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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 7fd6b0fff74a7c9fbc054b3303fee1a8f22002b2 / . / docs / LangRef.html
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5 <title>LLVM Assembly Language Reference Manual</title>
6 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
7 <meta name="author" content="Chris Lattner">
8 <meta name="description"
9 content="LLVM Assembly Language Reference Manual.">
10 <link rel="stylesheet" href="llvm.css" type="text/css">
11</head>
12
13<body>
14
15<div class="doc_title"> LLVM Language Reference Manual </div>
16<ol>
17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Bill Wendling41a07852009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendlinge2753242009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
27 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
28 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
29 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
30 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
31 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
32 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
33 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
34 <li><a href="#linkage_linkonce">'<tt>linkonce_odr</tt>' Linkage</a></li>
35 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
36 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
37 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
38 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendling41a07852009-07-20 01:03:30 +0000[diff] [blame]39 </ol>
40 </li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]41 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner5b6dc6e2009-01-11 20:53:49 +0000[diff] [blame]42 <li><a href="#namedtypes">Named Types</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]43 <li><a href="#globalvars">Global Variables</a></li>
44 <li><a href="#functionstructure">Functions</a></li>
Dan Gohman2672f3e2008-10-14 16:51:45 +0000[diff] [blame]45 <li><a href="#aliasstructure">Aliases</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]46 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel008cd3e2008-09-26 23:51:19 +0000[diff] [blame]47 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen13fe5e32007-12-10 03:18:06 +0000[diff] [blame]48 <li><a href="#gc">Garbage Collector Names</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]49 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
50 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman27b47012009-07-27 18:07:55 +0000[diff] [blame]51 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]52 </ol>
53 </li>
54 <li><a href="#typesystem">Type System</a>
55 <ol>
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]56 <li><a href="#t_classifications">Type Classifications</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]57 <li><a href="#t_primitive">Primitive Types</a>
58 <ol>
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]59 <li><a href="#t_floating">Floating Point Types</a></li>
60 <li><a href="#t_void">Void Type</a></li>
61 <li><a href="#t_label">Label Type</a></li>
Nick Lewycky29aaef82009-05-30 05:06:04 +0000[diff] [blame]62 <li><a href="#t_metadata">Metadata Type</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]63 </ol>
64 </li>
65 <li><a href="#t_derived">Derived Types</a>
66 <ol>
Chris Lattner251ab812007-12-18 06:18:21 +0000[diff] [blame]67 <li><a href="#t_integer">Integer Type</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]68 <li><a href="#t_array">Array Type</a></li>
69 <li><a href="#t_function">Function Type</a></li>
70 <li><a href="#t_pointer">Pointer Type</a></li>
71 <li><a href="#t_struct">Structure Type</a></li>
72 <li><a href="#t_pstruct">Packed Structure Type</a></li>
73 <li><a href="#t_vector">Vector Type</a></li>
74 <li><a href="#t_opaque">Opaque Type</a></li>
75 </ol>
76 </li>
Chris Lattner515195a2009-02-02 07:32:36 +0000[diff] [blame]77 <li><a href="#t_uprefs">Type Up-references</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]78 </ol>
79 </li>
80 <li><a href="#constants">Constants</a>
81 <ol>
Dan Gohman2672f3e2008-10-14 16:51:45 +0000[diff] [blame]82 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner97063852009-02-28 18:32:25 +0000[diff] [blame]83 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman2672f3e2008-10-14 16:51:45 +0000[diff] [blame]84 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
85 <li><a href="#undefvalues">Undefined Values</a></li>
86 <li><a href="#constantexprs">Constant Expressions</a></li>
Nick Lewycky4dcf8102009-04-04 07:22:01 +0000[diff] [blame]87 <li><a href="#metadata">Embedded Metadata</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]88 </ol>
89 </li>
90 <li><a href="#othervalues">Other Values</a>
91 <ol>
Dan Gohman2672f3e2008-10-14 16:51:45 +0000[diff] [blame]92 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]93 </ol>
94 </li>
Chris Lattner75c24e02009-07-20 05:55:19 +0000[diff] [blame]95 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
96 <ol>
97 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner1e0e0d12009-07-20 06:14:25 +0000[diff] [blame]98 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
99 Global Variable</a></li>
Chris Lattner75c24e02009-07-20 05:55:19 +0000[diff] [blame]100 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
101 Global Variable</a></li>
102 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
103 Global Variable</a></li>
104 </ol>
105 </li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]106 <li><a href="#instref">Instruction Reference</a>
107 <ol>
108 <li><a href="#terminators">Terminator Instructions</a>
109 <ol>
110 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
111 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
112 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
113 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
114 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
115 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
116 </ol>
117 </li>
118 <li><a href="#binaryops">Binary Operations</a>
119 <ol>
120 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]121 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]122 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]123 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]124 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]125 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]126 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
127 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
128 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
129 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
130 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
131 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
132 </ol>
133 </li>
134 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
135 <ol>
136 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
137 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
138 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
139 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
140 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
141 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
142 </ol>
143 </li>
144 <li><a href="#vectorops">Vector Operations</a>
145 <ol>
146 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
147 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
148 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
149 </ol>
150 </li>
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]151 <li><a href="#aggregateops">Aggregate Operations</a>
152 <ol>
153 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
154 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
155 </ol>
156 </li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]157 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
158 <ol>
159 <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
160 <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
161 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
162 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
163 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
164 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
165 </ol>
166 </li>
167 <li><a href="#convertops">Conversion Operations</a>
168 <ol>
169 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
170 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
171 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
172 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
173 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
174 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
175 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
176 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
177 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
178 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
179 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
180 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
181 </ol>
Dan Gohman2672f3e2008-10-14 16:51:45 +0000[diff] [blame]182 </li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]183 <li><a href="#otherops">Other Operations</a>
184 <ol>
185 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
186 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
187 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
188 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
189 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
190 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
191 </ol>
192 </li>
193 </ol>
194 </li>
195 <li><a href="#intrinsics">Intrinsic Functions</a>
196 <ol>
197 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
198 <ol>
199 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
200 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
201 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
202 </ol>
203 </li>
204 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
205 <ol>
206 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
207 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
208 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
209 </ol>
210 </li>
211 <li><a href="#int_codegen">Code Generator Intrinsics</a>
212 <ol>
213 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
214 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
215 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
216 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
217 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
218 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
219 <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
220 </ol>
221 </li>
222 <li><a href="#int_libc">Standard C Library Intrinsics</a>
223 <ol>
224 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
225 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
226 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
227 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
228 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman361079c2007-10-15 20:30:11 +0000[diff] [blame]229 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
230 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
231 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]232 </ol>
233 </li>
234 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
235 <ol>
236 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
237 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
238 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
239 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]240 </ol>
241 </li>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]242 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
243 <ol>
Bill Wendling3e1258b2009-02-08 04:04:40 +0000[diff] [blame]244 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
245 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
246 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
247 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
248 <li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingbda98b62009-02-08 23:00:09 +0000[diff] [blame]249 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]250 </ol>
251 </li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]252 <li><a href="#int_debugger">Debugger intrinsics</a></li>
253 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands7407a9f2007-09-11 14:10:23 +0000[diff] [blame]254 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands38947cd2007-07-27 12:58:54 +0000[diff] [blame]255 <ol>
256 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands38947cd2007-07-27 12:58:54 +0000[diff] [blame]257 </ol>
258 </li>
Bill Wendling9127adb2008-11-18 22:10:53 +0000[diff] [blame]259 <li><a href="#int_atomics">Atomic intrinsics</a>
260 <ol>
261 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
262 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
263 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
264 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
265 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
266 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
267 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
268 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
269 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
270 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
271 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
272 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
273 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
274 </ol>
275 </li>
Reid Spencerb043f672007-07-20 19:59:11 +0000[diff] [blame]276 <li><a href="#int_general">General intrinsics</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]277 <ol>
Reid Spencerb043f672007-07-20 19:59:11 +0000[diff] [blame]278 <li><a href="#int_var_annotation">
Bill Wendlinge4164592008-11-19 05:56:17 +0000[diff] [blame]279 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattnerb306a9e2007-09-21 22:59:12 +0000[diff] [blame]280 <li><a href="#int_annotation">
Bill Wendlinge4164592008-11-19 05:56:17 +0000[diff] [blame]281 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikove6e764f2008-01-15 22:31:34 +0000[diff] [blame]282 <li><a href="#int_trap">
Bill Wendlinge4164592008-11-19 05:56:17 +0000[diff] [blame]283 '<tt>llvm.trap</tt>' Intrinsic</a></li>
284 <li><a href="#int_stackprotector">
285 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattnerb306a9e2007-09-21 22:59:12 +0000[diff] [blame]286 </ol>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]287 </li>
288 </ol>
289 </li>
290</ol>
291
292<div class="doc_author">
293 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
294 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
295</div>
296
297<!-- *********************************************************************** -->
298<div class="doc_section"> <a name="abstract">Abstract </a></div>
299<!-- *********************************************************************** -->
300
301<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]302
303<p>This document is a reference manual for the LLVM assembly language. LLVM is
304 a Static Single Assignment (SSA) based representation that provides type
305 safety, low-level operations, flexibility, and the capability of representing
306 'all' high-level languages cleanly. It is the common code representation
307 used throughout all phases of the LLVM compilation strategy.</p>
308
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]309</div>
310
311<!-- *********************************************************************** -->
312<div class="doc_section"> <a name="introduction">Introduction</a> </div>
313<!-- *********************************************************************** -->
314
315<div class="doc_text">
316
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]317<p>The LLVM code representation is designed to be used in three different forms:
318 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
319 for fast loading by a Just-In-Time compiler), and as a human readable
320 assembly language representation. This allows LLVM to provide a powerful
321 intermediate representation for efficient compiler transformations and
322 analysis, while providing a natural means to debug and visualize the
323 transformations. The three different forms of LLVM are all equivalent. This
324 document describes the human readable representation and notation.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]325
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]326<p>The LLVM representation aims to be light-weight and low-level while being
327 expressive, typed, and extensible at the same time. It aims to be a
328 "universal IR" of sorts, by being at a low enough level that high-level ideas
329 may be cleanly mapped to it (similar to how microprocessors are "universal
330 IR's", allowing many source languages to be mapped to them). By providing
331 type information, LLVM can be used as the target of optimizations: for
332 example, through pointer analysis, it can be proven that a C automatic
333 variable is never accessed outside of the current function... allowing it to
334 be promoted to a simple SSA value instead of a memory location.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]335
336</div>
337
338<!-- _______________________________________________________________________ -->
339<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
340
341<div class="doc_text">
342
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]343<p>It is important to note that this document describes 'well formed' LLVM
344 assembly language. There is a difference between what the parser accepts and
345 what is considered 'well formed'. For example, the following instruction is
346 syntactically okay, but not well formed:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]347
348<div class="doc_code">
349<pre>
350%x = <a href="#i_add">add</a> i32 1, %x
351</pre>
352</div>
353
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]354<p>...because the definition of <tt>%x</tt> does not dominate all of its
355 uses. The LLVM infrastructure provides a verification pass that may be used
356 to verify that an LLVM module is well formed. This pass is automatically run
357 by the parser after parsing input assembly and by the optimizer before it
358 outputs bitcode. The violations pointed out by the verifier pass indicate
359 bugs in transformation passes or input to the parser.</p>
360
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]361</div>
362
Chris Lattnera83fdc02007-10-03 17:34:29 +0000[diff] [blame]363<!-- Describe the typesetting conventions here. -->
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]364
365<!-- *********************************************************************** -->
366<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
367<!-- *********************************************************************** -->
368
369<div class="doc_text">
370
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]371<p>LLVM identifiers come in two basic types: global and local. Global
372 identifiers (functions, global variables) begin with the <tt>'@'</tt>
373 character. Local identifiers (register names, types) begin with
374 the <tt>'%'</tt> character. Additionally, there are three different formats
375 for identifiers, for different purposes:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]376
377<ol>
Reid Spencerc8245b02007-08-07 14:34:28 +0000[diff] [blame]378 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]379 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
380 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
381 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
382 other characters in their names can be surrounded with quotes. Special
383 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
384 ASCII code for the character in hexadecimal. In this way, any character
385 can be used in a name value, even quotes themselves.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]386
Reid Spencerc8245b02007-08-07 14:34:28 +0000[diff] [blame]387 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]388 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]389
390 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]391 constants</a>, below.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]392</ol>
393
Reid Spencerc8245b02007-08-07 14:34:28 +0000[diff] [blame]394<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]395 don't need to worry about name clashes with reserved words, and the set of
396 reserved words may be expanded in the future without penalty. Additionally,
397 unnamed identifiers allow a compiler to quickly come up with a temporary
398 variable without having to avoid symbol table conflicts.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]399
400<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]401 languages. There are keywords for different opcodes
402 ('<tt><a href="#i_add">add</a></tt>',
403 '<tt><a href="#i_bitcast">bitcast</a></tt>',
404 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
405 ('<tt><a href="#t_void">void</a></tt>',
406 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
407 reserved words cannot conflict with variable names, because none of them
408 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]409
410<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]411 '<tt>%X</tt>' by 8:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]412
413<p>The easy way:</p>
414
415<div class="doc_code">
416<pre>
417%result = <a href="#i_mul">mul</a> i32 %X, 8
418</pre>
419</div>
420
421<p>After strength reduction:</p>
422
423<div class="doc_code">
424<pre>
425%result = <a href="#i_shl">shl</a> i32 %X, i8 3
426</pre>
427</div>
428
429<p>And the hard way:</p>
430
431<div class="doc_code">
432<pre>
433<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
434<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
435%result = <a href="#i_add">add</a> i32 %1, %1
436</pre>
437</div>
438
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]439<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
440 lexical features of LLVM:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]441
442<ol>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]443 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]444 line.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]445
446 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]447 assigned to a named value.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]448
449 <li>Unnamed temporaries are numbered sequentially</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]450</ol>
451
452<p>...and it also shows a convention that we follow in this document. When
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]453 demonstrating instructions, we will follow an instruction with a comment that
454 defines the type and name of value produced. Comments are shown in italic
455 text.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]456
457</div>
458
459<!-- *********************************************************************** -->
460<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
461<!-- *********************************************************************** -->
462
463<!-- ======================================================================= -->
464<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
465</div>
466
467<div class="doc_text">
468
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]469<p>LLVM programs are composed of "Module"s, each of which is a translation unit
470 of the input programs. Each module consists of functions, global variables,
471 and symbol table entries. Modules may be combined together with the LLVM
472 linker, which merges function (and global variable) definitions, resolves
473 forward declarations, and merges symbol table entries. Here is an example of
474 the "hello world" module:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]475
476<div class="doc_code">
477<pre><i>; Declare the string constant as a global constant...</i>
478<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
479 href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
480
481<i>; External declaration of the puts function</i>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]482<a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]483
484<i>; Definition of main function</i>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]485define i32 @main() { <i>; i32()* </i>
Dan Gohman01852382009-01-04 23:44:43 +0000[diff] [blame]486 <i>; Convert [13 x i8]* to i8 *...</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]487 %cast210 = <a
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]488 href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]489
490 <i>; Call puts function to write out the string to stdout...</i>
491 <a
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]492 href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]493 <a
494 href="#i_ret">ret</a> i32 0<br>}<br>
495</pre>
496</div>
497
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]498<p>This example is made up of a <a href="#globalvars">global variable</a> named
499 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function, and
500 a <a href="#functionstructure">function definition</a> for
501 "<tt>main</tt>".</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]502
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]503<p>In general, a module is made up of a list of global values, where both
504 functions and global variables are global values. Global values are
505 represented by a pointer to a memory location (in this case, a pointer to an
506 array of char, and a pointer to a function), and have one of the
507 following <a href="#linkage">linkage types</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]508
509</div>
510
511<!-- ======================================================================= -->
512<div class="doc_subsection">
513 <a name="linkage">Linkage Types</a>
514</div>
515
516<div class="doc_text">
517
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]518<p>All Global Variables and Functions have one of the following types of
519 linkage:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]520
521<dl>
Rafael Espindolaa168fc92009-01-15 20:18:42 +0000[diff] [blame]522 <dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]523 <dd>Global values with private linkage are only directly accessible by objects
524 in the current module. In particular, linking code into a module with an
525 private global value may cause the private to be renamed as necessary to
526 avoid collisions. Because the symbol is private to the module, all
527 references can be updated. This doesn't show up in any symbol table in the
528 object file.</dd>
Rafael Espindolaa168fc92009-01-15 20:18:42 +0000[diff] [blame]529
Bill Wendling41a07852009-07-20 01:03:30 +0000[diff] [blame]530 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt>: </dt>
Bill Wendling41a07852009-07-20 01:03:30 +0000[diff] [blame]531 <dd>Similar to private, but the symbol is passed through the assembler and
Chris Lattner06c1ecc2009-08-24 04:32:16 +0000[diff] [blame]532 removed by the linker after evaluation. Note that (unlike private
533 symbols) linker_private symbols are subject to coalescing by the linker:
534 weak symbols get merged and redefinitions are rejected. However, unlike
535 normal strong symbols, they are removed by the linker from the final
536 linked image (executable or dynamic library).</dd>
Bill Wendling41a07852009-07-20 01:03:30 +0000[diff] [blame]537
Dale Johannesen96e7e092008-05-23 23:13:41 +0000[diff] [blame]538 <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]539 <dd>Similar to private, but the value shows as a local symbol
540 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
541 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]542
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]543 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt>: </dt>
Chris Lattner68433442009-04-13 05:44:34 +0000[diff] [blame]544 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]545 into the object file corresponding to the LLVM module. They exist to
546 allow inlining and other optimizations to take place given knowledge of
547 the definition of the global, which is known to be somewhere outside the
548 module. Globals with <tt>available_externally</tt> linkage are allowed to
549 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
550 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner68433442009-04-13 05:44:34 +0000[diff] [blame]551
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]552 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]553 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]554 the same name when linkage occurs. This is typically used to implement
555 inline functions, templates, or other code which must be generated in each
556 translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
557 allowed to be discarded.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]558
559 <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner7215c7f2009-08-05 05:21:07 +0000[diff] [blame]560 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
561 <tt>linkonce</tt> linkage, except that unreferenced globals with
562 <tt>weak</tt> linkage may not be discarded. This is used for globals that
563 are declared "weak" in C source code.</dd>
564
565 <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
566 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
567 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
568 global scope.
569 Symbols with "<tt>common</tt>" linkage are merged in the same way as
570 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattner83c4a712009-08-05 05:41:44 +0000[diff] [blame]571 <tt>common</tt> symbols may not have an explicit section,
572 must have a zero initializer, and may not be marked '<a
573 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
574 have common linkage.</dd>
Chris Lattner7215c7f2009-08-05 05:21:07 +0000[diff] [blame]575
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]576
577 <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]578 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]579 pointer to array type. When two global variables with appending linkage
580 are linked together, the two global arrays are appended together. This is
581 the LLVM, typesafe, equivalent of having the system linker append together
582 "sections" with identical names when .o files are linked.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]583
584 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]585 <dd>The semantics of this linkage follow the ELF object file model: the symbol
586 is weak until linked, if not linked, the symbol becomes null instead of
587 being an undefined reference.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]588
Duncan Sands19d161f2009-03-07 15:45:40 +0000[diff] [blame]589 <dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
Duncan Sands19d161f2009-03-07 15:45:40 +0000[diff] [blame]590 <dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]591 <dd>Some languages allow differing globals to be merged, such as two functions
592 with different semantics. Other languages, such as <tt>C++</tt>, ensure
593 that only equivalent globals are ever merged (the "one definition rule" -
594 "ODR"). Such languages can use the <tt>linkonce_odr</tt>
595 and <tt>weak_odr</tt> linkage types to indicate that the global will only
596 be merged with equivalent globals. These linkage types are otherwise the
597 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands19d161f2009-03-07 15:45:40 +0000[diff] [blame]598
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]599 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]600 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]601 visible, meaning that it participates in linkage and can be used to
602 resolve external symbol references.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]603</dl>
604
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]605<p>The next two types of linkage are targeted for Microsoft Windows platform
606 only. They are designed to support importing (exporting) symbols from (to)
607 DLLs (Dynamic Link Libraries).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]608
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]609<dl>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]610 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]611 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]612 or variable via a global pointer to a pointer that is set up by the DLL
613 exporting the symbol. On Microsoft Windows targets, the pointer name is
614 formed by combining <code>__imp_</code> and the function or variable
615 name.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]616
617 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]618 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]619 pointer to a pointer in a DLL, so that it can be referenced with the
620 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
621 name is formed by combining <code>__imp_</code> and the function or
622 variable name.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]623</dl>
624
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]625<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
626 another module defined a "<tt>.LC0</tt>" variable and was linked with this
627 one, one of the two would be renamed, preventing a collision. Since
628 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
629 declarations), they are accessible outside of the current module.</p>
630
631<p>It is illegal for a function <i>declaration</i> to have any linkage type
632 other than "externally visible", <tt>dllimport</tt>
633 or <tt>extern_weak</tt>.</p>
634
Duncan Sands19d161f2009-03-07 15:45:40 +0000[diff] [blame]635<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]636 or <tt>weak_odr</tt> linkages.</p>
637
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]638</div>
639
640<!-- ======================================================================= -->
641<div class="doc_subsection">
642 <a name="callingconv">Calling Conventions</a>
643</div>
644
645<div class="doc_text">
646
647<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]648 and <a href="#i_invoke">invokes</a> can all have an optional calling
649 convention specified for the call. The calling convention of any pair of
650 dynamic caller/callee must match, or the behavior of the program is
651 undefined. The following calling conventions are supported by LLVM, and more
652 may be added in the future:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]653
654<dl>
655 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]656 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]657 specified) matches the target C calling conventions. This calling
658 convention supports varargs function calls and tolerates some mismatch in
659 the declared prototype and implemented declaration of the function (as
660 does normal C).</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]661
662 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]663 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]664 (e.g. by passing things in registers). This calling convention allows the
665 target to use whatever tricks it wants to produce fast code for the
666 target, without having to conform to an externally specified ABI
667 (Application Binary Interface). Implementations of this convention should
668 allow arbitrary <a href="CodeGenerator.html#tailcallopt">tail call
669 optimization</a> to be supported. This calling convention does not
670 support varargs and requires the prototype of all callees to exactly match
671 the prototype of the function definition.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]672
673 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]674 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]675 as possible under the assumption that the call is not commonly executed.
676 As such, these calls often preserve all registers so that the call does
677 not break any live ranges in the caller side. This calling convention
678 does not support varargs and requires the prototype of all callees to
679 exactly match the prototype of the function definition.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]680
681 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]682 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]683 target-specific calling conventions to be used. Target specific calling
684 conventions start at 64.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]685</dl>
686
687<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]688 support Pascal conventions or any other well-known target-independent
689 convention.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]690
691</div>
692
693<!-- ======================================================================= -->
694<div class="doc_subsection">
695 <a name="visibility">Visibility Styles</a>
696</div>
697
698<div class="doc_text">
699
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]700<p>All Global Variables and Functions have one of the following visibility
701 styles:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]702
703<dl>
704 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner96451482008-08-05 18:29:16 +0000[diff] [blame]705 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]706 that the declaration is visible to other modules and, in shared libraries,
707 means that the declared entity may be overridden. On Darwin, default
708 visibility means that the declaration is visible to other modules. Default
709 visibility corresponds to "external linkage" in the language.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]710
711 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]712 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]713 object if they are in the same shared object. Usually, hidden visibility
714 indicates that the symbol will not be placed into the dynamic symbol
715 table, so no other module (executable or shared library) can reference it
716 directly.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]717
718 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]719 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]720 the dynamic symbol table, but that references within the defining module
721 will bind to the local symbol. That is, the symbol cannot be overridden by
722 another module.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]723</dl>
724
725</div>
726
727<!-- ======================================================================= -->
728<div class="doc_subsection">
Chris Lattner5b6dc6e2009-01-11 20:53:49 +0000[diff] [blame]729 <a name="namedtypes">Named Types</a>
730</div>
731
732<div class="doc_text">
733
734<p>LLVM IR allows you to specify name aliases for certain types. This can make
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]735 it easier to read the IR and make the IR more condensed (particularly when
736 recursive types are involved). An example of a name specification is:</p>
Chris Lattner5b6dc6e2009-01-11 20:53:49 +0000[diff] [blame]737
738<div class="doc_code">
739<pre>
740%mytype = type { %mytype*, i32 }
741</pre>
742</div>
743
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]744<p>You may give a name to any <a href="#typesystem">type</a> except
745 "<a href="t_void">void</a>". Type name aliases may be used anywhere a type
746 is expected with the syntax "%mytype".</p>
Chris Lattner5b6dc6e2009-01-11 20:53:49 +0000[diff] [blame]747
748<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]749 and that you can therefore specify multiple names for the same type. This
750 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
751 uses structural typing, the name is not part of the type. When printing out
752 LLVM IR, the printer will pick <em>one name</em> to render all types of a
753 particular shape. This means that if you have code where two different
754 source types end up having the same LLVM type, that the dumper will sometimes
755 print the "wrong" or unexpected type. This is an important design point and
756 isn't going to change.</p>
Chris Lattner5b6dc6e2009-01-11 20:53:49 +0000[diff] [blame]757
758</div>
759
Chris Lattner5b6dc6e2009-01-11 20:53:49 +0000[diff] [blame]760<!-- ======================================================================= -->
761<div class="doc_subsection">
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]762 <a name="globalvars">Global Variables</a>
763</div>
764
765<div class="doc_text">
766
767<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]768 instead of run-time. Global variables may optionally be initialized, may
769 have an explicit section to be placed in, and may have an optional explicit
770 alignment specified. A variable may be defined as "thread_local", which
771 means that it will not be shared by threads (each thread will have a
772 separated copy of the variable). A variable may be defined as a global
773 "constant," which indicates that the contents of the variable
774 will <b>never</b> be modified (enabling better optimization, allowing the
775 global data to be placed in the read-only section of an executable, etc).
