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				5	<title>LLVM Assembly Language Reference Manual</title>
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				7	<meta name="author" content="Chris Lattner">
				8	<meta name="description"
				9	content="LLVM Assembly Language Reference Manual.">
				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>
				23	<li><a href="#linkage">Linkage Types</a></li>
				24	<li><a href="#callingconv">Calling Conventions</a></li>
				25	<li><a href="#globalvars">Global Variables</a></li>
				26	<li><a href="#functionstructure">Functions</a></li>
				27	<li><a href="#aliasstructure">Aliases</a>
				28	<li><a href="#paramattrs">Parameter Attributes</a></li>
Gordon Henriksen	13fe5e3	2007-12-10 03:18:06 +0000	[diff] [blame]	29	<li><a href="#gc">Garbage Collector Names</a></li>
Devang Patel	25928cb	2008-09-04 23:10:26 +0000	[diff] [blame]	30	<li><a href="#notes">Function Notes</a></li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	31	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
				32	<li><a href="#datalayout">Data Layout</a></li>
				33	</ol>
				34	</li>
				35	<li><a href="#typesystem">Type System</a>
				36	<ol>
Chris Lattner	488772f	2008-01-04 04:32:38 +0000	[diff] [blame]	37	<li><a href="#t_classifications">Type Classifications</a></li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	38	<li><a href="#t_primitive">Primitive Types</a>
				39	<ol>
Chris Lattner	488772f	2008-01-04 04:32:38 +0000	[diff] [blame]	40	<li><a href="#t_floating">Floating Point Types</a></li>
				41	<li><a href="#t_void">Void Type</a></li>
				42	<li><a href="#t_label">Label Type</a></li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	43	</ol>
				44	</li>
				45	<li><a href="#t_derived">Derived Types</a>
				46	<ol>
Chris Lattner	251ab81	2007-12-18 06:18:21 +0000	[diff] [blame]	47	<li><a href="#t_integer">Integer Type</a></li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	48	<li><a href="#t_array">Array Type</a></li>
				49	<li><a href="#t_function">Function Type</a></li>
				50	<li><a href="#t_pointer">Pointer Type</a></li>
				51	<li><a href="#t_struct">Structure Type</a></li>
				52	<li><a href="#t_pstruct">Packed Structure Type</a></li>
				53	<li><a href="#t_vector">Vector Type</a></li>
				54	<li><a href="#t_opaque">Opaque Type</a></li>
				55	</ol>
				56	</li>
				57	</ol>
				58	</li>
				59	<li><a href="#constants">Constants</a>
				60	<ol>
				61	<li><a href="#simpleconstants">Simple Constants</a>
				62	<li><a href="#aggregateconstants">Aggregate Constants</a>
				63	<li><a href="#globalconstants">Global Variable and Function Addresses</a>
				64	<li><a href="#undefvalues">Undefined Values</a>
				65	<li><a href="#constantexprs">Constant Expressions</a>
				66	</ol>
				67	</li>
				68	<li><a href="#othervalues">Other Values</a>
				69	<ol>
				70	<li><a href="#inlineasm">Inline Assembler Expressions</a>
				71	</ol>
				72	</li>
				73	<li><a href="#instref">Instruction Reference</a>
				74	<ol>
				75	<li><a href="#terminators">Terminator Instructions</a>
				76	<ol>
				77	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				78	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
				79	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				80	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
				81	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
				82	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
				83	</ol>
				84	</li>
				85	<li><a href="#binaryops">Binary Operations</a>
				86	<ol>
				87	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
				88	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
				89	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
				90	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				91	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				92	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
				93	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				94	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				95	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
				96	</ol>
				97	</li>
				98	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				99	<ol>
				100	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				101	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				102	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
				103	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
				104	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
				105	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
				106	</ol>
				107	</li>
				108	<li><a href="#vectorops">Vector Operations</a>
				109	<ol>
				110	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				111	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				112	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
				113	</ol>
				114	</li>
Dan Gohman	74d6faf	2008-05-12 23:51:09 +0000	[diff] [blame]	115	<li><a href="#aggregateops">Aggregate Operations</a>
				116	<ol>
				117	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				118	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				119	</ol>
				120	</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	121	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
				122	<ol>
				123	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				124	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				125	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
				126	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				127	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				128	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
				129	</ol>
				130	</li>
				131	<li><a href="#convertops">Conversion Operations</a>
				132	<ol>
				133	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				134	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				135	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				136	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				137	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
				138	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				139	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				140	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				141	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
				142	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
				144	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
				145	</ol>
				146	<li><a href="#otherops">Other Operations</a>
				147	<ol>
				148	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				149	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begeman	646fa48	2008-05-12 19:01:56 +0000	[diff] [blame]	150	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				151	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	152	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
				153	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
				154	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
				155	<li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Devang Patel	a3cc537	2008-03-10 20:49:15 +0000	[diff] [blame]	156	<li><a href="#i_getresult">'<tt>getresult</tt>' Instruction</a></li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	157	</ol>
				158	</li>
				159	</ol>
				160	</li>
				161	<li><a href="#intrinsics">Intrinsic Functions</a>
				162	<ol>
				163	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				164	<ol>
				165	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				166	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				167	<li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
				168	</ol>
				169	</li>
				170	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				171	<ol>
				172	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				173	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				174	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
				175	</ol>
				176	</li>
				177	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				178	<ol>
				179	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				180	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				181	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				182	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				183	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				184	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				185	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
				186	</ol>
				187	</li>
				188	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				189	<ol>
				190	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				191	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				192	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				193	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				194	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	361079c	2007-10-15 20:30:11 +0000	[diff] [blame]	195	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				196	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				197	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	198	</ol>
				199	</li>
				200	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
				201	<ol>
				202	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
				203	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				204	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				205	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
				206	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				207	<li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
				208	</ol>
				209	</li>
				210	<li><a href="#int_debugger">Debugger intrinsics</a></li>
				211	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	7407a9f	2007-09-11 14:10:23 +0000	[diff] [blame]	212	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	38947cd	2007-07-27 12:58:54 +0000	[diff] [blame]	213	<ol>
				214	<li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands	38947cd	2007-07-27 12:58:54 +0000	[diff] [blame]	215	</ol>
				216	</li>
Andrew Lenharth	785610d	2008-02-16 01:24:58 +0000	[diff] [blame]	217	<li><a href="#int_atomics">Atomic intrinsics</a>
				218	<ol>
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	219	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	220	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	221	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	222	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				223	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				224	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				225	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				226	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				227	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				228	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				229	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				230	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				231	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
Andrew Lenharth	785610d	2008-02-16 01:24:58 +0000	[diff] [blame]	232	</ol>
				233	</li>
Reid Spencer	b043f67	2007-07-20 19:59:11 +0000	[diff] [blame]	234	<li><a href="#int_general">General intrinsics</a>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	235	<ol>
Reid Spencer	b043f67	2007-07-20 19:59:11 +0000	[diff] [blame]	236	<li><a href="#int_var_annotation">
Tanya Lattner	51369f3	2007-09-22 00:01:26 +0000	[diff] [blame]	237	<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	b306a9e	2007-09-21 22:59:12 +0000	[diff] [blame]	238	<li><a href="#int_annotation">
Tanya Lattner	51369f3	2007-09-22 00:01:26 +0000	[diff] [blame]	239	<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	e6e764f	2008-01-15 22:31:34 +0000	[diff] [blame]	240	<li><a href="#int_trap">
				241	<tt>llvm.trap</tt>' Intrinsic</a></li>
Tanya Lattner	b306a9e	2007-09-21 22:59:12 +0000	[diff] [blame]	242	</ol>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	243	</li>
				244	</ol>
				245	</li>
				246	</ol>
				247
				248	<div class="doc_author">
				249	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				250	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
				251	</div>
				252
				253	<!-- *********************************************************************** -->
				254	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				255	<!-- *********************************************************************** -->
				256
				257	<div class="doc_text">
				258	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	e7846a5	2008-08-05 22:29:16 +0000	[diff] [blame]	259	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	9645148	2008-08-05 18:29:16 +0000	[diff] [blame]	260	type safety, low-level operations, flexibility, and the capability of
				261	representing 'all' high-level languages cleanly. It is the common code
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	262	representation used throughout all phases of the LLVM compilation
				263	strategy.</p>
				264	</div>
				265
				266	<!-- *********************************************************************** -->
				267	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				268	<!-- *********************************************************************** -->
				269
				270	<div class="doc_text">
				271
				272	<p>The LLVM code representation is designed to be used in three
				273	different forms: as an in-memory compiler IR, as an on-disk bitcode
				274	representation (suitable for fast loading by a Just-In-Time compiler),
				275	and as a human readable assembly language representation. This allows
				276	LLVM to provide a powerful intermediate representation for efficient
				277	compiler transformations and analysis, while providing a natural means
				278	to debug and visualize the transformations. The three different forms
				279	of LLVM are all equivalent. This document describes the human readable
				280	representation and notation.</p>
				281
				282	<p>The LLVM representation aims to be light-weight and low-level
				283	while being expressive, typed, and extensible at the same time. It
				284	aims to be a "universal IR" of sorts, by being at a low enough level
				285	that high-level ideas may be cleanly mapped to it (similar to how
				286	microprocessors are "universal IR's", allowing many source languages to
				287	be mapped to them). By providing type information, LLVM can be used as
				288	the target of optimizations: for example, through pointer analysis, it
				289	can be proven that a C automatic variable is never accessed outside of
				290	the current function... allowing it to be promoted to a simple SSA
				291	value instead of a memory location.</p>
				292
				293	</div>
				294
				295	<!-- _______________________________________________________________________ -->
				296	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
				297
				298	<div class="doc_text">
				299
				300	<p>It is important to note that this document describes 'well formed'
				301	LLVM assembly language. There is a difference between what the parser
				302	accepts and what is considered 'well formed'. For example, the
				303	following instruction is syntactically okay, but not well formed:</p>
				304
				305	<div class="doc_code">
				306	<pre>
				307	%x = <a href="#i_add">add</a> i32 1, %x
				308	</pre>
				309	</div>
				310
				311	<p>...because the definition of <tt>%x</tt> does not dominate all of
				312	its uses. The LLVM infrastructure provides a verification pass that may
				313	be used to verify that an LLVM module is well formed. This pass is
				314	automatically run by the parser after parsing input assembly and by
				315	the optimizer before it outputs bitcode. The violations pointed out
				316	by the verifier pass indicate bugs in transformation passes or input to
				317	the parser.</p>
				318	</div>
				319
Chris Lattner	a83fdc0	2007-10-03 17:34:29 +0000	[diff] [blame]	320	<!-- Describe the typesetting conventions here. -->
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	321
				322	<!-- *********************************************************************** -->
				323	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
				324	<!-- *********************************************************************** -->
				325
				326	<div class="doc_text">
				327
Reid Spencer	c8245b0	2007-08-07 14:34:28 +0000	[diff] [blame]	328	<p>LLVM identifiers come in two basic types: global and local. Global
				329	identifiers (functions, global variables) begin with the @ character. Local
				330	identifiers (register names, types) begin with the % character. Additionally,
				331	there are three different formats for identifiers, for different purposes:
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	332
				333	<ol>
Reid Spencer	c8245b0	2007-08-07 14:34:28 +0000	[diff] [blame]	334	<li>Named values are represented as a string of characters with their prefix.
				335	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				336	regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	337	Identifiers which require other characters in their names can be surrounded
Reid Spencer	c8245b0	2007-08-07 14:34:28 +0000	[diff] [blame]	338	with quotes. In this way, anything except a <tt>"</tt> character can
				339	be used in a named value.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	340
Reid Spencer	c8245b0	2007-08-07 14:34:28 +0000	[diff] [blame]	341	<li>Unnamed values are represented as an unsigned numeric value with their
				342	prefix. For example, %12, @2, %44.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	343
				344	<li>Constants, which are described in a <a href="#constants">section about
				345	constants</a>, below.</li>
				346	</ol>
				347
Reid Spencer	c8245b0	2007-08-07 14:34:28 +0000	[diff] [blame]	348	<p>LLVM requires that values start with a prefix for two reasons: Compilers
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	349	don't need to worry about name clashes with reserved words, and the set of
				350	reserved words may be expanded in the future without penalty. Additionally,
				351	unnamed identifiers allow a compiler to quickly come up with a temporary
				352	variable without having to avoid symbol table conflicts.</p>
				353
				354	<p>Reserved words in LLVM are very similar to reserved words in other
				355	languages. There are keywords for different opcodes
				356	('<tt><a href="#i_add">add</a></tt>',
				357	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				358	'<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
				359	href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
				360	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	c8245b0	2007-08-07 14:34:28 +0000	[diff] [blame]	361	none of them start with a prefix character ('%' or '@').</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	362
				363	<p>Here is an example of LLVM code to multiply the integer variable
				364	'<tt>%X</tt>' by 8:</p>
				365
				366	<p>The easy way:</p>
				367
				368	<div class="doc_code">
				369	<pre>
				370	%result = <a href="#i_mul">mul</a> i32 %X, 8
				371	</pre>
				372	</div>
				373
				374	<p>After strength reduction:</p>
				375
				376	<div class="doc_code">
				377	<pre>
				378	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
				379	</pre>
				380	</div>
				381
				382	<p>And the hard way:</p>
				383
				384	<div class="doc_code">
				385	<pre>
				386	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				387	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				388	%result = <a href="#i_add">add</a> i32 %1, %1
				389	</pre>
				390	</div>
				391
				392	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				393	important lexical features of LLVM:</p>
				394
				395	<ol>
				396
				397	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				398	line.</li>
				399
				400	<li>Unnamed temporaries are created when the result of a computation is not
				401	assigned to a named value.</li>
				402
				403	<li>Unnamed temporaries are numbered sequentially</li>
				404
				405	</ol>
				406
				407	<p>...and it also shows a convention that we follow in this document. When
				408	demonstrating instructions, we will follow an instruction with a comment that
				409	defines the type and name of value produced. Comments are shown in italic
				410	text.</p>
				411
				412	</div>
				413
				414	<!-- *********************************************************************** -->
				415	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				416	<!-- *********************************************************************** -->
				417
				418	<!-- ======================================================================= -->
				419	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				420	</div>
				421
				422	<div class="doc_text">
				423
				424	<p>LLVM programs are composed of "Module"s, each of which is a
				425	translation unit of the input programs. Each module consists of
				426	functions, global variables, and symbol table entries. Modules may be
				427	combined together with the LLVM linker, which merges function (and
				428	global variable) definitions, resolves forward declarations, and merges
				429	symbol table entries. Here is an example of the "hello world" module:</p>
				430
				431	<div class="doc_code">
				432	<pre><i>; Declare the string constant as a global constant...</i>
				433	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				434	href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
				435
				436	<i>; External declaration of the puts function</i>
				437	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
				438
				439	<i>; Definition of main function</i>
				440	define i32 @main() { <i>; i32()* </i>
				441	<i>; Convert [13x i8 ]* to i8 *...</i>
				442	%cast210 = <a
				443	href="#i_getelementptr">getelementptr</a> [13 x i8 ]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
				444
				445	<i>; Call puts function to write out the string to stdout...</i>
				446	<a
				447	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
				448	<a
				449	href="#i_ret">ret</a> i32 0<br>}<br>
				450	</pre>
				451	</div>
				452
				453	<p>This example is made up of a <a href="#globalvars">global variable</a>
				454	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				455	function, and a <a href="#functionstructure">function definition</a>
				456	for "<tt>main</tt>".</p>
				457
				458	<p>In general, a module is made up of a list of global values,
				459	where both functions and global variables are global values. Global values are
				460	represented by a pointer to a memory location (in this case, a pointer to an
				461	array of char, and a pointer to a function), and have one of the following <a
				462	href="#linkage">linkage types</a>.</p>
				463
				464	</div>
				465
				466	<!-- ======================================================================= -->
				467	<div class="doc_subsection">
				468	<a name="linkage">Linkage Types</a>
				469	</div>
				470
				471	<div class="doc_text">
				472
				473	<p>
				474	All Global Variables and Functions have one of the following types of linkage:
				475	</p>
				476
				477	<dl>
				478
Dale Johannesen	96e7e09	2008-05-23 23:13:41 +0000	[diff] [blame]	479	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	480
				481	<dd>Global values with internal linkage are only directly accessible by
				482	objects in the current module. In particular, linking code into a module with
				483	an internal global value may cause the internal to be renamed as necessary to
				484	avoid collisions. Because the symbol is internal to the module, all
				485	references can be updated. This corresponds to the notion of the
				486	'<tt>static</tt>' keyword in C.
