
3905<tt>va_list</tt> element to which the argument points. Calls to <a
3906href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
3907<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
3908<tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]3909
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3910</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3911
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3912<!-- _______________________________________________________________________ -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3913<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3914 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3915</div>
3916
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3917<div class="doc_text">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3918
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3919<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3920
3921<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]3922 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3923</pre>
3924
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3925<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3926
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3927<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
3928from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3929
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3930<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3931
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]3932<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]3933The 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]3934
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3935
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]3936<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3937
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]3938<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
3939macro available in C. In a target-dependent way, it copies the source
3940<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
3941intrinsic is necessary because the <tt><a href="#int_va_start">
3942llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
3943example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3944
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3945</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]3946
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]3947<!-- ======================================================================= -->
3948<div class="doc_subsection">
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3949 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
3950</div>
3951
3952<div class="doc_text">
3953
3954<p>
3955LLVM support for <a href="GarbageCollection.html">Accurate Garbage
3956Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3957These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3958stack</a>, as well as garbage collector implementations that require <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3959href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3960Front-ends for type-safe garbage collected languages should generate these
3961intrinsics to make use of the LLVM garbage collectors. For more details, see <a
3962href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
3963</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]3964
3965<p>The garbage collection intrinsics only operate on objects in the generic
3966 address space (address space zero).</p>
3967
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3968</div>
3969
3970<!-- _______________________________________________________________________ -->
3971<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]3972 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3973</div>
3974
3975<div class="doc_text">
3976
3977<h5>Syntax:</h5>
3978
3979<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]3980 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]3981</pre>
3982
3983<h5>Overview:</h5>
3984
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]3985<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]3986the code generator, and allows some metadata to be associated with it.</p>
3987
3988<h5>Arguments:</h5>
3989
3990<p>The first argument specifies the address of a stack object that contains the
3991root pointer. The second pointer (which must be either a constant or a global
3992value address) contains the meta-data to be associated with the root.</p>
3993
3994<h5>Semantics:</h5>
3995
3996<p>At runtime, a call to this intrinsics stores a null pointer into the "ptrloc"
3997location. At compile-time, the code generator generates information to allow
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]3998the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
3999intrinsic may only be used in a function which <a href="#gc">specifies a GC
4000algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4001
4002</div>
4003
4004
4005<!-- _______________________________________________________________________ -->
4006<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4007 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4008</div>
4009
4010<div class="doc_text">
4011
4012<h5>Syntax:</h5>
4013
4014<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4015 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4016</pre>
4017
4018<h5>Overview:</h5>
4019
4020<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
4021locations, allowing garbage collector implementations that require read
4022barriers.</p>
4023
4024<h5>Arguments:</h5>
4025
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4026<p>The second argument is the address to read from, which should be an address
4027allocated from the garbage collector. The first object is a pointer to the
4028start of the referenced object, if needed by the language runtime (otherwise
4029null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4030
4031<h5>Semantics:</h5>
4032
4033<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
4034instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4035garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
4036may only be used in a function which <a href="#gc">specifies a GC
4037algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4038
4039</div>
4040
4041
4042<!-- _______________________________________________________________________ -->
4043<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4044 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4045</div>
4046
4047<div class="doc_text">
4048
4049<h5>Syntax:</h5>
4050
4051<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4052 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4053</pre>
4054
4055<h5>Overview:</h5>
4056
4057<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
4058locations, allowing garbage collector implementations that require write
4059barriers (such as generational or reference counting collectors).</p>
4060
4061<h5>Arguments:</h5>
4062
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]4063<p>The first argument is the reference to store, the second is the start of the
4064object to store it to, and the third is the address of the field of Obj to
4065store to. If the runtime does not require a pointer to the object, Obj may be
4066null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4067
4068<h5>Semantics:</h5>
4069
4070<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
4071instruction, but may be replaced with substantially more complex code by the
Gordon Henriksenfb56bde2007-12-25 02:31:26 +0000[diff] [blame]4072garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
4073may only be used in a function which <a href="#gc">specifies a GC
4074algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]4075
4076</div>
4077
4078
4079
4080<!-- ======================================================================= -->
4081<div class="doc_subsection">
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4082 <a name="int_codegen">Code Generator Intrinsics</a>
4083</div>
4084
4085<div class="doc_text">
4086<p>
4087These intrinsics are provided by LLVM to expose special features that may only
4088be implemented with code generator support.