776 Note that variables that need runtime initialization cannot be marked
777 "constant" as there is a store to the variable.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]778
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]779<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
780 constant, even if the final definition of the global is not. This capability
781 can be used to enable slightly better optimization of the program, but
782 requires the language definition to guarantee that optimizations based on the
783 'constantness' are valid for the translation units that do not include the
784 definition.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]785
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]786<p>As SSA values, global variables define pointer values that are in scope
787 (i.e. they dominate) all basic blocks in the program. Global variables
788 always define a pointer to their "content" type because they describe a
789 region of memory, and all memory objects in LLVM are accessed through
790 pointers.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]791
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]792<p>A global variable may be declared to reside in a target-specific numbered
793 address space. For targets that support them, address spaces may affect how
794 optimizations are performed and/or what target instructions are used to
795 access the variable. The default address space is zero. The address space
796 qualifier must precede any other attributes.</p>
Christopher Lambdd0049d2007-12-11 09:31:00 +0000[diff] [blame]797
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]798<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]799 supports it, it will emit globals to the section specified.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]800
801<p>An explicit alignment may be specified for a global. If not present, or if
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]802 the alignment is set to zero, the alignment of the global is set by the
803 target to whatever it feels convenient. If an explicit alignment is
804 specified, the global is forced to have at least that much alignment. All
805 alignments must be a power of 2.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]806
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]807<p>For example, the following defines a global in a numbered address space with
808 an initializer, section, and alignment:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]809
810<div class="doc_code">
811<pre>
Dan Gohman21ef02c2009-01-11 00:40:00 +0000[diff] [blame]812@G = addrspace(5) constant float 1.0, section "foo", align 4
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]813</pre>
814</div>
815
816</div>
817
818
819<!-- ======================================================================= -->
820<div class="doc_subsection">
821 <a name="functionstructure">Functions</a>
822</div>
823
824<div class="doc_text">
825
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]826<p>LLVM function definitions consist of the "<tt>define</tt>" keyord, an
827 optional <a href="#linkage">linkage type</a>, an optional
828 <a href="#visibility">visibility style</a>, an optional
829 <a href="#callingconv">calling convention</a>, a return type, an optional
830 <a href="#paramattrs">parameter attribute</a> for the return type, a function
831 name, a (possibly empty) argument list (each with optional
832 <a href="#paramattrs">parameter attributes</a>), optional
833 <a href="#fnattrs">function attributes</a>, an optional section, an optional
834 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
835 curly brace, a list of basic blocks, and a closing curly brace.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]836
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]837<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
838 optional <a href="#linkage">linkage type</a>, an optional
839 <a href="#visibility">visibility style</a>, an optional
840 <a href="#callingconv">calling convention</a>, a return type, an optional
841 <a href="#paramattrs">parameter attribute</a> for the return type, a function
842 name, a possibly empty list of arguments, an optional alignment, and an
843 optional <a href="#gc">garbage collector name</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]844
Chris Lattner96451482008-08-05 18:29:16 +0000[diff] [blame]845<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]846 (Control Flow Graph) for the function. Each basic block may optionally start
847 with a label (giving the basic block a symbol table entry), contains a list
848 of instructions, and ends with a <a href="#terminators">terminator</a>
849 instruction (such as a branch or function return).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]850
851<p>The first basic block in a function is special in two ways: it is immediately
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]852 executed on entrance to the function, and it is not allowed to have
853 predecessor basic blocks (i.e. there can not be any branches to the entry
854 block of a function). Because the block can have no predecessors, it also
855 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]856
857<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]858 supports it, it will emit functions to the section specified.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]859
860<p>An explicit alignment may be specified for a function. If not present, or if
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]861 the alignment is set to zero, the alignment of the function is set by the
862 target to whatever it feels convenient. If an explicit alignment is
863 specified, the function is forced to have at least that much alignment. All
864 alignments must be a power of 2.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]865
Bill Wendling6ec40612009-07-20 02:39:26 +0000[diff] [blame]866<h5>Syntax:</h5>
Devang Pateld0bfcc72008-10-07 17:48:33 +0000[diff] [blame]867<div class="doc_code">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]868<pre>
Chris Lattner1e5c5cd02008-10-13 16:55:18 +0000[diff] [blame]869define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]870 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
871 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
872 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
873 [<a href="#gc">gc</a>] { ... }
874</pre>
Devang Pateld0bfcc72008-10-07 17:48:33 +0000[diff] [blame]875</div>
876
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]877</div>
878
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]879<!-- ======================================================================= -->
880<div class="doc_subsection">
881 <a name="aliasstructure">Aliases</a>
882</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]883
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]884<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]885
886<p>Aliases act as "second name" for the aliasee value (which can be either
887 function, global variable, another alias or bitcast of global value). Aliases
888 may have an optional <a href="#linkage">linkage type</a>, and an
889 optional <a href="#visibility">visibility style</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]890
Bill Wendling6ec40612009-07-20 02:39:26 +0000[diff] [blame]891<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]892<div class="doc_code">
893<pre>
Duncan Sandsd7bfabf2008-09-12 20:48:21 +0000[diff] [blame]894@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]895</pre>
896</div>
897
898</div>
899
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]900<!-- ======================================================================= -->
901<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]902
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]903<div class="doc_text">
904
905<p>The return type and each parameter of a function type may have a set of
906 <i>parameter attributes</i> associated with them. Parameter attributes are
907 used to communicate additional information about the result or parameters of
908 a function. Parameter attributes are considered to be part of the function,
909 not of the function type, so functions with different parameter attributes
910 can have the same function type.</p>
911
912<p>Parameter attributes are simple keywords that follow the type specified. If
913 multiple parameter attributes are needed, they are space separated. For
914 example:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]915
916<div class="doc_code">
917<pre>
Nick Lewycky3022a742009-02-15 23:06:14 +0000[diff] [blame]918declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerf33b8452008-10-04 18:33:34 +0000[diff] [blame]919declare i32 @atoi(i8 zeroext)
920declare signext i8 @returns_signed_char()
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]921</pre>
922</div>
923
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]924<p>Note that any attributes for the function result (<tt>nounwind</tt>,
925 <tt>readonly</tt>) come immediately after the argument list.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]926
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]927<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner275e6be2008-01-11 06:20:47 +0000[diff] [blame]928
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]929<dl>
930 <dt><tt>zeroext</tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]931 <dd>This indicates to the code generator that the parameter or return value
932 should be zero-extended to a 32-bit value by the caller (for a parameter)
933 or the callee (for a return value).</dd>
Chris Lattner275e6be2008-01-11 06:20:47 +0000[diff] [blame]934
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]935 <dt><tt>signext</tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]936 <dd>This indicates to the code generator that the parameter or return value
937 should be sign-extended to a 32-bit value by the caller (for a parameter)
938 or the callee (for a return value).</dd>
Chris Lattner275e6be2008-01-11 06:20:47 +0000[diff] [blame]939
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]940 <dt><tt>inreg</tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]941 <dd>This indicates that this parameter or return value should be treated in a
942 special target-dependent fashion during while emitting code for a function
943 call or return (usually, by putting it in a register as opposed to memory,
944 though some targets use it to distinguish between two different kinds of
945 registers). Use of this attribute is target-specific.</dd>
Chris Lattner275e6be2008-01-11 06:20:47 +0000[diff] [blame]946
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]947 <dt><tt><a name="byval">byval</a></tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]948 <dd>This indicates that the pointer parameter should really be passed by value
949 to the function. The attribute implies that a hidden copy of the pointee
950 is made between the caller and the callee, so the callee is unable to
951 modify the value in the callee. This attribute is only valid on LLVM
952 pointer arguments. It is generally used to pass structs and arrays by
953 value, but is also valid on pointers to scalars. The copy is considered
954 to belong to the caller not the callee (for example,
955 <tt><a href="#readonly">readonly</a></tt> functions should not write to
956 <tt>byval</tt> parameters). This is not a valid attribute for return
957 values. The byval attribute also supports specifying an alignment with
958 the align attribute. This has a target-specific effect on the code
959 generator that usually indicates a desired alignment for the synthesized
960 stack slot.</dd>
961
962 <dt><tt>sret</tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]963 <dd>This indicates that the pointer parameter specifies the address of a
964 structure that is the return value of the function in the source program.
965 This pointer must be guaranteed by the caller to be valid: loads and
966 stores to the structure may be assumed by the callee to not to trap. This
967 may only be applied to the first parameter. This is not a valid attribute
968 for return values. </dd>
969
970 <dt><tt>noalias</tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]971 <dd>This indicates that the pointer does not alias any global or any other
972 parameter. The caller is responsible for ensuring that this is the
973 case. On a function return value, <tt>noalias</tt> additionally indicates
974 that the pointer does not alias any other pointers visible to the
975 caller. For further details, please see the discussion of the NoAlias
976 response in
977 <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
978 analysis</a>.</dd>
979
980 <dt><tt>nocapture</tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]981 <dd>This indicates that the callee does not make any copies of the pointer
982 that outlive the callee itself. This is not a valid attribute for return
983 values.</dd>
984
985 <dt><tt>nest</tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]986 <dd>This indicates that the pointer parameter can be excised using the
987 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
988 attribute for return values.</dd>
989</dl>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]990
991</div>
992
993<!-- ======================================================================= -->
994<div class="doc_subsection">
Gordon Henriksen13fe5e32007-12-10 03:18:06 +0000[diff] [blame]995 <a name="gc">Garbage Collector Names</a>
996</div>
997
998<div class="doc_text">
Gordon Henriksen13fe5e32007-12-10 03:18:06 +0000[diff] [blame]999
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1000<p>Each function may specify a garbage collector name, which is simply a
1001 string:</p>
1002
1003<div class="doc_code">
1004<pre>
1005define void @f() gc "name" { ...
1006</pre>
1007</div>
Gordon Henriksen13fe5e32007-12-10 03:18:06 +0000[diff] [blame]1008
1009<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1010 collector which will cause the compiler to alter its output in order to
1011 support the named garbage collection algorithm.</p>
1012
Gordon Henriksen13fe5e32007-12-10 03:18:06 +0000[diff] [blame]1013</div>
1014
1015<!-- ======================================================================= -->
1016<div class="doc_subsection">
Devang Patel008cd3e2008-09-26 23:51:19 +0000[diff] [blame]1017 <a name="fnattrs">Function Attributes</a>
Devang Pateld468f1c2008-09-04 23:05:13 +0000[diff] [blame]1018</div>
1019
1020<div class="doc_text">
Devang Patel008cd3e2008-09-26 23:51:19 +0000[diff] [blame]1021
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1022<p>Function attributes are set to communicate additional information about a
1023 function. Function attributes are considered to be part of the function, not
1024 of the function type, so functions with different parameter attributes can
1025 have the same function type.</p>
Devang Patel008cd3e2008-09-26 23:51:19 +0000[diff] [blame]1026
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1027<p>Function attributes are simple keywords that follow the type specified. If
1028 multiple attributes are needed, they are space separated. For example:</p>
Devang Pateld468f1c2008-09-04 23:05:13 +0000[diff] [blame]1029
1030<div class="doc_code">
Bill Wendling74d3eac2008-09-07 10:26:33 +0000[diff] [blame]1031<pre>
Devang Patel008cd3e2008-09-26 23:51:19 +0000[diff] [blame]1032define void @f() noinline { ... }
1033define void @f() alwaysinline { ... }
1034define void @f() alwaysinline optsize { ... }
1035define void @f() optsize
Bill Wendling74d3eac2008-09-07 10:26:33 +0000[diff] [blame]1036</pre>
Devang Pateld468f1c2008-09-04 23:05:13 +0000[diff] [blame]1037</div>
1038
Bill Wendling74d3eac2008-09-07 10:26:33 +0000[diff] [blame]1039<dl>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1040 <dt><tt>alwaysinline</tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1041 <dd>This attribute indicates that the inliner should attempt to inline this
1042 function into callers whenever possible, ignoring any active inlining size
1043 threshold for this caller.</dd>
Bill Wendling74d3eac2008-09-07 10:26:33 +0000[diff] [blame]1044
Dale Johannesen7fd6b0f2009-08-26 01:08:21 +0000[diff] [blame^]1045 <dt><tt>inlinehint</tt></dt>
1046 <dd>This attribute indicates that the source code contained a hint that inlining
1047 this function is desirable (such as the "inline" keyword in C/C++). It
1048 is just a hint; it imposes no requirements on the inliner.</dd>
1049
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1050 <dt><tt>noinline</tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1051 <dd>This attribute indicates that the inliner should never inline this
1052 function in any situation. This attribute may not be used together with
1053 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel008cd3e2008-09-26 23:51:19 +0000[diff] [blame]1054
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1055 <dt><tt>optsize</tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1056 <dd>This attribute suggests that optimization passes and code generator passes
1057 make choices that keep the code size of this function low, and otherwise
1058 do optimizations specifically to reduce code size.</dd>
Devang Patel008cd3e2008-09-26 23:51:19 +0000[diff] [blame]1059
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1060 <dt><tt>noreturn</tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1061 <dd>This function attribute indicates that the function never returns
1062 normally. This produces undefined behavior at runtime if the function
1063 ever does dynamically return.</dd>
Bill Wendlingdfaabba2008-11-13 01:02:51 +0000[diff] [blame]1064
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1065 <dt><tt>nounwind</tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1066 <dd>This function attribute indicates that the function never returns with an
1067 unwind or exceptional control flow. If the function does unwind, its
1068 runtime behavior is undefined.</dd>
Bill Wendlingbe9ec3f2008-11-26 19:07:40 +0000[diff] [blame]1069
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1070 <dt><tt>readnone</tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1071 <dd>This attribute indicates that the function computes its result (or decides
1072 to unwind an exception) based strictly on its arguments, without
1073 dereferencing any pointer arguments or otherwise accessing any mutable
1074 state (e.g. memory, control registers, etc) visible to caller functions.
1075 It does not write through any pointer arguments
1076 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1077 changes any state visible to callers. This means that it cannot unwind
1078 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1079 could use the <tt>unwind</tt> instruction.</dd>
Devang Patela2f9f412009-06-12 19:45:19 +0000[diff] [blame]1080
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1081 <dt><tt><a name="readonly">readonly</a></tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1082 <dd>This attribute indicates that the function does not write through any
1083 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1084 arguments) or otherwise modify any state (e.g. memory, control registers,
1085 etc) visible to caller functions. It may dereference pointer arguments
1086 and read state that may be set in the caller. A readonly function always
1087 returns the same value (or unwinds an exception identically) when called
1088 with the same set of arguments and global state. It cannot unwind an
1089 exception by calling the <tt>C++</tt> exception throwing methods, but may
1090 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovedd7d112009-07-17 18:07:26 +0000[diff] [blame]1091
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1092 <dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1093 <dd>This attribute indicates that the function should emit a stack smashing
1094 protector. It is in the form of a "canary"&mdash;a random value placed on
1095 the stack before the local variables that's checked upon return from the
1096 function to see if it has been overwritten. A heuristic is used to
1097 determine if a function needs stack protectors or not.<br>
1098<br>
1099 If a function that has an <tt>ssp</tt> attribute is inlined into a
1100 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1101 function will have an <tt>ssp</tt> attribute.</dd>
1102
1103 <dt><tt>sspreq</tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1104 <dd>This attribute indicates that the function should <em>always</em> emit a
1105 stack smashing protector. This overrides
Bill Wendling6ec40612009-07-20 02:39:26 +0000[diff] [blame]1106 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1107<br>
1108 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1109 function that doesn't have an <tt>sspreq</tt> attribute or which has
1110 an <tt>ssp</tt> attribute, then the resulting function will have
1111 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1112
1113 <dt><tt>noredzone</tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1114 <dd>This attribute indicates that the code generator should not use a red
1115 zone, even if the target-specific ABI normally permits it.</dd>
1116
1117 <dt><tt>noimplicitfloat</tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1118 <dd>This attributes disables implicit floating point instructions.</dd>
1119
1120 <dt><tt>naked</tt></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1121 <dd>This attribute disables prologue / epilogue emission for the function.
1122 This can have very system-specific consequences.</dd>
Bill Wendling74d3eac2008-09-07 10:26:33 +0000[diff] [blame]1123</dl>
1124
Devang Pateld468f1c2008-09-04 23:05:13 +0000[diff] [blame]1125</div>
1126
1127<!-- ======================================================================= -->
1128<div class="doc_subsection">
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1129 <a name="moduleasm">Module-Level Inline Assembly</a>
1130</div>
1131
1132<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1133
1134<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1135 the GCC "file scope inline asm" blocks. These blocks are internally
1136 concatenated by LLVM and treated as a single unit, but may be separated in
1137 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1138
1139<div class="doc_code">
1140<pre>
1141module asm "inline asm code goes here"
1142module asm "more can go here"
1143</pre>
1144</div>
1145
1146<p>The strings can contain any character by escaping non-printable characters.
1147 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1148 for the number.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1149
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1150<p>The inline asm code is simply printed to the machine code .s file when
1151 assembly code is generated.</p>
1152
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1153</div>
1154
1155<!-- ======================================================================= -->
1156<div class="doc_subsection">
1157 <a name="datalayout">Data Layout</a>
1158</div>
1159
1160<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1161
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1162<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1163 data is to be laid out in memory. The syntax for the data layout is
1164 simply:</p>
1165
1166<div class="doc_code">
1167<pre>
1168target datalayout = "<i>layout specification</i>"
1169</pre>
1170</div>
1171
1172<p>The <i>layout specification</i> consists of a list of specifications
1173 separated by the minus sign character ('-'). Each specification starts with
1174 a letter and may include other information after the letter to define some
1175 aspect of the data layout. The specifications accepted are as follows:</p>
1176
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1177<dl>
1178 <dt><tt>E</tt></dt>
1179 <dd>Specifies that the target lays out data in big-endian form. That is, the
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1180 bits with the most significance have the lowest address location.</dd>
1181
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1182 <dt><tt>e</tt></dt>
Chris Lattner96451482008-08-05 18:29:16 +0000[diff] [blame]1183 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1184 the bits with the least significance have the lowest address
1185 location.</dd>
1186
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1187 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1188 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1189 <i>preferred</i> alignments. All sizes are in bits. Specifying
1190 the <i>pref</i> alignment is optional. If omitted, the
1191 preceding <tt>:</tt> should be omitted too.</dd>
1192
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1193 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1194 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1195 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1196
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1197 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1198 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1199 <i>size</i>.</dd>
1200
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1201 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1202 <dd>This specifies the alignment for a floating point type of a given bit
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1203 <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
1204 (double).</dd>
1205
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1206 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1207 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1208 <i>size</i>.</dd>
1209
Daniel Dunbard88a97b2009-06-08 22:17:53 +0000[diff] [blame]1210 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1211 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1212 <i>size</i>.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1213</dl>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1214
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1215<p>When constructing the data layout for a given target, LLVM starts with a
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1216 default set of specifications which are then (possibly) overriden by the
1217 specifications in the <tt>datalayout</tt> keyword. The default specifications
1218 are given in this list:</p>
1219
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1220<ul>
1221 <li><tt>E</tt> - big endian</li>
1222 <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
1223 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1224 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1225 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1226 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner96451482008-08-05 18:29:16 +0000[diff] [blame]1227 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1228 alignment of 64-bits</li>
1229 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1230 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1231 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1232 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1233 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbard88a97b2009-06-08 22:17:53 +0000[diff] [blame]1234 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1235</ul>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1236
1237<p>When LLVM is determining the alignment for a given type, it uses the
1238 following rules:</p>
1239
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1240<ol>
1241 <li>If the type sought is an exact match for one of the specifications, that
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1242 specification is used.</li>
1243
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1244 <li>If no match is found, and the type sought is an integer type, then the
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1245 smallest integer type that is larger than the bitwidth of the sought type
1246 is used. If none of the specifications are larger than the bitwidth then
1247 the the largest integer type is used. For example, given the default
1248 specifications above, the i7 type will use the alignment of i8 (next
1249 largest) while both i65 and i256 will use the alignment of i64 (largest
1250 specified).</li>
1251
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1252 <li>If no match is found, and the type sought is a vector type, then the
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1253 largest vector type that is smaller than the sought vector type will be
1254 used as a fall back. This happens because &lt;128 x double&gt; can be
1255 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1256</ol>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1257
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1258</div>
1259
Dan Gohman27b47012009-07-27 18:07:55 +0000[diff] [blame]1260<!-- ======================================================================= -->
1261<div class="doc_subsection">
1262 <a name="pointeraliasing">Pointer Aliasing Rules</a>
1263</div>
1264
1265<div class="doc_text">
1266
Andreas Bolka11fbf432009-07-29 00:02:05 +0000[diff] [blame]1267<p>Any memory access must be done through a pointer value associated
Andreas Bolka23bece42009-07-27 20:37:10 +0000[diff] [blame]1268with an address range of the memory access, otherwise the behavior
Dan Gohman27b47012009-07-27 18:07:55 +0000[diff] [blame]1269is undefined. Pointer values are associated with address ranges
1270according to the following rules:</p>
1271
1272<ul>
Andreas Bolka11fbf432009-07-29 00:02:05 +0000[diff] [blame]1273 <li>A pointer value formed from a
1274 <tt><a href="#i_getelementptr">getelementptr</a></tt> instruction
1275 is associated with the addresses associated with the first operand
1276 of the <tt>getelementptr</tt>.</li>
1277 <li>An address of a global variable is associated with the address
Dan Gohman27b47012009-07-27 18:07:55 +0000[diff] [blame]1278 range of the variable's storage.</li>
1279 <li>The result value of an allocation instruction is associated with
1280 the address range of the allocated storage.</li>
1281 <li>A null pointer in the default address-space is associated with
Andreas Bolka11fbf432009-07-29 00:02:05 +0000[diff] [blame]1282 no address.</li>
1283 <li>A pointer value formed by an
1284 <tt><a href="#i_inttoptr">inttoptr</a></tt> is associated with all
1285 address ranges of all pointer values that contribute (directly or
1286 indirectly) to the computation of the pointer's value.</li>
1287 <li>The result value of a
1288 <tt><a href="#i_bitcast">bitcast</a></tt> is associated with all
Dan Gohman27b47012009-07-27 18:07:55 +0000[diff] [blame]1289 addresses associated with the operand of the <tt>bitcast</tt>.</li>
1290 <li>An integer constant other than zero or a pointer value returned
1291 from a function not defined within LLVM may be associated with address
1292 ranges allocated through mechanisms other than those provided by
Andreas Bolka11fbf432009-07-29 00:02:05 +0000[diff] [blame]1293 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman27b47012009-07-27 18:07:55 +0000[diff] [blame]1294 allocated by mechanisms provided by LLVM.</li>
1295 </ul>
1296
1297<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka11fbf432009-07-29 00:02:05 +0000[diff] [blame]1298<tt><a href="#i_load">load</a></tt> merely indicates the size and
1299alignment of the memory from which to load, as well as the
1300interpretation of the value. The first operand of a
1301<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1302and alignment of the store.</p>
Dan Gohman27b47012009-07-27 18:07:55 +0000[diff] [blame]1303
1304<p>Consequently, type-based alias analysis, aka TBAA, aka
1305<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1306LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1307additional information which specialized optimization passes may use
1308to implement type-based alias analysis.</p>
1309
1310</div>
1311
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1312<!-- *********************************************************************** -->
1313<div class="doc_section"> <a name="typesystem">Type System</a> </div>
1314<!-- *********************************************************************** -->
1315
1316<div class="doc_text">
1317
1318<p>The LLVM type system is one of the most important features of the
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1319 intermediate representation. Being typed enables a number of optimizations
1320 to be performed on the intermediate representation directly, without having
1321 to do extra analyses on the side before the transformation. A strong type
1322 system makes it easier to read the generated code and enables novel analyses
1323 and transformations that are not feasible to perform on normal three address
1324 code representations.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1325
1326</div>
1327
1328<!-- ======================================================================= -->
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1329<div class="doc_subsection"> <a name="t_classifications">Type
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1330Classifications</a> </div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1331
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1332<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1333
1334<p>The types fall into a few useful classifications:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1335
1336<table border="1" cellspacing="0" cellpadding="4">
1337 <tbody>
1338 <tr><th>Classification</th><th>Types</th></tr>
1339 <tr>
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1340 <td><a href="#t_integer">integer</a></td>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1341 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
1342 </tr>
1343 <tr>
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1344 <td><a href="#t_floating">floating point</a></td>
1345 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1346 </tr>
1347 <tr>
1348 <td><a name="t_firstclass">first class</a></td>
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1349 <td><a href="#t_integer">integer</a>,
1350 <a href="#t_floating">floating point</a>,
1351 <a href="#t_pointer">pointer</a>,
Dan Gohmanf6237db2008-06-18 18:42:13 +0000[diff] [blame]1352 <a href="#t_vector">vector</a>,
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]1353 <a href="#t_struct">structure</a>,
1354 <a href="#t_array">array</a>,
Nick Lewycky29aaef82009-05-30 05:06:04 +0000[diff] [blame]1355 <a href="#t_label">label</a>,
1356 <a href="#t_metadata">metadata</a>.
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1357 </td>
1358 </tr>
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1359 <tr>
1360 <td><a href="#t_primitive">primitive</a></td>
1361 <td><a href="#t_label">label</a>,
1362 <a href="#t_void">void</a>,
Nick Lewycky29aaef82009-05-30 05:06:04 +0000[diff] [blame]1363 <a href="#t_floating">floating point</a>,
1364 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1365 </tr>
1366 <tr>
1367 <td><a href="#t_derived">derived</a></td>
1368 <td><a href="#t_integer">integer</a>,
1369 <a href="#t_array">array</a>,
1370 <a href="#t_function">function</a>,
1371 <a href="#t_pointer">pointer</a>,
1372 <a href="#t_struct">structure</a>,
1373 <a href="#t_pstruct">packed structure</a>,
1374 <a href="#t_vector">vector</a>,
1375 <a href="#t_opaque">opaque</a>.
Dan Gohman032ba852008-10-14 16:32:04 +0000[diff] [blame]1376 </td>
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1377 </tr>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1378 </tbody>
1379</table>
1380
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1381<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1382 important. Values of these types are the only ones which can be produced by
1383 instructions, passed as arguments, or used as operands to instructions.</p>
1384
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1385</div>
1386
1387<!-- ======================================================================= -->
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1388<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner86437612008-01-04 04:34:14 +0000[diff] [blame]1389
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1390<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1391
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1392<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1393 system.</p>
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1394
Chris Lattner86437612008-01-04 04:34:14 +0000[diff] [blame]1395</div>
1396
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1397<!-- _______________________________________________________________________ -->
1398<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
1399
1400<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1401
1402<table>
1403 <tbody>
1404 <tr><th>Type</th><th>Description</th></tr>
1405 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1406 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1407 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1408 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1409 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1410 </tbody>
1411</table>
1412
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1413</div>
1414
1415<!-- _______________________________________________________________________ -->
1416<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
1417
1418<div class="doc_text">
Bill Wendling6ec40612009-07-20 02:39:26 +0000[diff] [blame]1419
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1420<h5>Overview:</h5>
1421<p>The void type does not represent any value and has no size.</p>
1422
1423<h5>Syntax:</h5>
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1424<pre>
1425 void
1426</pre>
Bill Wendling6ec40612009-07-20 02:39:26 +0000[diff] [blame]1427
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1428</div>
1429
1430<!-- _______________________________________________________________________ -->
1431<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
1432
1433<div class="doc_text">
Bill Wendling6ec40612009-07-20 02:39:26 +0000[diff] [blame]1434
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1435<h5>Overview:</h5>
1436<p>The label type represents code labels.</p>
1437
1438<h5>Syntax:</h5>
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1439<pre>
1440 label
1441</pre>
Bill Wendling6ec40612009-07-20 02:39:26 +0000[diff] [blame]1442
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1443</div>
1444
Nick Lewycky29aaef82009-05-30 05:06:04 +0000[diff] [blame]1445<!-- _______________________________________________________________________ -->
1446<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
1447
1448<div class="doc_text">
Bill Wendling6ec40612009-07-20 02:39:26 +0000[diff] [blame]1449
Nick Lewycky29aaef82009-05-30 05:06:04 +0000[diff] [blame]1450<h5>Overview:</h5>
1451<p>The metadata type represents embedded metadata. The only derived type that
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1452 may contain metadata is <tt>metadata*</tt> or a function type that returns or
1453 takes metadata typed parameters, but not pointer to metadata types.</p>
Nick Lewycky29aaef82009-05-30 05:06:04 +0000[diff] [blame]1454
1455<h5>Syntax:</h5>
Nick Lewycky29aaef82009-05-30 05:06:04 +0000[diff] [blame]1456<pre>
1457 metadata
1458</pre>
Bill Wendling6ec40612009-07-20 02:39:26 +0000[diff] [blame]1459
Nick Lewycky29aaef82009-05-30 05:06:04 +0000[diff] [blame]1460</div>
1461
Chris Lattner488772f2008-01-04 04:32:38 +0000[diff] [blame]1462
1463<!-- ======================================================================= -->
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1464<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
1465
1466<div class="doc_text">
1467
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1468<p>The real power in LLVM comes from the derived types in the system. This is
1469 what allows a programmer to represent arrays, functions, pointers, and other
1470 useful types. Note that these derived types may be recursive: For example,
1471 it is possible to have a two dimensional array.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1472
1473</div>
1474
1475<!-- _______________________________________________________________________ -->
1476<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
1477
1478<div class="doc_text">
1479
1480<h5>Overview:</h5>
1481<p>The integer type is a very simple derived type that simply specifies an
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1482 arbitrary bit width for the integer type desired. Any bit width from 1 bit to
1483 2^23-1 (about 8 million) can be specified.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1484
1485<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1486<pre>
1487 iN
1488</pre>
1489
1490<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1491 value.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1492
1493<h5>Examples:</h5>
1494<table class="layout">
Nick Lewycky39382d62009-05-24 02:46:06 +0000[diff] [blame]1495 <tr class="layout">
1496 <td class="left"><tt>i1</tt></td>
1497 <td class="left">a single-bit integer.</td>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1498 </tr>
Nick Lewycky39382d62009-05-24 02:46:06 +0000[diff] [blame]1499 <tr class="layout">
1500 <td class="left"><tt>i32</tt></td>
1501 <td class="left">a 32-bit integer.</td>
1502 </tr>
1503 <tr class="layout">
1504 <td class="left"><tt>i1942652</tt></td>
1505 <td class="left">a really big integer of over 1 million bits.</td>
1506 </tr>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1507</table>
djge93155c2009-01-24 15:58:40 +0000[diff] [blame]1508
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1509<p>Note that the code generator does not yet support large integer types to be
1510 used as function return types. The specific limit on how large a return type
1511 the code generator can currently handle is target-dependent; currently it's
1512 often 64 bits for 32-bit targets and 128 bits for 64-bit targets.</p>
djge93155c2009-01-24 15:58:40 +0000[diff] [blame]1513
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1514</div>
1515
1516<!-- _______________________________________________________________________ -->
1517<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
1518
1519<div class="doc_text">
1520
1521<h5>Overview:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1522<p>The array type is a very simple derived type that arranges elements
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1523 sequentially in memory. The array type requires a size (number of elements)
1524 and an underlying data type.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1525
1526<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1527<pre>
1528 [&lt;# elements&gt; x &lt;elementtype&gt;]
1529</pre>
1530
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1531<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1532 be any type with a size.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1533
1534<h5>Examples:</h5>
1535<table class="layout">
1536 <tr class="layout">
Chris Lattner7311d222007-12-19 05:04:11 +0000[diff] [blame]1537 <td class="left"><tt>[40 x i32]</tt></td>
1538 <td class="left">Array of 40 32-bit integer values.</td>
1539 </tr>
1540 <tr class="layout">
1541 <td class="left"><tt>[41 x i32]</tt></td>
1542 <td class="left">Array of 41 32-bit integer values.</td>
1543 </tr>
1544 <tr class="layout">
1545 <td class="left"><tt>[4 x i8]</tt></td>
1546 <td class="left">Array of 4 8-bit integer values.</td>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1547 </tr>
1548</table>
1549<p>Here are some examples of multidimensional arrays:</p>
1550<table class="layout">
1551 <tr class="layout">
Chris Lattner7311d222007-12-19 05:04:11 +0000[diff] [blame]1552 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1553 <td class="left">3x4 array of 32-bit integer values.</td>
1554 </tr>
1555 <tr class="layout">
1556 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1557 <td class="left">12x10 array of single precision floating point values.</td>
1558 </tr>
1559 <tr class="layout">
1560 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1561 <td class="left">2x3x4 array of 16-bit integer values.</td>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1562 </tr>
1563</table>
1564
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1565<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
1566 length array. Normally, accesses past the end of an array are undefined in
1567 LLVM (e.g. it is illegal to access the 5th element of a 3 element array). As
1568 a special case, however, zero length arrays are recognized to be variable
1569 length. This allows implementation of 'pascal style arrays' with the LLVM
1570 type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1571
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1572<p>Note that the code generator does not yet support large aggregate types to be
1573 used as function return types. The specific limit on how large an aggregate
1574 return type the code generator can currently handle is target-dependent, and
1575 also dependent on the aggregate element types.</p>
djge93155c2009-01-24 15:58:40 +0000[diff] [blame]1576
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1577</div>
1578
1579<!-- _______________________________________________________________________ -->
1580<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1581
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1582<div class="doc_text">
Chris Lattner43030e72008-04-23 04:59:35 +0000[diff] [blame]1583
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1584<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1585<p>The function type can be thought of as a function signature. It consists of
1586 a return type and a list of formal parameter types. The return type of a
1587 function type is a scalar type, a void type, or a struct type. If the return
1588 type is a struct type then all struct elements must be of first class types,
1589 and the struct must have at least one element.</p>
Devang Patela3cc5372008-03-10 20:49:15 +0000[diff] [blame]1590
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1591<h5>Syntax:</h5>
Chris Lattner43030e72008-04-23 04:59:35 +0000[diff] [blame]1592<pre>
1593 &lt;returntype list&gt; (&lt;parameter list&gt;)
1594</pre>
1595
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1596<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1597 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1598 which indicates that the function takes a variable number of arguments.