				487	</dd>
				488
				489	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
				490
				491	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				492	the same name when linkage occurs. This is typically used to implement
				493	inline functions, templates, or other code which must be generated in each
				494	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				495	allowed to be discarded.
				496	</dd>
				497
Dale Johannesen	96e7e09	2008-05-23 23:13:41 +0000	[diff] [blame]	498	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				499
				500	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				501	linkage, except that unreferenced <tt>common</tt> globals may not be
				502	discarded. This is used for globals that may be emitted in multiple
				503	translation units, but that are not guaranteed to be emitted into every
				504	translation unit that uses them. One example of this is tentative
				505	definitions in C, such as "<tt>int X;</tt>" at global scope.
				506	</dd>
				507
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	508	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
				509
Dale Johannesen	96e7e09	2008-05-23 23:13:41 +0000	[diff] [blame]	510	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				511	that some targets may choose to emit different assembly sequences for them
				512	for target-dependent reasons. This is used for globals that are declared
				513	"weak" in C source code.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	514	</dd>
				515
				516	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
				517
				518	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				519	pointer to array type. When two global variables with appending linkage are
				520	linked together, the two global arrays are appended together. This is the
				521	LLVM, typesafe, equivalent of having the system linker append together
				522	"sections" with identical names when .o files are linked.
				523	</dd>
				524
				525	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner	9645148	2008-08-05 18:29:16 +0000	[diff] [blame]	526	<dd>The semantics of this linkage follow the ELF object file model: the
				527	symbol is weak until linked, if not linked, the symbol becomes null instead
				528	of being an undefined reference.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	529	</dd>
				530
				531	<dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
				532
				533	<dd>If none of the above identifiers are used, the global is externally
				534	visible, meaning that it participates in linkage and can be used to resolve
				535	external symbol references.
				536	</dd>
				537	</dl>
				538
				539	<p>
				540	The next two types of linkage are targeted for Microsoft Windows platform
				541	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	9645148	2008-08-05 18:29:16 +0000	[diff] [blame]	542	DLLs (Dynamic Link Libraries).
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	543	</p>
				544
				545	<dl>
				546	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				547
				548	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				549	or variable via a global pointer to a pointer that is set up by the DLL
				550	exporting the symbol. On Microsoft Windows targets, the pointer name is
				551	formed by combining <code>_imp__</code> and the function or variable name.
				552	</dd>
				553
				554	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				555
				556	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				557	pointer to a pointer in a DLL, so that it can be referenced with the
				558	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
				559	name is formed by combining <code>_imp__</code> and the function or variable
				560	name.
				561	</dd>
				562
				563	</dl>
				564
				565	<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
				566	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				567	variable and was linked with this one, one of the two would be renamed,
				568	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				569	external (i.e., lacking any linkage declarations), they are accessible
				570	outside of the current module.</p>
				571	<p>It is illegal for a function <i>declaration</i>
				572	to have any linkage type other than "externally visible", <tt>dllimport</tt>,
				573	or <tt>extern_weak</tt>.</p>
				574	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
				575	linkages.
				576	</div>
				577
				578	<!-- ======================================================================= -->
				579	<div class="doc_subsection">
				580	<a name="callingconv">Calling Conventions</a>
				581	</div>
				582
				583	<div class="doc_text">
				584
				585	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				586	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				587	specified for the call. The calling convention of any pair of dynamic
				588	caller/callee must match, or the behavior of the program is undefined. The
				589	following calling conventions are supported by LLVM, and more may be added in
				590	the future:</p>
				591
				592	<dl>
				593	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				594
				595	<dd>This calling convention (the default if no other calling convention is
				596	specified) matches the target C calling conventions. This calling convention
				597	supports varargs function calls and tolerates some mismatch in the declared
				598	prototype and implemented declaration of the function (as does normal C).
				599	</dd>
				600
				601	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				602
				603	<dd>This calling convention attempts to make calls as fast as possible
				604	(e.g. by passing things in registers). This calling convention allows the
				605	target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner	9645148	2008-08-05 18:29:16 +0000	[diff] [blame]	606	without having to conform to an externally specified ABI (Application Binary
				607	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	0744492	2008-05-14 09:17:12 +0000	[diff] [blame]	608	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				609	supported. This calling convention does not support varargs and requires the
				610	prototype of all callees to exactly match the prototype of the function
				611	definition.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	612	</dd>
				613
				614	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				615
				616	<dd>This calling convention attempts to make code in the caller as efficient
				617	as possible under the assumption that the call is not commonly executed. As
				618	such, these calls often preserve all registers so that the call does not break
				619	any live ranges in the caller side. This calling convention does not support
				620	varargs and requires the prototype of all callees to exactly match the
				621	prototype of the function definition.
				622	</dd>
				623
				624	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
				625
				626	<dd>Any calling convention may be specified by number, allowing
				627	target-specific calling conventions to be used. Target specific calling
				628	conventions start at 64.
				629	</dd>
				630	</dl>
				631
				632	<p>More calling conventions can be added/defined on an as-needed basis, to
				633	support pascal conventions or any other well-known target-independent
				634	convention.</p>
				635
				636	</div>
				637
				638	<!-- ======================================================================= -->
				639	<div class="doc_subsection">
				640	<a name="visibility">Visibility Styles</a>
				641	</div>
				642
				643	<div class="doc_text">
				644
				645	<p>
				646	All Global Variables and Functions have one of the following visibility styles:
				647	</p>
				648
				649	<dl>
				650	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				651
Chris Lattner	9645148	2008-08-05 18:29:16 +0000	[diff] [blame]	652	<dd>On targets that use the ELF object file format, default visibility means
				653	that the declaration is visible to other
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	654	modules and, in shared libraries, means that the declared entity may be
				655	overridden. On Darwin, default visibility means that the declaration is
				656	visible to other modules. Default visibility corresponds to "external
				657	linkage" in the language.
				658	</dd>
				659
				660	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				661
				662	<dd>Two declarations of an object with hidden visibility refer to the same
				663	object if they are in the same shared object. Usually, hidden visibility
				664	indicates that the symbol will not be placed into the dynamic symbol table,
				665	so no other module (executable or shared library) can reference it
				666	directly.
				667	</dd>
				668
				669	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				670
				671	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				672	the dynamic symbol table, but that references within the defining module will
				673	bind to the local symbol. That is, the symbol cannot be overridden by another
				674	module.
				675	</dd>
				676	</dl>
				677
				678	</div>
				679
				680	<!-- ======================================================================= -->
				681	<div class="doc_subsection">
				682	<a name="globalvars">Global Variables</a>
				683	</div>
				684
				685	<div class="doc_text">
				686
				687	<p>Global variables define regions of memory allocated at compilation time
				688	instead of run-time. Global variables may optionally be initialized, may have
				689	an explicit section to be placed in, and may have an optional explicit alignment
				690	specified. A variable may be defined as "thread_local", which means that it
				691	will not be shared by threads (each thread will have a separated copy of the
				692	variable). A variable may be defined as a global "constant," which indicates
				693	that the contents of the variable will <b>never</b> be modified (enabling better
				694	optimization, allowing the global data to be placed in the read-only section of
				695	an executable, etc). Note that variables that need runtime initialization
				696	cannot be marked "constant" as there is a store to the variable.</p>
				697
				698	<p>
				699	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				700	constant, even if the final definition of the global is not. This capability
				701	can be used to enable slightly better optimization of the program, but requires
				702	the language definition to guarantee that optimizations based on the
				703	'constantness' are valid for the translation units that do not include the
				704	definition.
				705	</p>
				706
				707	<p>As SSA values, global variables define pointer values that are in
				708	scope (i.e. they dominate) all basic blocks in the program. Global
				709	variables always define a pointer to their "content" type because they
				710	describe a region of memory, and all memory objects in LLVM are
				711	accessed through pointers.</p>
				712
Christopher Lamb	dd0049d	2007-12-11 09:31:00 +0000	[diff] [blame]	713	<p>A global variable may be declared to reside in a target-specifc numbered
				714	address space. For targets that support them, address spaces may affect how
				715	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	20a39e9	2007-12-12 08:44:39 +0000	[diff] [blame]	716	the variable. The default address space is zero. The address space qualifier
				717	must precede any other attributes.</p>
Christopher Lamb	dd0049d	2007-12-11 09:31:00 +0000	[diff] [blame]	718
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	719	<p>LLVM allows an explicit section to be specified for globals. If the target
				720	supports it, it will emit globals to the section specified.</p>
				721
				722	<p>An explicit alignment may be specified for a global. If not present, or if
				723	the alignment is set to zero, the alignment of the global is set by the target
				724	to whatever it feels convenient. If an explicit alignment is specified, the
				725	global is forced to have at least that much alignment. All alignments must be
				726	a power of 2.</p>
				727
Christopher Lamb	dd0049d	2007-12-11 09:31:00 +0000	[diff] [blame]	728	<p>For example, the following defines a global in a numbered address space with
				729	an initializer, section, and alignment:</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	730
				731	<div class="doc_code">
				732	<pre>
Christopher Lamb	dd0049d	2007-12-11 09:31:00 +0000	[diff] [blame]	733	@G = constant float 1.0 addrspace(5), section "foo", align 4
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	734	</pre>
				735	</div>
				736
				737	</div>
				738
				739
				740	<!-- ======================================================================= -->
				741	<div class="doc_subsection">
				742	<a name="functionstructure">Functions</a>
				743	</div>
				744
				745	<div class="doc_text">
				746
				747	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				748	an optional <a href="#linkage">linkage type</a>, an optional
				749	<a href="#visibility">visibility style</a>, an optional
				750	<a href="#callingconv">calling convention</a>, a return type, an optional
				751	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				752	name, a (possibly empty) argument list (each with optional
				753	<a href="#paramattrs">parameter attributes</a>), an optional section, an
Devang Patel	d468f1c	2008-09-04 23:05:13 +0000	[diff] [blame]	754	optional alignment, an optional <a href="#gc">garbage collector name</a>,
				755	an optional <a href="#notes">function notes</a>, an
Gordon Henriksen	13fe5e3	2007-12-10 03:18:06 +0000	[diff] [blame]	756	opening curly brace, a list of basic blocks, and a closing curly brace.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	757
				758	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				759	optional <a href="#linkage">linkage type</a>, an optional
				760	<a href="#visibility">visibility style</a>, an optional
				761	<a href="#callingconv">calling convention</a>, a return type, an optional
				762	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	13fe5e3	2007-12-10 03:18:06 +0000	[diff] [blame]	763	name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksen	d606f5b	2007-12-10 03:30:21 +0000	[diff] [blame]	764	<a href="#gc">garbage collector name</a>.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	765
Chris Lattner	9645148	2008-08-05 18:29:16 +0000	[diff] [blame]	766	<p>A function definition contains a list of basic blocks, forming the CFG
				767	(Control Flow Graph) for
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	768	the function. Each basic block may optionally start with a label (giving the
				769	basic block a symbol table entry), contains a list of instructions, and ends
				770	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				771	function return).</p>
				772
				773	<p>The first basic block in a function is special in two ways: it is immediately
				774	executed on entrance to the function, and it is not allowed to have predecessor
				775	basic blocks (i.e. there can not be any branches to the entry block of a
				776	function). Because the block can have no predecessors, it also cannot have any
				777	<a href="#i_phi">PHI nodes</a>.</p>
				778
				779	<p>LLVM allows an explicit section to be specified for functions. If the target
				780	supports it, it will emit functions to the section specified.</p>
				781
				782	<p>An explicit alignment may be specified for a function. If not present, or if
				783	the alignment is set to zero, the alignment of the function is set by the target
				784	to whatever it feels convenient. If an explicit alignment is specified, the
				785	function is forced to have at least that much alignment. All alignments must be
				786	a power of 2.</p>
				787
				788	</div>
				789
				790
				791	<!-- ======================================================================= -->
				792	<div class="doc_subsection">
				793	<a name="aliasstructure">Aliases</a>
				794	</div>
				795	<div class="doc_text">
				796	<p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov	9682281	2008-03-22 08:36:14 +0000	[diff] [blame]	797	function, global variable, another alias or bitcast of global value). Aliases
				798	may have an optional <a href="#linkage">linkage type</a>, and an
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	799	optional <a href="#visibility">visibility style</a>.</p>
				800
				801	<h5>Syntax:</h5>
				802
				803	<div class="doc_code">
				804	<pre>
				805	@<Name> = [Linkage] [Visibility] alias <AliaseeTy> @<Aliasee>
				806	</pre>
				807	</div>
				808
				809	</div>
				810
				811
				812
				813	<!-- ======================================================================= -->
				814	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				815	<div class="doc_text">
				816	<p>The return type and each parameter of a function type may have a set of
				817	<i>parameter attributes</i> associated with them. Parameter attributes are
				818	used to communicate additional information about the result or parameters of
Duncan Sands	f5588dc	2007-11-27 13:23:08 +0000	[diff] [blame]	819	a function. Parameter attributes are considered to be part of the function,
				820	not of the function type, so functions with different parameter attributes
				821	can have the same function type.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	822
				823	<p>Parameter attributes are simple keywords that follow the type specified. If
				824	multiple parameter attributes are needed, they are space separated. For
				825	example:</p>
				826
				827	<div class="doc_code">
				828	<pre>
Duncan Sands	f5588dc	2007-11-27 13:23:08 +0000	[diff] [blame]	829	declare i32 @printf(i8* noalias , ...) nounwind
				830	declare i32 @atoi(i8*) nounwind readonly
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	831	</pre>
				832	</div>
				833
Duncan Sands	f5588dc	2007-11-27 13:23:08 +0000	[diff] [blame]	834	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				835	<tt>readonly</tt>) come immediately after the argument list.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	836
				837	<p>Currently, only the following parameter attributes are defined:</p>
				838	<dl>
Reid Spencer	f234bed	2007-07-19 23:13:04 +0000	[diff] [blame]	839	<dt><tt>zeroext</tt></dt>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	840	<dd>This indicates that the parameter should be zero extended just before
				841	a call to this function.</dd>
Chris Lattner	275e6be	2008-01-11 06:20:47 +0000	[diff] [blame]	842
Reid Spencer	f234bed	2007-07-19 23:13:04 +0000	[diff] [blame]	843	<dt><tt>signext</tt></dt>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	844	<dd>This indicates that the parameter should be sign extended just before
				845	a call to this function.</dd>
Chris Lattner	275e6be	2008-01-11 06:20:47 +0000	[diff] [blame]	846
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	847	<dt><tt>inreg</tt></dt>
				848	<dd>This indicates that the parameter should be placed in register (if
				849	possible) during assembling function call. Support for this attribute is
				850	target-specific</dd>
Chris Lattner	275e6be	2008-01-11 06:20:47 +0000	[diff] [blame]	851
				852	<dt><tt>byval</tt></dt>
Chris Lattner	04c8618	2008-01-15 04:34:22 +0000	[diff] [blame]	853	<dd>This indicates that the pointer parameter should really be passed by
				854	value to the function. The attribute implies that a hidden copy of the
				855	pointee is made between the caller and the callee, so the callee is unable
Chris Lattner	6a9f3c4	2008-08-05 18:21:08 +0000	[diff] [blame]	856	to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner	04c8618	2008-01-15 04:34:22 +0000	[diff] [blame]	857	pointer arguments. It is generally used to pass structs and arrays by
				858	value, but is also valid on scalars (even though this is silly).</dd>
Chris Lattner	275e6be	2008-01-11 06:20:47 +0000	[diff] [blame]	859
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	860	<dt><tt>sret</tt></dt>
Duncan Sands	616cc03	2008-02-18 04:19:38 +0000	[diff] [blame]	861	<dd>This indicates that the pointer parameter specifies the address of a
				862	structure that is the return value of the function in the source program.