4089</p>
4090
4091</div>
4092
4093<!-- _______________________________________________________________________ -->
4094<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4095 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4096</div>
4097
4098<div class="doc_text">
4099
4100<h5>Syntax:</h5>
4101<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4102 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4103</pre>
4104
4105<h5>Overview:</h5>
4106
4107<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4108The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
4109target-specific value indicating the return address of the current function
4110or one of its callers.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4111</p>
4112
4113<h5>Arguments:</h5>
4114
4115<p>
4116The argument to this intrinsic indicates which function to return the address
4117for. Zero indicates the calling function, one indicates its caller, etc. The
4118argument is <b>required</b> to be a constant integer value.
4119</p>
4120
4121<h5>Semantics:</h5>
4122
4123<p>
4124The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
4125the return address of the specified call frame, or zero if it cannot be
4126identified. The value returned by this intrinsic is likely to be incorrect or 0
4127for arguments other than zero, so it should only be used for debugging purposes.
4128</p>
4129
4130<p>
4131Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4132aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4133source-language caller.
4134</p>
4135</div>
4136
4137
4138<!-- _______________________________________________________________________ -->
4139<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4140 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4141</div>
4142
4143<div class="doc_text">
4144
4145<h5>Syntax:</h5>
4146<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4147 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4148</pre>
4149
4150<h5>Overview:</h5>
4151
4152<p>
Chris Lattnerc1fb4262006-10-15 20:05:59 +0000[diff] [blame]4153The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
4154target-specific frame pointer value for the specified stack frame.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4155</p>
4156
4157<h5>Arguments:</h5>
4158
4159<p>
4160The argument to this intrinsic indicates which function to return the frame
4161pointer for. Zero indicates the calling function, one indicates its caller,
4162etc. The argument is <b>required</b> to be a constant integer value.
4163</p>
4164
4165<h5>Semantics:</h5>
4166
4167<p>
4168The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
4169the frame address of the specified call frame, or zero if it cannot be
4170identified. The value returned by this intrinsic is likely to be incorrect or 0
4171for arguments other than zero, so it should only be used for debugging purposes.
4172</p>
4173
4174<p>
4175Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner2e6eb5f2005-03-07 20:30:51 +0000[diff] [blame]4176aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4177source-language caller.
4178</p>
4179</div>
4180
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4181<!-- _______________________________________________________________________ -->
4182<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4183 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4184</div>
4185
4186<div class="doc_text">
4187
4188<h5>Syntax:</h5>
4189<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4190 declare i8 *@llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4191</pre>
4192
4193<h5>Overview:</h5>
4194
4195<p>
4196The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4197the function stack, for use with <a href="#int_stackrestore">
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4198<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
4199features like scoped automatic variable sized arrays in C99.
4200</p>
4201
4202<h5>Semantics:</h5>
4203
4204<p>
4205This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4206href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4207<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
4208<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
4209state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
4210practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
4211that were allocated after the <tt>llvm.stacksave</tt> was executed.
4212</p>
4213
4214</div>
4215
4216<!-- _______________________________________________________________________ -->
4217<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4218 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4219</div>
4220
4221<div class="doc_text">
4222
4223<h5>Syntax:</h5>
4224<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4225 declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4226</pre>
4227
4228<h5>Overview:</h5>
4229
4230<p>
4231The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
4232the function stack to the state it was in when the corresponding <a
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4233href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4234useful for implementing language features like scoped automatic variable sized
4235arrays in C99.
4236</p>
4237
4238<h5>Semantics:</h5>
4239
4240<p>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4241See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]4242</p>
4243
4244</div>
4245
4246
4247<!-- _______________________________________________________________________ -->
4248<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4249 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4250</div>
4251
4252<div class="doc_text">
4253
4254<h5>Syntax:</h5>
4255<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4256 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]4257</pre>
4258
4259<h5>Overview:</h5>
4260
4261
4262<p>
4263The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4264a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
4265no
4266effect on the behavior of the program but can change its performance
Chris Lattnerff851072005-02-28 19:47:14 +0000[diff] [blame]4267characteristics.