1599 Variable argument functions can access their arguments with
1600 the <a href="#int_varargs">variable argument handling intrinsic</a>
1601 functions. '<tt>&lt;returntype list&gt;</tt>' is a comma-separated list of
1602 <a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner43030e72008-04-23 04:59:35 +0000[diff] [blame]1603
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1604<h5>Examples:</h5>
1605<table class="layout">
1606 <tr class="layout">
1607 <td class="left"><tt>i32 (i32)</tt></td>
1608 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
1609 </td>
1610 </tr><tr class="layout">
Reid Spencerf234bed2007-07-19 23:13:04 +0000[diff] [blame]1611 <td class="left"><tt>float&nbsp;(i16&nbsp;signext,&nbsp;i32&nbsp;*)&nbsp;*
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1612 </tt></td>
1613 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
1614 an <tt>i16</tt> that should be sign extended and a
1615 <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
1616 <tt>float</tt>.
1617 </td>
1618 </tr><tr class="layout">
1619 <td class="left"><tt>i32 (i8*, ...)</tt></td>
1620 <td class="left">A vararg function that takes at least one
1621 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1622 which returns an integer. This is the signature for <tt>printf</tt> in
1623 LLVM.
1624 </td>
Devang Pateld4ba41d2008-03-24 05:35:41 +0000[diff] [blame]1625 </tr><tr class="layout">
1626 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukmanafc88b02008-11-27 06:41:20 +0000[diff] [blame]1627 <td class="left">A function taking an <tt>i32</tt>, returning two
1628 <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Pateld4ba41d2008-03-24 05:35:41 +0000[diff] [blame]1629 </td>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1630 </tr>
1631</table>
1632
1633</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1634
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1635<!-- _______________________________________________________________________ -->
1636<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1637
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1638<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1639
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1640<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1641<p>The structure type is used to represent a collection of data members together
1642 in memory. The packing of the field types is defined to match the ABI of the
1643 underlying processor. The elements of a structure may be any type that has a
1644 size.</p>
1645
1646<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1647 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1648 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1649
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1650<h5>Syntax:</h5>
Bill Wendling6ec40612009-07-20 02:39:26 +0000[diff] [blame]1651<pre>
1652 { &lt;type list&gt; }
1653</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1654
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1655<h5>Examples:</h5>
1656<table class="layout">
1657 <tr class="layout">
1658 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1659 <td class="left">A triple of three <tt>i32</tt> values</td>
1660 </tr><tr class="layout">
1661 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1662 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1663 second element is a <a href="#t_pointer">pointer</a> to a
1664 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1665 an <tt>i32</tt>.</td>
1666 </tr>
1667</table>
djge93155c2009-01-24 15:58:40 +0000[diff] [blame]1668
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1669<p>Note that the code generator does not yet support large aggregate types to be
1670 used as function return types. The specific limit on how large an aggregate
1671 return type the code generator can currently handle is target-dependent, and
1672 also dependent on the aggregate element types.</p>
djge93155c2009-01-24 15:58:40 +0000[diff] [blame]1673
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1674</div>
1675
1676<!-- _______________________________________________________________________ -->
1677<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
1678</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1679
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1680<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1681
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1682<h5>Overview:</h5>
1683<p>The packed structure type is used to represent a collection of data members
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1684 together in memory. There is no padding between fields. Further, the
1685 alignment of a packed structure is 1 byte. The elements of a packed
1686 structure may be any type that has a size.</p>
1687
1688<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> and
1689 '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field with
1690 the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
1691
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1692<h5>Syntax:</h5>
Bill Wendling6ec40612009-07-20 02:39:26 +0000[diff] [blame]1693<pre>
1694 &lt; { &lt;type list&gt; } &gt;
1695</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1696
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1697<h5>Examples:</h5>
1698<table class="layout">
1699 <tr class="layout">
1700 <td class="left"><tt>&lt; { i32, i32, i32 } &gt;</tt></td>
1701 <td class="left">A triple of three <tt>i32</tt> values</td>
1702 </tr><tr class="layout">
Bill Wendling74d3eac2008-09-07 10:26:33 +0000[diff] [blame]1703 <td class="left">
1704<tt>&lt;&nbsp;{&nbsp;float,&nbsp;i32&nbsp;(i32)*&nbsp;}&nbsp;&gt;</tt></td>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1705 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1706 second element is a <a href="#t_pointer">pointer</a> to a
1707 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1708 an <tt>i32</tt>.</td>
1709 </tr>
1710</table>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1711
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1712</div>
1713
1714<!-- _______________________________________________________________________ -->
1715<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Chris Lattner96edbd32009-02-08 19:53:29 +0000[diff] [blame]1716
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1717<div class="doc_text">
1718
1719<h5>Overview:</h5>
1720<p>As in many languages, the pointer type represents a pointer or reference to
1721 another object, which must live in memory. Pointer types may have an optional
1722 address space attribute defining the target-specific numbered address space
1723 where the pointed-to object resides. The default address space is zero.</p>
1724
1725<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1726 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner96edbd32009-02-08 19:53:29 +0000[diff] [blame]1727
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1728<h5>Syntax:</h5>
Bill Wendling6ec40612009-07-20 02:39:26 +0000[diff] [blame]1729<pre>
1730 &lt;type&gt; *
1731</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1732
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1733<h5>Examples:</h5>
1734<table class="layout">
1735 <tr class="layout">
Dan Gohman01852382009-01-04 23:44:43 +0000[diff] [blame]1736 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner7311d222007-12-19 05:04:11 +0000[diff] [blame]1737 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1738 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1739 </tr>
1740 <tr class="layout">
1741 <td class="left"><tt>i32 (i32 *) *</tt></td>
1742 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1743 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner7311d222007-12-19 05:04:11 +0000[diff] [blame]1744 <tt>i32</tt>.</td>
1745 </tr>
1746 <tr class="layout">
1747 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1748 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1749 that resides in address space #5.</td>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1750 </tr>
1751</table>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1752
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1753</div>
1754
1755<!-- _______________________________________________________________________ -->
1756<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1757
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1758<div class="doc_text">
1759
1760<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1761<p>A vector type is a simple derived type that represents a vector of elements.
1762 Vector types are used when multiple primitive data are operated in parallel
1763 using a single instruction (SIMD). A vector type requires a size (number of
1764 elements) and an underlying primitive data type. Vectors must have a power
1765 of two length (1, 2, 4, 8, 16 ...). Vector types are considered
1766 <a href="#t_firstclass">first class</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1767
1768<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1769<pre>
1770 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1771</pre>
1772
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1773<p>The number of elements is a constant integer value; elementtype may be any
1774 integer or floating point type.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1775
1776<h5>Examples:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1777<table class="layout">
1778 <tr class="layout">
Chris Lattner7311d222007-12-19 05:04:11 +0000[diff] [blame]1779 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1780 <td class="left">Vector of 4 32-bit integer values.</td>
1781 </tr>
1782 <tr class="layout">
1783 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1784 <td class="left">Vector of 8 32-bit floating-point values.</td>
1785 </tr>
1786 <tr class="layout">
1787 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
1788 <td class="left">Vector of 2 64-bit integer values.</td>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1789 </tr>
1790</table>
djge93155c2009-01-24 15:58:40 +0000[diff] [blame]1791
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1792<p>Note that the code generator does not yet support large vector types to be
1793 used as function return types. The specific limit on how large a vector
1794 return type codegen can currently handle is target-dependent; currently it's
1795 often a few times longer than a hardware vector register.</p>
djge93155c2009-01-24 15:58:40 +0000[diff] [blame]1796
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1797</div>
1798
1799<!-- _______________________________________________________________________ -->
1800<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
1801<div class="doc_text">
1802
1803<h5>Overview:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1804<p>Opaque types are used to represent unknown types in the system. This
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1805 corresponds (for example) to the C notion of a forward declared structure
1806 type. In LLVM, opaque types can eventually be resolved to any type (not just
1807 a structure type).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1808
1809<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1810<pre>
1811 opaque
1812</pre>
1813
1814<h5>Examples:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1815<table class="layout">
1816 <tr class="layout">
Chris Lattner7311d222007-12-19 05:04:11 +0000[diff] [blame]1817 <td class="left"><tt>opaque</tt></td>
1818 <td class="left">An opaque type.</td>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1819 </tr>
1820</table>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1821
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1822</div>
1823
Chris Lattner515195a2009-02-02 07:32:36 +0000[diff] [blame]1824<!-- ======================================================================= -->
1825<div class="doc_subsection">
1826 <a name="t_uprefs">Type Up-references</a>
1827</div>
1828
1829<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1830
Chris Lattner515195a2009-02-02 07:32:36 +0000[diff] [blame]1831<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1832<p>An "up reference" allows you to refer to a lexically enclosing type without
1833 requiring it to have a name. For instance, a structure declaration may
1834 contain a pointer to any of the types it is lexically a member of. Example
1835 of up references (with their equivalent as named type declarations)
1836 include:</p>
Chris Lattner515195a2009-02-02 07:32:36 +0000[diff] [blame]1837
1838<pre>
Chris Lattner5ad632d2009-02-09 10:00:56 +0000[diff] [blame]1839 { \2 * } %x = type { %x* }
Chris Lattner515195a2009-02-02 07:32:36 +0000[diff] [blame]1840 { \2 }* %y = type { %y }*
1841 \1* %z = type %z*
1842</pre>
1843
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1844<p>An up reference is needed by the asmprinter for printing out cyclic types
1845 when there is no declared name for a type in the cycle. Because the
1846 asmprinter does not want to print out an infinite type string, it needs a
1847 syntax to handle recursive types that have no names (all names are optional
1848 in llvm IR).</p>
Chris Lattner515195a2009-02-02 07:32:36 +0000[diff] [blame]1849
1850<h5>Syntax:</h5>
1851<pre>
1852 \&lt;level&gt;
1853</pre>
1854
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1855<p>The level is the count of the lexical type that is being referred to.</p>
Chris Lattner515195a2009-02-02 07:32:36 +0000[diff] [blame]1856
1857<h5>Examples:</h5>
Chris Lattner515195a2009-02-02 07:32:36 +0000[diff] [blame]1858<table class="layout">
1859 <tr class="layout">
1860 <td class="left"><tt>\1*</tt></td>
1861 <td class="left">Self-referential pointer.</td>
1862 </tr>
1863 <tr class="layout">
1864 <td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
1865 <td class="left">Recursive structure where the upref refers to the out-most
1866 structure.</td>
1867 </tr>
1868</table>
Chris Lattner515195a2009-02-02 07:32:36 +0000[diff] [blame]1869
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1870</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1871
1872<!-- *********************************************************************** -->
1873<div class="doc_section"> <a name="constants">Constants</a> </div>
1874<!-- *********************************************************************** -->
1875
1876<div class="doc_text">
1877
1878<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1879 them all and their syntax.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1880
1881</div>
1882
1883<!-- ======================================================================= -->
1884<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
1885
1886<div class="doc_text">
1887
1888<dl>
1889 <dt><b>Boolean constants</b></dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1890 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1891 constants of the <tt><a href="#t_primitive">i1</a></tt> type.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1892
1893 <dt><b>Integer constants</b></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1894 <dd>Standard integers (such as '4') are constants of
1895 the <a href="#t_integer">integer</a> type. Negative numbers may be used
1896 with integer types.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1897
1898 <dt><b>Floating point constants</b></dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1899 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1900 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
1901 notation (see below). The assembler requires the exact decimal value of a
1902 floating-point constant. For example, the assembler accepts 1.25 but
1903 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
1904 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1905
1906 <dt><b>Null pointer constants</b></dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1907 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1908 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1909</dl>
1910
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1911<p>The one non-intuitive notation for constants is the hexadecimal form of
1912 floating point constants. For example, the form '<tt>double
1913 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
1914 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
1915 constants are required (and the only time that they are generated by the
1916 disassembler) is when a floating point constant must be emitted but it cannot
1917 be represented as a decimal floating point number in a reasonable number of
1918 digits. For example, NaN's, infinities, and other special values are
1919 represented in their IEEE hexadecimal format so that assembly and disassembly
1920 do not cause any bits to change in the constants.</p>
1921
Dale Johannesenf82a52f2009-02-11 22:14:51 +0000[diff] [blame]1922<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1923 represented using the 16-digit form shown above (which matches the IEEE754
1924 representation for double); float values must, however, be exactly
1925 representable as IEE754 single precision. Hexadecimal format is always used
1926 for long double, and there are three forms of long double. The 80-bit format
1927 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
1928 The 128-bit format used by PowerPC (two adjacent doubles) is represented
1929 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
1930 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
1931 currently supported target uses this format. Long doubles will only work if
1932 they match the long double format on your target. All hexadecimal formats
1933 are big-endian (sign bit at the left).</p>
1934
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1935</div>
1936
1937<!-- ======================================================================= -->
Chris Lattner97063852009-02-28 18:32:25 +0000[diff] [blame]1938<div class="doc_subsection">
Bill Wendling1a2630a2009-07-20 02:32:41 +0000[diff] [blame]1939<a name="aggregateconstants"></a> <!-- old anchor -->
1940<a name="complexconstants">Complex Constants</a>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1941</div>
1942
1943<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1944
Chris Lattner97063852009-02-28 18:32:25 +0000[diff] [blame]1945<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1946 constants and smaller complex constants.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1947
1948<dl>
1949 <dt><b>Structure constants</b></dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1950 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1951 type definitions (a comma separated list of elements, surrounded by braces
1952 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
1953 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
1954 Structure constants must have <a href="#t_struct">structure type</a>, and
1955 the number and types of elements must match those specified by the
1956 type.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1957
1958 <dt><b>Array constants</b></dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1959 <dd>Array constants are represented with notation similar to array type
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1960 definitions (a comma separated list of elements, surrounded by square
1961 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
1962 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
1963 the number and types of elements must match those specified by the
1964 type.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1965
1966 <dt><b>Vector constants</b></dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1967 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1968 definitions (a comma separated list of elements, surrounded by
1969 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
1970 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
1971 have <a href="#t_vector">vector type</a>, and the number and types of
1972 elements must match those specified by the type.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1973
1974 <dt><b>Zero initialization</b></dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1975 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1976 value to zero of <em>any</em> type, including scalar and aggregate types.
1977 This is often used to avoid having to print large zero initializers
1978 (e.g. for large arrays) and is always exactly equivalent to using explicit
1979 zero initializers.</dd>
Nick Lewycky4dcf8102009-04-04 07:22:01 +0000[diff] [blame]1980
1981 <dt><b>Metadata node</b></dt>
Nick Lewyckyf122c7e2009-05-30 16:08:30 +0000[diff] [blame]1982 <dd>A metadata node is a structure-like constant with
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1983 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
1984 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
1985 be interpreted as part of the instruction stream, metadata is a place to
1986 attach additional information such as debug info.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]1987</dl>
1988
1989</div>
1990
1991<!-- ======================================================================= -->
1992<div class="doc_subsection">
1993 <a name="globalconstants">Global Variable and Function Addresses</a>
1994</div>
1995
1996<div class="doc_text">
1997
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]1998<p>The addresses of <a href="#globalvars">global variables</a>
1999 and <a href="#functionstructure">functions</a> are always implicitly valid
2000 (link-time) constants. These constants are explicitly referenced when
2001 the <a href="#identifiers">identifier for the global</a> is used and always
2002 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2003 legal LLVM file:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2004
2005<div class="doc_code">
2006<pre>
2007@X = global i32 17
2008@Y = global i32 42
2009@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
2010</pre>
2011</div>
2012
2013</div>
2014
2015<!-- ======================================================================= -->
2016<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
2017<div class="doc_text">
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2018
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2019<p>The string '<tt>undef</tt>' is recognized as a type-less constant that has no
2020 specific value. Undefined values may be of any type and be used anywhere a
2021 constant is permitted.</p>
2022
2023<p>Undefined values indicate to the compiler that the program is well defined no
2024 matter what value is used, giving the compiler more freedom to optimize.</p>
2025
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2026</div>
2027
2028<!-- ======================================================================= -->
2029<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
2030</div>
2031
2032<div class="doc_text">
2033
2034<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2035 to be used as constants. Constant expressions may be of
2036 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2037 operation that does not have side effects (e.g. load and call are not
2038 supported). The following is the syntax for constant expressions:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2039
2040<dl>
2041 <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2042 <dd>Truncate a constant to another type. The bit size of CST must be larger
2043 than the bit size of TYPE. Both types must be integers.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2044
2045 <dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2046 <dd>Zero extend a constant to another type. The bit size of CST must be
2047 smaller or equal to the bit size of TYPE. Both types must be
2048 integers.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2049
2050 <dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2051 <dd>Sign extend a constant to another type. The bit size of CST must be
2052 smaller or equal to the bit size of TYPE. Both types must be
2053 integers.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2054
2055 <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2056 <dd>Truncate a floating point constant to another floating point type. The
2057 size of CST must be larger than the size of TYPE. Both types must be
2058 floating point.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2059
2060 <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2061 <dd>Floating point extend a constant to another type. The size of CST must be
2062 smaller or equal to the size of TYPE. Both types must be floating
2063 point.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2064
Reid Spencere6adee82007-07-31 14:40:14 +0000[diff] [blame]2065 <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2066 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2067 constant. TYPE must be a scalar or vector integer type. CST must be of
2068 scalar or vector floating point type. Both CST and TYPE must be scalars,
2069 or vectors of the same number of elements. If the value won't fit in the
2070 integer type, the results are undefined.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2071
2072 <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
2073 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2074 constant. TYPE must be a scalar or vector integer type. CST must be of
2075 scalar or vector floating point type. Both CST and TYPE must be scalars,
2076 or vectors of the same number of elements. If the value won't fit in the
2077 integer type, the results are undefined.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2078
2079 <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
2080 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2081 constant. TYPE must be a scalar or vector floating point type. CST must be
2082 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2083 vectors of the same number of elements. If the value won't fit in the
2084 floating point type, the results are undefined.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2085
2086 <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
2087 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2088 constant. TYPE must be a scalar or vector floating point type. CST must be
2089 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2090 vectors of the same number of elements. If the value won't fit in the
2091 floating point type, the results are undefined.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2092
2093 <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
2094 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2095 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2096 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2097 make it fit in <tt>TYPE</tt>.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2098
2099 <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2100 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2101 type. CST must be of integer type. The CST value is zero extended,
2102 truncated, or unchanged to make it fit in a pointer size. This one is
2103 <i>really</i> dangerous!</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2104
2105 <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner557bc5d2009-02-28 18:27:03 +0000[diff] [blame]2106 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2107 are the same as those for the <a href="#i_bitcast">bitcast
2108 instruction</a>.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2109
2110 <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Dan Gohman106b2ae2009-07-27 21:53:46 +0000[diff] [blame]2111 <dt><b><tt>getelementptr inbounds ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2112 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2113 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2114 instruction, the index list may have zero or more indexes, which are
2115 required to make sense for the type of "CSTPTR".</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2116
2117 <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2118 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2119
2120 <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
2121 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2122
2123 <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
2124 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
2125
2126 <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2127 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2128 constants.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2129
2130 <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2131 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2132 constants.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2133
2134 <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2135 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2136 constants.</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2137
2138 <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2139 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2140 be any of the <a href="#binaryops">binary</a>
2141 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2142 on operands are the same as those for the corresponding instruction
2143 (e.g. no bitwise operations on floating point values are allowed).</dd>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2144</dl>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2145
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2146</div>
2147
Nick Lewycky4dcf8102009-04-04 07:22:01 +0000[diff] [blame]2148<!-- ======================================================================= -->
2149<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
2150</div>
2151
2152<div class="doc_text">
2153
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2154<p>Embedded metadata provides a way to attach arbitrary data to the instruction
2155 stream without affecting the behaviour of the program. There are two
2156 metadata primitives, strings and nodes. All metadata has the
2157 <tt>metadata</tt> type and is identified in syntax by a preceding exclamation
2158 point ('<tt>!</tt>').</p>
Nick Lewycky4dcf8102009-04-04 07:22:01 +0000[diff] [blame]2159
2160<p>A metadata string is a string surrounded by double quotes. It can contain
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2161 any character by escaping non-printable characters with "\xx" where "xx" is
2162 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
Nick Lewycky4dcf8102009-04-04 07:22:01 +0000[diff] [blame]2163
2164<p>Metadata nodes are represented with notation similar to structure constants
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2165 (a comma separated list of elements, surrounded by braces and preceeded by an
2166 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2167 10}</tt>".</p>
Nick Lewycky4dcf8102009-04-04 07:22:01 +0000[diff] [blame]2168
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2169<p>A metadata node will attempt to track changes to the values it holds. In the
2170 event that a value is deleted, it will be replaced with a typeless
2171 "<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewycky117f4382009-05-10 20:57:05 +0000[diff] [blame]2172
Nick Lewycky4dcf8102009-04-04 07:22:01 +0000[diff] [blame]2173<p>Optimizations may rely on metadata to provide additional information about
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2174 the program that isn't available in the instructions, or that isn't easily
2175 computable. Similarly, the code generator may expect a certain metadata
2176 format to be used to express debugging information.</p>
2177
Nick Lewycky4dcf8102009-04-04 07:22:01 +0000[diff] [blame]2178</div>
2179
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2180<!-- *********************************************************************** -->
2181<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
2182<!-- *********************************************************************** -->
2183
2184<!-- ======================================================================= -->
2185<div class="doc_subsection">
2186<a name="inlineasm">Inline Assembler Expressions</a>
2187</div>
2188
2189<div class="doc_text">
2190
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2191<p>LLVM supports inline assembler expressions (as opposed
2192 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2193 a special value. This value represents the inline assembler as a string
2194 (containing the instructions to emit), a list of operand constraints (stored
2195 as a string), and a flag that indicates whether or not the inline asm
2196 expression has side effects. An example inline assembler expression is:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2197
2198<div class="doc_code">
2199<pre>
2200i32 (i32) asm "bswap $0", "=r,r"
2201</pre>
2202</div>
2203
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2204<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2205 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2206 have:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2207
2208<div class="doc_code">
2209<pre>
2210%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
2211</pre>
2212</div>
2213
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2214<p>Inline asms with side effects not visible in the constraint list must be
2215 marked as having side effects. This is done through the use of the
2216 '<tt>sideeffect</tt>' keyword, like so:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2217
2218<div class="doc_code">
2219<pre>
2220call void asm sideeffect "eieio", ""()
2221</pre>
2222</div>
2223
2224<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2225 documented here. Constraints on what can be done (e.g. duplication, moving,
2226 etc need to be documented). This is probably best done by reference to
2227 another document that covers inline asm from a holistic perspective.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2228
2229</div>
2230
Chris Lattner75c24e02009-07-20 05:55:19 +0000[diff] [blame]2231
2232<!-- *********************************************************************** -->
2233<div class="doc_section">
2234 <a name="intrinsic_globals">Intrinsic Global Variables</a>
2235</div>
2236<!-- *********************************************************************** -->
2237
2238<p>LLVM has a number of "magic" global variables that contain data that affect
2239code generation or other IR semantics. These are documented here. All globals
Chris Lattner1e0e0d12009-07-20 06:14:25 +0000[diff] [blame]2240of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2241section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2242by LLVM.</p>
Chris Lattner75c24e02009-07-20 05:55:19 +0000[diff] [blame]2243
2244<!-- ======================================================================= -->
2245<div class="doc_subsection">
2246<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
2247</div>
2248
2249<div class="doc_text">
2250
2251<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2252href="#linkage_appending">appending linkage</a>. This array contains a list of
2253pointers to global variables and functions which may optionally have a pointer
2254cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2255
2256<pre>
2257 @X = global i8 4
2258 @Y = global i32 123
2259
2260 @llvm.used = appending global [2 x i8*] [
2261 i8* @X,
2262 i8* bitcast (i32* @Y to i8*)
2263 ], section "llvm.metadata"
2264</pre>
2265
2266<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2267compiler, assembler, and linker are required to treat the symbol as if there is
2268a reference to the global that it cannot see. For example, if a variable has
2269internal linkage and no references other than that from the <tt>@llvm.used</tt>
2270list, it cannot be deleted. This is commonly used to represent references from
2271inline asms and other things the compiler cannot "see", and corresponds to
2272"attribute((used))" in GNU C.</p>
2273
2274<p>On some targets, the code generator must emit a directive to the assembler or
2275object file to prevent the assembler and linker from molesting the symbol.</p>
2276
2277</div>
2278
2279<!-- ======================================================================= -->
2280<div class="doc_subsection">
Chris Lattner1e0e0d12009-07-20 06:14:25 +0000[diff] [blame]2281<a name="intg_compiler_used">The '<tt>llvm.compiler.used</tt>' Global Variable</a>
2282</div>
2283
2284<div class="doc_text">
2285
2286<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2287<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2288touching the symbol. On targets that support it, this allows an intelligent
2289linker to optimize references to the symbol without being impeded as it would be
2290by <tt>@llvm.used</tt>.</p>
2291
2292<p>This is a rare construct that should only be used in rare circumstances, and
2293should not be exposed to source languages.</p>
2294
2295</div>
2296
2297<!-- ======================================================================= -->
2298<div class="doc_subsection">
Chris Lattner75c24e02009-07-20 05:55:19 +0000[diff] [blame]2299<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
2300</div>
2301
2302<div class="doc_text">
2303
2304<p>TODO: Describe this.</p>
2305
2306</div>
2307
2308<!-- ======================================================================= -->
2309<div class="doc_subsection">
2310<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
2311</div>
2312
2313<div class="doc_text">
2314
2315<p>TODO: Describe this.</p>
2316
2317</div>
2318
2319
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2320<!-- *********************************************************************** -->
2321<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
2322<!-- *********************************************************************** -->
2323
2324<div class="doc_text">
2325
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2326<p>The LLVM instruction set consists of several different classifications of
2327 instructions: <a href="#terminators">terminator
2328 instructions</a>, <a href="#binaryops">binary instructions</a>,
2329 <a href="#bitwiseops">bitwise binary instructions</a>,
2330 <a href="#memoryops">memory instructions</a>, and
2331 <a href="#otherops">other instructions</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2332
2333</div>
2334
2335<!-- ======================================================================= -->
2336<div class="doc_subsection"> <a name="terminators">Terminator
2337Instructions</a> </div>
2338
2339<div class="doc_text">
2340
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2341<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2342 in a program ends with a "Terminator" instruction, which indicates which
2343 block should be executed after the current block is finished. These
2344 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2345 control flow, not values (the one exception being the
2346 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2347
2348<p>There are six different terminator instructions: the
2349 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2350 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2351 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
2352 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2353 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2354 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2355
2356</div>
2357
2358<!-- _______________________________________________________________________ -->
2359<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
2360Instruction</a> </div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2361
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2362<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2363
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2364<h5>Syntax:</h5>
Dan Gohman3e700032008-10-04 19:00:07 +0000[diff] [blame]2365<pre>
2366 ret &lt;type&gt; &lt;value&gt; <i>; Return a value from a non-void function</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2367 ret void <i>; Return from void function</i>
2368</pre>
Chris Lattner43030e72008-04-23 04:59:35 +0000[diff] [blame]2369
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2370<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2371<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2372 a value) from a function back to the caller.</p>
2373
2374<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2375 value and then causes control flow, and one that just causes control flow to
2376 occur.</p>
Chris Lattner43030e72008-04-23 04:59:35 +0000[diff] [blame]2377
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2378<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2379<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2380 return value. The type of the return value must be a
2381 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohman3e700032008-10-04 19:00:07 +0000[diff] [blame]2382
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2383<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2384 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2385 value or a return value with a type that does not match its type, or if it
2386 has a void return type and contains a '<tt>ret</tt>' instruction with a
2387 return value.</p>
Chris Lattner43030e72008-04-23 04:59:35 +0000[diff] [blame]2388
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2389<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2390<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2391 the calling function's context. If the caller is a
2392 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2393 instruction after the call. If the caller was an
2394 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2395 the beginning of the "normal" destination block. If the instruction returns
2396 a value, that value shall set the call or invoke instruction's return
2397 value.</p>
Chris Lattner43030e72008-04-23 04:59:35 +0000[diff] [blame]2398
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2399<h5>Example:</h5>
Chris Lattner43030e72008-04-23 04:59:35 +0000[diff] [blame]2400<pre>
2401 ret i32 5 <i>; Return an integer value of 5</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2402 ret void <i>; Return from a void function</i>
Bill Wendlingd163e2d2009-02-28 22:12:54 +0000[diff] [blame]2403 ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2404</pre>
Dan Gohman60967192009-01-12 23:12:39 +0000[diff] [blame]2405
djge93155c2009-01-24 15:58:40 +0000[diff] [blame]2406<p>Note that the code generator does not yet fully support large
2407 return values. The specific sizes that are currently supported are
2408 dependent on the target. For integers, on 32-bit targets the limit
2409 is often 64 bits, and on 64-bit targets the limit is often 128 bits.