Duncan Sands	ef0e9e4	2008-03-17 12:17:41 +0000	[diff] [blame]	863	Loads and stores to the structure are assumed not to trap.
Duncan Sands	616cc03	2008-02-18 04:19:38 +0000	[diff] [blame]	864	May only be applied to the first parameter.</dd>
Chris Lattner	275e6be	2008-01-11 06:20:47 +0000	[diff] [blame]	865
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	866	<dt><tt>noalias</tt></dt>
Owen Anderson	c4fc4cd	2008-02-18 04:09:01 +0000	[diff] [blame]	867	<dd>This indicates that the parameter does not alias any global or any other
				868	parameter. The caller is responsible for ensuring that this is the case,
				869	usually by placing the value in a stack allocation.</dd>
Chris Lattner	275e6be	2008-01-11 06:20:47 +0000	[diff] [blame]	870
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	871	<dt><tt>noreturn</tt></dt>
				872	<dd>This function attribute indicates that the function never returns. This
				873	indicates to LLVM that every call to this function should be treated as if
				874	an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Chris Lattner	275e6be	2008-01-11 06:20:47 +0000	[diff] [blame]	875
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	876	<dt><tt>nounwind</tt></dt>
Duncan Sands	ef0e9e4	2008-03-17 12:17:41 +0000	[diff] [blame]	877	<dd>This function attribute indicates that no exceptions unwind out of the
				878	function. Usually this is because the function makes no use of exceptions,
				879	but it may also be that the function catches any exceptions thrown when
				880	executing it.</dd>
				881
Duncan Sands	4ee4681	2007-07-27 19:57:41 +0000	[diff] [blame]	882	<dt><tt>nest</tt></dt>
Duncan Sands	f1a7d4c	2008-07-08 09:27:25 +0000	[diff] [blame]	883	<dd>This indicates that the pointer parameter can be excised using the
Duncan Sands	4ee4681	2007-07-27 19:57:41 +0000	[diff] [blame]	884	<a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sands	13e13f8	2007-11-22 20:23:04 +0000	[diff] [blame]	885	<dt><tt>readonly</tt></dt>
Duncan Sands	d69c0e6	2007-11-14 21:14:02 +0000	[diff] [blame]	886	<dd>This function attribute indicates that the function has no side-effects
Duncan Sands	13e13f8	2007-11-22 20:23:04 +0000	[diff] [blame]	887	except for producing a return value or throwing an exception. The value
				888	returned must only depend on the function arguments and/or global variables.
				889	It may use values obtained by dereferencing pointers.</dd>
				890	<dt><tt>readnone</tt></dt>
				891	<dd>A <tt>readnone</tt> function has the same restrictions as a <tt>readonly</tt>
Duncan Sands	d69c0e6	2007-11-14 21:14:02 +0000	[diff] [blame]	892	function, but in addition it is not allowed to dereference any pointer arguments
				893	or global variables.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	894	</dl>
				895
				896	</div>
				897
				898	<!-- ======================================================================= -->
				899	<div class="doc_subsection">
Gordon Henriksen	13fe5e3	2007-12-10 03:18:06 +0000	[diff] [blame]	900	<a name="gc">Garbage Collector Names</a>
				901	</div>
				902
				903	<div class="doc_text">
				904	<p>Each function may specify a garbage collector name, which is simply a
				905	string.</p>
				906
				907	<div class="doc_code"><pre
				908	>define void @f() gc "name" { ...</pre></div>
				909
				910	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				911	collector which will cause the compiler to alter its output in order to support
				912	the named garbage collection algorithm.</p>
				913	</div>
				914
				915	<!-- ======================================================================= -->
				916	<div class="doc_subsection">
Devang Patel	d468f1c	2008-09-04 23:05:13 +0000	[diff] [blame]	917	<a name="notes">Function Notes</a>
				918	</div>
				919
				920	<div class="doc_text">
Devang Patel	25928cb	2008-09-04 23:10:26 +0000	[diff] [blame]	921	<p>The function definition may list function notes which are used by
				922	various passes.</p>
Devang Patel	d468f1c	2008-09-04 23:05:13 +0000	[diff] [blame]	923
				924	<div class="doc_code">
Bill Wendling	74d3eac	2008-09-07 10:26:33 +0000	[diff] [blame]	925	<pre>
				926	define void @f() notes(inline=Always) { ... }
				927	define void @f() notes(inline=Always,opt-size) { ... }
				928	define void @f() notes(inline=Never,opt-size) { ... }
				929	define void @f() notes(opt-size) { ... }
				930	</pre>
Devang Patel	d468f1c	2008-09-04 23:05:13 +0000	[diff] [blame]	931	</div>
				932
Bill Wendling	74d3eac	2008-09-07 10:26:33 +0000	[diff] [blame]	933	<dl>
				934	<dt><tt>inline=Always</tt></dt>
				935	<dd>This note requests inliner to inline this function irrespective of inlining
				936	size threshold for this function.</dd>
				937
				938	<dt><tt>inline=Never</tt></dt>
				939	<dd>This note requests inliner to never inline this function in any situation.
				940	This note may not be used together with <tt>inline=Always</tt> note.</dd>
				941
				942	<dt><tt>opt-size</tt></dt>
				943	<dd>This note suggests optimization passes and code generator passes to make
				944	choices that help reduce code size.</dd>
				945
				946	</dl>
				947
				948	<p>Any notes that are not documented here are considered invalid notes.</p>
Devang Patel	d468f1c	2008-09-04 23:05:13 +0000	[diff] [blame]	949	</div>
				950
				951	<!-- ======================================================================= -->
				952	<div class="doc_subsection">
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	953	<a name="moduleasm">Module-Level Inline Assembly</a>
				954	</div>
				955
				956	<div class="doc_text">
				957	<p>
				958	Modules may contain "module-level inline asm" blocks, which corresponds to the
				959	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				960	LLVM and treated as a single unit, but may be separated in the .ll file if
				961	desired. The syntax is very simple:
				962	</p>
				963
				964	<div class="doc_code">
				965	<pre>
				966	module asm "inline asm code goes here"
				967	module asm "more can go here"
				968	</pre>
				969	</div>
				970
				971	<p>The strings can contain any character by escaping non-printable characters.
				972	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				973	for the number.
				974	</p>
				975
				976	<p>
				977	The inline asm code is simply printed to the machine code .s file when
				978	assembly code is generated.
				979	</p>
				980	</div>
				981
				982	<!-- ======================================================================= -->
				983	<div class="doc_subsection">
				984	<a name="datalayout">Data Layout</a>
				985	</div>
				986
				987	<div class="doc_text">
				988	<p>A module may specify a target specific data layout string that specifies how
				989	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				990	<pre> target datalayout = "<i>layout specification</i>"</pre>
				991	<p>The <i>layout specification</i> consists of a list of specifications
				992	separated by the minus sign character ('-'). Each specification starts with a
				993	letter and may include other information after the letter to define some
				994	aspect of the data layout. The specifications accepted are as follows: </p>
				995	<dl>
				996	<dt><tt>E</tt></dt>
				997	<dd>Specifies that the target lays out data in big-endian form. That is, the
				998	bits with the most significance have the lowest address location.</dd>
				999	<dt><tt>e</tt></dt>
Chris Lattner	9645148	2008-08-05 18:29:16 +0000	[diff] [blame]	1000	<dd>Specifies that the target lays out data in little-endian form. That is,
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1001	the bits with the least significance have the lowest address location.</dd>
				1002	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1003	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1004	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1005	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1006	too.</dd>
				1007	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1008	<dd>This specifies the alignment for an integer type of a given bit
				1009	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1010	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1011	<dd>This specifies the alignment for a vector type of a given bit
				1012	<i>size</i>.</dd>
				1013	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1014	<dd>This specifies the alignment for a floating point type of a given bit
				1015	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1016	(double).</dd>
				1017	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1018	<dd>This specifies the alignment for an aggregate type of a given bit
				1019	<i>size</i>.</dd>
				1020	</dl>
				1021	<p>When constructing the data layout for a given target, LLVM starts with a
				1022	default set of specifications which are then (possibly) overriden by the
				1023	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1024	are given in this list:</p>
				1025	<ul>
				1026	<li><tt>E</tt> - big endian</li>
				1027	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1028	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1029	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1030	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1031	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	9645148	2008-08-05 18:29:16 +0000	[diff] [blame]	1032	<li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1033	alignment of 64-bits</li>
				1034	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1035	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1036	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1037	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1038	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				1039	</ul>
Chris Lattner	6a9f3c4	2008-08-05 18:21:08 +0000	[diff] [blame]	1040	<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1041	following rules:
				1042	<ol>
				1043	<li>If the type sought is an exact match for one of the specifications, that
				1044	specification is used.</li>
				1045	<li>If no match is found, and the type sought is an integer type, then the
				1046	smallest integer type that is larger than the bitwidth of the sought type is
				1047	used. If none of the specifications are larger than the bitwidth then the the
				1048	largest integer type is used. For example, given the default specifications
				1049	above, the i7 type will use the alignment of i8 (next largest) while both
				1050	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1051	<li>If no match is found, and the type sought is a vector type, then the
				1052	largest vector type that is smaller than the sought vector type will be used
				1053	as a fall back. This happens because <128 x double> can be implemented in
				1054	terms of 64 <2 x double>, for example.</li>
				1055	</ol>
				1056	</div>
				1057
				1058	<!-- *********************************************************************** -->
				1059	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1060	<!-- *********************************************************************** -->
				1061
				1062	<div class="doc_text">
				1063
				1064	<p>The LLVM type system is one of the most important features of the
				1065	intermediate representation. Being typed enables a number of
Chris Lattner	9645148	2008-08-05 18:29:16 +0000	[diff] [blame]	1066	optimizations to be performed on the intermediate representation directly,
				1067	without having to do
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1068	extra analyses on the side before the transformation. A strong type
				1069	system makes it easier to read the generated code and enables novel
				1070	analyses and transformations that are not feasible to perform on normal
				1071	three address code representations.</p>
				1072
				1073	</div>
				1074
				1075	<!-- ======================================================================= -->
Chris Lattner	488772f	2008-01-04 04:32:38 +0000	[diff] [blame]	1076	<div class="doc_subsection"> <a name="t_classifications">Type
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1077	Classifications</a> </div>
				1078	<div class="doc_text">
Chris Lattner	488772f	2008-01-04 04:32:38 +0000	[diff] [blame]	1079	<p>The types fall into a few useful
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1080	classifications:</p>
				1081
				1082	<table border="1" cellspacing="0" cellpadding="4">
				1083	<tbody>
				1084	<tr><th>Classification</th><th>Types</th></tr>
				1085	<tr>
Chris Lattner	488772f	2008-01-04 04:32:38 +0000	[diff] [blame]	1086	<td><a href="#t_integer">integer</a></td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1087	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
				1088	</tr>
				1089	<tr>
Chris Lattner	488772f	2008-01-04 04:32:38 +0000	[diff] [blame]	1090	<td><a href="#t_floating">floating point</a></td>
				1091	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1092	</tr>
				1093	<tr>
				1094	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	488772f	2008-01-04 04:32:38 +0000	[diff] [blame]	1095	<td><a href="#t_integer">integer</a>,
				1096	<a href="#t_floating">floating point</a>,
				1097	<a href="#t_pointer">pointer</a>,
Dan Gohman	f6237db	2008-06-18 18:42:13 +0000	[diff] [blame]	1098	<a href="#t_vector">vector</a>,
Dan Gohman	74d6faf	2008-05-12 23:51:09 +0000	[diff] [blame]	1099	<a href="#t_struct">structure</a>,
				1100	<a href="#t_array">array</a>,
Dan Gohman	d13951e	2008-05-23 22:50:26 +0000	[diff] [blame]	1101	<a href="#t_label">label</a>.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1102	</td>
				1103	</tr>
Chris Lattner	488772f	2008-01-04 04:32:38 +0000	[diff] [blame]	1104	<tr>
				1105	<td><a href="#t_primitive">primitive</a></td>
				1106	<td><a href="#t_label">label</a>,
				1107	<a href="#t_void">void</a>,
Chris Lattner	488772f	2008-01-04 04:32:38 +0000	[diff] [blame]	1108	<a href="#t_floating">floating point</a>.</td>
				1109	</tr>
				1110	<tr>
				1111	<td><a href="#t_derived">derived</a></td>
				1112	<td><a href="#t_integer">integer</a>,
				1113	<a href="#t_array">array</a>,
				1114	<a href="#t_function">function</a>,
				1115	<a href="#t_pointer">pointer</a>,
				1116	<a href="#t_struct">structure</a>,
				1117	<a href="#t_pstruct">packed structure</a>,
				1118	<a href="#t_vector">vector</a>,
				1119	<a href="#t_opaque">opaque</a>.