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4268</p>
4269
4270<h5>Arguments:</h5>
4271
4272<p>
4273<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
4274determining if the fetch should be for a read (0) or write (1), and
4275<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattnerd3e641c2005-03-07 20:31:38 +0000[diff] [blame]4276locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]4277<tt>locality</tt> arguments must be constant integers.
4278</p>
4279
4280<h5>Semantics:</h5>
4281
4282<p>
4283This intrinsic does not modify the behavior of the program. In particular,
4284prefetches cannot trap and do not produce a value. On targets that support this
4285intrinsic, the prefetch can provide hints to the processor cache for better
4286performance.
4287</p>
4288
4289</div>
4290
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4291<!-- _______________________________________________________________________ -->
4292<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4293 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4294</div>
4295
4296<div class="doc_text">
4297
4298<h5>Syntax:</h5>
4299<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]4300 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4301</pre>
4302
4303<h5>Overview:</h5>
4304
4305
4306<p>
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4307The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
4308(PC) in a region of
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4309code to simulators and other tools. The method is target specific, but it is
4310expected that the marker will use exported symbols to transmit the PC of the marker.
Jeff Cohendc6bfea2005-11-11 02:15:27 +0000[diff] [blame]4311The marker makes no guarantees that it will remain with any specific instruction
Chris Lattnere64d41d2005-11-15 06:07:55 +0000[diff] [blame]4312after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattnerb40261e2006-03-24 07:16:10 +0000[diff] [blame]4313optimizations. The intended use is to be inserted after optimizations to allow
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]4314correlations of simulation runs.
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]4315</p>
4316
4317<h5>Arguments:</h5>
4318
4319<p>
4320<tt>id</tt> is a numerical id identifying the marker.
4321</p>
4322
4323<h5>Semantics:</h5>
4324
4325<p>
4326This intrinsic does not modify the behavior of the program. Backends that do not
4327support this intrinisic may ignore it.
4328</p>
4329
4330</div>
4331
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]4332<!-- _______________________________________________________________________ -->
4333<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4334 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]4335</div>
4336
4337<div class="doc_text">
4338
4339<h5>Syntax:</h5>
4340<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4341 declare i64 @llvm.readcyclecounter( )
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]4342</pre>
4343
4344<h5>Overview:</h5>
4345
4346
4347<p>
4348The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
4349counter register (or similar low latency, high accuracy clocks) on those targets
4350that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
4351As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
4352should only be used for small timings.
4353</p>
4354
4355<h5>Semantics:</h5>
4356
4357<p>
4358When directly supported, reading the cycle counter should not modify any memory.
4359Implementations are allowed to either return a application specific value or a
4360system wide value. On backends without support, this is lowered to a constant 0.
4361</p>
4362
4363</div>
4364
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4365<!-- ======================================================================= -->
4366<div class="doc_subsection">
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4367 <a name="int_libc">Standard C Library Intrinsics</a>
4368</div>
4369
4370<div class="doc_text">
4371<p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4372LLVM provides intrinsics for a few important standard C library functions.
4373These intrinsics allow source-language front-ends to pass information about the
4374alignment of the pointer arguments to the code generator, providing opportunity
4375for more efficient code generation.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4376</p>
4377
4378</div>
4379
4380<!-- _______________________________________________________________________ -->
4381<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4382 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4383</div>
4384
4385<div class="doc_text">
4386
4387<h5>Syntax:</h5>
4388<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4389 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4390 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4391 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4392 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4393</pre>
4394
4395<h5>Overview:</h5>
4396
4397<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4398The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4399location to the destination location.
4400</p>
4401
4402<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4403Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
4404intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4405</p>
4406
4407<h5>Arguments:</h5>
4408
4409<p>
4410The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4411the source. The third argument is an integer argument
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4412specifying the number of bytes to copy, and the fourth argument is the alignment
4413of the source and destination locations.