2410 For aggregate types, the current limits are dependent on the element
2411 types; for example targets are often limited to 2 total integer
2412 elements and 2 total floating-point elements.</p>
Dan Gohman60967192009-01-12 23:12:39 +0000[diff] [blame]2413
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2414</div>
2415<!-- _______________________________________________________________________ -->
2416<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2417
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2418<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2419
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2420<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2421<pre>
2422 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2423</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2424
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2425<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2426<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2427 different basic block in the current function. There are two forms of this
2428 instruction, corresponding to a conditional branch and an unconditional
2429 branch.</p>
2430
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2431<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2432<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2433 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2434 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2435 target.</p>
2436
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2437<h5>Semantics:</h5>
2438<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2439 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2440 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2441 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2442
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2443<h5>Example:</h5>
Bill Wendling6ec40612009-07-20 02:39:26 +0000[diff] [blame]2444<pre>
2445Test:
2446 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2447 br i1 %cond, label %IfEqual, label %IfUnequal
2448IfEqual:
2449 <a href="#i_ret">ret</a> i32 1
2450IfUnequal:
2451 <a href="#i_ret">ret</a> i32 0
2452</pre>
2453
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2454</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2455
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2456<!-- _______________________________________________________________________ -->
2457<div class="doc_subsubsection">
2458 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
2459</div>
2460
2461<div class="doc_text">
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2462
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2463<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2464<pre>
2465 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2466</pre>
2467
2468<h5>Overview:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2469<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2470 several different places. It is a generalization of the '<tt>br</tt>'
2471 instruction, allowing a branch to occur to one of many possible
2472 destinations.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2473
2474<h5>Arguments:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2475<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2476 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2477 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2478 The table is not allowed to contain duplicate constant entries.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2479
2480<h5>Semantics:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2481<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2482 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2483 is searched for the given value. If the value is found, control flow is
2484 transfered to the corresponding destination; otherwise, control flow is
2485 transfered to the default destination.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2486
2487<h5>Implementation:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2488<p>Depending on properties of the target machine and the particular
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2489 <tt>switch</tt> instruction, this instruction may be code generated in
2490 different ways. For example, it could be generated as a series of chained
2491 conditional branches or with a lookup table.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2492
2493<h5>Example:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2494<pre>
2495 <i>; Emulate a conditional br instruction</i>
2496 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman01852382009-01-04 23:44:43 +0000[diff] [blame]2497 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2498
2499 <i>; Emulate an unconditional br instruction</i>
2500 switch i32 0, label %dest [ ]
2501
2502 <i>; Implement a jump table:</i>
Dan Gohman01852382009-01-04 23:44:43 +0000[diff] [blame]2503 switch i32 %val, label %otherwise [ i32 0, label %onzero
2504 i32 1, label %onone
2505 i32 2, label %ontwo ]
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2506</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2507
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2508</div>
2509
2510<!-- _______________________________________________________________________ -->
2511<div class="doc_subsubsection">
2512 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
2513</div>
2514
2515<div class="doc_text">
2516
2517<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2518<pre>
Devang Pateld0bfcc72008-10-07 17:48:33 +0000[diff] [blame]2519 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ptr to function ty&gt; &lt;function ptr val&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2520 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
2521</pre>
2522
2523<h5>Overview:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2524<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2525 function, with the possibility of control flow transfer to either the
2526 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
2527 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
2528 control flow will return to the "normal" label. If the callee (or any
2529 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
2530 instruction, control is interrupted and continued at the dynamically nearest
2531 "exception" label.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2532
2533<h5>Arguments:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2534<p>This instruction requires several arguments:</p>
2535
2536<ol>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2537 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
2538 convention</a> the call should use. If none is specified, the call
2539 defaults to using C calling conventions.</li>
Devang Patelac2fc272008-10-06 18:50:38 +0000[diff] [blame]2540
2541 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2542 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
2543 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patelac2fc272008-10-06 18:50:38 +0000[diff] [blame]2544
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2545 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2546 function value being invoked. In most cases, this is a direct function
2547 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
2548 off an arbitrary pointer to function value.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2549
2550 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2551 function to be invoked. </li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2552
2553 <li>'<tt>function args</tt>': argument list whose types match the function
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2554 signature argument types. If the function signature indicates the
2555 function accepts a variable number of arguments, the extra arguments can
2556 be specified.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2557
2558 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2559 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2560
2561 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2562 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2563
Devang Pateld0bfcc72008-10-07 17:48:33 +0000[diff] [blame]2564 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2565 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
2566 '<tt>readnone</tt>' attributes are valid here.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2567</ol>
2568
2569<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2570<p>This instruction is designed to operate as a standard
2571 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
2572 primary difference is that it establishes an association with a label, which
2573 is used by the runtime library to unwind the stack.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2574
2575<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2576 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
2577 exception. Additionally, this is important for implementation of
2578 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2579
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2580<p>For the purposes of the SSA form, the definition of the value returned by the
2581 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
2582 block to the "normal" label. If the callee unwinds then no return value is
2583 available.</p>
Dan Gohman140ba5d2009-05-22 21:47:08 +0000[diff] [blame]2584
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2585<h5>Example:</h5>
2586<pre>
Nick Lewyckya1c11a12008-03-16 07:18:12 +0000[diff] [blame]2587 %retval = invoke i32 @Test(i32 15) to label %Continue
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2588 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewyckya1c11a12008-03-16 07:18:12 +0000[diff] [blame]2589 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2590 unwind label %TestCleanup <i>; {i32}:retval set</i>
2591</pre>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2592
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2593</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2594
2595<!-- _______________________________________________________________________ -->
2596
2597<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
2598Instruction</a> </div>
2599
2600<div class="doc_text">
2601
2602<h5>Syntax:</h5>
2603<pre>
2604 unwind
2605</pre>
2606
2607<h5>Overview:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2608<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2609 at the first callee in the dynamic call stack which used
2610 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
2611 This is primarily used to implement exception handling.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2612
2613<h5>Semantics:</h5>
Chris Lattner8b094fc2008-04-19 21:01:16 +0000[diff] [blame]2614<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2615 immediately halt. The dynamic call stack is then searched for the
2616 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
2617 Once found, execution continues at the "exceptional" destination block
2618 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
2619 instruction in the dynamic call chain, undefined behavior results.</p>
2620
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2621</div>
2622
2623<!-- _______________________________________________________________________ -->
2624
2625<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
2626Instruction</a> </div>
2627
2628<div class="doc_text">
2629
2630<h5>Syntax:</h5>
2631<pre>
2632 unreachable
2633</pre>
2634
2635<h5>Overview:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2636<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2637 instruction is used to inform the optimizer that a particular portion of the
2638 code is not reachable. This can be used to indicate that the code after a
2639 no-return function cannot be reached, and other facts.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2640
2641<h5>Semantics:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2642<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2643
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2644</div>
2645
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2646<!-- ======================================================================= -->
2647<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2648
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2649<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2650
2651<p>Binary operators are used to do most of the computation in a program. They
2652 require two operands of the same type, execute an operation on them, and
2653 produce a single value. The operands might represent multiple data, as is
2654 the case with the <a href="#t_vector">vector</a> data type. The result value
2655 has the same type as its operands.</p>
2656
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2657<p>There are several different binary operators:</p>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2658
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2659</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2660
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2661<!-- _______________________________________________________________________ -->
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2662<div class="doc_subsubsection">
2663 <a name="i_add">'<tt>add</tt>' Instruction</a>
2664</div>
2665
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2666<div class="doc_text">
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2667
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2668<h5>Syntax:</h5>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2669<pre>
Dan Gohmaned5fcb22009-07-20 22:41:19 +0000[diff] [blame]2670 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman46e96012009-07-22 22:44:56 +0000[diff] [blame]2671 &lt;result&gt; = nuw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2672 &lt;result&gt; = nsw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2673 &lt;result&gt; = nuw nsw add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2674</pre>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2675
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2676<h5>Overview:</h5>
2677<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2678
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2679<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2680<p>The two arguments to the '<tt>add</tt>' instruction must
2681 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2682 integer values. Both arguments must have identical types.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2683
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2684<h5>Semantics:</h5>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2685<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2686
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2687<p>If the sum has unsigned overflow, the result returned is the mathematical
2688 result modulo 2<sup>n</sup>, where n is the bit width of the result.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2689
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2690<p>Because LLVM integers use a two's complement representation, this instruction
2691 is appropriate for both signed and unsigned integers.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2692
Dan Gohman46e96012009-07-22 22:44:56 +0000[diff] [blame]2693<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2694 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2695 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
2696 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmaned5fcb22009-07-20 22:41:19 +0000[diff] [blame]2697
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2698<h5>Example:</h5>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2699<pre>
2700 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2701</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2702
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2703</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2704
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2705<!-- _______________________________________________________________________ -->
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2706<div class="doc_subsubsection">
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2707 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
2708</div>
2709
2710<div class="doc_text">
2711
2712<h5>Syntax:</h5>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2713<pre>
2714 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2715</pre>
2716
2717<h5>Overview:</h5>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2718<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
2719
2720<h5>Arguments:</h5>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2721<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2722 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2723 floating point values. Both arguments must have identical types.</p>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2724
2725<h5>Semantics:</h5>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2726<p>The value produced is the floating point sum of the two operands.</p>
2727
2728<h5>Example:</h5>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2729<pre>
2730 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
2731</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2732
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2733</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2734
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2735<!-- _______________________________________________________________________ -->
2736<div class="doc_subsubsection">
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2737 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
2738</div>
2739
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2740<div class="doc_text">
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2741
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2742<h5>Syntax:</h5>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2743<pre>
Dan Gohman46e96012009-07-22 22:44:56 +0000[diff] [blame]2744 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2745 &lt;result&gt; = nuw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2746 &lt;result&gt; = nsw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2747 &lt;result&gt; = nuw nsw sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2748</pre>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2749
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2750<h5>Overview:</h5>
2751<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2752 operands.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2753
2754<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2755 '<tt>neg</tt>' instruction present in most other intermediate
2756 representations.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2757
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2758<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2759<p>The two arguments to the '<tt>sub</tt>' instruction must
2760 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2761 integer values. Both arguments must have identical types.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2762
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2763<h5>Semantics:</h5>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2764<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2765
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2766<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2767 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
2768 result.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2769
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2770<p>Because LLVM integers use a two's complement representation, this instruction
2771 is appropriate for both signed and unsigned integers.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2772
Dan Gohman46e96012009-07-22 22:44:56 +0000[diff] [blame]2773<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2774 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2775 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
2776 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmaned5fcb22009-07-20 22:41:19 +0000[diff] [blame]2777
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2778<h5>Example:</h5>
2779<pre>
2780 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
2781 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
2782</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2783
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2784</div>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2785
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2786<!-- _______________________________________________________________________ -->
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2787<div class="doc_subsubsection">
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2788 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
2789</div>
2790
2791<div class="doc_text">
2792
2793<h5>Syntax:</h5>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2794<pre>
2795 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2796</pre>
2797
2798<h5>Overview:</h5>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2799<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2800 operands.</p>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2801
2802<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2803 '<tt>fneg</tt>' instruction present in most other intermediate
2804 representations.</p>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2805
2806<h5>Arguments:</h5>
Bill Wendling1a2630a2009-07-20 02:32:41 +0000[diff] [blame]2807<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2808 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2809 floating point values. Both arguments must have identical types.</p>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2810
2811<h5>Semantics:</h5>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2812<p>The value produced is the floating point difference of the two operands.</p>
2813
2814<h5>Example:</h5>
2815<pre>
2816 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
2817 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
2818</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2819
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2820</div>
2821
2822<!-- _______________________________________________________________________ -->
2823<div class="doc_subsubsection">
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2824 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
2825</div>
2826
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2827<div class="doc_text">
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2828
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2829<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2830<pre>
Dan Gohman46e96012009-07-22 22:44:56 +0000[diff] [blame]2831 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2832 &lt;result&gt; = nuw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2833 &lt;result&gt; = nsw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2834 &lt;result&gt; = nuw nsw mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2835</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2836
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2837<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2838<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2839
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2840<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2841<p>The two arguments to the '<tt>mul</tt>' instruction must
2842 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
2843 integer values. Both arguments must have identical types.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2844
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2845<h5>Semantics:</h5>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2846<p>The value produced is the integer product of the two operands.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2847
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2848<p>If the result of the multiplication has unsigned overflow, the result
2849 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
2850 width of the result.</p>
2851
2852<p>Because LLVM integers use a two's complement representation, and the result
2853 is the same width as the operands, this instruction returns the correct
2854 result for both signed and unsigned integers. If a full product
2855 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
2856 be sign-extended or zero-extended as appropriate to the width of the full
2857 product.</p>
2858
Dan Gohman46e96012009-07-22 22:44:56 +0000[diff] [blame]2859<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
2860 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
2861 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
2862 is undefined if unsigned and/or signed overflow, respectively, occurs.</p>
Dan Gohmaned5fcb22009-07-20 22:41:19 +0000[diff] [blame]2863
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2864<h5>Example:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2865<pre>
2866 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2867</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2868
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2869</div>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2870
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2871<!-- _______________________________________________________________________ -->
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2872<div class="doc_subsubsection">
2873 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
2874</div>
2875
2876<div class="doc_text">
2877
2878<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2879<pre>
2880 &lt;result&gt; = fmul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2881</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2882
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2883<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2884<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2885
2886<h5>Arguments:</h5>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2887<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2888 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2889 floating point values. Both arguments must have identical types.</p>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2890
2891<h5>Semantics:</h5>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2892<p>The value produced is the floating point product of the two operands.</p>
2893
2894<h5>Example:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2895<pre>
2896 &lt;result&gt; = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2897</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2898
Dan Gohman7ce405e2009-06-04 22:49:04 +0000[diff] [blame]2899</div>
2900
2901<!-- _______________________________________________________________________ -->
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2902<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
2903</a></div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2904
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2905<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2906
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2907<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2908<pre>
2909 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2910</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2911
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2912<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2913<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2914
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2915<h5>Arguments:</h5>
2916<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2917 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2918 values. Both arguments must have identical types.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2919
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2920<h5>Semantics:</h5>
Chris Lattner9aba1e22008-01-28 00:36:27 +0000[diff] [blame]2921<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2922
Chris Lattner9aba1e22008-01-28 00:36:27 +0000[diff] [blame]2923<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2924 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
2925
Chris Lattner9aba1e22008-01-28 00:36:27 +0000[diff] [blame]2926<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2927
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2928<h5>Example:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2929<pre>
2930 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2931</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2932
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2933</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2934
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2935<!-- _______________________________________________________________________ -->
2936<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
2937</a> </div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2938
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2939<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2940
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2941<h5>Syntax:</h5>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2942<pre>
Dan Gohmaned5fcb22009-07-20 22:41:19 +0000[diff] [blame]2943 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
2944 &lt;result&gt; = exact sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2945</pre>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2946
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2947<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2948<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2949
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2950<h5>Arguments:</h5>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2951<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2952 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
2953 values. Both arguments must have identical types.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2954
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2955<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2956<p>The value produced is the signed integer quotient of the two operands rounded
2957 towards zero.</p>
2958
Chris Lattner9aba1e22008-01-28 00:36:27 +0000[diff] [blame]2959<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2960 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
2961
Chris Lattner9aba1e22008-01-28 00:36:27 +0000[diff] [blame]2962<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2963 undefined behavior; this is a rare case, but can occur, for example, by doing
2964 a 32-bit division of -2147483648 by -1.</p>
2965
Dan Gohman67fa48e2009-07-22 00:04:19 +0000[diff] [blame]2966<p>If the <tt>exact</tt> keyword is present, the result value of the
2967 <tt>sdiv</tt> is undefined if the result would be rounded or if overflow
2968 would occur.</p>
Dan Gohmaned5fcb22009-07-20 22:41:19 +0000[diff] [blame]2969
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2970<h5>Example:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2971<pre>
2972 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2973</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2974
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2975</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2976
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2977<!-- _______________________________________________________________________ -->
2978<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
2979Instruction</a> </div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2980
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2981<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2982
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2983<h5>Syntax:</h5>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2984<pre>
Gabor Greifd9068fe2008-08-07 21:46:00 +0000[diff] [blame]2985 &lt;result&gt; = fdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2986</pre>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2987
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2988<h5>Overview:</h5>
2989<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2990
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2991<h5>Arguments:</h5>
2992<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]2993 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
2994 floating point values. Both arguments must have identical types.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2995
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2996<h5>Semantics:</h5>
2997<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]2998
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]2999<h5>Example:</h5>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3000<pre>
3001 &lt;result&gt; = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3002</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3003
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3004</div>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3005
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3006<!-- _______________________________________________________________________ -->
3007<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3008</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3009
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3010<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3011
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3012<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3013<pre>
3014 &lt;result&gt; = urem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3015</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3016
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3017<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3018<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3019 division of its two arguments.</p>
3020
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3021<h5>Arguments:</h5>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3022<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3023 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3024 values. Both arguments must have identical types.</p>
3025
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3026<h5>Semantics:</h5>
3027<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3028 This instruction always performs an unsigned division to get the
3029 remainder.</p>
3030
Chris Lattner9aba1e22008-01-28 00:36:27 +0000[diff] [blame]3031<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3032 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3033
Chris Lattner9aba1e22008-01-28 00:36:27 +0000[diff] [blame]3034<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3035
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3036<h5>Example:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3037<pre>
3038 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3039</pre>
3040
3041</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3042
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3043<!-- _______________________________________________________________________ -->
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3044<div class="doc_subsubsection">
3045 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
3046</div>
3047
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3048<div class="doc_text">
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3049
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3050<h5>Syntax:</h5>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3051<pre>
Gabor Greifd9068fe2008-08-07 21:46:00 +0000[diff] [blame]3052 &lt;result&gt; = srem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3053</pre>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3054
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3055<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3056<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3057 division of its two operands. This instruction can also take
3058 <a href="#t_vector">vector</a> versions of the values in which case the
3059 elements must be integers.</p>
Chris Lattner08497ce2008-01-04 04:33:49 +0000[diff] [blame]3060
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3061<h5>Arguments:</h5>
3062<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3063 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3064 values. Both arguments must have identical types.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3065
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3066<h5>Semantics:</h5>
3067<p>This instruction returns the <i>remainder</i> of a division (where the result
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3068 has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
3069 operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
3070 a value. For more information about the difference,
3071 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3072 Math Forum</a>. For a table of how this is implemented in various languages,
3073 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3074 Wikipedia: modulo operation</a>.</p>
3075
Chris Lattner9aba1e22008-01-28 00:36:27 +0000[diff] [blame]3076<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3077 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3078
Chris Lattner9aba1e22008-01-28 00:36:27 +0000[diff] [blame]3079<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3080 Overflow also leads to undefined behavior; this is a rare case, but can
3081 occur, for example, by taking the remainder of a 32-bit division of
3082 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3083 lets srem be implemented using instructions that return both the result of
3084 the division and the remainder.)</p>
3085
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3086<h5>Example:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3087<pre>
3088 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3089</pre>
3090
3091</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3092
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3093<!-- _______________________________________________________________________ -->
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3094<div class="doc_subsubsection">
3095 <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
3096
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3097<div class="doc_text">
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3098
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3099<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3100<pre>
3101 &lt;result&gt; = frem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3102</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3103
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3104<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3105<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3106 its two operands.</p>
3107
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3108<h5>Arguments:</h5>
3109<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3110 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3111 floating point values. Both arguments must have identical types.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3112
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3113<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3114<p>This instruction returns the <i>remainder</i> of a division. The remainder
3115 has the same sign as the dividend.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3116
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3117<h5>Example:</h5>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3118<pre>
3119 &lt;result&gt; = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3120</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3121
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3122</div>
3123
3124<!-- ======================================================================= -->
3125<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
3126Operations</a> </div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3127
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3128<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3129
3130<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3131 program. They are generally very efficient instructions and can commonly be
3132 strength reduced from other instructions. They require two operands of the
3133 same type, execute an operation on them, and produce a single value. The
3134 resulting value is the same type as its operands.</p>
3135
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3136</div>
3137
3138<!-- _______________________________________________________________________ -->
3139<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
3140Instruction</a> </div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3141
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3142<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3143
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3144<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3145<pre>
3146 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3147</pre>
Chris Lattnerd939d9f2007-10-03 21:01:14 +0000[diff] [blame]3148
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3149<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3150<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3151 a specified number of bits.</p>
Chris Lattnerd939d9f2007-10-03 21:01:14 +0000[diff] [blame]3152
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3153<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3154<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3155 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3156 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattnerd939d9f2007-10-03 21:01:14 +0000[diff] [blame]3157
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3158<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3159<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3160 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3161 is (statically or dynamically) negative or equal to or larger than the number
3162 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3163 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3164 shift amount in <tt>op2</tt>.</p>
Chris Lattnerd939d9f2007-10-03 21:01:14 +0000[diff] [blame]3165
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3166<h5>Example:</h5>
3167<pre>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3168 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3169 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3170 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerd939d9f2007-10-03 21:01:14 +0000[diff] [blame]3171 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang9901e732008-12-09 05:46:39 +0000[diff] [blame]3172 &lt;result&gt; = shl &lt;2 x i32&gt; &lt; i32 1, i32 1&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 2, i32 4&gt;</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3173</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3174
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3175</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3176
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3177<!-- _______________________________________________________________________ -->
3178<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
3179Instruction</a> </div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3180
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3181<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3182
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3183<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3184<pre>
3185 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3186</pre>
3187
3188<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3189<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3190 operand shifted to the right a specified number of bits with zero fill.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3191
3192<h5>Arguments:</h5>
3193<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3194 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3195 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3196
3197<h5>Semantics:</h5>
3198<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3199 significant bits of the result will be filled with zero bits after the shift.