				1120	</tr>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1121	</tbody>
				1122	</table>
				1123
				1124	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1125	most important. Values of these types are the only ones which can be
				1126	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	4f29e42	2008-05-23 21:53:15 +0000	[diff] [blame]	1127	instructions.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1128	</div>
				1129
				1130	<!-- ======================================================================= -->
Chris Lattner	488772f	2008-01-04 04:32:38 +0000	[diff] [blame]	1131	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8643761	2008-01-04 04:34:14 +0000	[diff] [blame]	1132
Chris Lattner	488772f	2008-01-04 04:32:38 +0000	[diff] [blame]	1133	<div class="doc_text">
				1134	<p>The primitive types are the fundamental building blocks of the LLVM
				1135	system.</p>
				1136
Chris Lattner	8643761	2008-01-04 04:34:14 +0000	[diff] [blame]	1137	</div>
				1138
Chris Lattner	488772f	2008-01-04 04:32:38 +0000	[diff] [blame]	1139	<!-- _______________________________________________________________________ -->
				1140	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1141
				1142	<div class="doc_text">
				1143	<table>
				1144	<tbody>
				1145	<tr><th>Type</th><th>Description</th></tr>
				1146	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1147	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1148	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1149	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1150	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1151	</tbody>
				1152	</table>
				1153	</div>
				1154
				1155	<!-- _______________________________________________________________________ -->
				1156	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1157
				1158	<div class="doc_text">
				1159	<h5>Overview:</h5>
				1160	<p>The void type does not represent any value and has no size.</p>
				1161
				1162	<h5>Syntax:</h5>
				1163
				1164	<pre>
				1165	void
				1166	</pre>
				1167	</div>
				1168
				1169	<!-- _______________________________________________________________________ -->
				1170	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1171
				1172	<div class="doc_text">
				1173	<h5>Overview:</h5>
				1174	<p>The label type represents code labels.</p>
				1175
				1176	<h5>Syntax:</h5>
				1177
				1178	<pre>
				1179	label
				1180	</pre>
				1181	</div>
				1182
				1183
				1184	<!-- ======================================================================= -->
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1185	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
				1186
				1187	<div class="doc_text">
				1188
				1189	<p>The real power in LLVM comes from the derived types in the system.
				1190	This is what allows a programmer to represent arrays, functions,
				1191	pointers, and other useful types. Note that these derived types may be
				1192	recursive: For example, it is possible to have a two dimensional array.</p>
				1193
				1194	</div>
				1195
				1196	<!-- _______________________________________________________________________ -->
				1197	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1198
				1199	<div class="doc_text">
				1200
				1201	<h5>Overview:</h5>
				1202	<p>The integer type is a very simple derived type that simply specifies an
				1203	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1204	2^23-1 (about 8 million) can be specified.</p>
				1205
				1206	<h5>Syntax:</h5>
				1207
				1208	<pre>
				1209	iN
				1210	</pre>
				1211
				1212	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1213	value.</p>
				1214
				1215	<h5>Examples:</h5>
				1216	<table class="layout">
Chris Lattner	251ab81	2007-12-18 06:18:21 +0000	[diff] [blame]	1217	<tbody>
				1218	<tr>
				1219	<td><tt>i1</tt></td>
				1220	<td>a single-bit integer.</td>
				1221	</tr><tr>
				1222	<td><tt>i32</tt></td>
				1223	<td>a 32-bit integer.</td>
				1224	</tr><tr>
				1225	<td><tt>i1942652</tt></td>
				1226	<td>a really big integer of over 1 million bits.</td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1227	</tr>
Chris Lattner	251ab81	2007-12-18 06:18:21 +0000	[diff] [blame]	1228	</tbody>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1229	</table>
				1230	</div>
				1231
				1232	<!-- _______________________________________________________________________ -->
				1233	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
				1234
				1235	<div class="doc_text">
				1236
				1237	<h5>Overview:</h5>
				1238
				1239	<p>The array type is a very simple derived type that arranges elements
				1240	sequentially in memory. The array type requires a size (number of
				1241	elements) and an underlying data type.</p>
				1242
				1243	<h5>Syntax:</h5>
				1244
				1245	<pre>
				1246	[<# elements> x <elementtype>]
				1247	</pre>
				1248
				1249	<p>The number of elements is a constant integer value; elementtype may
				1250	be any type with a size.</p>
				1251
				1252	<h5>Examples:</h5>
				1253	<table class="layout">
				1254	<tr class="layout">
Chris Lattner	7311d22	2007-12-19 05:04:11 +0000	[diff] [blame]	1255	<td class="left"><tt>[40 x i32]</tt></td>
				1256	<td class="left">Array of 40 32-bit integer values.</td>
				1257	</tr>
				1258	<tr class="layout">
				1259	<td class="left"><tt>[41 x i32]</tt></td>
				1260	<td class="left">Array of 41 32-bit integer values.</td>
				1261	</tr>
				1262	<tr class="layout">
				1263	<td class="left"><tt>[4 x i8]</tt></td>
				1264	<td class="left">Array of 4 8-bit integer values.</td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1265	</tr>
				1266	</table>
				1267	<p>Here are some examples of multidimensional arrays:</p>
				1268	<table class="layout">
				1269	<tr class="layout">
Chris Lattner	7311d22	2007-12-19 05:04:11 +0000	[diff] [blame]	1270	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1271	<td class="left">3x4 array of 32-bit integer values.</td>
				1272	</tr>
				1273	<tr class="layout">
				1274	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1275	<td class="left">12x10 array of single precision floating point values.</td>
				1276	</tr>
				1277	<tr class="layout">
				1278	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1279	<td class="left">2x3x4 array of 16-bit integer values.</td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1280	</tr>
				1281	</table>
				1282
				1283	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1284	length array. Normally, accesses past the end of an array are undefined in
				1285	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1286	As a special case, however, zero length arrays are recognized to be variable
				1287	length. This allows implementation of 'pascal style arrays' with the LLVM
				1288	type "{ i32, [0 x float]}", for example.</p>
				1289
				1290	</div>
				1291
				1292	<!-- _______________________________________________________________________ -->
				1293	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
				1294	<div class="doc_text">
Chris Lattner	43030e7	2008-04-23 04:59:35 +0000	[diff] [blame]	1295
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1296	<h5>Overview:</h5>
Chris Lattner	43030e7	2008-04-23 04:59:35 +0000	[diff] [blame]	1297
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1298	<p>The function type can be thought of as a function signature. It
Devang Patel	d4ba41d	2008-03-24 05:35:41 +0000	[diff] [blame]	1299	consists of a return type and a list of formal parameter types. The
Chris Lattner	43030e7	2008-04-23 04:59:35 +0000	[diff] [blame]	1300	return type of a function type is a scalar type, a void type, or a struct type.
Devang Patel	d5404c0	2008-03-24 20:52:42 +0000	[diff] [blame]	1301	If the return type is a struct type then all struct elements must be of first
Chris Lattner	43030e7	2008-04-23 04:59:35 +0000	[diff] [blame]	1302	class types, and the struct must have at least one element.</p>
Devang Patel	a3cc537	2008-03-10 20:49:15 +0000	[diff] [blame]	1303
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1304	<h5>Syntax:</h5>
Chris Lattner	43030e7	2008-04-23 04:59:35 +0000	[diff] [blame]	1305
				1306	<pre>
				1307	<returntype list> (<parameter list>)
				1308	</pre>
				1309
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1310	<p>...where '<tt><parameter list></tt>' is a comma-separated list of type
				1311	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
				1312	which indicates that the function takes a variable number of arguments.
				1313	Variable argument functions can access their arguments with the <a
Devang Patel	a3cc537	2008-03-10 20:49:15 +0000	[diff] [blame]	1314	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1315	'<tt><returntype list></tt>' is a comma-separated list of
				1316	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	43030e7	2008-04-23 04:59:35 +0000	[diff] [blame]	1317
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1318	<h5>Examples:</h5>
				1319	<table class="layout">
				1320	<tr class="layout">
				1321	<td class="left"><tt>i32 (i32)</tt></td>
				1322	<td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
				1323	</td>
				1324	</tr><tr class="layout">
Reid Spencer	f234bed	2007-07-19 23:13:04 +0000	[diff] [blame]	1325	<td class="left"><tt>float (i16 signext, i32 )
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1326	</tt></td>
				1327	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1328	an <tt>i16</tt> that should be sign extended and a
				1329	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
				1330	<tt>float</tt>.
				1331	</td>
				1332	</tr><tr class="layout">
				1333	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1334	<td class="left">A vararg function that takes at least one
				1335	<a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
				1336	which returns an integer. This is the signature for <tt>printf</tt> in
				1337	LLVM.
				1338	</td>
Devang Patel	d4ba41d	2008-03-24 05:35:41 +0000	[diff] [blame]	1339	</tr><tr class="layout">
				1340	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel	6dddba2	2008-03-24 18:10:52 +0000	[diff] [blame]	1341	<td class="left">A function taking an <tt>i32></tt>, returning two
				1342	<tt> i32 </tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patel	d4ba41d	2008-03-24 05:35:41 +0000	[diff] [blame]	1343	</td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1344	</tr>
				1345	</table>
				1346
				1347	</div>
				1348	<!-- _______________________________________________________________________ -->
				1349	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
				1350	<div class="doc_text">
				1351	<h5>Overview:</h5>
				1352	<p>The structure type is used to represent a collection of data members
				1353	together in memory. The packing of the field types is defined to match
				1354	the ABI of the underlying processor. The elements of a structure may
				1355	be any type that has a size.</p>
				1356	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1357	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1358	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1359	instruction.</p>
				1360	<h5>Syntax:</h5>
				1361	<pre> { <type list> }<br></pre>
				1362	<h5>Examples:</h5>
				1363	<table class="layout">
				1364	<tr class="layout">
				1365	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1366	<td class="left">A triple of three <tt>i32</tt> values</td>
				1367	</tr><tr class="layout">
				1368	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1369	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1370	second element is a <a href="#t_pointer">pointer</a> to a
				1371	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1372	an <tt>i32</tt>.</td>
				1373	</tr>
				1374	</table>
				1375	</div>
				1376
				1377	<!-- _______________________________________________________________________ -->
				1378	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1379	</div>
				1380	<div class="doc_text">
				1381	<h5>Overview:</h5>
				1382	<p>The packed structure type is used to represent a collection of data members
				1383	together in memory. There is no padding between fields. Further, the alignment
				1384	of a packed structure is 1 byte. The elements of a packed structure may
				1385	be any type that has a size.</p>
				1386	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1387	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1388	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1389	instruction.</p>
				1390	<h5>Syntax:</h5>
				1391	<pre> < { <type list> } > <br></pre>
				1392	<h5>Examples:</h5>
				1393	<table class="layout">
				1394	<tr class="layout">
				1395	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1396	<td class="left">A triple of three <tt>i32</tt> values</td>
				1397	</tr><tr class="layout">
Bill Wendling	74d3eac	2008-09-07 10:26:33 +0000	[diff] [blame]	1398	<td class="left">
				1399	<tt>< { float, i32 (i32)* } ></tt></td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1400	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1401	second element is a <a href="#t_pointer">pointer</a> to a
				1402	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1403	an <tt>i32</tt>.</td>
				1404	</tr>
				1405	</table>
				1406	</div>
				1407
				1408	<!-- _______________________________________________________________________ -->
				1409	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
				1410	<div class="doc_text">
				1411	<h5>Overview:</h5>
				1412	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	dd0049d	2007-12-11 09:31:00 +0000	[diff] [blame]	1413	reference to another object, which must live in memory. Pointer types may have
				1414	an optional address space attribute defining the target-specific numbered
				1415	address space where the pointed-to object resides. The default address space is
				1416	zero.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1417	<h5>Syntax:</h5>
				1418	<pre> <type> *<br></pre>
				1419	<h5>Examples:</h5>
				1420	<table class="layout">
				1421	<tr class="layout">
Chris Lattner	7311d22	2007-12-19 05:04:11 +0000	[diff] [blame]	1422	<td class="left"><tt>[4x i32]*</tt></td>
				1423	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1424	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1425	</tr>
				1426	<tr class="layout">
				1427	<td class="left"><tt>i32 (i32 ) </tt></td>
				1428	<td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1429	href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner	7311d22	2007-12-19 05:04:11 +0000	[diff] [blame]	1430	<tt>i32</tt>.</td>
				1431	</tr>
				1432	<tr class="layout">
				1433	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1434	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1435	that resides in address space #5.</td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1436	</tr>
				1437	</table>
				1438	</div>
				1439
				1440	<!-- _______________________________________________________________________ -->
				1441	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
				1442	<div class="doc_text">
				1443
				1444	<h5>Overview:</h5>
				1445
				1446	<p>A vector type is a simple derived type that represents a vector
				1447	of elements. Vector types are used when multiple primitive data
				1448	are operated in parallel using a single instruction (SIMD).