4414</p>
4415
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4416<p>
4417If 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]4418the caller guarantees that both the source and destination pointers are aligned
4419to that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4420</p>
4421
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4422<h5>Semantics:</h5>
4423
4424<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4425The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]4426location to the destination location, which are not allowed to overlap. It
4427copies "len" bytes of memory over. If the argument is known to be aligned to
4428some boundary, this can be specified as the fourth argument, otherwise it should
4429be set to 0 or 1.
4430</p>
4431</div>
4432
4433
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4434<!-- _______________________________________________________________________ -->
4435<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4436 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4437</div>
4438
4439<div class="doc_text">
4440
4441<h5>Syntax:</h5>
4442<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4443 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4444 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4445 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4446 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4447</pre>
4448
4449<h5>Overview:</h5>
4450
4451<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4452The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
4453location to the destination location. It is similar to the
4454'<tt>llvm.memcmp</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4455</p>
4456
4457<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4458Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
4459intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4460</p>
4461
4462<h5>Arguments:</h5>
4463
4464<p>
4465The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4466the source. The third argument is an integer argument
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4467specifying the number of bytes to copy, and the fourth argument is the alignment
4468of the source and destination locations.
4469</p>
4470
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4471<p>
4472If 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]4473the caller guarantees that the source and destination pointers are aligned to
4474that boundary.
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]4475</p>
4476
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4477<h5>Semantics:</h5>
4478
4479<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4480The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]4481location to the destination location, which may overlap. It
4482copies "len" bytes of memory over. If the argument is known to be aligned to
4483some boundary, this can be specified as the fourth argument, otherwise it should
4484be set to 0 or 1.
4485</p>
4486</div>
4487
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]4488
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4489<!-- _______________________________________________________________________ -->
4490<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4491 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4492</div>
4493
4494<div class="doc_text">
4495
4496<h5>Syntax:</h5>
4497<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4498 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4499 i32 &lt;len&gt;, i32 &lt;align&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4500 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4501 i64 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4502</pre>
4503
4504<h5>Overview:</h5>
4505
4506<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4507The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4508byte value.
4509</p>
4510
4511<p>
4512Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
4513does not return a value, and takes an extra alignment argument.
4514</p>
4515
4516<h5>Arguments:</h5>
4517
4518<p>
4519The first argument is a pointer to the destination to fill, the second is the
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4520byte value to fill it with, the third argument is an integer
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4521argument specifying the number of bytes to fill, and the fourth argument is the
4522known alignment of destination location.
4523</p>
4524
4525<p>
4526If 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]4527the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4528</p>
4529
4530<h5>Semantics:</h5>
4531
4532<p>
Chris Lattner0c8b2592006-03-03 00:07:20 +0000[diff] [blame]4533The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
4534the
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]4535destination location. If the argument is known to be aligned to some boundary,
4536this can be specified as the fourth argument, otherwise it should be set to 0 or
45371.
4538</p>
4539</div>
4540
4541
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]4542<!-- _______________________________________________________________________ -->
4543<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4544 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4545</div>
4546
4547<div class="doc_text">
4548
4549<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]4550<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]4551floating point or vector of floating point type. Not all targets support all
4552types however.
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4553<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]4554 declare float @llvm.sqrt.f32(float %Val)
4555 declare double @llvm.sqrt.f64(double %Val)
4556 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
4557 declare fp128 @llvm.sqrt.f128(fp128 %Val)
4558 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4559</pre>
4560
4561<h5>Overview:</h5>
4562
4563<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]4564The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4565returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4566<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
4567negative numbers (which allows for better optimization).
4568</p>
4569
4570<h5>Arguments:</h5>
4571
4572<p>
4573The argument and return value are floating point numbers of the same type.
4574</p>
4575
4576<h5>Semantics:</h5>
4577
4578<p>
Dan Gohman33988db2007-07-16 14:37:41 +0000[diff] [blame]4579This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]4580floating point number.
4581</p>
4582</div>
4583
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4584<!-- _______________________________________________________________________ -->
4585<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4586 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4587</div>
4588
4589<div class="doc_text">
4590
4591<h5>Syntax:</h5>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]4592<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]4593floating point or vector of floating point type. Not all targets support all
4594types however.