3200 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3201 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3202 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3203 shift amount in <tt>op2</tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3204
3205<h5>Example:</h5>
3206<pre>
3207 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3208 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3209 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3210 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerd939d9f2007-10-03 21:01:14 +0000[diff] [blame]3211 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang9901e732008-12-09 05:46:39 +0000[diff] [blame]3212 &lt;result&gt; = lshr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0x7FFFFFFF, i32 1&gt;</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3213</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3214
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3215</div>
3216
3217<!-- _______________________________________________________________________ -->
3218<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
3219Instruction</a> </div>
3220<div class="doc_text">
3221
3222<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3223<pre>
3224 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3225</pre>
3226
3227<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3228<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3229 operand shifted to the right a specified number of bits with sign
3230 extension.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3231
3232<h5>Arguments:</h5>
3233<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3234 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3235 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3236
3237<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3238<p>This instruction always performs an arithmetic shift right operation, The
3239 most significant bits of the result will be filled with the sign bit
3240 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3241 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3242 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3243 the corresponding shift amount in <tt>op2</tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3244
3245<h5>Example:</h5>
3246<pre>
3247 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3248 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3249 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3250 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerd939d9f2007-10-03 21:01:14 +0000[diff] [blame]3251 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang9901e732008-12-09 05:46:39 +0000[diff] [blame]3252 &lt;result&gt; = ashr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 3&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 -1, i32 0&gt;</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3253</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3254
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3255</div>
3256
3257<!-- _______________________________________________________________________ -->
3258<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
3259Instruction</a> </div>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3260
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3261<div class="doc_text">
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3262
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3263<h5>Syntax:</h5>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3264<pre>
Gabor Greifd9068fe2008-08-07 21:46:00 +0000[diff] [blame]3265 &lt;result&gt; = and &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3266</pre>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3267
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3268<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3269<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3270 operands.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3271
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3272<h5>Arguments:</h5>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3273<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3274 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3275 values. Both arguments must have identical types.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3276
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3277<h5>Semantics:</h5>
3278<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3279
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3280<table border="1" cellspacing="0" cellpadding="4">
3281 <tbody>
3282 <tr>
3283 <td>In0</td>
3284 <td>In1</td>
3285 <td>Out</td>
3286 </tr>
3287 <tr>
3288 <td>0</td>
3289 <td>0</td>
3290 <td>0</td>
3291 </tr>
3292 <tr>
3293 <td>0</td>
3294 <td>1</td>
3295 <td>0</td>
3296 </tr>
3297 <tr>
3298 <td>1</td>
3299 <td>0</td>
3300 <td>0</td>
3301 </tr>
3302 <tr>
3303 <td>1</td>
3304 <td>1</td>
3305 <td>1</td>
3306 </tr>
3307 </tbody>
3308</table>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3309
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3310<h5>Example:</h5>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3311<pre>
3312 &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3313 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3314 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
3315</pre>
3316</div>
3317<!-- _______________________________________________________________________ -->
3318<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3319
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3320<div class="doc_text">
3321
3322<h5>Syntax:</h5>
3323<pre>
3324 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3325</pre>
3326
3327<h5>Overview:</h5>
3328<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3329 two operands.</p>
3330
3331<h5>Arguments:</h5>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3332<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3333 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3334 values. Both arguments must have identical types.</p>
3335
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3336<h5>Semantics:</h5>
3337<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3338
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3339<table border="1" cellspacing="0" cellpadding="4">
3340 <tbody>
3341 <tr>
3342 <td>In0</td>
3343 <td>In1</td>
3344 <td>Out</td>
3345 </tr>
3346 <tr>
3347 <td>0</td>
3348 <td>0</td>
3349 <td>0</td>
3350 </tr>
3351 <tr>
3352 <td>0</td>
3353 <td>1</td>
3354 <td>1</td>
3355 </tr>
3356 <tr>
3357 <td>1</td>
3358 <td>0</td>
3359 <td>1</td>
3360 </tr>
3361 <tr>
3362 <td>1</td>
3363 <td>1</td>
3364 <td>1</td>
3365 </tr>
3366 </tbody>
3367</table>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3368
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3369<h5>Example:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3370<pre>
3371 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3372 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3373 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
3374</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3375
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3376</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3377
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3378<!-- _______________________________________________________________________ -->
3379<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
3380Instruction</a> </div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3381
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3382<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3383
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3384<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3385<pre>
3386 &lt;result&gt; = xor &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3387</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3388
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3389<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3390<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3391 its two operands. The <tt>xor</tt> is used to implement the "one's
3392 complement" operation, which is the "~" operator in C.</p>
3393
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3394<h5>Arguments:</h5>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3395<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3396 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3397 values. Both arguments must have identical types.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]3398
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3399<h5>Semantics:</h5>
3400<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3401
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3402<table border="1" cellspacing="0" cellpadding="4">
3403 <tbody>
3404 <tr>
3405 <td>In0</td>
3406 <td>In1</td>
3407 <td>Out</td>
3408 </tr>
3409 <tr>
3410 <td>0</td>
3411 <td>0</td>
3412 <td>0</td>
3413 </tr>
3414 <tr>
3415 <td>0</td>
3416 <td>1</td>
3417 <td>1</td>
3418 </tr>
3419 <tr>
3420 <td>1</td>
3421 <td>0</td>
3422 <td>1</td>
3423 </tr>
3424 <tr>
3425 <td>1</td>
3426 <td>1</td>
3427 <td>0</td>
3428 </tr>
3429 </tbody>
3430</table>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3431
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3432<h5>Example:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3433<pre>
3434 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3435 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
3436 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
3437 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
3438</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3439
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3440</div>
3441
3442<!-- ======================================================================= -->
3443<div class="doc_subsection">
3444 <a name="vectorops">Vector Operations</a>
3445</div>
3446
3447<div class="doc_text">
3448
3449<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3450 target-independent manner. These instructions cover the element-access and
3451 vector-specific operations needed to process vectors effectively. While LLVM
3452 does directly support these vector operations, many sophisticated algorithms
3453 will want to use target-specific intrinsics to take full advantage of a
3454 specific target.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3455
3456</div>
3457
3458<!-- _______________________________________________________________________ -->
3459<div class="doc_subsubsection">
3460 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
3461</div>
3462
3463<div class="doc_text">
3464
3465<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3466<pre>
3467 &lt;result&gt; = extractelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, i32 &lt;idx&gt; <i>; yields &lt;ty&gt;</i>
3468</pre>
3469
3470<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3471<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
3472 from a vector at a specified index.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3473
3474
3475<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3476<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
3477 of <a href="#t_vector">vector</a> type. The second operand is an index
3478 indicating the position from which to extract the element. The index may be
3479 a variable.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3480
3481<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3482<p>The result is a scalar of the same type as the element type of
3483 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
3484 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3485 results are undefined.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3486
3487<h5>Example:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3488<pre>
3489 %result = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
3490</pre>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3491
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3492</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3493
3494<!-- _______________________________________________________________________ -->
3495<div class="doc_subsubsection">
3496 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
3497</div>
3498
3499<div class="doc_text">
3500
3501<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3502<pre>
Dan Gohmanbcc3c502008-05-12 23:38:42 +0000[diff] [blame]3503 &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>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3504</pre>
3505
3506<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3507<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
3508 vector at a specified index.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3509
3510<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3511<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
3512 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
3513 whose type must equal the element type of the first operand. The third
3514 operand is an index indicating the position at which to insert the value.
3515 The index may be a variable.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3516
3517<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3518<p>The result is a vector of the same type as <tt>val</tt>. Its element values
3519 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
3520 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
3521 results are undefined.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3522
3523<h5>Example:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3524<pre>
3525 %result = insertelement &lt;4 x i32&gt; %vec, i32 1, i32 0 <i>; yields &lt;4 x i32&gt;</i>
3526</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3527
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3528</div>
3529
3530<!-- _______________________________________________________________________ -->
3531<div class="doc_subsubsection">
3532 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
3533</div>
3534
3535<div class="doc_text">
3536
3537<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3538<pre>
Mon P Wangbff5d9c2008-11-10 04:46:22 +0000[diff] [blame]3539 &lt;result&gt; = shufflevector &lt;n x &lt;ty&gt;&gt; &lt;v1&gt;, &lt;n x &lt;ty&gt;&gt; &lt;v2&gt;, &lt;m x i32&gt; &lt;mask&gt; <i>; yields &lt;m x &lt;ty&gt;&gt;</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3540</pre>
3541
3542<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3543<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
3544 from two input vectors, returning a vector with the same element type as the
3545 input and length that is the same as the shuffle mask.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3546
3547<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3548<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
3549 with types that match each other. The third argument is a shuffle mask whose
3550 element type is always 'i32'. The result of the instruction is a vector
3551 whose length is the same as the shuffle mask and whose element type is the
3552 same as the element type of the first two operands.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3553
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3554<p>The shuffle mask operand is required to be a constant vector with either
3555 constant integer or undef values.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3556
3557<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3558<p>The elements of the two input vectors are numbered from left to right across
3559 both of the vectors. The shuffle mask operand specifies, for each element of
3560 the result vector, which element of the two input vectors the result element
3561 gets. The element selector may be undef (meaning "don't care") and the
3562 second operand may be undef if performing a shuffle from only one vector.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3563
3564<h5>Example:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3565<pre>
3566 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3567 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
3568 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
3569 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i> - Identity shuffle.
Mon P Wangbff5d9c2008-11-10 04:46:22 +0000[diff] [blame]3570 %result = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
3571 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
3572 %result = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
3573 &lt;8 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 &gt; <i>; yields &lt;8 x i32&gt;</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3574</pre>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3575
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3576</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3577
3578<!-- ======================================================================= -->
3579<div class="doc_subsection">
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3580 <a name="aggregateops">Aggregate Operations</a>
3581</div>
3582
3583<div class="doc_text">
3584
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3585<p>LLVM supports several instructions for working with aggregate values.</p>
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3586
3587</div>
3588
3589<!-- _______________________________________________________________________ -->
3590<div class="doc_subsubsection">
3591 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
3592</div>
3593
3594<div class="doc_text">
3595
3596<h5>Syntax:</h5>
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3597<pre>
3598 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
3599</pre>
3600
3601<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3602<p>The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
3603 or array element from an aggregate value.</p>
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3604
3605<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3606<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
3607 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3608 operands are constant indices to specify which value to extract in a similar
3609 manner as indices in a
3610 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3611
3612<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3613<p>The result is the value at the position in the aggregate specified by the
3614 index operands.</p>
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3615
3616<h5>Example:</h5>
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3617<pre>
Dan Gohmane5febe42008-05-31 00:58:22 +0000[diff] [blame]3618 %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3619</pre>
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3620
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3621</div>
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3622
3623<!-- _______________________________________________________________________ -->
3624<div class="doc_subsubsection">
3625 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
3626</div>
3627
3628<div class="doc_text">
3629
3630<h5>Syntax:</h5>
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3631<pre>
Dan Gohmane5febe42008-05-31 00:58:22 +0000[diff] [blame]3632 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;val&gt;, &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3633</pre>
3634
3635<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3636<p>The '<tt>insertvalue</tt>' instruction inserts a value into a struct field or
3637 array element in an aggregate.</p>
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3638
3639
3640<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3641<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
3642 of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. The
3643 second operand is a first-class value to insert. The following operands are
3644 constant indices indicating the position at which to insert the value in a
3645 similar manner as indices in a
3646 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. The
3647 value to insert must have the same type as the value identified by the
3648 indices.</p>
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3649
3650<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3651<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
3652 that of <tt>val</tt> except that the value at the position specified by the
3653 indices is that of <tt>elt</tt>.</p>
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3654
3655<h5>Example:</h5>
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3656<pre>
Dan Gohmanb1aab4e2008-06-23 15:26:37 +0000[diff] [blame]3657 %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3658</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3659
Dan Gohman74d6faf2008-05-12 23:51:09 +0000[diff] [blame]3660</div>
3661
3662
3663<!-- ======================================================================= -->
3664<div class="doc_subsection">
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3665 <a name="memoryops">Memory Access and Addressing Operations</a>
3666</div>
3667
3668<div class="doc_text">
3669
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3670<p>A key design point of an SSA-based representation is how it represents
3671 memory. In LLVM, no memory locations are in SSA form, which makes things
3672 very simple. This section describes how to read, write, allocate, and free
3673 memory in LLVM.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3674
3675</div>
3676
3677<!-- _______________________________________________________________________ -->
3678<div class="doc_subsubsection">
3679 <a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
3680</div>
3681
3682<div class="doc_text">
3683
3684<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3685<pre>
3686 &lt;result&gt; = malloc &lt;type&gt;[, i32 &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
3687</pre>
3688
3689<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3690<p>The '<tt>malloc</tt>' instruction allocates memory from the system heap and
3691 returns a pointer to it. The object is always allocated in the generic
3692 address space (address space zero).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3693
3694<h5>Arguments:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3695<p>The '<tt>malloc</tt>' instruction allocates
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3696 <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory from the operating
3697 system and returns a pointer of the appropriate type to the program. If
3698 "NumElements" is specified, it is the number of elements allocated, otherwise
3699 "NumElements" is defaulted to be one. If a constant alignment is specified,
3700 the value result of the allocation is guaranteed to be aligned to at least
3701 that boundary. If not specified, or if zero, the target can choose to align
3702 the allocation on any convenient boundary compatible with the type.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3703
3704<p>'<tt>type</tt>' must be a sized type.</p>
3705
3706<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3707<p>Memory is allocated using the system "<tt>malloc</tt>" function, and a
3708 pointer is returned. The result of a zero byte allocation is undefined. The
3709 result is null if there is insufficient memory available.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3710
3711<h5>Example:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3712<pre>
Dan Gohmanf54f50a2009-01-04 23:49:44 +0000[diff] [blame]3713 %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3714
3715 %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
3716 %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
3717 %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
3718 %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
3719 %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
3720</pre>
Dan Gohman60967192009-01-12 23:12:39 +0000[diff] [blame]3721
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3722<p>Note that the code generator does not yet respect the alignment value.</p>
Dan Gohman60967192009-01-12 23:12:39 +0000[diff] [blame]3723
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3724</div>
3725
3726<!-- _______________________________________________________________________ -->
3727<div class="doc_subsubsection">
3728 <a name="i_free">'<tt>free</tt>' Instruction</a>
3729</div>
3730
3731<div class="doc_text">
3732
3733<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3734<pre>
Dan Gohmanf54f50a2009-01-04 23:49:44 +0000[diff] [blame]3735 free &lt;type&gt; &lt;value&gt; <i>; yields {void}</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3736</pre>
3737
3738<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3739<p>The '<tt>free</tt>' instruction returns memory back to the unused memory heap
3740 to be reallocated in the future.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3741
3742<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3743<p>'<tt>value</tt>' shall be a pointer value that points to a value that was
3744 allocated with the '<tt><a href="#i_malloc">malloc</a></tt>' instruction.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3745
3746<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3747<p>Access to the memory pointed to by the pointer is no longer defined after
3748 this instruction executes. If the pointer is null, the operation is a
3749 noop.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3750
3751<h5>Example:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3752<pre>
Dan Gohmanf54f50a2009-01-04 23:49:44 +0000[diff] [blame]3753 %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3754 free [4 x i8]* %array
3755</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3756
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3757</div>
3758
3759<!-- _______________________________________________________________________ -->
3760<div class="doc_subsubsection">
3761 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
3762</div>
3763
3764<div class="doc_text">
3765
3766<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3767<pre>
3768 &lt;result&gt; = alloca &lt;type&gt;[, i32 &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
3769</pre>
3770
3771<h5>Overview:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3772<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3773 currently executing function, to be automatically released when this function
3774 returns to its caller. The object is always allocated in the generic address
3775 space (address space zero).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3776
3777<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3778<p>The '<tt>alloca</tt>' instruction
3779 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
3780 runtime stack, returning a pointer of the appropriate type to the program.
3781 If "NumElements" is specified, it is the number of elements allocated,
3782 otherwise "NumElements" is defaulted to be one. If a constant alignment is
3783 specified, the value result of the allocation is guaranteed to be aligned to
3784 at least that boundary. If not specified, or if zero, the target can choose
3785 to align the allocation on any convenient boundary compatible with the
3786 type.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3787
3788<p>'<tt>type</tt>' may be any sized type.</p>
3789
3790<h5>Semantics:</h5>
Bill Wendling2a454572009-05-08 20:49:29 +0000[diff] [blame]3791<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3792 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
3793 memory is automatically released when the function returns. The
3794 '<tt>alloca</tt>' instruction is commonly used to represent automatic
3795 variables that must have an address available. When the function returns
3796 (either with the <tt><a href="#i_ret">ret</a></tt>
3797 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
3798 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3799
3800<h5>Example:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3801<pre>
Dan Gohmanf54f50a2009-01-04 23:49:44 +0000[diff] [blame]3802 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
3803 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
3804 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
3805 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3806</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3807
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3808</div>
3809
3810<!-- _______________________________________________________________________ -->
3811<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
3812Instruction</a> </div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3813
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3814<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3815
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3816<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3817<pre>
3818 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3819 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;]
3820</pre>
3821
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3822<h5>Overview:</h5>
3823<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3824
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3825<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3826<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
3827 from which to load. The pointer must point to
3828 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
3829 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
3830 number or order of execution of this <tt>load</tt> with other
3831 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3832 instructions. </p>
3833
3834<p>The optional constant "align" argument specifies the alignment of the
3835 operation (that is, the alignment of the memory address). A value of 0 or an
3836 omitted "align" argument means that the operation has the preferential
3837 alignment for the target. It is the responsibility of the code emitter to
3838 ensure that the alignment information is correct. Overestimating the
3839 alignment results in an undefined behavior. Underestimating the alignment may
3840 produce less efficient code. An alignment of 1 is always safe.</p>
3841
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3842<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3843<p>The location of memory pointed to is loaded. If the value being loaded is of
3844 scalar type then the number of bytes read does not exceed the minimum number
3845 of bytes needed to hold all bits of the type. For example, loading an
3846 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
3847 <tt>i20</tt> with a size that is not an integral number of bytes, the result
3848 is undefined if the value was not originally written using a store of the
3849 same type.</p>
3850
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3851<h5>Examples:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3852<pre>
3853 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
3854 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3855 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
3856</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3857
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3858</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3859
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3860<!-- _______________________________________________________________________ -->
3861<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
3862Instruction</a> </div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3863
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3864<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3865
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3866<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3867<pre>
3868 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3869 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;] <i>; yields {void}</i>
3870</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3871
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3872<h5>Overview:</h5>
3873<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3874
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3875<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3876<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
3877 and an address at which to store it. The type of the
3878 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
3879 the <a href="#t_firstclass">first class</a> type of the
3880 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked
3881 as <tt>volatile</tt>, then the optimizer is not allowed to modify the number
3882 or order of execution of this <tt>store</tt> with other
3883 volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
3884 instructions.</p>
3885
3886<p>The optional constant "align" argument specifies the alignment of the
3887 operation (that is, the alignment of the memory address). A value of 0 or an
3888 omitted "align" argument means that the operation has the preferential
3889 alignment for the target. It is the responsibility of the code emitter to
3890 ensure that the alignment information is correct. Overestimating the
3891 alignment results in an undefined behavior. Underestimating the alignment may
3892 produce less efficient code. An alignment of 1 is always safe.</p>
3893
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3894<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3895<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
3896 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
3897 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
3898 does not exceed the minimum number of bytes needed to hold all bits of the
3899 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
3900 writing a value of a type like <tt>i20</tt> with a size that is not an
3901 integral number of bytes, it is unspecified what happens to the extra bits
3902 that do not belong to the type, but they will typically be overwritten.</p>
3903
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3904<h5>Example:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3905<pre>
3906 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling63ffa142007-10-22 05:10:05 +0000[diff] [blame]3907 store i32 3, i32* %ptr <i>; yields {void}</i>
3908 %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3909</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3910
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3911</div>
3912
3913<!-- _______________________________________________________________________ -->
3914<div class="doc_subsubsection">
3915 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
3916</div>
3917
3918<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3919
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3920<h5>Syntax:</h5>
3921<pre>
Matthijs Kooijman32a080e2008-10-13 13:44:15 +0000[diff] [blame]3922 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Dan Gohman106b2ae2009-07-27 21:53:46 +0000[diff] [blame]3923 &lt;result&gt; = getelementptr inbounds &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3924</pre>
3925
3926<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3927<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
3928 subelement of an aggregate data structure. It performs address calculation
3929 only and does not access memory.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3930
3931<h5>Arguments:</h5>
Matthijs Kooijman32a080e2008-10-13 13:44:15 +0000[diff] [blame]3932<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnere92fc832009-07-29 06:44:13 +0000[diff] [blame]3933 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3934 elements of the aggregate object are indexed. The interpretation of each
3935 index is dependent on the type being indexed into. The first index always
3936 indexes the pointer value given as the first argument, the second index
3937 indexes a value of the type pointed to (not necessarily the value directly
3938 pointed to, since the first index can be non-zero), etc. The first type
3939 indexed into must be a pointer value, subsequent types can be arrays, vectors
3940 and structs. Note that subsequent types being indexed into can never be
3941 pointers, since that would require loading the pointer before continuing
3942 calculation.</p>
Matthijs Kooijman32a080e2008-10-13 13:44:15 +0000[diff] [blame]3943
3944<p>The type of each index argument depends on the type it is indexing into.
Chris Lattnere92fc832009-07-29 06:44:13 +0000[diff] [blame]3945 When indexing into a (optionally packed) structure, only <tt>i32</tt> integer
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3946 <b>constants</b> are allowed. When indexing into an array, pointer or
Chris Lattnere92fc832009-07-29 06:44:13 +0000[diff] [blame]3947 vector, integers of any width are allowed, and they are not required to be
3948 constant.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3949
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3950<p>For example, let's consider a C code fragment and how it gets compiled to
3951 LLVM:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3952
3953<div class="doc_code">
3954<pre>
3955struct RT {
3956 char A;
3957 int B[10][20];
3958 char C;
3959};
3960struct ST {
3961 int X;
3962 double Y;
3963 struct RT Z;
3964};
3965
3966int *foo(struct ST *s) {
3967 return &amp;s[1].Z.B[5][13];
3968}
3969</pre>
3970</div>
3971
3972<p>The LLVM code generated by the GCC frontend is:</p>
3973
3974<div class="doc_code">
3975<pre>
Chris Lattner5b6dc6e2009-01-11 20:53:49 +0000[diff] [blame]3976%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
3977%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3978
Dan Gohman47360842009-07-25 02:23:48 +0000[diff] [blame]3979define i32* @foo(%ST* %s) {
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3980entry:
3981 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
3982 ret i32* %reg
3983}
3984</pre>
3985</div>
3986
3987<h5>Semantics:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3988<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3989 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
3990 }</tt>' type, a structure. The second index indexes into the third element
3991 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
3992 i8 }</tt>' type, another structure. The third index indexes into the second
3993 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
3994 array. The two dimensions of the array are subscripted into, yielding an
3995 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
3996 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]3997
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]3998<p>Note that it is perfectly legal to index partially through a structure,
3999 returning a pointer to an inner element. Because of this, the LLVM code for
4000 the given testcase is equivalent to:</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4001
4002<pre>
Dan Gohman47360842009-07-25 02:23:48 +0000[diff] [blame]4003 define i32* @foo(%ST* %s) {
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4004 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
4005 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4006 %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
4007 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4008 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4009 ret i32* %t5
4010 }
4011</pre>
4012
Dan Gohman106b2ae2009-07-27 21:53:46 +0000[diff] [blame]4013<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman4cba1562009-07-29 16:00:30 +0000[diff] [blame]4014 <tt>getelementptr</tt> is undefined if the base pointer is not an
4015 <i>in bounds</i> address of an allocated object, or if any of the addresses
Dan Gohmanbc4c87f2009-08-20 17:08:17 +0000[diff] [blame]4016 that would be formed by successive addition of the offsets implied by the
4017 indices to the base address with infinitely precise arithmetic are not an
4018 <i>in bounds</i> address of that allocated object.