				1449	A vector type requires a size (number of
				1450	elements) and an underlying primitive data type. Vectors must have a power
				1451	of two length (1, 2, 4, 8, 16 ...). Vector types are
				1452	considered <a href="#t_firstclass">first class</a>.</p>
				1453
				1454	<h5>Syntax:</h5>
				1455
				1456	<pre>
				1457	< <# elements> x <elementtype> >
				1458	</pre>
				1459
				1460	<p>The number of elements is a constant integer value; elementtype may
				1461	be any integer or floating point type.</p>
				1462
				1463	<h5>Examples:</h5>
				1464
				1465	<table class="layout">
				1466	<tr class="layout">
Chris Lattner	7311d22	2007-12-19 05:04:11 +0000	[diff] [blame]	1467	<td class="left"><tt><4 x i32></tt></td>
				1468	<td class="left">Vector of 4 32-bit integer values.</td>
				1469	</tr>
				1470	<tr class="layout">
				1471	<td class="left"><tt><8 x float></tt></td>
				1472	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1473	</tr>
				1474	<tr class="layout">
				1475	<td class="left"><tt><2 x i64></tt></td>
				1476	<td class="left">Vector of 2 64-bit integer values.</td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1477	</tr>
				1478	</table>
				1479	</div>
				1480
				1481	<!-- _______________________________________________________________________ -->
				1482	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1483	<div class="doc_text">
				1484
				1485	<h5>Overview:</h5>
				1486
				1487	<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen	da0706e	2007-10-14 00:34:53 +0000	[diff] [blame]	1488	corresponds (for example) to the C notion of a forward declared structure type.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1489	In LLVM, opaque types can eventually be resolved to any type (not just a
				1490	structure type).</p>
				1491
				1492	<h5>Syntax:</h5>
				1493
				1494	<pre>
				1495	opaque
				1496	</pre>
				1497
				1498	<h5>Examples:</h5>
				1499
				1500	<table class="layout">
				1501	<tr class="layout">
Chris Lattner	7311d22	2007-12-19 05:04:11 +0000	[diff] [blame]	1502	<td class="left"><tt>opaque</tt></td>
				1503	<td class="left">An opaque type.</td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1504	</tr>
				1505	</table>
				1506	</div>
				1507
				1508
				1509	<!-- *********************************************************************** -->
				1510	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1511	<!-- *********************************************************************** -->
				1512
				1513	<div class="doc_text">
				1514
				1515	<p>LLVM has several different basic types of constants. This section describes
				1516	them all and their syntax.</p>
				1517
				1518	</div>
				1519
				1520	<!-- ======================================================================= -->
				1521	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
				1522
				1523	<div class="doc_text">
				1524
				1525	<dl>
				1526	<dt><b>Boolean constants</b></dt>
				1527
				1528	<dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
				1529	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
				1530	</dd>
				1531
				1532	<dt><b>Integer constants</b></dt>
				1533
				1534	<dd>Standard integers (such as '4') are constants of the <a
				1535	href="#t_integer">integer</a> type. Negative numbers may be used with
				1536	integer types.
				1537	</dd>
				1538
				1539	<dt><b>Floating point constants</b></dt>
				1540
				1541	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1542	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	dc15b1d	2008-04-01 18:45:27 +0000	[diff] [blame]	1543	notation (see below). The assembler requires the exact decimal value of
				1544	a floating-point constant. For example, the assembler accepts 1.25 but
				1545	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1546	constants must have a <a href="#t_floating">floating point</a> type. </dd>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1547
				1548	<dt><b>Null pointer constants</b></dt>
				1549
				1550	<dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
				1551	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1552
				1553	</dl>
				1554
				1555	<p>The one non-intuitive notation for constants is the optional hexadecimal form
				1556	of floating point constants. For example, the form '<tt>double
				1557	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1558	4.5e+15</tt>'. The only time hexadecimal floating point constants are required
				1559	(and the only time that they are generated by the disassembler) is when a
				1560	floating point constant must be emitted but it cannot be represented as a
				1561	decimal floating point number. For example, NaN's, infinities, and other
				1562	special values are represented in their IEEE hexadecimal format so that
				1563	assembly and disassembly do not cause any bits to change in the constants.</p>
				1564
				1565	</div>
				1566
				1567	<!-- ======================================================================= -->
				1568	<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
				1569	</div>
				1570
				1571	<div class="doc_text">
				1572	<p>Aggregate constants arise from aggregation of simple constants
				1573	and smaller aggregate constants.</p>
				1574
				1575	<dl>
				1576	<dt><b>Structure constants</b></dt>
				1577
				1578	<dd>Structure constants are represented with notation similar to structure
				1579	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	6c8de96	2007-12-25 20:34:52 +0000	[diff] [blame]	1580	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1581	where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1582	must have <a href="#t_struct">structure type</a>, and the number and
				1583	types of elements must match those specified by the type.
				1584	</dd>
				1585
				1586	<dt><b>Array constants</b></dt>
				1587
				1588	<dd>Array constants are represented with notation similar to array type
				1589	definitions (a comma separated list of elements, surrounded by square brackets
				1590	(<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
				1591	constants must have <a href="#t_array">array type</a>, and the number and
				1592	types of elements must match those specified by the type.
				1593	</dd>
				1594
				1595	<dt><b>Vector constants</b></dt>
				1596
				1597	<dd>Vector constants are represented with notation similar to vector type
				1598	definitions (a comma separated list of elements, surrounded by
				1599	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
				1600	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
				1601	href="#t_vector">vector type</a>, and the number and types of elements must
				1602	match those specified by the type.
				1603	</dd>
				1604
				1605	<dt><b>Zero initialization</b></dt>
				1606
				1607	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1608	value to zero of <em>any</em> type, including scalar and aggregate types.
				1609	This is often used to avoid having to print large zero initializers (e.g. for
				1610	large arrays) and is always exactly equivalent to using explicit zero
				1611	initializers.
				1612	</dd>
				1613	</dl>
				1614
				1615	</div>
				1616
				1617	<!-- ======================================================================= -->
				1618	<div class="doc_subsection">
				1619	<a name="globalconstants">Global Variable and Function Addresses</a>
				1620	</div>
				1621
				1622	<div class="doc_text">
				1623
				1624	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1625	href="#functionstructure">functions</a> are always implicitly valid (link-time)
				1626	constants. These constants are explicitly referenced when the <a
				1627	href="#identifiers">identifier for the global</a> is used and always have <a
				1628	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1629	file:</p>
				1630
				1631	<div class="doc_code">
				1632	<pre>
				1633	@X = global i32 17
				1634	@Y = global i32 42
				1635	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
				1636	</pre>
				1637	</div>
				1638
				1639	</div>
				1640
				1641	<!-- ======================================================================= -->
				1642	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
				1643	<div class="doc_text">
				1644	<p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
				1645	no specific value. Undefined values may be of any type and be used anywhere
				1646	a constant is permitted.</p>
				1647
				1648	<p>Undefined values indicate to the compiler that the program is well defined
				1649	no matter what value is used, giving the compiler more freedom to optimize.
				1650	</p>
				1651	</div>
				1652
				1653	<!-- ======================================================================= -->
				1654	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1655	</div>
				1656
				1657	<div class="doc_text">
				1658
				1659	<p>Constant expressions are used to allow expressions involving other constants
				1660	to be used as constants. Constant expressions may be of any <a
				1661	href="#t_firstclass">first class</a> type and may involve any LLVM operation
				1662	that does not have side effects (e.g. load and call are not supported). The
				1663	following is the syntax for constant expressions:</p>
				1664
				1665	<dl>
				1666	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1667	<dd>Truncate a constant to another type. The bit size of CST must be larger
				1668	than the bit size of TYPE. Both types must be integers.</dd>
				1669
				1670	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1671	<dd>Zero extend a constant to another type. The bit size of CST must be
				1672	smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
				1673
				1674	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1675	<dd>Sign extend a constant to another type. The bit size of CST must be
				1676	smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
				1677
				1678	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1679	<dd>Truncate a floating point constant to another floating point type. The
				1680	size of CST must be larger than the size of TYPE. Both types must be
				1681	floating point.</dd>
				1682
				1683	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1684	<dd>Floating point extend a constant to another type. The size of CST must be
				1685	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1686
Reid Spencer	e6adee8	2007-07-31 14:40:14 +0000	[diff] [blame]	1687	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1688	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	78246ca	2007-11-17 03:58:34 +0000	[diff] [blame]	1689	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1690	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1691	of the same number of elements. If the value won't fit in the integer type,
				1692	the results are undefined.</dd>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1693
				1694	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
				1695	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	78246ca	2007-11-17 03:58:34 +0000	[diff] [blame]	1696	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1697	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1698	of the same number of elements. If the value won't fit in the integer type,
				1699	the results are undefined.</dd>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1700
				1701	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
				1702	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	78246ca	2007-11-17 03:58:34 +0000	[diff] [blame]	1703	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1704	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1705	of the same number of elements. If the value won't fit in the floating point
				1706	type, the results are undefined.</dd>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1707
				1708	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
				1709	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	78246ca	2007-11-17 03:58:34 +0000	[diff] [blame]	1710	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1711	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1712	of the same number of elements. If the value won't fit in the floating point
				1713	type, the results are undefined.</dd>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1714
				1715	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1716	<dd>Convert a pointer typed constant to the corresponding integer constant
				1717	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1718	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1719
				1720	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1721	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1722	pointer type. CST must be of integer type. The CST value is zero extended,
				1723	truncated, or unchanged to make it fit in a pointer size. This one is
				1724	<i>really</i> dangerous!</dd>
				1725
				1726	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
				1727	<dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
				1728	identical (same number of bits). The conversion is done as if the CST value
				1729	was stored to memory and read back as TYPE. In other words, no bits change
				1730	with this operator, just the type. This can be used for conversion of
				1731	vector types to any other type, as long as they have the same bit width. For
				1732	pointers it is only valid to cast to another pointer type.
				1733	</dd>
				1734
				1735	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1736
				1737	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1738	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1739	instruction, the index list may have zero or more indexes, which are required
				1740	to make sense for the type of "CSTPTR".</dd>
				1741
				1742	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1743
				1744	<dd>Perform the <a href="#i_select">select operation</a> on
				1745	constants.</dd>
				1746
				1747	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1748	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1749
				1750	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1751	<dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
				1752
Nate Begeman	646fa48	2008-05-12 19:01:56 +0000	[diff] [blame]	1753	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1754	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1755
				1756	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1757	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1758
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1759	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1760
				1761	<dd>Perform the <a href="#i_extractelement">extractelement
				1762	operation</a> on constants.
				1763
				1764	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				1765
				1766	<dd>Perform the <a href="#i_insertelement">insertelement
				1767	operation</a> on constants.</dd>
				1768
				1769
				1770	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				1771
				1772	<dd>Perform the <a href="#i_shufflevector">shufflevector
				1773	operation</a> on constants.</dd>
				1774
				1775	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				1776
				1777	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				1778	be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
				1779	binary</a> operations. The constraints on operands are the same as those for
				1780	the corresponding instruction (e.g. no bitwise operations on floating point
				1781	values are allowed).</dd>
				1782	</dl>
				1783	</div>
				1784
				1785	<!-- *********************************************************************** -->
				1786	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				1787	<!-- *********************************************************************** -->
				1788
				1789	<!-- ======================================================================= -->
				1790	<div class="doc_subsection">
				1791	<a name="inlineasm">Inline Assembler Expressions</a>
				1792	</div>
				1793
				1794	<div class="doc_text">
				1795
				1796	<p>
				1797	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				1798	Module-Level Inline Assembly</a>) through the use of a special value. This
				1799	value represents the inline assembler as a string (containing the instructions
				1800	to emit), a list of operand constraints (stored as a string), and a flag that
				1801	indicates whether or not the inline asm expression has side effects. An example
				1802	inline assembler expression is:
				1803	</p>
				1804
				1805	<div class="doc_code">
				1806	<pre>
				1807	i32 (i32) asm "bswap $0", "=r,r"
				1808	</pre>
				1809	</div>
				1810
				1811	<p>
				1812	Inline assembler expressions may <b>only</b> be used as the callee operand of
				1813	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				1814	</p>
				1815
				1816	<div class="doc_code">
				1817	<pre>
				1818	%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
				1819	</pre>
				1820	</div>
				1821
				1822	<p>
				1823	Inline asms with side effects not visible in the constraint list must be marked
				1824	as having side effects. This is done through the use of the
				1825	'<tt>sideeffect</tt>' keyword, like so:
				1826	</p>
				1827
				1828	<div class="doc_code">
				1829	<pre>
				1830	call void asm sideeffect "eieio", ""()
				1831	</pre>
				1832	</div>
				1833
				1834	<p>TODO: The format of the asm and constraints string still need to be
				1835	documented here. Constraints on what can be done (e.g. duplication, moving, etc
				1836	need to be documented).
				1837	</p>
				1838
				1839	</div>
				1840
				1841	<!-- *********************************************************************** -->
				1842	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				1843	<!-- *********************************************************************** -->
				1844
				1845	<div class="doc_text">
				1846
				1847	<p>The LLVM instruction set consists of several different
				1848	classifications of instructions: <a href="#terminators">terminator
				1849	instructions</a>, <a href="#binaryops">binary instructions</a>,
				1850	<a href="#bitwiseops">bitwise binary instructions</a>, <a
				1851	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				1852	instructions</a>.</p>
				1853
				1854	</div>
				1855
				1856	<!-- ======================================================================= -->
				1857	<div class="doc_subsection"> <a name="terminators">Terminator
				1858	Instructions</a> </div>
				1859
				1860	<div class="doc_text">
				1861
				1862	<p>As mentioned <a href="#functionstructure">previously</a>, every
				1863	basic block in a program ends with a "Terminator" instruction, which
				1864	indicates which block should be executed after the current block is
				1865	finished. These terminator instructions typically yield a '<tt>void</tt>'
				1866	value: they produce control flow, not values (the one exception being
				1867	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
				1868	<p>There are six different terminator instructions: the '<a
				1869	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				1870	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
				1871	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				1872	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				1873	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
				1874
				1875	</div>
				1876
				1877	<!-- _______________________________________________________________________ -->
				1878	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				1879	Instruction</a> </div>
				1880	<div class="doc_text">
				1881	<h5>Syntax:</h5>
				1882	<pre> ret <type> <value> <i>; Return a value from a non-void function</i>
				1883	ret void <i>; Return from void function</i>
Devang Patel	a3cc537	2008-03-10 20:49:15 +0000	[diff] [blame]	1884	ret <type> <value>, <type> <value> <i>; Return two values from a non-void function </i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1885	</pre>
Chris Lattner	43030e7	2008-04-23 04:59:35 +0000	[diff] [blame]	1886
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1887	<h5>Overview:</h5>
Chris Lattner	43030e7	2008-04-23 04:59:35 +0000	[diff] [blame]	1888
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1889	<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
				1890	value) from a function back to the caller.</p>
				1891	<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner	43030e7	2008-04-23 04:59:35 +0000	[diff] [blame]	1892	returns value(s) and then causes control flow, and one that just causes
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1893	control flow to occur.</p>
Chris Lattner	43030e7	2008-04-23 04:59:35 +0000	[diff] [blame]	1894
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1895	<h5>Arguments:</h5>
Chris Lattner	43030e7	2008-04-23 04:59:35 +0000	[diff] [blame]	1896
				1897	<p>The '<tt>ret</tt>' instruction may return zero, one or multiple values.