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4595<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]4596 declare float @llvm.powi.f32(float %Val, i32 %power)
4597 declare double @llvm.powi.f64(double %Val, i32 %power)
4598 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
4599 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
4600 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4601</pre>
4602
4603<h5>Overview:</h5>
4604
4605<p>
4606The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
4607specified (positive or negative) power. The order of evaluation of
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4608multiplications is not defined. When a vector of floating point type is
4609used, the second argument remains a scalar integer value.
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4610</p>
4611
4612<h5>Arguments:</h5>
4613
4614<p>
4615The second argument is an integer power, and the first is a value to raise to
4616that power.
4617</p>
4618
4619<h5>Semantics:</h5>
4620
4621<p>
4622This function returns the first value raised to the second power with an
4623unspecified sequence of rounding operations.</p>
4624</div>
4625
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4626<!-- _______________________________________________________________________ -->
4627<div class="doc_subsubsection">
4628 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
4629</div>
4630
4631<div class="doc_text">
4632
4633<h5>Syntax:</h5>
4634<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
4635floating point or vector of floating point type. Not all targets support all
4636types however.
4637<pre>
4638 declare float @llvm.sin.f32(float %Val)
4639 declare double @llvm.sin.f64(double %Val)
4640 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
4641 declare fp128 @llvm.sin.f128(fp128 %Val)
4642 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
4643</pre>
4644
4645<h5>Overview:</h5>
4646
4647<p>
4648The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
4649</p>
4650
4651<h5>Arguments:</h5>
4652
4653<p>
4654The argument and return value are floating point numbers of the same type.
4655</p>
4656
4657<h5>Semantics:</h5>
4658
4659<p>
4660This function returns the sine of the specified operand, returning the
4661same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]4662conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4663</div>
4664
4665<!-- _______________________________________________________________________ -->
4666<div class="doc_subsubsection">
4667 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
4668</div>
4669
4670<div class="doc_text">
4671
4672<h5>Syntax:</h5>
4673<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
4674floating point or vector of floating point type. Not all targets support all
4675types however.
4676<pre>
4677 declare float @llvm.cos.f32(float %Val)
4678 declare double @llvm.cos.f64(double %Val)
4679 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
4680 declare fp128 @llvm.cos.f128(fp128 %Val)
4681 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
4682</pre>
4683
4684<h5>Overview:</h5>
4685
4686<p>
4687The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
4688</p>
4689
4690<h5>Arguments:</h5>
4691
4692<p>
4693The argument and return value are floating point numbers of the same type.
4694</p>
4695
4696<h5>Semantics:</h5>
4697
4698<p>
4699This function returns the cosine of the specified operand, returning the
4700same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]4701conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4702</div>
4703
4704<!-- _______________________________________________________________________ -->
4705<div class="doc_subsubsection">
4706 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
4707</div>
4708
4709<div class="doc_text">
4710
4711<h5>Syntax:</h5>
4712<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
4713floating point or vector of floating point type. Not all targets support all
4714types however.
4715<pre>
4716 declare float @llvm.pow.f32(float %Val, float %Power)
4717 declare double @llvm.pow.f64(double %Val, double %Power)
4718 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
4719 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
4720 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
4721</pre>
4722
4723<h5>Overview:</h5>
4724
4725<p>
4726The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
4727specified (positive or negative) power.
4728</p>
4729
4730<h5>Arguments:</h5>
4731
4732<p>
4733The second argument is a floating point power, and the first is a value to
4734raise to that power.
4735</p>
4736
4737<h5>Semantics:</h5>
4738
4739<p>
4740This function returns the first value raised to the second power,
4741returning the
4742same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohmand0806a02007-10-17 18:05:13 +0000[diff] [blame]4743conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]4744</div>
4745
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]4746
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4747<!-- ======================================================================= -->
4748<div class="doc_subsection">
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4749 <a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4750</div>
4751
4752<div class="doc_text">
4753<p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4754LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4755These allow efficient code generation for some algorithms.
4756</p>
4757
4758</div>
4759
4760<!-- _______________________________________________________________________ -->
4761<div class="doc_subsubsection">
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4762 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4763</div>
4764
4765<div class="doc_text">
4766
4767<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4768<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4769type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4770<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4771 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
4772 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
4773 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4774</pre>
4775
4776<h5>Overview:</h5>
4777
4778<p>
Reid Spencerf361c4f2007-04-02 02:25:19 +0000[diff] [blame]4779The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4780values with an even number of bytes (positive multiple of 16 bits). These are
4781useful for performing operations on data that is not in the target's native
4782byte order.