Dan Gohman4cba1562009-07-29 16:00:30 +0000[diff] [blame]4019 The <i>in bounds</i> addresses for an allocated object are all the addresses
Dan Gohmanbc4c87f2009-08-20 17:08:17 +0000[diff] [blame]4020 that point into the object, plus the address one byte past the end.</p>
Dan Gohman106b2ae2009-07-27 21:53:46 +0000[diff] [blame]4021
4022<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4023 the base address with silently-wrapping two's complement arithmetic, and
4024 the result value of the <tt>getelementptr</tt> may be outside the object
4025 pointed to by the base pointer. The result value may not necessarily be
4026 used to access memory though, even if it happens to point into allocated
4027 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4028 section for more information.</p>
4029
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4030<p>The getelementptr instruction is often confusing. For some more insight into
4031 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4032
4033<h5>Example:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4034<pre>
4035 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman32a080e2008-10-13 13:44:15 +0000[diff] [blame]4036 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4037 <i>; yields i8*:vptr</i>
Dan Gohman2672f3e2008-10-14 16:51:45 +0000[diff] [blame]4038 %vptr = getelementptr {i32, &lt;2 x i8&gt;}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijman32a080e2008-10-13 13:44:15 +0000[diff] [blame]4039 <i>; yields i8*:eptr</i>
4040 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta4f9a0dc2009-04-25 07:27:44 +0000[diff] [blame]4041 <i>; yields i32*:iptr</i>
Sanjiv Gupta1e46c582009-04-24 16:38:13 +0000[diff] [blame]4042 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4043</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4044
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4045</div>
4046
4047<!-- ======================================================================= -->
4048<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
4049</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4050
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4051<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4052
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4053<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4054 which all take a single operand and a type. They perform various bit
4055 conversions on the operand.</p>
4056
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4057</div>
4058
4059<!-- _______________________________________________________________________ -->
4060<div class="doc_subsubsection">
4061 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
4062</div>
4063<div class="doc_text">
4064
4065<h5>Syntax:</h5>
4066<pre>
4067 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4068</pre>
4069
4070<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4071<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4072 type <tt>ty2</tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4073
4074<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4075<p>The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
4076 be an <a href="#t_integer">integer</a> type, and a type that specifies the
4077 size and type of the result, which must be
4078 an <a href="#t_integer">integer</a> type. The bit size of <tt>value</tt> must
4079 be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
4080 allowed.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4081
4082<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4083<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4084 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4085 source size must be larger than the destination size, <tt>trunc</tt> cannot
4086 be a <i>no-op cast</i>. It will always truncate bits.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4087
4088<h5>Example:</h5>
4089<pre>
4090 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
4091 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4092 %Y = trunc i32 122 to i1 <i>; yields i1:false</i>
4093</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4094
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4095</div>
4096
4097<!-- _______________________________________________________________________ -->
4098<div class="doc_subsubsection">
4099 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
4100</div>
4101<div class="doc_text">
4102
4103<h5>Syntax:</h5>
4104<pre>
4105 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4106</pre>
4107
4108<h5>Overview:</h5>
4109<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4110 <tt>ty2</tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4111
4112
4113<h5>Arguments:</h5>
4114<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4115 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4116 also be of <a href="#t_integer">integer</a> type. The bit size of the
4117 <tt>value</tt> must be smaller than the bit size of the destination type,
4118 <tt>ty2</tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4119
4120<h5>Semantics:</h5>
4121<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4122 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4123
4124<p>When zero extending from i1, the result will always be either 0 or 1.</p>
4125
4126<h5>Example:</h5>
4127<pre>
4128 %X = zext i32 257 to i64 <i>; yields i64:257</i>
4129 %Y = zext i1 true to i32 <i>; yields i32:1</i>
4130</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4131
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4132</div>
4133
4134<!-- _______________________________________________________________________ -->
4135<div class="doc_subsubsection">
4136 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
4137</div>
4138<div class="doc_text">
4139
4140<h5>Syntax:</h5>
4141<pre>
4142 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4143</pre>
4144
4145<h5>Overview:</h5>
4146<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4147
4148<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4149<p>The '<tt>sext</tt>' instruction takes a value to cast, which must be of
4150 <a href="#t_integer">integer</a> type, and a type to cast it to, which must
4151 also be of <a href="#t_integer">integer</a> type. The bit size of the
4152 <tt>value</tt> must be smaller than the bit size of the destination type,
4153 <tt>ty2</tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4154
4155<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4156<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4157 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4158 of the type <tt>ty2</tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4159
4160<p>When sign extending from i1, the extension always results in -1 or 0.</p>
4161
4162<h5>Example:</h5>
4163<pre>
4164 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
4165 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
4166</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4167
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4168</div>
4169
4170<!-- _______________________________________________________________________ -->
4171<div class="doc_subsubsection">
4172 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
4173</div>
4174
4175<div class="doc_text">
4176
4177<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4178<pre>
4179 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4180</pre>
4181
4182<h5>Overview:</h5>
4183<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4184 <tt>ty2</tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4185
4186<h5>Arguments:</h5>
4187<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4188 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4189 to cast it to. The size of <tt>value</tt> must be larger than the size of
4190 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
4191 <i>no-op cast</i>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4192
4193<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4194<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
4195 <a href="#t_floating">floating point</a> type to a smaller
4196 <a href="#t_floating">floating point</a> type. If the value cannot fit
4197 within the destination type, <tt>ty2</tt>, then the results are
4198 undefined.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4199
4200<h5>Example:</h5>
4201<pre>
4202 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4203 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4204</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4205
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4206</div>
4207
4208<!-- _______________________________________________________________________ -->
4209<div class="doc_subsubsection">
4210 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
4211</div>
4212<div class="doc_text">
4213
4214<h5>Syntax:</h5>
4215<pre>
4216 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4217</pre>
4218
4219<h5>Overview:</h5>
4220<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4221 floating point value.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4222
4223<h5>Arguments:</h5>
4224<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4225 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4226 a <a href="#t_floating">floating point</a> type to cast it to. The source
4227 type must be smaller than the destination type.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4228
4229<h5>Semantics:</h5>
4230<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4231 <a href="#t_floating">floating point</a> type to a larger
4232 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4233 used to make a <i>no-op cast</i> because it always changes bits. Use
4234 <tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4235
4236<h5>Example:</h5>
4237<pre>
4238 %X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
4239 %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
4240</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4241
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4242</div>
4243
4244<!-- _______________________________________________________________________ -->
4245<div class="doc_subsubsection">
4246 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
4247</div>
4248<div class="doc_text">
4249
4250<h5>Syntax:</h5>
4251<pre>
Reid Spencere6adee82007-07-31 14:40:14 +0000[diff] [blame]4252 &lt;result&gt; = fptoui &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4253</pre>
4254
4255<h5>Overview:</h5>
Reid Spencere6adee82007-07-31 14:40:14 +0000[diff] [blame]4256<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4257 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4258
4259<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4260<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4261 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4262 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4263 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4264 vector integer type with the same number of elements as <tt>ty</tt></p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4265
4266<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4267<p>The '<tt>fptoui</tt>' instruction converts its
4268 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4269 towards zero) unsigned integer value. If the value cannot fit
4270 in <tt>ty2</tt>, the results are undefined.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4271
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4272<h5>Example:</h5>
4273<pre>
Reid Spencere6adee82007-07-31 14:40:14 +0000[diff] [blame]4274 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner681f1e82007-09-22 03:17:52 +0000[diff] [blame]4275 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencere6adee82007-07-31 14:40:14 +0000[diff] [blame]4276 %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4277</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4278
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4279</div>
4280
4281<!-- _______________________________________________________________________ -->
4282<div class="doc_subsubsection">
4283 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
4284</div>
4285<div class="doc_text">
4286
4287<h5>Syntax:</h5>
4288<pre>
4289 &lt;result&gt; = fptosi &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4290</pre>
4291
4292<h5>Overview:</h5>
4293<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4294 <a href="#t_floating">floating point</a> <tt>value</tt> to
4295 type <tt>ty2</tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4296
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4297<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4298<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4299 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4300 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4301 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4302 vector integer type with the same number of elements as <tt>ty</tt></p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4303
4304<h5>Semantics:</h5>
4305<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4306 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4307 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4308 the results are undefined.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4309
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4310<h5>Example:</h5>
4311<pre>
4312 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner681f1e82007-09-22 03:17:52 +0000[diff] [blame]4313 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4314 %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
4315</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4316
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4317</div>
4318
4319<!-- _______________________________________________________________________ -->
4320<div class="doc_subsubsection">
4321 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
4322</div>
4323<div class="doc_text">
4324
4325<h5>Syntax:</h5>
4326<pre>
4327 &lt;result&gt; = uitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4328</pre>
4329
4330<h5>Overview:</h5>
4331<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4332 integer and converts that value to the <tt>ty2</tt> type.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4333
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4334<h5>Arguments:</h5>
Nate Begeman78246ca2007-11-17 03:58:34 +0000[diff] [blame]4335<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4336 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4337 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4338 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4339 floating point type with the same number of elements as <tt>ty</tt></p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4340
4341<h5>Semantics:</h5>
4342<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4343 integer quantity and converts it to the corresponding floating point
4344 value. If the value cannot fit in the floating point value, the results are
4345 undefined.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4346
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4347<h5>Example:</h5>
4348<pre>
4349 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman2672f3e2008-10-14 16:51:45 +0000[diff] [blame]4350 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4351</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4352
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4353</div>
4354
4355<!-- _______________________________________________________________________ -->
4356<div class="doc_subsubsection">
4357 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
4358</div>
4359<div class="doc_text">
4360
4361<h5>Syntax:</h5>
4362<pre>
4363 &lt;result&gt; = sitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4364</pre>
4365
4366<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4367<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4368 and converts that value to the <tt>ty2</tt> type.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4369
4370<h5>Arguments:</h5>
Nate Begeman78246ca2007-11-17 03:58:34 +0000[diff] [blame]4371<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4372 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4373 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4374 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4375 floating point type with the same number of elements as <tt>ty</tt></p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4376
4377<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4378<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4379 quantity and converts it to the corresponding floating point value. If the
4380 value cannot fit in the floating point value, the results are undefined.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4381
4382<h5>Example:</h5>
4383<pre>
4384 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman2672f3e2008-10-14 16:51:45 +0000[diff] [blame]4385 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4386</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4387
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4388</div>
4389
4390<!-- _______________________________________________________________________ -->
4391<div class="doc_subsubsection">
4392 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
4393</div>
4394<div class="doc_text">
4395
4396<h5>Syntax:</h5>
4397<pre>
4398 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4399</pre>
4400
4401<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4402<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4403 the integer type <tt>ty2</tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4404
4405<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4406<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4407 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4408 <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4409
4410<h5>Semantics:</h5>
4411<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4412 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4413 truncating or zero extending that value to the size of the integer type. If
4414 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4415 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4416 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4417 change.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4418
4419<h5>Example:</h5>
4420<pre>
4421 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4422 %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
4423</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4424
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4425</div>
4426
4427<!-- _______________________________________________________________________ -->
4428<div class="doc_subsubsection">
4429 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
4430</div>
4431<div class="doc_text">
4432
4433<h5>Syntax:</h5>
4434<pre>
4435 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4436</pre>
4437
4438<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4439<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4440 pointer type, <tt>ty2</tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4441
4442<h5>Arguments:</h5>
4443<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4444 value to cast, and a type to cast it to, which must be a
4445 <a href="#t_pointer">pointer</a> type.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4446
4447<h5>Semantics:</h5>
4448<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4449 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
4450 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
4451 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
4452 than the size of a pointer then a zero extension is done. If they are the
4453 same size, nothing is done (<i>no-op cast</i>).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4454
4455<h5>Example:</h5>
4456<pre>
4457 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
4458 %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
4459 %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
4460</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4461
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4462</div>
4463
4464<!-- _______________________________________________________________________ -->
4465<div class="doc_subsubsection">
4466 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
4467</div>
4468<div class="doc_text">
4469
4470<h5>Syntax:</h5>
4471<pre>
4472 &lt;result&gt; = bitcast &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4473</pre>
4474
4475<h5>Overview:</h5>
4476<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4477 <tt>ty2</tt> without changing any bits.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4478
4479<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4480<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
4481 non-aggregate first class value, and a type to cast it to, which must also be
4482 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
4483 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
4484 identical. If the source type is a pointer, the destination type must also be
4485 a pointer. This instruction supports bitwise conversion of vectors to
4486 integers and to vectors of other types (as long as they have the same
4487 size).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4488
4489<h5>Semantics:</h5>
4490<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4491 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
4492 this conversion. The conversion is done as if the <tt>value</tt> had been
4493 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
4494 be converted to other pointer types with this instruction. To convert
4495 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
4496 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4497
4498<h5>Example:</h5>
4499<pre>
4500 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
4501 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman2672f3e2008-10-14 16:51:45 +0000[diff] [blame]4502 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4503</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4504
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4505</div>
4506
4507<!-- ======================================================================= -->
4508<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4509
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4510<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4511
4512<p>The instructions in this category are the "miscellaneous" instructions, which
4513 defy better classification.</p>
4514
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4515</div>
4516
4517<!-- _______________________________________________________________________ -->
4518<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
4519</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4520
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4521<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4522
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4523<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4524<pre>
4525 &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4526</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4527
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4528<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4529<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
4530 boolean values based on comparison of its two integer, integer vector, or
4531 pointer operands.</p>
4532
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4533<h5>Arguments:</h5>
4534<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4535 the condition code indicating the kind of comparison to perform. It is not a
4536 value, just a keyword. The possible condition code are:</p>
4537
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4538<ol>
4539 <li><tt>eq</tt>: equal</li>
4540 <li><tt>ne</tt>: not equal </li>
4541 <li><tt>ugt</tt>: unsigned greater than</li>
4542 <li><tt>uge</tt>: unsigned greater or equal</li>
4543 <li><tt>ult</tt>: unsigned less than</li>
4544 <li><tt>ule</tt>: unsigned less or equal</li>
4545 <li><tt>sgt</tt>: signed greater than</li>
4546 <li><tt>sge</tt>: signed greater or equal</li>
4547 <li><tt>slt</tt>: signed less than</li>
4548 <li><tt>sle</tt>: signed less or equal</li>
4549</ol>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4550
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4551<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4552 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
4553 typed. They must also be identical types.</p>
4554
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4555<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4556<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
4557 condition code given as <tt>cond</tt>. The comparison performed always yields
4558 either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt>
4559 result, as follows:</p>
4560
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4561<ol>
4562 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4563 <tt>false</tt> otherwise. No sign interpretation is necessary or
4564 performed.</li>
4565
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4566 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4567 <tt>false</tt> otherwise. No sign interpretation is necessary or
4568 performed.</li>
4569
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4570 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4571 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4572
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4573 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4574 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4575 to <tt>op2</tt>.</li>
4576
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4577 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4578 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4579
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4580 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4581 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4582
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4583 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4584 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4585
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4586 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4587 <tt>true</tt> if <tt>op1</tt> is greater than or equal
4588 to <tt>op2</tt>.</li>
4589
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4590 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4591 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
4592
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4593 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4594 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4595</ol>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4596
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4597<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4598 values are compared as if they were integers.</p>
4599
4600<p>If the operands are integer vectors, then they are compared element by
4601 element. The result is an <tt>i1</tt> vector with the same number of elements
4602 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4603
4604<h5>Example:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4605<pre>
4606 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4607 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
4608 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
4609 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
4610 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
4611 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
4612</pre>
Dan Gohmana53eb382009-01-22 01:39:38 +0000[diff] [blame]4613
4614<p>Note that the code generator does not yet support vector types with
4615 the <tt>icmp</tt> instruction.</p>
4616
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4617</div>
4618
4619<!-- _______________________________________________________________________ -->
4620<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
4621</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4622
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4623<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4624
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4625<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4626<pre>
4627 &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4628</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4629
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4630<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4631<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
4632 values based on comparison of its operands.</p>
4633
4634<p>If the operands are floating point scalars, then the result type is a boolean
4635(<a href="#t_primitive"><tt>i1</tt></a>).</p>
4636
4637<p>If the operands are floating point vectors, then the result type is a vector
4638 of boolean with the same number of elements as the operands being
4639 compared.</p>
4640
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4641<h5>Arguments:</h5>
4642<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4643 the condition code indicating the kind of comparison to perform. It is not a
4644 value, just a keyword. The possible condition code are:</p>
4645
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4646<ol>
4647 <li><tt>false</tt>: no comparison, always returns false</li>
4648 <li><tt>oeq</tt>: ordered and equal</li>
4649 <li><tt>ogt</tt>: ordered and greater than </li>
4650 <li><tt>oge</tt>: ordered and greater than or equal</li>
4651 <li><tt>olt</tt>: ordered and less than </li>
4652 <li><tt>ole</tt>: ordered and less than or equal</li>
4653 <li><tt>one</tt>: ordered and not equal</li>
4654 <li><tt>ord</tt>: ordered (no nans)</li>
4655 <li><tt>ueq</tt>: unordered or equal</li>
4656 <li><tt>ugt</tt>: unordered or greater than </li>
4657 <li><tt>uge</tt>: unordered or greater than or equal</li>
4658 <li><tt>ult</tt>: unordered or less than </li>
4659 <li><tt>ule</tt>: unordered or less than or equal</li>
4660 <li><tt>une</tt>: unordered or not equal</li>
4661 <li><tt>uno</tt>: unordered (either nans)</li>
4662 <li><tt>true</tt>: no comparison, always returns true</li>
4663</ol>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4664
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4665<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4666 <i>unordered</i> means that either operand may be a QNAN.</p>
4667
4668<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
4669 a <a href="#t_floating">floating point</a> type or
4670 a <a href="#t_vector">vector</a> of floating point type. They must have
4671 identical types.</p>
4672
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4673<h5>Semantics:</h5>
Gabor Greifd9068fe2008-08-07 21:46:00 +0000[diff] [blame]4674<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4675 according to the condition code given as <tt>cond</tt>. If the operands are
4676 vectors, then the vectors are compared element by element. Each comparison
4677 performed always yields an <a href="#t_primitive">i1</a> result, as
4678 follows:</p>
4679
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4680<ol>
4681 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4682
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4683 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4684 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4685
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4686 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4687 <tt>op1</tt> is greather than <tt>op2</tt>.</li>
4688
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4689 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4690 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4691
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4692 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4693 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4694
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4695 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4696 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4697
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4698 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4699 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4700
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4701 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4702
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4703 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4704 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
4705
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4706 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4707 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
4708
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4709 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4710 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
4711
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4712 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4713 <tt>op1</tt> is less than <tt>op2</tt>.</li>
4714
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4715 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4716 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
4717
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4718 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4719 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
4720
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4721 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4722
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4723 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
4724</ol>
4725
4726<h5>Example:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4727<pre>
4728 &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohmanb60ca3c2008-09-09 01:02:47 +0000[diff] [blame]4729 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
4730 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
4731 &lt;result&gt; = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4732</pre>
Dan Gohmana53eb382009-01-22 01:39:38 +0000[diff] [blame]4733
4734<p>Note that the code generator does not yet support vector types with
4735 the <tt>fcmp</tt> instruction.</p>
4736
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4737</div>
4738
4739<!-- _______________________________________________________________________ -->
Nate Begeman646fa482008-05-12 19:01:56 +0000[diff] [blame]4740<div class="doc_subsubsection">
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]4741 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
4742</div>
4743
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4744<div class="doc_text">
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]4745
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4746<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4747<pre>
4748 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
4749</pre>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]4750
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4751<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4752<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
4753 SSA graph representing the function.</p>
4754
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4755<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4756<p>The type of the incoming values is specified with the first type field. After
4757 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
4758 one pair for each predecessor basic block of the current block. Only values
4759 of <a href="#t_firstclass">first class</a> type may be used as the value
4760 arguments to the PHI node. Only labels may be used as the label
4761 arguments.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]4762
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4763<p>There must be no non-phi instructions between the start of a basic block and
4764 the PHI instructions: i.e. PHI instructions must be first in a basic
4765 block.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]4766
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4767<p>For the purposes of the SSA form, the use of each incoming value is deemed to
4768 occur on the edge from the corresponding predecessor block to the current
4769 block (but after any definition of an '<tt>invoke</tt>' instruction's return
4770 value on the same edge).</p>
Jay Foad8e2fd2c2009-06-03 10:20:10 +0000[diff] [blame]4771
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4772<h5>Semantics:</h5>
4773<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4774 specified by the pair corresponding to the predecessor basic block that
4775 executed just prior to the current block.</p>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]4776
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4777<h5>Example:</h5>
Chris Lattner6704c212008-05-20 20:48:21 +0000[diff] [blame]4778<pre>
4779Loop: ; Infinite loop that counts from 0 on up...
4780 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
4781 %nextindvar = add i32 %indvar, 1
4782 br label %Loop
4783</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4784
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4785</div>
4786
4787<!-- _______________________________________________________________________ -->
4788<div class="doc_subsubsection">
4789 <a name="i_select">'<tt>select</tt>' Instruction</a>
4790</div>
4791
4792<div class="doc_text">
4793
4794<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4795<pre>
Dan Gohmanb60ca3c2008-09-09 01:02:47 +0000[diff] [blame]4796 &lt;result&gt; = select <i>selty</i> &lt;cond&gt;, &lt;ty&gt; &lt;val1&gt;, &lt;ty&gt; &lt;val2&gt; <i>; yields ty</i>
4797
Dan Gohman2672f3e2008-10-14 16:51:45 +0000[diff] [blame]4798 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4799</pre>
4800
4801<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4802<p>The '<tt>select</tt>' instruction is used to choose one value based on a
4803 condition, without branching.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4804
4805
4806<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4807<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
4808 values indicating the condition, and two values of the
4809 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
4810 vectors and the condition is a scalar, then entire vectors are selected, not
4811 individual elements.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4812
4813<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4814<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
4815 first value argument; otherwise, it returns the second value argument.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4816
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4817<p>If the condition is a vector of i1, then the value arguments must be vectors
4818 of the same size, and the selection is done element by element.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4819
4820<h5>Example:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4821<pre>
4822 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
4823</pre>
Dan Gohmana53eb382009-01-22 01:39:38 +0000[diff] [blame]4824
4825<p>Note that the code generator does not yet support conditions
4826 with vector type.</p>
4827
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4828</div>
4829
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4830<!-- _______________________________________________________________________ -->
4831<div class="doc_subsubsection">
4832 <a name="i_call">'<tt>call</tt>' Instruction</a>
4833</div>
4834
4835<div class="doc_text">
4836
4837<h5>Syntax:</h5>
4838<pre>
Devang Pateld0bfcc72008-10-07 17:48:33 +0000[diff] [blame]4839 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4840</pre>
4841
4842<h5>Overview:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4843<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
4844
4845<h5>Arguments:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4846<p>This instruction requires several arguments:</p>
4847
4848<ol>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4849 <li>The optional "tail" marker indicates whether the callee function accesses
4850 any allocas or varargs in the caller. If the "tail" marker is present,
4851 the function call is eligible for tail call optimization. Note that calls
4852 may be marked "tail" even if they do not occur before
4853 a <a href="#i_ret"><tt>ret</tt></a> instruction.</li>
Devang Patelac2fc272008-10-06 18:50:38 +0000[diff] [blame]4854
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4855 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
4856 convention</a> the call should use. If none is specified, the call
4857 defaults to using C calling conventions.</li>
Devang Patelac2fc272008-10-06 18:50:38 +0000[diff] [blame]4858
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4859 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
4860 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
4861 '<tt>inreg</tt>' attributes are valid here.</li>
4862
4863 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
4864 type of the return value. Functions that return no value are marked
4865 <tt><a href="#t_void">void</a></tt>.</li>
4866
4867 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
4868 being invoked. The argument types must match the types implied by this
4869 signature. This type can be omitted if the function is not varargs and if
4870 the function type does not return a pointer to a function.</li>
4871
4872 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
4873 be invoked. In most cases, this is a direct function invocation, but
4874 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
4875 to function value.</li>
4876
4877 <li>'<tt>function args</tt>': argument list whose types match the function
4878 signature argument types. All arguments must be of
4879 <a href="#t_firstclass">first class</a> type. If the function signature
4880 indicates the function accepts a variable number of arguments, the extra
4881 arguments can be specified.</li>
4882
4883 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
4884 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
4885 '<tt>readnone</tt>' attributes are valid here.</li>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4886</ol>
4887
4888<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4889<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
4890 a specified function, with its incoming arguments bound to the specified
4891 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
4892 function, control flow continues with the instruction after the function
4893 call, and the return value of the function is bound to the result
4894 argument.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4895
4896<h5>Example:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4897<pre>
Nick Lewycky93082fc2007-09-08 13:57:50 +0000[diff] [blame]4898 %retval = call i32 @test(i32 %argc)
Chris Lattner5e893ef2008-03-21 17:24:17 +0000[diff] [blame]4899 call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
4900 %X = tail call i32 @foo() <i>; yields i32</i>
4901 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
4902 call void %foo(i8 97 signext)
Devang Patela3cc5372008-03-10 20:49:15 +0000[diff] [blame]4903
4904 %struct.A = type { i32, i8 }
Devang Patelac2fc272008-10-06 18:50:38 +0000[diff] [blame]4905 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman3e700032008-10-04 19:00:07 +0000[diff] [blame]4906 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
4907 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattnerac454b32008-10-08 06:26:11 +0000[diff] [blame]4908 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijman2c4e05a2008-10-07 10:03:45 +0000[diff] [blame]4909 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4910</pre>
4911
4912</div>
4913
4914<!-- _______________________________________________________________________ -->
4915<div class="doc_subsubsection">
4916 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
4917</div>
4918
4919<div class="doc_text">
4920
4921<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4922<pre>
4923 &lt;resultval&gt; = va_arg &lt;va_list*&gt; &lt;arglist&gt;, &lt;argty&gt;
4924</pre>
4925
4926<h5>Overview:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4927<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4928 the "variable argument" area of a function call. It is used to implement the
4929 <tt>va_arg</tt> macro in C.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4930
4931<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4932<p>This instruction takes a <tt>va_list*</tt> value and the type of the
4933 argument. It returns a value of the specified argument type and increments
4934 the <tt>va_list</tt> to point to the next argument. The actual type
4935 of <tt>va_list</tt> is target specific.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4936
4937<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4938<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
4939 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
4940 to the next argument. For more information, see the variable argument
4941 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4942
4943<p>It is legal for this instruction to be called in a function which does not
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4944 take a variable number of arguments, for example, the <tt>vfprintf</tt>
4945 function.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4946
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4947<p><tt>va_arg</tt> is an LLVM instruction instead of
4948 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
4949 argument.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4950
4951<h5>Example:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4952<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
4953
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4954<p>Note that the code generator does not yet fully support va_arg on many
4955 targets. Also, it does not currently support va_arg with aggregate types on
4956 any target.</p>
Dan Gohman60967192009-01-12 23:12:39 +0000[diff] [blame]4957
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4958</div>
4959
4960<!-- *********************************************************************** -->
4961<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
4962<!-- *********************************************************************** -->
4963
4964<div class="doc_text">
4965
4966<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4967 well known names and semantics and are required to follow certain
4968 restrictions. Overall, these intrinsics represent an extension mechanism for
4969 the LLVM language that does not require changing all of the transformations
4970 in LLVM when adding to the language (or the bitcode reader/writer, the
4971 parser, etc...).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4972
4973<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4974 prefix is reserved in LLVM for intrinsic names; thus, function names may not
4975 begin with this prefix. Intrinsic functions must always be external
4976 functions: you cannot define the body of intrinsic functions. Intrinsic
4977 functions may only be used in call or invoke instructions: it is illegal to
4978 take the address of an intrinsic function. Additionally, because intrinsic
4979 functions are part of the LLVM language, it is required if any are added that
4980 they be documented here.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4981
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4982<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
4983 family of functions that perform the same operation but on different data
4984 types. Because LLVM can represent over 8 million different integer types,
4985 overloading is used commonly to allow an intrinsic function to operate on any
4986 integer type. One or more of the argument types or the result type can be
4987 overloaded to accept any integer type. Argument types may also be defined as
4988 exactly matching a previous argument's type or the result type. This allows
4989 an intrinsic function which accepts multiple arguments, but needs all of them
4990 to be of the same type, to only be overloaded with respect to a single
4991 argument or the result.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]4992
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]4993<p>Overloaded intrinsics will have the names of its overloaded argument types
4994 encoded into its function name, each preceded by a period. Only those types
4995 which are overloaded result in a name suffix. Arguments whose type is matched
4996 against another type do not. For example, the <tt>llvm.ctpop</tt> function
4997 can take an integer of any width and returns an integer of exactly the same
4998 integer width. This leads to a family of functions such as
4999 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5000 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5001 suffix is required. Because the argument's type is matched against the return
5002 type, it does not require its own name suffix.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5003
5004<p>To learn how to add an intrinsic function, please see the
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5005 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5006
5007</div>
5008
5009<!-- ======================================================================= -->
5010<div class="doc_subsection">
5011 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
5012</div>
5013
5014<div class="doc_text">
5015
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5016<p>Variable argument support is defined in LLVM with
5017 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5018 intrinsic functions. These functions are related to the similarly named
5019 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5020
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5021<p>All of these functions operate on arguments that use a target-specific value
5022 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5023 not define what this type is, so all transformations should be prepared to
5024 handle these functions regardless of the type used.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5025
5026<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5027 instruction and the variable argument handling intrinsic functions are
5028 used.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5029
5030<div class="doc_code">
5031<pre>
5032define i32 @test(i32 %X, ...) {
5033 ; Initialize variable argument processing
5034 %ap = alloca i8*
5035 %ap2 = bitcast i8** %ap to i8*
5036 call void @llvm.va_start(i8* %ap2)
5037
5038 ; Read a single integer argument
5039 %tmp = va_arg i8** %ap, i32
5040
5041 ; Demonstrate usage of llvm.va_copy and llvm.va_end
5042 %aq = alloca i8*
5043 %aq2 = bitcast i8** %aq to i8*
5044 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
5045 call void @llvm.va_end(i8* %aq2)
5046
5047 ; Stop processing of arguments.
5048 call void @llvm.va_end(i8* %ap2)
5049 ret i32 %tmp
5050}
5051
5052declare void @llvm.va_start(i8*)
5053declare void @llvm.va_copy(i8*, i8*)
5054declare void @llvm.va_end(i8*)
5055</pre>
5056</div>
5057
5058</div>
5059
5060<!-- _______________________________________________________________________ -->
5061<div class="doc_subsubsection">
5062 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
5063</div>
5064
5065
5066<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5067
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5068<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5069<pre>
5070 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5071</pre>
5072
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5073<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5074<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5075 for subsequent use by <tt><a href="#i_va_arg">va_arg</a></tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5076
5077<h5>Arguments:</h5>
Dan Gohman2672f3e2008-10-14 16:51:45 +0000[diff] [blame]5078<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5079
5080<h5>Semantics:</h5>
Dan Gohman2672f3e2008-10-14 16:51:45 +0000[diff] [blame]5081<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5082 macro available in C. In a target-dependent way, it initializes
5083 the <tt>va_list</tt> element to which the argument points, so that the next
5084 call to <tt>va_arg</tt> will produce the first variable argument passed to
5085 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5086 need to know the last argument of the function as the compiler can figure
5087 that out.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5088
5089</div>
5090
5091<!-- _______________________________________________________________________ -->
5092<div class="doc_subsubsection">
5093 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
5094</div>
5095
5096<div class="doc_text">
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5097
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5098<h5>Syntax:</h5>
5099<pre>
5100 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5101</pre>
5102
5103<h5>Overview:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5104<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5105 which has been initialized previously
5106 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5107 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5108
5109<h5>Arguments:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5110<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
5111
5112<h5>Semantics:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5113<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5114 macro available in C. In a target-dependent way, it destroys
5115 the <tt>va_list</tt> element to which the argument points. Calls
5116 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5117 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5118 with calls to <tt>llvm.va_end</tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5119
5120</div>
5121
5122<!-- _______________________________________________________________________ -->
5123<div class="doc_subsubsection">
5124 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
5125</div>
5126
5127<div class="doc_text">
5128
5129<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5130<pre>
5131 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
5132</pre>
5133
5134<h5>Overview:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5135<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5136 from the source argument list to the destination argument list.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5137
5138<h5>Arguments:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5139<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5140 The second argument is a pointer to a <tt>va_list</tt> element to copy
5141 from.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5142
5143<h5>Semantics:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5144<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5145 macro available in C. In a target-dependent way, it copies the
5146 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5147 element. This intrinsic is necessary because
5148 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5149 arbitrarily complex and require, for example, memory allocation.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5150
5151</div>
5152
5153<!-- ======================================================================= -->
5154<div class="doc_subsection">
5155 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
5156</div>
5157
5158<div class="doc_text">
5159
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5160<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner96451482008-08-05 18:29:16 +0000[diff] [blame]5161Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5162intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5163roots on the stack</a>, as well as garbage collector implementations that
5164require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5165barriers. Front-ends for type-safe garbage collected languages should generate
5166these intrinsics to make use of the LLVM garbage collectors. For more details,
5167see <a href="GarbageCollection.html">Accurate Garbage Collection with
5168LLVM</a>.</p>
Christopher Lambcfe00962007-12-17 01:00:21 +0000[diff] [blame]5169
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5170<p>The garbage collection intrinsics only operate on objects in the generic
5171 address space (address space zero).</p>
Christopher Lambcfe00962007-12-17 01:00:21 +0000[diff] [blame]5172
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5173</div>
5174
5175<!-- _______________________________________________________________________ -->
5176<div class="doc_subsubsection">
5177 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
5178</div>
5179
5180<div class="doc_text">
5181
5182<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5183<pre>
Chris Lattner38bd5dd2007-09-21 17:30:40 +0000[diff] [blame]5184 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5185</pre>
5186
5187<h5>Overview:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5188<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5189 the code generator, and allows some metadata to be associated with it.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5190
5191<h5>Arguments:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5192<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5193 root pointer. The second pointer (which must be either a constant or a
5194 global value address) contains the meta-data to be associated with the
5195 root.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5196
5197<h5>Semantics:</h5>
Chris Lattnera7d94ba2008-04-24 05:59:56 +0000[diff] [blame]5198<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5199 location. At compile-time, the code generator generates information to allow
5200 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5201 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5202 algorithm</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5203
5204</div>
5205
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5206<!-- _______________________________________________________________________ -->
5207<div class="doc_subsubsection">
5208 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
5209</div>
5210
5211<div class="doc_text">
5212
5213<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5214<pre>
Chris Lattner38bd5dd2007-09-21 17:30:40 +0000[diff] [blame]5215 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5216</pre>
5217
5218<h5>Overview:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5219<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5220 locations, allowing garbage collector implementations that require read
5221 barriers.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5222
5223<h5>Arguments:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5224<p>The second argument is the address to read from, which should be an address
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5225 allocated from the garbage collector. The first object is a pointer to the
5226 start of the referenced object, if needed by the language runtime (otherwise
5227 null).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5228
5229<h5>Semantics:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5230<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5231 instruction, but may be replaced with substantially more complex code by the
5232 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5233 may only be used in a function which <a href="#gc">specifies a GC
5234 algorithm</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5235
5236</div>
5237
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5238<!-- _______________________________________________________________________ -->
5239<div class="doc_subsubsection">
5240 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
5241</div>
5242
5243<div class="doc_text">
5244
5245<h5>Syntax:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5246<pre>
Chris Lattner38bd5dd2007-09-21 17:30:40 +0000[diff] [blame]5247 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5248</pre>
5249
5250<h5>Overview:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5251<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5252 locations, allowing garbage collector implementations that require write
5253 barriers (such as generational or reference counting collectors).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5254
5255<h5>Arguments:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5256<p>The first argument is the reference to store, the second is the start of the
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5257 object to store it to, and the third is the address of the field of Obj to
5258 store to. If the runtime does not require a pointer to the object, Obj may
5259 be null.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5260
5261<h5>Semantics:</h5>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5262<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5263 instruction, but may be replaced with substantially more complex code by the
5264 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5265 may only be used in a function which <a href="#gc">specifies a GC
5266 algorithm</a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5267
5268</div>
5269
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5270<!-- ======================================================================= -->
5271<div class="doc_subsection">
5272 <a name="int_codegen">Code Generator Intrinsics</a>
5273</div>
5274
5275<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5276
5277<p>These intrinsics are provided by LLVM to expose special features that may
5278 only be implemented with code generator support.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5279
5280</div>
5281
5282<!-- _______________________________________________________________________ -->
5283<div class="doc_subsubsection">
5284 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
5285</div>
5286
5287<div class="doc_text">
5288
5289<h5>Syntax:</h5>
5290<pre>
5291 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
5292</pre>
5293
5294<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5295<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5296 target-specific value indicating the return address of the current function
5297 or one of its callers.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5298
5299<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5300<p>The argument to this intrinsic indicates which function to return the address
5301 for. Zero indicates the calling function, one indicates its caller, etc.