				1898	The type of each return value must be a '<a href="#t_firstclass">first
				1899	class</a>' type. Note that a function is not <a href="#wellformed">well
				1900	formed</a> if there exists a '<tt>ret</tt>' instruction inside of the
				1901	function that returns values that do not match the return type of the
				1902	function.</p>
				1903
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1904	<h5>Semantics:</h5>
Chris Lattner	43030e7	2008-04-23 04:59:35 +0000	[diff] [blame]	1905
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1906	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				1907	returns back to the calling function's context. If the caller is a "<a
				1908	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
				1909	the instruction after the call. If the caller was an "<a
				1910	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
				1911	at the beginning of the "normal" destination block. If the instruction
				1912	returns a value, that value shall set the call or invoke instruction's
Devang Patel	a3cc537	2008-03-10 20:49:15 +0000	[diff] [blame]	1913	return value. If the instruction returns multiple values then these
Devang Patel	ec8a5b0	2008-03-11 05:51:59 +0000	[diff] [blame]	1914	values can only be accessed through a '<a href="#i_getresult"><tt>getresult</tt>
				1915	</a>' instruction.</p>
Chris Lattner	43030e7	2008-04-23 04:59:35 +0000	[diff] [blame]	1916
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1917	<h5>Example:</h5>
Chris Lattner	43030e7	2008-04-23 04:59:35 +0000	[diff] [blame]	1918
				1919	<pre>
				1920	ret i32 5 <i>; Return an integer value of 5</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1921	ret void <i>; Return from a void function</i>
Devang Patel	a3cc537	2008-03-10 20:49:15 +0000	[diff] [blame]	1922	ret i32 4, i8 2 <i>; Return two values 4 and 2 </i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1923	</pre>
				1924	</div>
				1925	<!-- _______________________________________________________________________ -->
				1926	<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
				1927	<div class="doc_text">
				1928	<h5>Syntax:</h5>
				1929	<pre> br i1 <cond>, label <iftrue>, label <iffalse><br> br label <dest> <i>; Unconditional branch</i>
				1930	</pre>
				1931	<h5>Overview:</h5>
				1932	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				1933	transfer to a different basic block in the current function. There are
				1934	two forms of this instruction, corresponding to a conditional branch
				1935	and an unconditional branch.</p>
				1936	<h5>Arguments:</h5>
				1937	<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
				1938	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
				1939	unconditional form of the '<tt>br</tt>' instruction takes a single
				1940	'<tt>label</tt>' value as a target.</p>
				1941	<h5>Semantics:</h5>
				1942	<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
				1943	argument is evaluated. If the value is <tt>true</tt>, control flows
				1944	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				1945	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
				1946	<h5>Example:</h5>
				1947	<pre>Test:<br> %cond = <a href="#i_icmp">icmp</a> eq, i32 %a, %b<br> br i1 %cond, label %IfEqual, label %IfUnequal<br>IfEqual:<br> <a
				1948	href="#i_ret">ret</a> i32 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> i32 0<br></pre>
				1949	</div>
				1950	<!-- _______________________________________________________________________ -->
				1951	<div class="doc_subsubsection">
				1952	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				1953	</div>
				1954
				1955	<div class="doc_text">
				1956	<h5>Syntax:</h5>
				1957
				1958	<pre>
				1959	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				1960	</pre>
				1961
				1962	<h5>Overview:</h5>
				1963
				1964	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				1965	several different places. It is a generalization of the '<tt>br</tt>'
				1966	instruction, allowing a branch to occur to one of many possible
				1967	destinations.</p>
				1968
				1969
				1970	<h5>Arguments:</h5>
				1971
				1972	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				1973	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				1974	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				1975	table is not allowed to contain duplicate constant entries.</p>
				1976
				1977	<h5>Semantics:</h5>
				1978
				1979	<p>The <tt>switch</tt> instruction specifies a table of values and
				1980	destinations. When the '<tt>switch</tt>' instruction is executed, this
				1981	table is searched for the given value. If the value is found, control flow is
				1982	transfered to the corresponding destination; otherwise, control flow is
				1983	transfered to the default destination.</p>
				1984
				1985	<h5>Implementation:</h5>
				1986
				1987	<p>Depending on properties of the target machine and the particular
				1988	<tt>switch</tt> instruction, this instruction may be code generated in different
				1989	ways. For example, it could be generated as a series of chained conditional
				1990	branches or with a lookup table.</p>
				1991
				1992	<h5>Example:</h5>
				1993
				1994	<pre>
				1995	<i>; Emulate a conditional br instruction</i>
				1996	%Val = <a href="#i_zext">zext</a> i1 %value to i32
				1997	switch i32 %Val, label %truedest [i32 0, label %falsedest ]
				1998
				1999	<i>; Emulate an unconditional br instruction</i>
				2000	switch i32 0, label %dest [ ]
				2001
				2002	<i>; Implement a jump table:</i>
				2003	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2004	i32 1, label %onone
				2005	i32 2, label %ontwo ]
				2006	</pre>
				2007	</div>
				2008
				2009	<!-- _______________________________________________________________________ -->
				2010	<div class="doc_subsubsection">
				2011	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2012	</div>
				2013
				2014	<div class="doc_text">
				2015
				2016	<h5>Syntax:</h5>
				2017
				2018	<pre>
Nick Lewycky	a1c11a1	2008-03-16 07:18:12 +0000	[diff] [blame]	2019	<result> = invoke [<a href="#callingconv">cconv</a>] <ptr to function ty> <function ptr val>(<function args>)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2020	to label <normal label> unwind label <exception label>
				2021	</pre>
				2022
				2023	<h5>Overview:</h5>
				2024
				2025	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2026	function, with the possibility of control flow transfer to either the
				2027	'<tt>normal</tt>' label or the
				2028	'<tt>exception</tt>' label. If the callee function returns with the
				2029	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2030	"normal" label. If the callee (or any indirect callees) returns with the "<a
				2031	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Devang Patel	a3cc537	2008-03-10 20:49:15 +0000	[diff] [blame]	2032	continued at the dynamically nearest "exception" label. If the callee function
Devang Patel	ec8a5b0	2008-03-11 05:51:59 +0000	[diff] [blame]	2033	returns multiple values then individual return values are only accessible through
				2034	a '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2035
				2036	<h5>Arguments:</h5>
				2037
				2038	<p>This instruction requires several arguments:</p>
				2039
				2040	<ol>
				2041	<li>
				2042	The optional "cconv" marker indicates which <a href="#callingconv">calling
				2043	convention</a> the call should use. If none is specified, the call defaults
				2044	to using C calling conventions.
				2045	</li>
				2046	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2047	function value being invoked. In most cases, this is a direct function
				2048	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2049	an arbitrary pointer to function value.
				2050	</li>
				2051
				2052	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2053	function to be invoked. </li>
				2054
				2055	<li>'<tt>function args</tt>': argument list whose types match the function
				2056	signature argument types. If the function signature indicates the function
				2057	accepts a variable number of arguments, the extra arguments can be
				2058	specified. </li>
				2059
				2060	<li>'<tt>normal label</tt>': the label reached when the called function
				2061	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2062
				2063	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2064	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2065
				2066	</ol>
				2067
				2068	<h5>Semantics:</h5>
				2069
				2070	<p>This instruction is designed to operate as a standard '<tt><a
				2071	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2072	difference is that it establishes an association with a label, which is used by
				2073	the runtime library to unwind the stack.</p>
				2074
				2075	<p>This instruction is used in languages with destructors to ensure that proper
				2076	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2077	exception. Additionally, this is important for implementation of
				2078	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2079
				2080	<h5>Example:</h5>
				2081	<pre>
Nick Lewycky	a1c11a1	2008-03-16 07:18:12 +0000	[diff] [blame]	2082	%retval = invoke i32 @Test(i32 15) to label %Continue
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2083	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	a1c11a1	2008-03-16 07:18:12 +0000	[diff] [blame]	2084	%retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2085	unwind label %TestCleanup <i>; {i32}:retval set</i>
				2086	</pre>
				2087	</div>
				2088
				2089
				2090	<!-- _______________________________________________________________________ -->
				2091
				2092	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2093	Instruction</a> </div>
				2094
				2095	<div class="doc_text">
				2096
				2097	<h5>Syntax:</h5>
				2098	<pre>
				2099	unwind
				2100	</pre>
				2101
				2102	<h5>Overview:</h5>
				2103
				2104	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2105	at the first callee in the dynamic call stack which used an <a
				2106	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2107	primarily used to implement exception handling.</p>
				2108
				2109	<h5>Semantics:</h5>
				2110
Chris Lattner	8b094fc	2008-04-19 21:01:16 +0000	[diff] [blame]	2111	<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2112	immediately halt. The dynamic call stack is then searched for the first <a
				2113	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2114	execution continues at the "exceptional" destination block specified by the
				2115	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2116	dynamic call chain, undefined behavior results.</p>
				2117	</div>
				2118
				2119	<!-- _______________________________________________________________________ -->
				2120
				2121	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2122	Instruction</a> </div>
				2123
				2124	<div class="doc_text">
				2125
				2126	<h5>Syntax:</h5>
				2127	<pre>
				2128	unreachable
				2129	</pre>
				2130
				2131	<h5>Overview:</h5>
				2132
				2133	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2134	instruction is used to inform the optimizer that a particular portion of the
				2135	code is not reachable. This can be used to indicate that the code after a
				2136	no-return function cannot be reached, and other facts.</p>
				2137
				2138	<h5>Semantics:</h5>
				2139
				2140	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2141	</div>
				2142
				2143
				2144
				2145	<!-- ======================================================================= -->
				2146	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
				2147	<div class="doc_text">
				2148	<p>Binary operators are used to do most of the computation in a
Chris Lattner	ab596d9	2008-04-01 18:47:32 +0000	[diff] [blame]	2149	program. They require two operands of the same type, execute an operation on them, and
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2150	produce a single value. The operands might represent
				2151	multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattner	ab596d9	2008-04-01 18:47:32 +0000	[diff] [blame]	2152	The result value has the same type as its operands.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2153	<p>There are several different binary operators:</p>
				2154	</div>
				2155	<!-- _______________________________________________________________________ -->
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2156	<div class="doc_subsubsection">
				2157	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2158	</div>
				2159
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2160	<div class="doc_text">
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2161
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2162	<h5>Syntax:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2163
				2164	<pre>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2165	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2166	</pre>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2167
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2168	<h5>Overview:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2169
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2170	<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2171
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2172	<h5>Arguments:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2173
				2174	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2175	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2176	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2177	types.</p>
				2178
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2179	<h5>Semantics:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2180
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2181	<p>The value produced is the integer or floating point sum of the two
				2182	operands.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2183
Chris Lattner	9aba1e2	2008-01-28 00:36:27 +0000	[diff] [blame]	2184	<p>If an integer sum has unsigned overflow, the result returned is the
				2185	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2186	the result.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2187
Chris Lattner	9aba1e2	2008-01-28 00:36:27 +0000	[diff] [blame]	2188	<p>Because LLVM integers use a two's complement representation, this
				2189	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2190
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2191	<h5>Example:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2192
				2193	<pre>
				2194	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2195	</pre>
				2196	</div>
				2197	<!-- _______________________________________________________________________ -->
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2198	<div class="doc_subsubsection">
				2199	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2200	</div>
				2201
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2202	<div class="doc_text">
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2203
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2204	<h5>Syntax:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2205
				2206	<pre>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2207	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2208	</pre>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2209
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2210	<h5>Overview:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2211
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2212	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2213	operands.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2214
				2215	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2216	'<tt>neg</tt>' instruction present in most other intermediate
				2217	representations.</p>
				2218
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2219	<h5>Arguments:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2220
				2221	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2222	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2223	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2224	types.</p>
				2225
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2226	<h5>Semantics:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2227
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2228	<p>The value produced is the integer or floating point difference of
				2229	the two operands.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2230
Chris Lattner	9aba1e2	2008-01-28 00:36:27 +0000	[diff] [blame]	2231	<p>If an integer difference has unsigned overflow, the result returned is the
				2232	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2233	the result.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2234
Chris Lattner	9aba1e2	2008-01-28 00:36:27 +0000	[diff] [blame]	2235	<p>Because LLVM integers use a two's complement representation, this
				2236	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2237
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2238	<h5>Example:</h5>
				2239	<pre>
				2240	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
				2241	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
				2242	</pre>
				2243	</div>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2244
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2245	<!-- _______________________________________________________________________ -->
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2246	<div class="doc_subsubsection">
				2247	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2248	</div>
				2249
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2250	<div class="doc_text">
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2251
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2252	<h5>Syntax:</h5>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2253	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2254	</pre>
				2255	<h5>Overview:</h5>
				2256	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2257	operands.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2258
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2259	<h5>Arguments:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2260
				2261	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2262	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2263	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2264	types.</p>
				2265
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2266	<h5>Semantics:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2267
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2268	<p>The value produced is the integer or floating point product of the
				2269	two operands.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2270
Chris Lattner	9aba1e2	2008-01-28 00:36:27 +0000	[diff] [blame]	2271	<p>If the result of an integer multiplication has unsigned overflow,
				2272	the result returned is the mathematical result modulo
				2273	2<sup>n</sup>, where n is the bit width of the result.</p>
				2274	<p>Because LLVM integers use a two's complement representation, and the
				2275	result is the same width as the operands, this instruction returns the
				2276	correct result for both signed and unsigned integers. If a full product
				2277	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2278	should be sign-extended or zero-extended as appropriate to the
				2279	width of the full product.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2280	<h5>Example:</h5>
				2281	<pre> <result> = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
				2282	</pre>
				2283	</div>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2284
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2285	<!-- _______________________________________________________________________ -->
				2286	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2287	</a></div>
				2288	<div class="doc_text">
				2289	<h5>Syntax:</h5>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2290	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2291	</pre>
				2292	<h5>Overview:</h5>
				2293	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2294	operands.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2295
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2296	<h5>Arguments:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2297
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2298	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2299	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2300	values. Both arguments must have identical types.</p>
				2301
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2302	<h5>Semantics:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2303
Chris Lattner	9aba1e2	2008-01-28 00:36:27 +0000	[diff] [blame]	2304	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2305	<p>Note that unsigned integer division and signed integer division are distinct
				2306	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2307	<p>Division by zero leads to undefined behavior.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2308	<h5>Example:</h5>
				2309	<pre> <result> = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
				2310	</pre>
				2311	</div>
				2312	<!-- _______________________________________________________________________ -->
				2313	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2314	</a> </div>
				2315	<div class="doc_text">
				2316	<h5>Syntax:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2317	<pre>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2318	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2319	</pre>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2320
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2321	<h5>Overview:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2322
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2323	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2324	operands.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2325
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2326	<h5>Arguments:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2327
				2328	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2329	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2330	values. Both arguments must have identical types.</p>
				2331
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2332	<h5>Semantics:</h5>
Chris Lattner	dc15b1d	2008-04-01 18:45:27 +0000	[diff] [blame]	2333	<p>The value produced is the signed integer quotient of the two operands rounded towards zero.</p>