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4783</p>
4784
4785<h5>Semantics:</h5>
4786
4787<p>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4788The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4789and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
4790intrinsic returns an i32 value that has the four bytes of the input i32
4791swapped, 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]4792i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
4793<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4794additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]4795</p>
4796
4797</div>
4798
4799<!-- _______________________________________________________________________ -->
4800<div class="doc_subsubsection">
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]4801 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4802</div>
4803
4804<div class="doc_text">
4805
4806<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4807<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
4808width. Not all targets support all bit widths however.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4809<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4810 declare i8 @llvm.ctpop.i8 (i8 &lt;src&gt;)
4811 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4812 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4813 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
4814 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4815</pre>
4816
4817<h5>Overview:</h5>
4818
4819<p>
Chris Lattner069b5bd2006-01-16 22:38:59 +0000[diff] [blame]4820The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
4821value.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4822</p>
4823
4824<h5>Arguments:</h5>
4825
4826<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]4827The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]4828integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4829</p>
4830
4831<h5>Semantics:</h5>
4832
4833<p>
4834The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
4835</p>
4836</div>
4837
4838<!-- _______________________________________________________________________ -->
4839<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]4840 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4841</div>
4842
4843<div class="doc_text">
4844
4845<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4846<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
4847integer bit width. Not all targets support all bit widths however.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4848<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4849 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
4850 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4851 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4852 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
4853 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4854</pre>
4855
4856<h5>Overview:</h5>
4857
4858<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]4859The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
4860leading zeros in a variable.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4861</p>
4862
4863<h5>Arguments:</h5>
4864
4865<p>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]4866The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]4867integer type. The return type must match the argument type.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4868</p>
4869
4870<h5>Semantics:</h5>
4871
4872<p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4873The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
4874in 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]4875of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]4876</p>
4877</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]4878
4879
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4880
4881<!-- _______________________________________________________________________ -->
4882<div class="doc_subsubsection">
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]4883 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4884</div>
4885
4886<div class="doc_text">
4887
4888<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]4889<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
4890integer bit width. Not all targets support all bit widths however.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4891<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4892 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
4893 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]4894 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4895 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
4896 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4897</pre>
4898
4899<h5>Overview:</h5>
4900
4901<p>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]4902The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
4903trailing zeros.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4904</p>
4905
4906<h5>Arguments:</h5>
4907
4908<p>
4909The only argument is the value to be counted. The argument may be of any
Reid Spencer3e628eb92007-01-04 16:43:23 +0000[diff] [blame]4910integer type. The return type must match the argument type.
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]4911</p>
4912
4913<h5>Semantics:</h5>
4914
4915<p>
4916The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
4917in a variable. If the src == 0 then the result is the size in bits of the type
4918of src. For example, <tt>llvm.cttz(2) = 1</tt>.
4919</p>
4920</div>
4921
Reid Spencer8a5799f2007-04-01 08:27:01 +0000[diff] [blame]4922<!-- _______________________________________________________________________ -->
4923<div class="doc_subsubsection">
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]4924 <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4925</div>
4926
4927<div class="doc_text">
4928
4929<h5>Syntax:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]4930<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4931on any integer bit width.
4932<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4933 declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
4934 declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4935</pre>
4936
4937<h5>Overview:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]4938<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4939range of bits from an integer value and returns them in the same bit width as
4940the original value.</p>
4941
4942<h5>Arguments:</h5>
4943<p>The first argument, <tt>%val</tt> and the result may be integer types of
4944any bit width but they must have the same bit width. The second and third
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4945arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4946
4947<h5>Semantics:</h5>
Reid Spencerea2945e2007-04-10 02:51:31 +0000[diff] [blame]4948<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]4949of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
4950<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
4951operates in forward mode.</p>
4952<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
4953right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4954only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
4955<ol>
4956 <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
4957 by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
4958 <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
4959 to determine the number of bits to retain.</li>
4960 <li>A mask of the retained bits is created by shifting a -1 value.</li>
4961 <li>The mask is ANDed with <tt>%val</tt> to produce the result.