5302 The argument is <b>required</b> to be a constant integer value.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5303
5304<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5305<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5306 indicating the return address of the specified call frame, or zero if it
5307 cannot be identified. The value returned by this intrinsic is likely to be
5308 incorrect or 0 for arguments other than zero, so it should only be used for
5309 debugging purposes.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5310
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5311<p>Note that calling this intrinsic does not prevent function inlining or other
5312 aggressive transformations, so the value returned may not be that of the
5313 obvious source-language caller.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5314
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5315</div>
5316
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5317<!-- _______________________________________________________________________ -->
5318<div class="doc_subsubsection">
5319 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
5320</div>
5321
5322<div class="doc_text">
5323
5324<h5>Syntax:</h5>
5325<pre>
Chris Lattner38bd5dd2007-09-21 17:30:40 +0000[diff] [blame]5326 declare i8 *@llvm.frameaddress(i32 &lt;level&gt;)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5327</pre>
5328
5329<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5330<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5331 target-specific frame pointer value for the specified stack frame.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5332
5333<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5334<p>The argument to this intrinsic indicates which function to return the frame
5335 pointer for. Zero indicates the calling function, one indicates its caller,
5336 etc. The argument is <b>required</b> to be a constant integer value.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5337
5338<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5339<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5340 indicating the frame address of the specified call frame, or zero if it
5341 cannot be identified. The value returned by this intrinsic is likely to be
5342 incorrect or 0 for arguments other than zero, so it should only be used for
5343 debugging purposes.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5344
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5345<p>Note that calling this intrinsic does not prevent function inlining or other
5346 aggressive transformations, so the value returned may not be that of the
5347 obvious source-language caller.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5348
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5349</div>
5350
5351<!-- _______________________________________________________________________ -->
5352<div class="doc_subsubsection">
5353 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
5354</div>
5355
5356<div class="doc_text">
5357
5358<h5>Syntax:</h5>
5359<pre>
Chris Lattner38bd5dd2007-09-21 17:30:40 +0000[diff] [blame]5360 declare i8 *@llvm.stacksave()
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5361</pre>
5362
5363<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5364<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5365 of the function stack, for use
5366 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5367 useful for implementing language features like scoped automatic variable
5368 sized arrays in C99.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5369
5370<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5371<p>This intrinsic returns a opaque pointer value that can be passed
5372 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5373 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5374 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5375 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5376 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5377 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5378
5379</div>
5380
5381<!-- _______________________________________________________________________ -->
5382<div class="doc_subsubsection">
5383 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
5384</div>
5385
5386<div class="doc_text">
5387
5388<h5>Syntax:</h5>
5389<pre>
5390 declare void @llvm.stackrestore(i8 * %ptr)
5391</pre>
5392
5393<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5394<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5395 the function stack to the state it was in when the
5396 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5397 executed. This is useful for implementing language features like scoped
5398 automatic variable sized arrays in C99.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5399
5400<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5401<p>See the description
5402 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5403
5404</div>
5405
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5406<!-- _______________________________________________________________________ -->
5407<div class="doc_subsubsection">
5408 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
5409</div>
5410
5411<div class="doc_text">
5412
5413<h5>Syntax:</h5>
5414<pre>
Chris Lattner38bd5dd2007-09-21 17:30:40 +0000[diff] [blame]5415 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5416</pre>
5417
5418<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5419<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
5420 insert a prefetch instruction if supported; otherwise, it is a noop.
5421 Prefetches have no effect on the behavior of the program but can change its
5422 performance characteristics.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5423
5424<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5425<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
5426 specifier determining if the fetch should be for a read (0) or write (1),
5427 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
5428 locality, to (3) - extremely local keep in cache. The <tt>rw</tt>
5429 and <tt>locality</tt> arguments must be constant integers.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5430
5431<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5432<p>This intrinsic does not modify the behavior of the program. In particular,
5433 prefetches cannot trap and do not produce a value. On targets that support
5434 this intrinsic, the prefetch can provide hints to the processor cache for
5435 better performance.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5436
5437</div>
5438
5439<!-- _______________________________________________________________________ -->
5440<div class="doc_subsubsection">
5441 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
5442</div>
5443
5444<div class="doc_text">
5445
5446<h5>Syntax:</h5>
5447<pre>
Chris Lattner38bd5dd2007-09-21 17:30:40 +0000[diff] [blame]5448 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5449</pre>
5450
5451<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5452<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
5453 Counter (PC) in a region of code to simulators and other tools. The method
5454 is target specific, but it is expected that the marker will use exported
5455 symbols to transmit the PC of the marker. The marker makes no guarantees
5456 that it will remain with any specific instruction after optimizations. It is
5457 possible that the presence of a marker will inhibit optimizations. The
5458 intended use is to be inserted after optimizations to allow correlations of
5459 simulation runs.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5460
5461<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5462<p><tt>id</tt> is a numerical id identifying the marker.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5463
5464<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5465<p>This intrinsic does not modify the behavior of the program. Backends that do
5466 not support this intrinisic may ignore it.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5467
5468</div>
5469
5470<!-- _______________________________________________________________________ -->
5471<div class="doc_subsubsection">
5472 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
5473</div>
5474
5475<div class="doc_text">
5476
5477<h5>Syntax:</h5>
5478<pre>
5479 declare i64 @llvm.readcyclecounter( )
5480</pre>
5481
5482<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5483<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
5484 counter register (or similar low latency, high accuracy clocks) on those
5485 targets that support it. On X86, it should map to RDTSC. On Alpha, it
5486 should map to RPCC. As the backing counters overflow quickly (on the order
5487 of 9 seconds on alpha), this should only be used for small timings.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5488
5489<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5490<p>When directly supported, reading the cycle counter should not modify any
5491 memory. Implementations are allowed to either return a application specific
5492 value or a system wide value. On backends without support, this is lowered
5493 to a constant 0.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5494
5495</div>
5496
5497<!-- ======================================================================= -->
5498<div class="doc_subsection">
5499 <a name="int_libc">Standard C Library Intrinsics</a>
5500</div>
5501
5502<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5503
5504<p>LLVM provides intrinsics for a few important standard C library functions.
5505 These intrinsics allow source-language front-ends to pass information about
5506 the alignment of the pointer arguments to the code generator, providing
5507 opportunity for more efficient code generation.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5508
5509</div>
5510
5511<!-- _______________________________________________________________________ -->
5512<div class="doc_subsubsection">
5513 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
5514</div>
5515
5516<div class="doc_text">
5517
5518<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5519<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
5520 integer bit width. Not all targets support all bit widths however.</p>
5521
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5522<pre>
Chris Lattner82c2e432008-11-21 16:42:48 +0000[diff] [blame]5523 declare void @llvm.memcpy.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5524 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner82c2e432008-11-21 16:42:48 +0000[diff] [blame]5525 declare void @llvm.memcpy.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5526 i16 &lt;len&gt;, i32 &lt;align&gt;)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5527 declare void @llvm.memcpy.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5528 i32 &lt;len&gt;, i32 &lt;align&gt;)
5529 declare void @llvm.memcpy.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5530 i64 &lt;len&gt;, i32 &lt;align&gt;)
5531</pre>
5532
5533<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5534<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5535 source location to the destination location.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5536
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5537<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
5538 intrinsics do not return a value, and takes an extra alignment argument.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5539
5540<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5541<p>The first argument is a pointer to the destination, the second is a pointer
5542 to the source. The third argument is an integer argument specifying the
5543 number of bytes to copy, and the fourth argument is the alignment of the
5544 source and destination locations.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5545
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5546<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5547 then the caller guarantees that both the source and destination pointers are
5548 aligned to that boundary.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5549
5550<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5551<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
5552 source location to the destination location, which are not allowed to
5553 overlap. It copies "len" bytes of memory over. If the argument is known to
5554 be aligned to some boundary, this can be specified as the fourth argument,
5555 otherwise it should be set to 0 or 1.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5556
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5557</div>
5558
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5559<!-- _______________________________________________________________________ -->
5560<div class="doc_subsubsection">
5561 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
5562</div>
5563
5564<div class="doc_text">
5565
5566<h5>Syntax:</h5>
Chris Lattner82c2e432008-11-21 16:42:48 +0000[diff] [blame]5567<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5568 width. Not all targets support all bit widths however.</p>
5569
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5570<pre>
Chris Lattner82c2e432008-11-21 16:42:48 +0000[diff] [blame]5571 declare void @llvm.memmove.i8(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5572 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner82c2e432008-11-21 16:42:48 +0000[diff] [blame]5573 declare void @llvm.memmove.i16(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5574 i16 &lt;len&gt;, i32 &lt;align&gt;)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5575 declare void @llvm.memmove.i32(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5576 i32 &lt;len&gt;, i32 &lt;align&gt;)
5577 declare void @llvm.memmove.i64(i8 * &lt;dest&gt;, i8 * &lt;src&gt;,
5578 i64 &lt;len&gt;, i32 &lt;align&gt;)
5579</pre>
5580
5581<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5582<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
5583 source location to the destination location. It is similar to the
5584 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
5585 overlap.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5586
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5587<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
5588 intrinsics do not return a value, and takes an extra alignment argument.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5589
5590<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5591<p>The first argument is a pointer to the destination, the second is a pointer
5592 to the source. The third argument is an integer argument specifying the
5593 number of bytes to copy, and the fourth argument is the alignment of the
5594 source and destination locations.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5595
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5596<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5597 then the caller guarantees that the source and destination pointers are
5598 aligned to that boundary.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5599
5600<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5601<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
5602 source location to the destination location, which may overlap. It copies
5603 "len" bytes of memory over. If the argument is known to be aligned to some
5604 boundary, this can be specified as the fourth argument, otherwise it should
5605 be set to 0 or 1.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5606
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5607</div>
5608
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5609<!-- _______________________________________________________________________ -->
5610<div class="doc_subsubsection">
5611 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
5612</div>
5613
5614<div class="doc_text">
5615
5616<h5>Syntax:</h5>
Chris Lattner82c2e432008-11-21 16:42:48 +0000[diff] [blame]5617<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5618 width. Not all targets support all bit widths however.</p>
5619
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5620<pre>
Chris Lattner82c2e432008-11-21 16:42:48 +0000[diff] [blame]5621 declare void @llvm.memset.i8(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5622 i8 &lt;len&gt;, i32 &lt;align&gt;)
Chris Lattner82c2e432008-11-21 16:42:48 +0000[diff] [blame]5623 declare void @llvm.memset.i16(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5624 i16 &lt;len&gt;, i32 &lt;align&gt;)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5625 declare void @llvm.memset.i32(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5626 i32 &lt;len&gt;, i32 &lt;align&gt;)
5627 declare void @llvm.memset.i64(i8 * &lt;dest&gt;, i8 &lt;val&gt;,
5628 i64 &lt;len&gt;, i32 &lt;align&gt;)
5629</pre>
5630
5631<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5632<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
5633 particular byte value.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5634
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5635<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
5636 intrinsic does not return a value, and takes an extra alignment argument.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5637
5638<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5639<p>The first argument is a pointer to the destination to fill, the second is the
5640 byte value to fill it with, the third argument is an integer argument
5641 specifying the number of bytes to fill, and the fourth argument is the known
5642 alignment of destination location.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5643
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5644<p>If the call to this intrinisic has an alignment value that is not 0 or 1,
5645 then the caller guarantees that the destination pointer is aligned to that
5646 boundary.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5647
5648<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5649<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
5650 at the destination location. If the argument is known to be aligned to some
5651 boundary, this can be specified as the fourth argument, otherwise it should
5652 be set to 0 or 1.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5653
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5654</div>
5655
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5656<!-- _______________________________________________________________________ -->
5657<div class="doc_subsubsection">
5658 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
5659</div>
5660
5661<div class="doc_text">
5662
5663<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5664<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
5665 floating point or vector of floating point type. Not all targets support all
5666 types however.</p>
5667
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5668<pre>
Dale Johannesenf9adbb62007-10-02 17:47:38 +0000[diff] [blame]5669 declare float @llvm.sqrt.f32(float %Val)
5670 declare double @llvm.sqrt.f64(double %Val)
5671 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
5672 declare fp128 @llvm.sqrt.f128(fp128 %Val)
5673 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5674</pre>
5675
5676<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5677<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
5678 returning the same value as the libm '<tt>sqrt</tt>' functions would.
5679 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
5680 behavior for negative numbers other than -0.0 (which allows for better
5681 optimization, because there is no need to worry about errno being
5682 set). <tt>llvm.sqrt(-0.0)</tt> is defined to return -0.0 like IEEE sqrt.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5683
5684<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5685<p>The argument and return value are floating point numbers of the same
5686 type.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5687
5688<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5689<p>This function returns the sqrt of the specified operand if it is a
5690 nonnegative floating point number.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5691
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5692</div>
5693
5694<!-- _______________________________________________________________________ -->
5695<div class="doc_subsubsection">
5696 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
5697</div>
5698
5699<div class="doc_text">
5700
5701<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5702<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
5703 floating point or vector of floating point type. Not all targets support all
5704 types however.</p>
5705
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5706<pre>
Dale Johannesenf9adbb62007-10-02 17:47:38 +0000[diff] [blame]5707 declare float @llvm.powi.f32(float %Val, i32 %power)
5708 declare double @llvm.powi.f64(double %Val, i32 %power)
5709 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
5710 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
5711 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5712</pre>
5713
5714<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5715<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
5716 specified (positive or negative) power. The order of evaluation of
5717 multiplications is not defined. When a vector of floating point type is
5718 used, the second argument remains a scalar integer value.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5719
5720<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5721<p>The second argument is an integer power, and the first is a value to raise to
5722 that power.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5723
5724<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5725<p>This function returns the first value raised to the second power with an
5726 unspecified sequence of rounding operations.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5727
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5728</div>
5729
Dan Gohman361079c2007-10-15 20:30:11 +0000[diff] [blame]5730<!-- _______________________________________________________________________ -->
5731<div class="doc_subsubsection">
5732 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
5733</div>
5734
5735<div class="doc_text">
5736
5737<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5738<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
5739 floating point or vector of floating point type. Not all targets support all
5740 types however.</p>
5741
Dan Gohman361079c2007-10-15 20:30:11 +0000[diff] [blame]5742<pre>
5743 declare float @llvm.sin.f32(float %Val)
5744 declare double @llvm.sin.f64(double %Val)
5745 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
5746 declare fp128 @llvm.sin.f128(fp128 %Val)
5747 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
5748</pre>
5749
5750<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5751<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohman361079c2007-10-15 20:30:11 +0000[diff] [blame]5752
5753<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5754<p>The argument and return value are floating point numbers of the same
5755 type.</p>
Dan Gohman361079c2007-10-15 20:30:11 +0000[diff] [blame]5756
5757<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5758<p>This function returns the sine of the specified operand, returning the same
5759 values as the libm <tt>sin</tt> functions would, and handles error conditions
5760 in the same way.</p>
Dan Gohman361079c2007-10-15 20:30:11 +0000[diff] [blame]5761
Dan Gohman361079c2007-10-15 20:30:11 +0000[diff] [blame]5762</div>
5763
5764<!-- _______________________________________________________________________ -->
5765<div class="doc_subsubsection">
5766 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
5767</div>
5768
5769<div class="doc_text">
5770
5771<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5772<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
5773 floating point or vector of floating point type. Not all targets support all
5774 types however.</p>
5775
Dan Gohman361079c2007-10-15 20:30:11 +0000[diff] [blame]5776<pre>
5777 declare float @llvm.cos.f32(float %Val)
5778 declare double @llvm.cos.f64(double %Val)
5779 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
5780 declare fp128 @llvm.cos.f128(fp128 %Val)
5781 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
5782</pre>
5783
5784<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5785<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohman361079c2007-10-15 20:30:11 +0000[diff] [blame]5786
5787<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5788<p>The argument and return value are floating point numbers of the same
5789 type.</p>
Dan Gohman361079c2007-10-15 20:30:11 +0000[diff] [blame]5790
5791<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5792<p>This function returns the cosine of the specified operand, returning the same
5793 values as the libm <tt>cos</tt> functions would, and handles error conditions
5794 in the same way.</p>
Dan Gohman361079c2007-10-15 20:30:11 +0000[diff] [blame]5795
Dan Gohman361079c2007-10-15 20:30:11 +0000[diff] [blame]5796</div>
5797
5798<!-- _______________________________________________________________________ -->
5799<div class="doc_subsubsection">
5800 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
5801</div>
5802
5803<div class="doc_text">
5804
5805<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5806<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
5807 floating point or vector of floating point type. Not all targets support all
5808 types however.</p>
5809
Dan Gohman361079c2007-10-15 20:30:11 +0000[diff] [blame]5810<pre>
5811 declare float @llvm.pow.f32(float %Val, float %Power)
5812 declare double @llvm.pow.f64(double %Val, double %Power)
5813 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
5814 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
5815 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
5816</pre>
5817
5818<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5819<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
5820 specified (positive or negative) power.</p>
Dan Gohman361079c2007-10-15 20:30:11 +0000[diff] [blame]5821
5822<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5823<p>The second argument is a floating point power, and the first is a value to
5824 raise to that power.</p>
Dan Gohman361079c2007-10-15 20:30:11 +0000[diff] [blame]5825
5826<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5827<p>This function returns the first value raised to the second power, returning
5828 the same values as the libm <tt>pow</tt> functions would, and handles error
5829 conditions in the same way.</p>
Dan Gohman361079c2007-10-15 20:30:11 +0000[diff] [blame]5830
Dan Gohman361079c2007-10-15 20:30:11 +0000[diff] [blame]5831</div>
5832
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5833<!-- ======================================================================= -->
5834<div class="doc_subsection">
5835 <a name="int_manip">Bit Manipulation Intrinsics</a>
5836</div>
5837
5838<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5839
5840<p>LLVM provides intrinsics for a few important bit manipulation operations.
5841 These allow efficient code generation for some algorithms.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5842
5843</div>
5844
5845<!-- _______________________________________________________________________ -->
5846<div class="doc_subsubsection">
5847 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
5848</div>
5849
5850<div class="doc_text">
5851
5852<h5>Syntax:</h5>
5853<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5854 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
5855
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5856<pre>
Chandler Carrutha228e392007-08-04 01:51:18 +0000[diff] [blame]5857 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
5858 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
5859 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5860</pre>
5861
5862<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5863<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
5864 values with an even number of bytes (positive multiple of 16 bits). These
5865 are useful for performing operations on data that is not in the target's
5866 native byte order.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5867
5868<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5869<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
5870 and low byte of the input i16 swapped. Similarly,
5871 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
5872 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
5873 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
5874 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
5875 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
5876 more, respectively).</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5877
5878</div>
5879
5880<!-- _______________________________________________________________________ -->
5881<div class="doc_subsubsection">
5882 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
5883</div>
5884
5885<div class="doc_text">
5886
5887<h5>Syntax:</h5>
5888<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5889 width. Not all targets support all bit widths however.</p>
5890
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5891<pre>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]5892 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carrutha228e392007-08-04 01:51:18 +0000[diff] [blame]5893 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5894 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carrutha228e392007-08-04 01:51:18 +0000[diff] [blame]5895 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
5896 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5897</pre>
5898
5899<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5900<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
5901 in a value.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5902
5903<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5904<p>The only argument is the value to be counted. The argument may be of any
5905 integer type. The return type must match the argument type.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5906
5907<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5908<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5909
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5910</div>
5911
5912<!-- _______________________________________________________________________ -->
5913<div class="doc_subsubsection">
5914 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
5915</div>
5916
5917<div class="doc_text">
5918
5919<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5920<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
5921 integer bit width. Not all targets support all bit widths however.</p>
5922
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5923<pre>
Chandler Carrutha228e392007-08-04 01:51:18 +0000[diff] [blame]5924 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
5925 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5926 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carrutha228e392007-08-04 01:51:18 +0000[diff] [blame]5927 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
5928 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5929</pre>
5930
5931<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5932<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
5933 leading zeros in a variable.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5934
5935<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5936<p>The only argument is the value to be counted. The argument may be of any
5937 integer type. The return type must match the argument type.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5938
5939<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5940<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
5941 zeros in a variable. If the src == 0 then the result is the size in bits of
5942 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5943
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5944</div>
5945
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5946<!-- _______________________________________________________________________ -->
5947<div class="doc_subsubsection">
5948 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
5949</div>
5950
5951<div class="doc_text">
5952
5953<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5954<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
5955 integer bit width. Not all targets support all bit widths however.</p>
5956
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5957<pre>
Chandler Carrutha228e392007-08-04 01:51:18 +0000[diff] [blame]5958 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
5959 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5960 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carrutha228e392007-08-04 01:51:18 +0000[diff] [blame]5961 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
5962 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5963</pre>
5964
5965<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5966<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
5967 trailing zeros.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5968
5969<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5970<p>The only argument is the value to be counted. The argument may be of any
5971 integer type. The return type must match the argument type.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5972
5973<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5974<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
5975 zeros in a variable. If the src == 0 then the result is the size in bits of
5976 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5977
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]5978</div>
5979
Bill Wendling3e1258b2009-02-08 04:04:40 +0000[diff] [blame]5980<!-- ======================================================================= -->
5981<div class="doc_subsection">
5982 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
5983</div>
5984
5985<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]5986
5987<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendling3e1258b2009-02-08 04:04:40 +0000[diff] [blame]5988
5989</div>
5990
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]5991<!-- _______________________________________________________________________ -->
5992<div class="doc_subsubsection">
Bill Wendling3e1258b2009-02-08 04:04:40 +0000[diff] [blame]5993 <a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]5994</div>
5995
5996<div class="doc_text">
5997
5998<h5>Syntax:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]5999<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6000 on any integer bit width.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6001
6002<pre>
6003 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6004 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6005 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6006</pre>
6007
6008<h5>Overview:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6009<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6010 a signed addition of the two arguments, and indicate whether an overflow
6011 occurred during the signed summation.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6012
6013<h5>Arguments:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6014<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6015 be of integer types of any bit width, but they must have the same bit
6016 width. The second element of the result structure must be of
6017 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6018 undergo signed addition.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6019
6020<h5>Semantics:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6021<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6022 a signed addition of the two variables. They return a structure &mdash; the
6023 first element of which is the signed summation, and the second element of
6024 which is a bit specifying if the signed summation resulted in an
6025 overflow.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6026
6027<h5>Examples:</h5>
6028<pre>
6029 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6030 %sum = extractvalue {i32, i1} %res, 0
6031 %obit = extractvalue {i32, i1} %res, 1
6032 br i1 %obit, label %overflow, label %normal
6033</pre>
6034
6035</div>
6036
6037<!-- _______________________________________________________________________ -->
6038<div class="doc_subsubsection">
Bill Wendling3e1258b2009-02-08 04:04:40 +0000[diff] [blame]6039 <a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6040</div>
6041
6042<div class="doc_text">
6043
6044<h5>Syntax:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6045<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6046 on any integer bit width.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6047
6048<pre>
6049 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6050 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6051 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6052</pre>
6053
6054<h5>Overview:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6055<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6056 an unsigned addition of the two arguments, and indicate whether a carry
6057 occurred during the unsigned summation.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6058
6059<h5>Arguments:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6060<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6061 be of integer types of any bit width, but they must have the same bit
6062 width. The second element of the result structure must be of
6063 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6064 undergo unsigned addition.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6065
6066<h5>Semantics:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6067<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6068 an unsigned addition of the two arguments. They return a structure &mdash;
6069 the first element of which is the sum, and the second element of which is a
6070 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6071
6072<h5>Examples:</h5>
6073<pre>
6074 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6075 %sum = extractvalue {i32, i1} %res, 0
6076 %obit = extractvalue {i32, i1} %res, 1
6077 br i1 %obit, label %carry, label %normal
6078</pre>
6079
6080</div>
6081
6082<!-- _______________________________________________________________________ -->
6083<div class="doc_subsubsection">
Bill Wendling3e1258b2009-02-08 04:04:40 +0000[diff] [blame]6084 <a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6085</div>
6086
6087<div class="doc_text">
6088
6089<h5>Syntax:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6090<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6091 on any integer bit width.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6092
6093<pre>
6094 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6095 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6096 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6097</pre>
6098
6099<h5>Overview:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6100<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6101 a signed subtraction of the two arguments, and indicate whether an overflow
6102 occurred during the signed subtraction.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6103
6104<h5>Arguments:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6105<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6106 be of integer types of any bit width, but they must have the same bit
6107 width. The second element of the result structure must be of
6108 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6109 undergo signed subtraction.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6110
6111<h5>Semantics:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6112<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6113 a signed subtraction of the two arguments. They return a structure &mdash;
6114 the first element of which is the subtraction, and the second element of
6115 which is a bit specifying if the signed subtraction resulted in an
6116 overflow.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6117
6118<h5>Examples:</h5>
6119<pre>
6120 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6121 %sum = extractvalue {i32, i1} %res, 0
6122 %obit = extractvalue {i32, i1} %res, 1
6123 br i1 %obit, label %overflow, label %normal
6124</pre>
6125
6126</div>
6127
6128<!-- _______________________________________________________________________ -->
6129<div class="doc_subsubsection">
Bill Wendling3e1258b2009-02-08 04:04:40 +0000[diff] [blame]6130 <a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6131</div>
6132
6133<div class="doc_text">
6134
6135<h5>Syntax:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6136<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6137 on any integer bit width.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6138
6139<pre>
6140 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6141 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6142 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6143</pre>
6144
6145<h5>Overview:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6146<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6147 an unsigned subtraction of the two arguments, and indicate whether an
6148 overflow occurred during the unsigned subtraction.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6149
6150<h5>Arguments:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6151<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6152 be of integer types of any bit width, but they must have the same bit
6153 width. The second element of the result structure must be of
6154 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6155 undergo unsigned subtraction.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6156
6157<h5>Semantics:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6158<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6159 an unsigned subtraction of the two arguments. They return a structure &mdash;
6160 the first element of which is the subtraction, and the second element of
6161 which is a bit specifying if the unsigned subtraction resulted in an
6162 overflow.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6163
6164<h5>Examples:</h5>
6165<pre>
6166 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6167 %sum = extractvalue {i32, i1} %res, 0
6168 %obit = extractvalue {i32, i1} %res, 1
6169 br i1 %obit, label %overflow, label %normal
6170</pre>
6171
6172</div>
6173
6174<!-- _______________________________________________________________________ -->
6175<div class="doc_subsubsection">
Bill Wendling3e1258b2009-02-08 04:04:40 +0000[diff] [blame]6176 <a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6177</div>
6178
6179<div class="doc_text">
6180
6181<h5>Syntax:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6182<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6183 on any integer bit width.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6184
6185<pre>
6186 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6187 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6188 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6189</pre>
6190
6191<h5>Overview:</h5>
6192
6193<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6194 a signed multiplication of the two arguments, and indicate whether an
6195 overflow occurred during the signed multiplication.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6196
6197<h5>Arguments:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6198<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6199 be of integer types of any bit width, but they must have the same bit
6200 width. The second element of the result structure must be of
6201 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6202 undergo signed multiplication.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6203
6204<h5>Semantics:</h5>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6205<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6206 a signed multiplication of the two arguments. They return a structure &mdash;
6207 the first element of which is the multiplication, and the second element of
6208 which is a bit specifying if the signed multiplication resulted in an
6209 overflow.</p>
Bill Wendling3f8cebe2009-02-08 01:40:31 +0000[diff] [blame]6210
6211<h5>Examples:</h5>
6212<pre>
6213 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6214 %sum = extractvalue {i32, i1} %res, 0
6215 %obit = extractvalue {i32, i1} %res, 1
6216 br i1 %obit, label %overflow, label %normal
6217</pre>
6218
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]6219</div>
6220
Bill Wendlingbda98b62009-02-08 23:00:09 +0000[diff] [blame]6221<!-- _______________________________________________________________________ -->
6222<div class="doc_subsubsection">
6223 <a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
6224</div>
6225
6226<div class="doc_text">
6227
6228<h5>Syntax:</h5>
Bill Wendlingbda98b62009-02-08 23:00:09 +0000[diff] [blame]6229<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6230 on any integer bit width.</p>
Bill Wendlingbda98b62009-02-08 23:00:09 +0000[diff] [blame]6231
6232<pre>
6233 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6234 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6235 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6236</pre>
6237
6238<h5>Overview:</h5>
Bill Wendlingbda98b62009-02-08 23:00:09 +0000[diff] [blame]6239<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6240 a unsigned multiplication of the two arguments, and indicate whether an
6241 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingbda98b62009-02-08 23:00:09 +0000[diff] [blame]6242
6243<h5>Arguments:</h5>
Bill Wendlingbda98b62009-02-08 23:00:09 +0000[diff] [blame]6244<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6245 be of integer types of any bit width, but they must have the same bit
6246 width. The second element of the result structure must be of
6247 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6248 undergo unsigned multiplication.</p>
Bill Wendlingbda98b62009-02-08 23:00:09 +0000[diff] [blame]6249
6250<h5>Semantics:</h5>
Bill Wendlingbda98b62009-02-08 23:00:09 +0000[diff] [blame]6251<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6252 an unsigned multiplication of the two arguments. They return a structure
6253 &mdash; the first element of which is the multiplication, and the second
6254 element of which is a bit specifying if the unsigned multiplication resulted
6255 in an overflow.</p>
Bill Wendlingbda98b62009-02-08 23:00:09 +0000[diff] [blame]6256
6257<h5>Examples:</h5>
6258<pre>
6259 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6260 %sum = extractvalue {i32, i1} %res, 0
6261 %obit = extractvalue {i32, i1} %res, 1
6262 br i1 %obit, label %overflow, label %normal
6263</pre>
6264
6265</div>
6266
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]6267<!-- ======================================================================= -->
6268<div class="doc_subsection">
6269 <a name="int_debugger">Debugger Intrinsics</a>
6270</div>
6271
6272<div class="doc_text">
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]6273
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6274<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
6275 prefix), are described in
6276 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
6277 Level Debugging</a> document.</p>
6278
6279</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]6280
6281<!-- ======================================================================= -->
6282<div class="doc_subsection">
6283 <a name="int_eh">Exception Handling Intrinsics</a>
6284</div>
6285
6286<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6287
6288<p>The LLVM exception handling intrinsics (which all start with
6289 <tt>llvm.eh.</tt> prefix), are described in
6290 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
6291 Handling</a> document.</p>
6292
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]6293</div>
6294
6295<!-- ======================================================================= -->
6296<div class="doc_subsection">
Duncan Sands7407a9f2007-09-11 14:10:23 +0000[diff] [blame]6297 <a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands38947cd2007-07-27 12:58:54 +0000[diff] [blame]6298</div>
6299
6300<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6301
6302<p>This intrinsic makes it possible to excise one parameter, marked with
6303 the <tt>nest</tt> attribute, from a function. The result is a callable
6304 function pointer lacking the nest parameter - the caller does not need to
6305 provide a value for it. Instead, the value to use is stored in advance in a
6306 "trampoline", a block of memory usually allocated on the stack, which also
6307 contains code to splice the nest value into the argument list. This is used
6308 to implement the GCC nested function address extension.</p>
6309
6310<p>For example, if the function is
6311 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
6312 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
6313 follows:</p>
6314
6315<div class="doc_code">
Duncan Sands38947cd2007-07-27 12:58:54 +0000[diff] [blame]6316<pre>
Duncan Sands7407a9f2007-09-11 14:10:23 +0000[diff] [blame]6317 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
6318 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
6319 %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval )
6320 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands38947cd2007-07-27 12:58:54 +0000[diff] [blame]6321</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6322</div>
6323
6324<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
6325 to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
6326
Duncan Sands38947cd2007-07-27 12:58:54 +0000[diff] [blame]6327</div>
6328
6329<!-- _______________________________________________________________________ -->
6330<div class="doc_subsubsection">
6331 <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
6332</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6333
Duncan Sands38947cd2007-07-27 12:58:54 +0000[diff] [blame]6334<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6335
Duncan Sands38947cd2007-07-27 12:58:54 +0000[diff] [blame]6336<h5>Syntax:</h5>
6337<pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6338 declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands38947cd2007-07-27 12:58:54 +0000[diff] [blame]6339</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6340
Duncan Sands38947cd2007-07-27 12:58:54 +0000[diff] [blame]6341<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6342<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
6343 function pointer suitable for executing it.</p>
6344
Duncan Sands38947cd2007-07-27 12:58:54 +0000[diff] [blame]6345<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6346<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
6347 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
6348 sufficiently aligned block of memory; this memory is written to by the
6349 intrinsic. Note that the size and the alignment are target-specific - LLVM
6350 currently provides no portable way of determining them, so a front-end that
6351 generates this intrinsic needs to have some target-specific knowledge.