Chris Lattner	9aba1e2	2008-01-28 00:36:27 +0000	[diff] [blame]	2334	<p>Note that signed integer division and unsigned integer division are distinct
				2335	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2336	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2337	undefined behavior; this is a rare case, but can occur, for example,
				2338	by doing a 32-bit division of -2147483648 by -1.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2339	<h5>Example:</h5>
				2340	<pre> <result> = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
				2341	</pre>
				2342	</div>
				2343	<!-- _______________________________________________________________________ -->
				2344	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
				2345	Instruction</a> </div>
				2346	<div class="doc_text">
				2347	<h5>Syntax:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2348	<pre>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2349	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2350	</pre>
				2351	<h5>Overview:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2352
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2353	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
				2354	operands.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2355
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2356	<h5>Arguments:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2357
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2358	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2359	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2360	of floating point values. Both arguments must have identical types.</p>
				2361
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2362	<h5>Semantics:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2363
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2364	<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2365
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2366	<h5>Example:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2367
				2368	<pre>
				2369	<result> = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2370	</pre>
				2371	</div>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2372
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2373	<!-- _______________________________________________________________________ -->
				2374	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2375	</div>
				2376	<div class="doc_text">
				2377	<h5>Syntax:</h5>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2378	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2379	</pre>
				2380	<h5>Overview:</h5>
				2381	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2382	unsigned division of its two arguments.</p>
				2383	<h5>Arguments:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2384	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2385	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2386	values. Both arguments must have identical types.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2387	<h5>Semantics:</h5>
				2388	<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattner	dc15b1d	2008-04-01 18:45:27 +0000	[diff] [blame]	2389	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	9aba1e2	2008-01-28 00:36:27 +0000	[diff] [blame]	2390	<p>Note that unsigned integer remainder and signed integer remainder are
				2391	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2392	<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2393	<h5>Example:</h5>
				2394	<pre> <result> = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
				2395	</pre>
				2396
				2397	</div>
				2398	<!-- _______________________________________________________________________ -->
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2399	<div class="doc_subsubsection">
				2400	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2401	</div>
				2402
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2403	<div class="doc_text">
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2404
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2405	<h5>Syntax:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2406
				2407	<pre>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2408	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2409	</pre>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2410
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2411	<h5>Overview:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2412
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2413	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	3e3fd8c	2007-11-05 23:35:22 +0000	[diff] [blame]	2414	signed division of its two operands. This instruction can also take
				2415	<a href="#t_vector">vector</a> versions of the values in which case
				2416	the elements must be integers.</p>
Chris Lattner	08497ce	2008-01-04 04:33:49 +0000	[diff] [blame]	2417
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2418	<h5>Arguments:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2419
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2420	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2421	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2422	values. Both arguments must have identical types.</p>
				2423
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2424	<h5>Semantics:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2425
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2426	<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2427	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2428	operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2429	a value. For more information about the difference, see <a
				2430	href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
				2431	Math Forum</a>. For a table of how this is implemented in various languages,
				2432	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
				2433	Wikipedia: modulo operation</a>.</p>
Chris Lattner	9aba1e2	2008-01-28 00:36:27 +0000	[diff] [blame]	2434	<p>Note that signed integer remainder and unsigned integer remainder are
				2435	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2436	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2437	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2438	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2439	(The remainder doesn't actually overflow, but this rule lets srem be
				2440	implemented using instructions that return both the result of the division
				2441	and the remainder.)</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2442	<h5>Example:</h5>
				2443	<pre> <result> = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
				2444	</pre>
				2445
				2446	</div>
				2447	<!-- _______________________________________________________________________ -->
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2448	<div class="doc_subsubsection">
				2449	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2450
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2451	<div class="doc_text">
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2452
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2453	<h5>Syntax:</h5>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2454	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2455	</pre>
				2456	<h5>Overview:</h5>
				2457	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2458	division of its two operands.</p>
				2459	<h5>Arguments:</h5>
				2460	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2461	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2462	of floating point values. Both arguments must have identical types.</p>
				2463
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2464	<h5>Semantics:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2465
Chris Lattner	dc15b1d	2008-04-01 18:45:27 +0000	[diff] [blame]	2466	<p>This instruction returns the <i>remainder</i> of a division.
				2467	The remainder has the same sign as the dividend.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2468
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2469	<h5>Example:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2470
				2471	<pre>
				2472	<result> = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2473	</pre>
				2474	</div>
				2475
				2476	<!-- ======================================================================= -->
				2477	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2478	Operations</a> </div>
				2479	<div class="doc_text">
				2480	<p>Bitwise binary operators are used to do various forms of
				2481	bit-twiddling in a program. They are generally very efficient
				2482	instructions and can commonly be strength reduced from other
Chris Lattner	dc15b1d	2008-04-01 18:45:27 +0000	[diff] [blame]	2483	instructions. They require two operands of the same type, execute an operation on them,
				2484	and produce a single value. The resulting value is the same type as its operands.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2485	</div>
				2486
				2487	<!-- _______________________________________________________________________ -->
				2488	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2489	Instruction</a> </div>
				2490	<div class="doc_text">
				2491	<h5>Syntax:</h5>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2492	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2493	</pre>
Chris Lattner	d939d9f	2007-10-03 21:01:14 +0000	[diff] [blame]	2494
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2495	<h5>Overview:</h5>
Chris Lattner	d939d9f	2007-10-03 21:01:14 +0000	[diff] [blame]	2496
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2497	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2498	the left a specified number of bits.</p>
Chris Lattner	d939d9f	2007-10-03 21:01:14 +0000	[diff] [blame]	2499
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2500	<h5>Arguments:</h5>
Chris Lattner	d939d9f	2007-10-03 21:01:14 +0000	[diff] [blame]	2501
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2502	<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman	bb1ce94	2008-07-29 15:49:41 +0000	[diff] [blame]	2503	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2504	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	d939d9f	2007-10-03 21:01:14 +0000	[diff] [blame]	2505
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2506	<h5>Semantics:</h5>
Chris Lattner	d939d9f	2007-10-03 21:01:14 +0000	[diff] [blame]	2507
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2508	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2509	where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
				2510	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.</p>
Chris Lattner	d939d9f	2007-10-03 21:01:14 +0000	[diff] [blame]	2511
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2512	<h5>Example:</h5><pre>
				2513	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2514	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2515	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	d939d9f	2007-10-03 21:01:14 +0000	[diff] [blame]	2516	<result> = shl i32 1, 32 <i>; undefined</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2517	</pre>
				2518	</div>
				2519	<!-- _______________________________________________________________________ -->
				2520	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2521	Instruction</a> </div>
				2522	<div class="doc_text">
				2523	<h5>Syntax:</h5>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2524	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2525	</pre>
				2526
				2527	<h5>Overview:</h5>
				2528	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
				2529	operand shifted to the right a specified number of bits with zero fill.</p>
				2530
				2531	<h5>Arguments:</h5>
				2532	<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman	bb1ce94	2008-07-29 15:49:41 +0000	[diff] [blame]	2533	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2534	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2535
				2536	<h5>Semantics:</h5>
Chris Lattner	d939d9f	2007-10-03 21:01:14 +0000	[diff] [blame]	2537
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2538	<p>This instruction always performs a logical shift right operation. The most
				2539	significant bits of the result will be filled with zero bits after the
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2540	shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
				2541	the number of bits in <tt>op1</tt>, the result is undefined.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2542
				2543	<h5>Example:</h5>
				2544	<pre>
				2545	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2546	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2547	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2548	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	d939d9f	2007-10-03 21:01:14 +0000	[diff] [blame]	2549	<result> = lshr i32 1, 32 <i>; undefined</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2550	</pre>
				2551	</div>
				2552
				2553	<!-- _______________________________________________________________________ -->
				2554	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2555	Instruction</a> </div>
				2556	<div class="doc_text">
				2557
				2558	<h5>Syntax:</h5>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2559	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2560	</pre>
				2561
				2562	<h5>Overview:</h5>
				2563	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
				2564	operand shifted to the right a specified number of bits with sign extension.</p>
				2565
				2566	<h5>Arguments:</h5>
				2567	<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman	bb1ce94	2008-07-29 15:49:41 +0000	[diff] [blame]	2568	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2569	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2570
				2571	<h5>Semantics:</h5>
				2572	<p>This instruction always performs an arithmetic shift right operation,
				2573	The most significant bits of the result will be filled with the sign bit
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2574	of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
				2575	larger than the number of bits in <tt>op1</tt>, the result is undefined.
Chris Lattner	d939d9f	2007-10-03 21:01:14 +0000	[diff] [blame]	2576	</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2577
				2578	<h5>Example:</h5>
				2579	<pre>
				2580	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2581	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2582	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2583	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	d939d9f	2007-10-03 21:01:14 +0000	[diff] [blame]	2584	<result> = ashr i32 1, 32 <i>; undefined</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2585	</pre>
				2586	</div>
				2587
				2588	<!-- _______________________________________________________________________ -->
				2589	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2590	Instruction</a> </div>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2591
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2592	<div class="doc_text">
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2593
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2594	<h5>Syntax:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2595
				2596	<pre>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2597	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2598	</pre>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2599
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2600	<h5>Overview:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2601
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2602	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2603	its two operands.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2604
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2605	<h5>Arguments:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2606
				2607	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2608	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2609	values. Both arguments must have identical types.</p>
				2610
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2611	<h5>Semantics:</h5>
				2612	<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
				2613	<p> </p>
Bill Wendling	1e19eac	2008-09-07 10:29:20 +0000	[diff] [blame^]	2614	<div>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2615	<table border="1" cellspacing="0" cellpadding="4">
				2616	<tbody>
				2617	<tr>
				2618	<td>In0</td>
				2619	<td>In1</td>
				2620	<td>Out</td>
				2621	</tr>
				2622	<tr>
				2623	<td>0</td>
				2624	<td>0</td>
				2625	<td>0</td>
				2626	</tr>
				2627	<tr>
				2628	<td>0</td>
				2629	<td>1</td>
				2630	<td>0</td>
				2631	</tr>
				2632	<tr>
				2633	<td>1</td>
				2634	<td>0</td>
				2635	<td>0</td>
				2636	</tr>
				2637	<tr>
				2638	<td>1</td>
				2639	<td>1</td>
				2640	<td>1</td>
				2641	</tr>
				2642	</tbody>
				2643	</table>
				2644	</div>
				2645	<h5>Example:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2646	<pre>
				2647	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2648	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2649	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
				2650	</pre>
				2651	</div>
				2652	<!-- _______________________________________________________________________ -->
				2653	<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
				2654	<div class="doc_text">
				2655	<h5>Syntax:</h5>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2656	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2657	</pre>
				2658	<h5>Overview:</h5>
				2659	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2660	or of its two operands.</p>
				2661	<h5>Arguments:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2662
				2663	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2664	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2665	values. Both arguments must have identical types.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2666	<h5>Semantics:</h5>
				2667	<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
				2668	<p> </p>
Bill Wendling	1e19eac	2008-09-07 10:29:20 +0000	[diff] [blame^]	2669	<div>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2670	<table border="1" cellspacing="0" cellpadding="4">
				2671	<tbody>
				2672	<tr>
				2673	<td>In0</td>
				2674	<td>In1</td>
				2675	<td>Out</td>
				2676	</tr>
				2677	<tr>
				2678	<td>0</td>
				2679	<td>0</td>
				2680	<td>0</td>
				2681	</tr>
				2682	<tr>
				2683	<td>0</td>
				2684	<td>1</td>
				2685	<td>1</td>
				2686	</tr>
				2687	<tr>
				2688	<td>1</td>
				2689	<td>0</td>
				2690	<td>1</td>
				2691	</tr>
				2692	<tr>
				2693	<td>1</td>
				2694	<td>1</td>
				2695	<td>1</td>
				2696	</tr>
				2697	</tbody>
				2698	</table>
				2699	</div>
				2700	<h5>Example:</h5>
				2701	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2702	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2703	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
				2704	</pre>
				2705	</div>
				2706	<!-- _______________________________________________________________________ -->
				2707	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2708	Instruction</a> </div>
				2709	<div class="doc_text">
				2710	<h5>Syntax:</h5>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	2711	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2712	</pre>
				2713	<h5>Overview:</h5>
				2714	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2715	or of its two operands. The <tt>xor</tt> is used to implement the
				2716	"one's complement" operation, which is the "~" operator in C.</p>
				2717	<h5>Arguments:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2718	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				2719	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2720	values. Both arguments must have identical types.</p>
				2721
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2722	<h5>Semantics:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	2723
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2724	<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
				2725	<p> </p>
Bill Wendling	1e19eac	2008-09-07 10:29:20 +0000	[diff] [blame^]	2726	<div>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2727	<table border="1" cellspacing="0" cellpadding="4">
				2728	<tbody>
				2729	<tr>
				2730	<td>In0</td>
				2731	<td>In1</td>
				2732	<td>Out</td>
				2733	</tr>
				2734	<tr>
				2735	<td>0</td>
				2736	<td>0</td>
				2737	<td>0</td>
				2738	</tr>
				2739	<tr>
				2740	<td>0</td>
				2741	<td>1</td>
				2742	<td>1</td>
				2743	</tr>
				2744	<tr>
				2745	<td>1</td>
				2746	<td>0</td>
				2747	<td>1</td>
				2748	</tr>
				2749	<tr>
				2750	<td>1</td>
				2751	<td>1</td>
				2752	<td>0</td>
				2753	</tr>
				2754	</tbody>
				2755	</table>
				2756	</div>
				2757	<p> </p>
				2758	<h5>Example:</h5>
				2759	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				2760	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				2761	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				2762	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
				2763	</pre>
				2764	</div>
				2765
				2766	<!-- ======================================================================= -->
				2767	<div class="doc_subsection">
				2768	<a name="vectorops">Vector Operations</a>
				2769	</div>
				2770
				2771	<div class="doc_text">
				2772
				2773	<p>LLVM supports several instructions to represent vector operations in a
				2774	target-independent manner. These instructions cover the element-access and
				2775	vector-specific operations needed to process vectors effectively. While LLVM
				2776	does directly support these vector operations, many sophisticated algorithms
				2777	will want to use target-specific intrinsics to take full advantage of a specific
				2778	target.</p>
				2779
				2780	</div>
				2781
				2782	<!-- _______________________________________________________________________ -->
				2783	<div class="doc_subsubsection">
				2784	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				2785	</div>
				2786
				2787	<div class="doc_text">
				2788
				2789	<h5>Syntax:</h5>
				2790
				2791	<pre>
				2792	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
				2793	</pre>
				2794
				2795	<h5>Overview:</h5>
				2796
				2797	<p>
				2798	The '<tt>extractelement</tt>' instruction extracts a single scalar
				2799	element from a vector at a specified index.