4962</ol>
Reid Spencer70845c02007-05-14 16:14:57 +0000[diff] [blame]4963<p>In reverse mode, a similar computation is made except that the bits are
4964returned in the reverse order. So, for example, if <tt>X</tt> has the value
4965<tt>i16 0x0ACF (101011001111)</tt> and we apply
4966<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
4967<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer8bc7d952007-04-01 19:00:37 +0000[diff] [blame]4968</div>
4969
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]4970<div class="doc_subsubsection">
4971 <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
4972</div>
4973
4974<div class="doc_text">
4975
4976<h5>Syntax:</h5>
4977<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
4978on any integer bit width.
4979<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]4980 declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
4981 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]4982</pre>
4983
4984<h5>Overview:</h5>
4985<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
4986of bits in an integer value with another integer value. It returns the integer
4987with the replaced bits.</p>
4988
4989<h5>Arguments:</h5>
4990<p>The first argument, <tt>%val</tt> and the result may be integer types of
4991any bit width but they must have the same bit width. <tt>%val</tt> is the value
4992whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
4993integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
4994type since they specify only a bit index.</p>
4995
4996<h5>Semantics:</h5>
4997<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
4998of operation: forwards and reverse. If <tt>%lo</tt> is greater than
4999<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
5000operates in forward mode.</p>
5001<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
5002truncating it down to the size of the replacement area or zero extending it
5003up to that size.</p>
5004<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
5005are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
5006in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
5007to the <tt>%hi</tt>th bit.
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5008<p>In reverse mode, a similar computation is made except that the bits are
5009reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
5010<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]5011<h5>Examples:</h5>
5012<pre>
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5013 llvm.part.set(0xFFFF, 0, 4, 7) -&gt; 0xFF0F
Reid Spencer146281c2007-05-14 16:50:20 +0000[diff] [blame]5014 llvm.part.set(0xFFFF, 0, 7, 4) -&gt; 0xFF0F
5015 llvm.part.set(0xFFFF, 1, 7, 4) -&gt; 0xFF8F
5016 llvm.part.set(0xFFFF, F, 8, 3) -&gt; 0xFFE7
Reid Spencerc70afc32007-04-12 01:03:03 +0000[diff] [blame]5017 llvm.part.set(0xFFFF, 0, 3, 8) -&gt; 0xFE07
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]5018</pre>
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]5019</div>
5020
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5021<!-- ======================================================================= -->
5022<div class="doc_subsection">
5023 <a name="int_debugger">Debugger Intrinsics</a>
5024</div>
5025
5026<div class="doc_text">
5027<p>
5028The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
5029are described in the <a
5030href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
5031Debugging</a> document.
5032</p>
5033</div>
5034
5035
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]5036<!-- ======================================================================= -->
5037<div class="doc_subsection">
5038 <a name="int_eh">Exception Handling Intrinsics</a>
5039</div>
5040
5041<div class="doc_text">
5042<p> The LLVM exception handling intrinsics (which all start with
5043<tt>llvm.eh.</tt> prefix), are described in the <a
5044href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
5045Handling</a> document. </p>
5046</div>
5047
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]5048<!-- ======================================================================= -->
5049<div class="doc_subsection">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5050 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5051</div>
5052
5053<div class="doc_text">
5054<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5055 This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5056 the <tt>nest</tt> attribute, from a function. The result is a callable
5057 function pointer lacking the nest parameter - the caller does not need
5058 to provide a value for it. Instead, the value to use is stored in
5059 advance in a "trampoline", a block of memory usually allocated
5060 on the stack, which also contains code to splice the nest value into the
5061 argument list. This is used to implement the GCC nested function address
5062 extension.