6352 The <tt>func</tt> argument must hold a function bitcast to
6353 an <tt>i8*</tt>.</p>
6354
Duncan Sands38947cd2007-07-27 12:58:54 +0000[diff] [blame]6355<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6356<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
6357 dependent code, turning it into a function. A pointer to this function is
6358 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
6359 function pointer type</a> before being called. The new function's signature
6360 is the same as that of <tt>func</tt> with any arguments marked with
6361 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
6362 is allowed, and it must be of pointer type. Calling the new function is
6363 equivalent to calling <tt>func</tt> with the same argument list, but
6364 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
6365 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
6366 by <tt>tramp</tt> is modified, then the effect of any later call to the
6367 returned function pointer is undefined.</p>
6368
Duncan Sands38947cd2007-07-27 12:58:54 +0000[diff] [blame]6369</div>
6370
6371<!-- ======================================================================= -->
6372<div class="doc_subsection">
Andrew Lenharth785610d2008-02-16 01:24:58 +0000[diff] [blame]6373 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
6374</div>
6375
6376<div class="doc_text">
Andrew Lenharth785610d2008-02-16 01:24:58 +0000[diff] [blame]6377
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6378<p>These intrinsic functions expand the "universal IR" of LLVM to represent
6379 hardware constructs for atomic operations and memory synchronization. This
6380 provides an interface to the hardware, not an interface to the programmer. It
6381 is aimed at a low enough level to allow any programming models or APIs
6382 (Application Programming Interfaces) which need atomic behaviors to map
6383 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
6384 hardware provides a "universal IR" for source languages, it also provides a
6385 starting point for developing a "universal" atomic operation and
6386 synchronization IR.</p>
6387
6388<p>These do <em>not</em> form an API such as high-level threading libraries,
6389 software transaction memory systems, atomic primitives, and intrinsic
6390 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
6391 application libraries. The hardware interface provided by LLVM should allow
6392 a clean implementation of all of these APIs and parallel programming models.
6393 No one model or paradigm should be selected above others unless the hardware
6394 itself ubiquitously does so.</p>
6395
Andrew Lenharth785610d2008-02-16 01:24:58 +0000[diff] [blame]6396</div>
6397
6398<!-- _______________________________________________________________________ -->
6399<div class="doc_subsubsection">
6400 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
6401</div>
6402<div class="doc_text">
6403<h5>Syntax:</h5>
6404<pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6405 declare void @llvm.memory.barrier( i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;, i1 &lt;device&gt; )
Andrew Lenharth785610d2008-02-16 01:24:58 +0000[diff] [blame]6406</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6407
Andrew Lenharth785610d2008-02-16 01:24:58 +0000[diff] [blame]6408<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6409<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
6410 specific pairs of memory access types.</p>
6411
Andrew Lenharth785610d2008-02-16 01:24:58 +0000[diff] [blame]6412<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6413<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
6414 The first four arguments enables a specific barrier as listed below. The
6415 fith argument specifies that the barrier applies to io or device or uncached
6416 memory.</p>
Andrew Lenharth785610d2008-02-16 01:24:58 +0000[diff] [blame]6417
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6418<ul>
6419 <li><tt>ll</tt>: load-load barrier</li>
6420 <li><tt>ls</tt>: load-store barrier</li>
6421 <li><tt>sl</tt>: store-load barrier</li>
6422 <li><tt>ss</tt>: store-store barrier</li>
6423 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
6424</ul>
6425
Andrew Lenharth785610d2008-02-16 01:24:58 +0000[diff] [blame]6426<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6427<p>This intrinsic causes the system to enforce some ordering constraints upon
6428 the loads and stores of the program. This barrier does not
6429 indicate <em>when</em> any events will occur, it only enforces
6430 an <em>order</em> in which they occur. For any of the specified pairs of load
6431 and store operations (f.ex. load-load, or store-load), all of the first
6432 operations preceding the barrier will complete before any of the second
6433 operations succeeding the barrier begin. Specifically the semantics for each
6434 pairing is as follows:</p>
Andrew Lenharth785610d2008-02-16 01:24:58 +0000[diff] [blame]6435
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6436<ul>
6437 <li><tt>ll</tt>: All loads before the barrier must complete before any load
6438 after the barrier begins.</li>
6439 <li><tt>ls</tt>: All loads before the barrier must complete before any
6440 store after the barrier begins.</li>
6441 <li><tt>ss</tt>: All stores before the barrier must complete before any
6442 store after the barrier begins.</li>
6443 <li><tt>sl</tt>: All stores before the barrier must complete before any
6444 load after the barrier begins.</li>
6445</ul>
6446
6447<p>These semantics are applied with a logical "and" behavior when more than one
6448 is enabled in a single memory barrier intrinsic.</p>
6449
6450<p>Backends may implement stronger barriers than those requested when they do
6451 not support as fine grained a barrier as requested. Some architectures do
6452 not need all types of barriers and on such architectures, these become
6453 noops.</p>
6454
Andrew Lenharth785610d2008-02-16 01:24:58 +0000[diff] [blame]6455<h5>Example:</h5>
6456<pre>
6457%ptr = malloc i32
6458 store i32 4, %ptr
6459
6460%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
6461 call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
6462 <i>; guarantee the above finishes</i>
6463 store i32 8, %ptr <i>; before this begins</i>
6464</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6465
Andrew Lenharth785610d2008-02-16 01:24:58 +0000[diff] [blame]6466</div>
6467
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6468<!-- _______________________________________________________________________ -->
6469<div class="doc_subsubsection">
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6470 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6471</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6472
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6473<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6474
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6475<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6476<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
6477 any integer bit width and for different address spaces. Not all targets
6478 support all bit widths however.</p>
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6479
6480<pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6481 declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt; )
6482 declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt; )
6483 declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt; )
6484 declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt; )
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6485</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6486
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6487<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6488<p>This loads a value in memory and compares it to a given value. If they are
6489 equal, it stores a new value into the memory.</p>
6490
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6491<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6492<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
6493 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
6494 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
6495 this integer type. While any bit width integer may be used, targets may only
6496 lower representations they support in hardware.</p>
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6497
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6498<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6499<p>This entire intrinsic must be executed atomically. It first loads the value
6500 in memory pointed to by <tt>ptr</tt> and compares it with the
6501 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
6502 memory. The loaded value is yielded in all cases. This provides the
6503 equivalent of an atomic compare-and-swap operation within the SSA
6504 framework.</p>
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6505
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6506<h5>Examples:</h5>
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6507<pre>
6508%ptr = malloc i32
6509 store i32 4, %ptr
6510
6511%val1 = add i32 4, 4
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6512%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6513 <i>; yields {i32}:result1 = 4</i>
6514%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6515%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6516
6517%val2 = add i32 1, 1
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6518%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6519 <i>; yields {i32}:result2 = 8</i>
6520%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
6521
6522%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
6523</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6524
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6525</div>
6526
6527<!-- _______________________________________________________________________ -->
6528<div class="doc_subsubsection">
6529 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
6530</div>
6531<div class="doc_text">
6532<h5>Syntax:</h5>
6533
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6534<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
6535 integer bit width. Not all targets support all bit widths however.</p>
6536
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6537<pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6538 declare i8 @llvm.atomic.swap.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;val&gt; )
6539 declare i16 @llvm.atomic.swap.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;val&gt; )
6540 declare i32 @llvm.atomic.swap.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;val&gt; )
6541 declare i64 @llvm.atomic.swap.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;val&gt; )
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6542</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6543
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6544<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6545<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
6546 the value from memory. It then stores the value in <tt>val</tt> in the memory
6547 at <tt>ptr</tt>.</p>
6548
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6549<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6550<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
6551 the <tt>val</tt> argument and the result must be integers of the same bit
6552 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
6553 integer type. The targets may only lower integer representations they
6554 support.</p>
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6555
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6556<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6557<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
6558 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
6559 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6560
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6561<h5>Examples:</h5>
6562<pre>
6563%ptr = malloc i32
6564 store i32 4, %ptr
6565
6566%val1 = add i32 4, 4
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6567%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6568 <i>; yields {i32}:result1 = 4</i>
6569%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
6570%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
6571
6572%val2 = add i32 1, 1
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6573%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6574 <i>; yields {i32}:result2 = 8</i>
6575
6576%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
6577%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
6578</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6579
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6580</div>
6581
6582<!-- _______________________________________________________________________ -->
6583<div class="doc_subsubsection">
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6584 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6585
6586</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6587
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6588<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6589
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6590<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6591<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
6592 any integer bit width. Not all targets support all bit widths however.</p>
6593
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6594<pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6595 declare i8 @llvm.atomic.load.add.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6596 declare i16 @llvm.atomic.load.add.i16..p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6597 declare i32 @llvm.atomic.load.add.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6598 declare i64 @llvm.atomic.load.add.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6599</pre>
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6600
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6601<h5>Overview:</h5>
6602<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
6603 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6604
6605<h5>Arguments:</h5>
6606<p>The intrinsic takes two arguments, the first a pointer to an integer value
6607 and the second an integer value. The result is also an integer value. These
6608 integer types can have any bit width, but they must all have the same bit
6609 width. The targets may only lower integer representations they support.</p>
6610
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6611<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6612<p>This intrinsic does a series of operations atomically. It first loads the
6613 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
6614 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.</p>
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6615
6616<h5>Examples:</h5>
6617<pre>
6618%ptr = malloc i32
6619 store i32 4, %ptr
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6620%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6621 <i>; yields {i32}:result1 = 4</i>
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6622%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6623 <i>; yields {i32}:result2 = 8</i>
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6624%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6625 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6626%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6627</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6628
Andrew Lenharthe44f3902008-02-21 06:45:13 +0000[diff] [blame]6629</div>
6630
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6631<!-- _______________________________________________________________________ -->
6632<div class="doc_subsubsection">
6633 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
6634
6635</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6636
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6637<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6638
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6639<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6640<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
6641 any integer bit width and for different address spaces. Not all targets
6642 support all bit widths however.</p>
6643
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6644<pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6645 declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6646 declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6647 declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6648 declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6649</pre>
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6650
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6651<h5>Overview:</h5>
6652<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
6653 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
6654
6655<h5>Arguments:</h5>
6656<p>The intrinsic takes two arguments, the first a pointer to an integer value
6657 and the second an integer value. The result is also an integer value. These
6658 integer types can have any bit width, but they must all have the same bit
6659 width. The targets may only lower integer representations they support.</p>
6660
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6661<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6662<p>This intrinsic does a series of operations atomically. It first loads the
6663 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
6664 result to <tt>ptr</tt>. It yields the original value stored
6665 at <tt>ptr</tt>.</p>
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6666
6667<h5>Examples:</h5>
6668<pre>
6669%ptr = malloc i32
6670 store i32 8, %ptr
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6671%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6672 <i>; yields {i32}:result1 = 8</i>
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6673%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6674 <i>; yields {i32}:result2 = 4</i>
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6675%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6676 <i>; yields {i32}:result3 = 2</i>
6677%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
6678</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6679
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6680</div>
6681
6682<!-- _______________________________________________________________________ -->
6683<div class="doc_subsubsection">
6684 <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
6685 <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
6686 <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
6687 <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6688</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6689
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6690<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6691
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6692<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6693<p>These are overloaded intrinsics. You can
6694 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
6695 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
6696 bit width and for different address spaces. Not all targets support all bit
6697 widths however.</p>
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6698
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6699<pre>
6700 declare i8 @llvm.atomic.load.and.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6701 declare i16 @llvm.atomic.load.and.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6702 declare i32 @llvm.atomic.load.and.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6703 declare i64 @llvm.atomic.load.and.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6704</pre>
6705
6706<pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6707 declare i8 @llvm.atomic.load.or.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6708 declare i16 @llvm.atomic.load.or.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6709 declare i32 @llvm.atomic.load.or.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6710 declare i64 @llvm.atomic.load.or.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6711</pre>
6712
6713<pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6714 declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6715 declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6716 declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6717 declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6718</pre>
6719
6720<pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6721 declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6722 declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6723 declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6724 declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6725</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6726
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6727<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6728<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
6729 the value stored in memory at <tt>ptr</tt>. It yields the original value
6730 at <tt>ptr</tt>.</p>
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6731
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6732<h5>Arguments:</h5>
6733<p>These intrinsics take two arguments, the first a pointer to an integer value
6734 and the second an integer value. The result is also an integer value. These
6735 integer types can have any bit width, but they must all have the same bit
6736 width. The targets may only lower integer representations they support.</p>
6737
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6738<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6739<p>These intrinsics does a series of operations atomically. They first load the
6740 value stored at <tt>ptr</tt>. They then do the bitwise
6741 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
6742 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6743
6744<h5>Examples:</h5>
6745<pre>
6746%ptr = malloc i32
6747 store i32 0x0F0F, %ptr
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6748%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6749 <i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6750%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6751 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6752%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6753 <i>; yields {i32}:result2 = 0xF0</i>
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6754%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6755 <i>; yields {i32}:result3 = FF</i>
6756%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
6757</pre>
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6758
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6759</div>
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6760
6761<!-- _______________________________________________________________________ -->
6762<div class="doc_subsubsection">
6763 <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
6764 <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
6765 <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
6766 <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6767</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6768
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6769<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6770
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6771<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6772<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
6773 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
6774 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
6775 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6776
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6777<pre>
6778 declare i8 @llvm.atomic.load.max.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6779 declare i16 @llvm.atomic.load.max.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6780 declare i32 @llvm.atomic.load.max.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6781 declare i64 @llvm.atomic.load.max.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6782</pre>
6783
6784<pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6785 declare i8 @llvm.atomic.load.min.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6786 declare i16 @llvm.atomic.load.min.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6787 declare i32 @llvm.atomic.load.min.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6788 declare i64 @llvm.atomic.load.min.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6789</pre>
6790
6791<pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6792 declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6793 declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6794 declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6795 declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6796</pre>
6797
6798<pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6799 declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* &lt;ptr&gt;, i8 &lt;delta&gt; )
6800 declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* &lt;ptr&gt;, i16 &lt;delta&gt; )
6801 declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* &lt;ptr&gt;, i32 &lt;delta&gt; )
6802 declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* &lt;ptr&gt;, i64 &lt;delta&gt; )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6803</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6804
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6805<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6806<p>These intrinsics takes the signed or unsigned minimum or maximum of
6807 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
6808 original value at <tt>ptr</tt>.</p>
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6809
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6810<h5>Arguments:</h5>
6811<p>These intrinsics take two arguments, the first a pointer to an integer value
6812 and the second an integer value. The result is also an integer value. These
6813 integer types can have any bit width, but they must all have the same bit
6814 width. The targets may only lower integer representations they support.</p>
6815
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6816<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6817<p>These intrinsics does a series of operations atomically. They first load the
6818 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
6819 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
6820 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6821
6822<h5>Examples:</h5>
6823<pre>
6824%ptr = malloc i32
6825 store i32 7, %ptr
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6826%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6827 <i>; yields {i32}:result0 = 7</i>
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6828%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6829 <i>; yields {i32}:result1 = -2</i>
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6830%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6831 <i>; yields {i32}:result2 = 8</i>
Mon P Wangce3ac892008-07-30 04:36:53 +0000[diff] [blame]6832%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6833 <i>; yields {i32}:result3 = 8</i>
6834%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
6835</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6836
Mon P Wang6bde9ec2008-06-25 08:15:39 +0000[diff] [blame]6837</div>
Andrew Lenharth785610d2008-02-16 01:24:58 +0000[diff] [blame]6838
6839<!-- ======================================================================= -->
6840<div class="doc_subsection">
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]6841 <a name="int_general">General Intrinsics</a>
6842</div>
6843
6844<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6845
6846<p>This class of intrinsics is designed to be generic and has no specific
6847 purpose.</p>
6848
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]6849</div>
6850
6851<!-- _______________________________________________________________________ -->
6852<div class="doc_subsubsection">
6853 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
6854</div>
6855
6856<div class="doc_text">
6857
6858<h5>Syntax:</h5>
6859<pre>
6860 declare void @llvm.var.annotation(i8* &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6861</pre>
6862
6863<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6864<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]6865
6866<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6867<p>The first argument is a pointer to a value, the second is a pointer to a
6868 global string, the third is a pointer to a global string which is the source
6869 file name, and the last argument is the line number.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]6870
6871<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6872<p>This intrinsic allows annotation of local variables with arbitrary strings.
6873 This can be useful for special purpose optimizations that want to look for
6874 these annotations. These have no other defined use, they are ignored by code
6875 generation and optimization.</p>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]6876
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]6877</div>
6878
Tanya Lattnerb306a9e2007-09-21 22:59:12 +0000[diff] [blame]6879<!-- _______________________________________________________________________ -->
6880<div class="doc_subsubsection">
Tanya Lattnerc9869b12007-09-21 23:57:59 +0000[diff] [blame]6881 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattnerb306a9e2007-09-21 22:59:12 +0000[diff] [blame]6882</div>
6883
6884<div class="doc_text">
6885
6886<h5>Syntax:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6887<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
6888 any integer bit width.</p>
6889
Tanya Lattnerb306a9e2007-09-21 22:59:12 +0000[diff] [blame]6890<pre>
Tanya Lattner09161fe2007-09-22 00:03:01 +0000[diff] [blame]6891 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6892 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6893 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6894 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
6895 declare i256 @llvm.annotation.i256(i256 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt; )
Tanya Lattnerb306a9e2007-09-21 22:59:12 +0000[diff] [blame]6896</pre>
6897
6898<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6899<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattnerb306a9e2007-09-21 22:59:12 +0000[diff] [blame]6900
6901<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6902<p>The first argument is an integer value (result of some expression), the
6903 second is a pointer to a global string, the third is a pointer to a global
6904 string which is the source file name, and the last argument is the line
6905 number. It returns the value of the first argument.</p>
Tanya Lattnerb306a9e2007-09-21 22:59:12 +0000[diff] [blame]6906
6907<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6908<p>This intrinsic allows annotations to be put on arbitrary expressions with
6909 arbitrary strings. This can be useful for special purpose optimizations that
6910 want to look for these annotations. These have no other defined use, they
6911 are ignored by code generation and optimization.</p>
Tanya Lattnerb306a9e2007-09-21 22:59:12 +0000[diff] [blame]6912
Tanya Lattnerb306a9e2007-09-21 22:59:12 +0000[diff] [blame]6913</div>
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]6914
Anton Korobeynikove6e764f2008-01-15 22:31:34 +0000[diff] [blame]6915<!-- _______________________________________________________________________ -->
6916<div class="doc_subsubsection">
6917 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
6918</div>
6919
6920<div class="doc_text">
6921
6922<h5>Syntax:</h5>
6923<pre>
6924 declare void @llvm.trap()
6925</pre>
6926
6927<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6928<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikove6e764f2008-01-15 22:31:34 +0000[diff] [blame]6929
6930<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6931<p>None.</p>
Anton Korobeynikove6e764f2008-01-15 22:31:34 +0000[diff] [blame]6932
6933<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6934<p>This intrinsics is lowered to the target dependent trap instruction. If the
6935 target does not have a trap instruction, this intrinsic will be lowered to
6936 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikove6e764f2008-01-15 22:31:34 +0000[diff] [blame]6937
Anton Korobeynikove6e764f2008-01-15 22:31:34 +0000[diff] [blame]6938</div>
6939
Bill Wendlinge4164592008-11-19 05:56:17 +0000[diff] [blame]6940<!-- _______________________________________________________________________ -->
6941<div class="doc_subsubsection">
Misha Brukman5dd7f4d2008-11-22 23:55:29 +0000[diff] [blame]6942 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendlinge4164592008-11-19 05:56:17 +0000[diff] [blame]6943</div>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6944
Bill Wendlinge4164592008-11-19 05:56:17 +0000[diff] [blame]6945<div class="doc_text">
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6946
Bill Wendlinge4164592008-11-19 05:56:17 +0000[diff] [blame]6947<h5>Syntax:</h5>
6948<pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6949 declare void @llvm.stackprotector( i8* &lt;guard&gt;, i8** &lt;slot&gt; )
Bill Wendlinge4164592008-11-19 05:56:17 +0000[diff] [blame]6950</pre>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6951
Bill Wendlinge4164592008-11-19 05:56:17 +0000[diff] [blame]6952<h5>Overview:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6953<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
6954 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
6955 ensure that it is placed on the stack before local variables.</p>
6956
Bill Wendlinge4164592008-11-19 05:56:17 +0000[diff] [blame]6957<h5>Arguments:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6958<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
6959 arguments. The first argument is the value loaded from the stack
6960 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
6961 that has enough space to hold the value of the guard.</p>
6962
Bill Wendlinge4164592008-11-19 05:56:17 +0000[diff] [blame]6963<h5>Semantics:</h5>
Bill Wendlingf85859d2009-07-20 02:29:24 +0000[diff] [blame]6964<p>This intrinsic causes the prologue/epilogue inserter to force the position of
6965 the <tt>AllocaInst</tt> stack slot to be before local variables on the
6966 stack. This is to ensure that if a local variable on the stack is
6967 overwritten, it will destroy the value of the guard. When the function exits,
6968 the guard on the stack is checked against the original guard. If they're
6969 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
6970 function.</p>
6971
Bill Wendlinge4164592008-11-19 05:56:17 +0000[diff] [blame]6972</div>
6973
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]6974<!-- *********************************************************************** -->
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Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]6981
6982 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
6983 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
6984 Last modified: $Date$
6985</address>
Chris Lattner08497ce2008-01-04 04:33:49 +0000[diff] [blame]6986
Dan Gohmanf17a25c2007-07-18 16:29:46 +0000[diff] [blame]6987</body>
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