5063</p>
5064<p>
5065 For example, if the function is
5066 <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]5067 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]5068<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5069 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
5070 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
5071 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
5072 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5073</pre>
Bill Wendling252570f2007-09-22 09:23:55 +0000[diff] [blame]5074 <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
5075 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5076</div>
5077
5078<!-- _______________________________________________________________________ -->
5079<div class="doc_subsubsection">
5080 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
5081</div>
5082<div class="doc_text">
5083<h5>Syntax:</h5>
5084<pre>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5085declare 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]5086</pre>
5087<h5>Overview:</h5>
5088<p>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5089 This fills the memory pointed to by <tt>tramp</tt> with code
5090 and returns a function pointer suitable for executing it.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5091</p>
5092<h5>Arguments:</h5>
5093<p>
5094 The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
5095 pointers. The <tt>tramp</tt> argument must point to a sufficiently large
5096 and sufficiently aligned block of memory; this memory is written to by the
Duncan Sandsf2bcd372007-08-22 23:39:54 +0000[diff] [blame]5097 intrinsic. Note that the size and the alignment are target-specific - LLVM
5098 currently provides no portable way of determining them, so a front-end that
5099 generates this intrinsic needs to have some target-specific knowledge.
5100 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]5101</p>
5102<h5>Semantics:</h5>
5103<p>
5104 The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5105 dependent code, turning it into a function. A pointer to this function is
5106 returned, but needs to be bitcast to an
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5107 <a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]5108 before being called. The new function's signature is the same as that of
5109 <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
5110 removed. At most one such <tt>nest</tt> argument is allowed, and it must be
5111 of pointer type. Calling the new function is equivalent to calling
5112 <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
5113 missing <tt>nest</tt> argument. If, after calling
5114 <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
5115 modified, then the effect of any later call to the returned function pointer is
5116 undefined.
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]5117</p>
5118</div>
5119
5120<!-- ======================================================================= -->
5121<div class="doc_subsection">
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]5122 <a name="int_general">General Intrinsics</a>
5123</div>
5124
5125<div class="doc_text">
5126<p> This class of intrinsics is designed to be generic and has
5127no specific purpose. </p>
5128</div>
5129
5130<!-- _______________________________________________________________________ -->
5131<div class="doc_subsubsection">
5132 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
5133</div>
5134
5135<div class="doc_text">
5136
5137<h5>Syntax:</h5>
5138<pre>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]5139 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]5140</pre>
5141
5142<h5>Overview:</h5>
5143
5144<p>
5145The '<tt>llvm.var.annotation</tt>' intrinsic
5146</p>
5147
5148<h5>Arguments:</h5>
5149
5150<p>
Tanya Lattnerbed1d4d2007-06-18 23:42:37 +0000[diff] [blame]5151The first argument is a pointer to a value, the second is a pointer to a
5152global string, the third is a pointer to a global string which is the source
5153file name, and the last argument is the line number.
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]5154</p>
5155
5156<h5>Semantics:</h5>
5157
5158<p>
5159This intrinsic allows annotation of local variables with arbitrary strings.
5160This can be useful for special purpose optimizations that want to look for these
5161 annotations. These have no other defined use, they are ignored by code
5162 generation and optimization.
5163</div>
5164
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]5165<!-- _______________________________________________________________________ -->
5166<div class="doc_subsubsection">
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]5167 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]5168</div>
5169
5170<div class="doc_text">
5171
5172<h5>Syntax:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]5173<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
5174any integer bit width.
5175</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]5176<pre>
Tanya Lattnercf3e26f2007-09-22 00:03:01 +0000[diff] [blame]5177 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5178 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5179 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5180 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
5181 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]5182</pre>
5183
5184<h5>Overview:</h5>
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]5185
5186<p>
5187The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]5188</p>
5189
5190<h5>Arguments:</h5>
5191
5192<p>
5193The first argument is an integer value (result of some expression),
5194the second is a pointer to a global string, the third is a pointer to a global
5195string which is the source file name, and the last argument is the line number.
Tanya Lattner23dbd572007-09-21 23:56:27 +0000[diff] [blame]5196It returns the value of the first argument.
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]5197</p>
5198
5199<h5>Semantics:</h5>
5200
5201<p>
5202This intrinsic allows annotations to be put on arbitrary expressions
5203with arbitrary strings. This can be useful for special purpose optimizations
5204that want to look for these annotations. These have no other defined use, they
5205are ignored by code generation and optimization.
5206</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]5207
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5208<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5209<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]5210<address>
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5215
5216 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencerca058542006-03-14 05:39:39 +0000[diff] [blame]5217 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]5218 Last modified: $Date$
5219</address>
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