				2800	</p>
				2801
				2802
				2803	<h5>Arguments:</h5>
				2804
				2805	<p>
				2806	The first operand of an '<tt>extractelement</tt>' instruction is a
				2807	value of <a href="#t_vector">vector</a> type. The second operand is
				2808	an index indicating the position from which to extract the element.
				2809	The index may be a variable.</p>
				2810
				2811	<h5>Semantics:</h5>
				2812
				2813	<p>
				2814	The result is a scalar of the same type as the element type of
				2815	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				2816	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				2817	results are undefined.
				2818	</p>
				2819
				2820	<h5>Example:</h5>
				2821
				2822	<pre>
				2823	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
				2824	</pre>
				2825	</div>
				2826
				2827
				2828	<!-- _______________________________________________________________________ -->
				2829	<div class="doc_subsubsection">
				2830	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				2831	</div>
				2832
				2833	<div class="doc_text">
				2834
				2835	<h5>Syntax:</h5>
				2836
				2837	<pre>
Dan Gohman	bcc3c50	2008-05-12 23:38:42 +0000	[diff] [blame]	2838	<result> = insertelement <n x <ty>> <val>, <ty> <elt>, i32 <idx> <i>; yields <n x <ty>></i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	2839	</pre>
				2840
				2841	<h5>Overview:</h5>
				2842
				2843	<p>
				2844	The '<tt>insertelement</tt>' instruction inserts a scalar
				2845	element into a vector at a specified index.
				2846	</p>
				2847
				2848
				2849	<h5>Arguments:</h5>
				2850
				2851	<p>
				2852	The first operand of an '<tt>insertelement</tt>' instruction is a
				2853	value of <a href="#t_vector">vector</a> type. The second operand is a
				2854	scalar value whose type must equal the element type of the first
				2855	operand. The third operand is an index indicating the position at
				2856	which to insert the value. The index may be a variable.</p>
				2857
				2858	<h5>Semantics:</h5>
				2859
				2860	<p>
				2861	The result is a vector of the same type as <tt>val</tt>. Its
				2862	element values are those of <tt>val</tt> except at position
				2863	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				2864	exceeds the length of <tt>val</tt>, the results are undefined.
				2865	</p>
				2866
				2867	<h5>Example:</h5>
				2868
				2869	<pre>
				2870	%result = insertelement <4 x i32> %vec, i32 1, i32 0 <i>; yields <4 x i32></i>
				2871	</pre>
				2872	</div>
				2873
				2874	<!-- _______________________________________________________________________ -->
				2875	<div class="doc_subsubsection">
				2876	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				2877	</div>
				2878
				2879	<div class="doc_text">
				2880
				2881	<h5>Syntax:</h5>
				2882
				2883	<pre>
				2884	<result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <n x i32> <mask> <i>; yields <n x <ty>></i>
				2885	</pre>
				2886
				2887	<h5>Overview:</h5>
				2888
				2889	<p>
				2890	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
				2891	from two input vectors, returning a vector of the same type.
				2892	</p>
				2893
				2894	<h5>Arguments:</h5>
				2895
				2896	<p>
				2897	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				2898	with types that match each other and types that match the result of the
				2899	instruction. The third argument is a shuffle mask, which has the same number
				2900	of elements as the other vector type, but whose element type is always 'i32'.
				2901	</p>
				2902
				2903	<p>
				2904	The shuffle mask operand is required to be a constant vector with either
				2905	constant integer or undef values.
				2906	</p>
				2907
				2908	<h5>Semantics:</h5>
				2909
				2910	<p>
				2911	The elements of the two input vectors are numbered from left to right across
				2912	both of the vectors. The shuffle mask operand specifies, for each element of
				2913	the result vector, which element of the two input registers the result element
				2914	gets. The element selector may be undef (meaning "don't care") and the second
				2915	operand may be undef if performing a shuffle from only one vector.
				2916	</p>
				2917
				2918	<h5>Example:</h5>
				2919
				2920	<pre>
				2921	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
				2922	<4 x i32> <i32 0, i32 4, i32 1, i32 5> <i>; yields <4 x i32></i>
				2923	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				2924	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> - Identity shuffle.
				2925	</pre>
				2926	</div>
				2927
				2928
				2929	<!-- ======================================================================= -->
				2930	<div class="doc_subsection">
Dan Gohman	74d6faf	2008-05-12 23:51:09 +0000	[diff] [blame]	2931	<a name="aggregateops">Aggregate Operations</a>
				2932	</div>
				2933
				2934	<div class="doc_text">
				2935
				2936	<p>LLVM supports several instructions for working with aggregate values.
				2937	</p>
				2938
				2939	</div>
				2940
				2941	<!-- _______________________________________________________________________ -->
				2942	<div class="doc_subsubsection">
				2943	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				2944	</div>
				2945
				2946	<div class="doc_text">
				2947
				2948	<h5>Syntax:</h5>
				2949
				2950	<pre>
				2951	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				2952	</pre>
				2953
				2954	<h5>Overview:</h5>
				2955
				2956	<p>
Dan Gohman	6c6dea0	2008-05-13 18:16:06 +0000	[diff] [blame]	2957	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				2958	or array element from an aggregate value.
Dan Gohman	74d6faf	2008-05-12 23:51:09 +0000	[diff] [blame]	2959	</p>
				2960
				2961
				2962	<h5>Arguments:</h5>
				2963
				2964	<p>
				2965	The first operand of an '<tt>extractvalue</tt>' instruction is a
				2966	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohman	6c6dea0	2008-05-13 18:16:06 +0000	[diff] [blame]	2967	type. The operands are constant indices to specify which value to extract
Dan Gohman	e5febe4	2008-05-31 00:58:22 +0000	[diff] [blame]	2968	in a similar manner as indices in a
Dan Gohman	74d6faf	2008-05-12 23:51:09 +0000	[diff] [blame]	2969	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2970	</p>
				2971
				2972	<h5>Semantics:</h5>
				2973
				2974	<p>
				2975	The result is the value at the position in the aggregate specified by
				2976	the index operands.
				2977	</p>
				2978
				2979	<h5>Example:</h5>
				2980
				2981	<pre>
Dan Gohman	e5febe4	2008-05-31 00:58:22 +0000	[diff] [blame]	2982	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	74d6faf	2008-05-12 23:51:09 +0000	[diff] [blame]	2983	</pre>
				2984	</div>
				2985
				2986
				2987	<!-- _______________________________________________________________________ -->
				2988	<div class="doc_subsubsection">
				2989	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				2990	</div>
				2991
				2992	<div class="doc_text">
				2993
				2994	<h5>Syntax:</h5>
				2995
				2996	<pre>
Dan Gohman	e5febe4	2008-05-31 00:58:22 +0000	[diff] [blame]	2997	<result> = insertvalue <aggregate type> <val>, <ty> <val>, <idx> <i>; yields <n x <ty>></i>
Dan Gohman	74d6faf	2008-05-12 23:51:09 +0000	[diff] [blame]	2998	</pre>
				2999
				3000	<h5>Overview:</h5>
				3001
				3002	<p>
				3003	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	6c6dea0	2008-05-13 18:16:06 +0000	[diff] [blame]	3004	into a struct field or array element in an aggregate.
Dan Gohman	74d6faf	2008-05-12 23:51:09 +0000	[diff] [blame]	3005	</p>
				3006
				3007
				3008	<h5>Arguments:</h5>
				3009
				3010	<p>
				3011	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3012	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3013	The second operand is a first-class value to insert.
Dan Gohman	4f29e42	2008-05-23 21:53:15 +0000	[diff] [blame]	3014	The following operands are constant indices
Dan Gohman	e5febe4	2008-05-31 00:58:22 +0000	[diff] [blame]	3015	indicating the position at which to insert the value in a similar manner as
Dan Gohman	6c6dea0	2008-05-13 18:16:06 +0000	[diff] [blame]	3016	indices in a
Dan Gohman	74d6faf	2008-05-12 23:51:09 +0000	[diff] [blame]	3017	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3018	The value to insert must have the same type as the value identified
Dan Gohman	6c6dea0	2008-05-13 18:16:06 +0000	[diff] [blame]	3019	by the indices.
Dan Gohman	74d6faf	2008-05-12 23:51:09 +0000	[diff] [blame]	3020
				3021	<h5>Semantics:</h5>
				3022
				3023	<p>
				3024	The result is an aggregate of the same type as <tt>val</tt>. Its
				3025	value is that of <tt>val</tt> except that the value at the position
Dan Gohman	6c6dea0	2008-05-13 18:16:06 +0000	[diff] [blame]	3026	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	74d6faf	2008-05-12 23:51:09 +0000	[diff] [blame]	3027	</p>
				3028
				3029	<h5>Example:</h5>
				3030
				3031	<pre>
Dan Gohman	b1aab4e	2008-06-23 15:26:37 +0000	[diff] [blame]	3032	%result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohman	74d6faf	2008-05-12 23:51:09 +0000	[diff] [blame]	3033	</pre>
				3034	</div>
				3035
				3036
				3037	<!-- ======================================================================= -->
				3038	<div class="doc_subsection">
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3039	<a name="memoryops">Memory Access and Addressing Operations</a>
				3040	</div>
				3041
				3042	<div class="doc_text">
				3043
				3044	<p>A key design point of an SSA-based representation is how it
				3045	represents memory. In LLVM, no memory locations are in SSA form, which
				3046	makes things very simple. This section describes how to read, write,
				3047	allocate, and free memory in LLVM.</p>
				3048
				3049	</div>
				3050
				3051	<!-- _______________________________________________________________________ -->
				3052	<div class="doc_subsubsection">
				3053	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3054	</div>
				3055
				3056	<div class="doc_text">
				3057
				3058	<h5>Syntax:</h5>
				3059
				3060	<pre>
				3061	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
				3062	</pre>
				3063
				3064	<h5>Overview:</h5>
				3065
				3066	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	cfe0096	2007-12-17 01:00:21 +0000	[diff] [blame]	3067	heap and returns a pointer to it. The object is always allocated in the generic
				3068	address space (address space zero).</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3069
				3070	<h5>Arguments:</h5>
				3071
				3072	<p>The '<tt>malloc</tt>' instruction allocates
				3073	<tt>sizeof(<type>)*NumElements</tt>
				3074	bytes of memory from the operating system and returns a pointer of the
				3075	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	5082cf4	2008-02-09 22:24:34 +0000	[diff] [blame]	3076	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	10368b6	2008-04-02 00:38:26 +0000	[diff] [blame]	3077	If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif	5082cf4	2008-02-09 22:24:34 +0000	[diff] [blame]	3078	be aligned to at least that boundary. If not specified, or if zero, the target can
				3079	choose to align the allocation on any convenient boundary.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3080
				3081	<p>'<tt>type</tt>' must be a sized type.</p>
				3082
				3083	<h5>Semantics:</h5>
				3084
				3085	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner	8b094fc	2008-04-19 21:01:16 +0000	[diff] [blame]	3086	a pointer is returned. The result of a zero byte allocattion is undefined. The
				3087	result is null if there is insufficient memory available.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3088
				3089	<h5>Example:</h5>
				3090
				3091	<pre>
				3092	%array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
				3093
				3094	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3095	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3096	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3097	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3098	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
				3099	</pre>
				3100	</div>
				3101
				3102	<!-- _______________________________________________________________________ -->
				3103	<div class="doc_subsubsection">
				3104	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3105	</div>
				3106
				3107	<div class="doc_text">
				3108
				3109	<h5>Syntax:</h5>
				3110
				3111	<pre>
				3112	free <type> <value> <i>; yields {void}</i>
				3113	</pre>
				3114
				3115	<h5>Overview:</h5>
				3116
				3117	<p>The '<tt>free</tt>' instruction returns memory back to the unused
				3118	memory heap to be reallocated in the future.</p>
				3119
				3120	<h5>Arguments:</h5>
				3121
				3122	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3123	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3124	instruction.</p>
				3125
				3126	<h5>Semantics:</h5>
				3127
				3128	<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner	329d653	2008-04-19 22:41:32 +0000	[diff] [blame]	3129	after this instruction executes. If the pointer is null, the operation
				3130	is a noop.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3131
				3132	<h5>Example:</h5>
				3133
				3134	<pre>
				3135	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
				3136	free [4 x i8]* %array
				3137	</pre>
				3138	</div>
				3139
				3140	<!-- _______________________________________________________________________ -->
				3141	<div class="doc_subsubsection">
				3142	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3143	</div>
				3144
				3145	<div class="doc_text">
				3146
				3147	<h5>Syntax:</h5>
				3148
				3149	<pre>
				3150	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
				3151	</pre>
				3152
				3153	<h5>Overview:</h5>
				3154
				3155	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3156	currently executing function, to be automatically released when this function
Christopher Lamb	cfe0096	2007-12-17 01:00:21 +0000	[diff] [blame]	3157	returns to its caller. The object is always allocated in the generic address
				3158	space (address space zero).</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3159
				3160	<h5>Arguments:</h5>
				3161
				3162	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
				3163	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	5082cf4	2008-02-09 22:24:34 +0000	[diff] [blame]	3164	appropriate type to the program. If "NumElements" is specified, it is the
				3165	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	10368b6	2008-04-02 00:38:26 +0000	[diff] [blame]	3166	If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif	5082cf4	2008-02-09 22:24:34 +0000	[diff] [blame]	3167	to be aligned to at least that boundary. If not specified, or if zero, the target
				3168	can choose to align the allocation on any convenient boundary.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3169
				3170	<p>'<tt>type</tt>' may be any sized type.</p>
				3171
				3172	<h5>Semantics:</h5>
				3173
Chris Lattner	8b094fc	2008-04-19 21:01:16 +0000	[diff] [blame]	3174	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3175	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3176	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3177	instruction is commonly used to represent automatic variables that must
				3178	have an address available. When the function returns (either with the <tt><a
				3179	href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Chris Lattner	10368b6	2008-04-02 00:38:26 +0000	[diff] [blame]	3180	instructions), the memory is reclaimed. Allocating zero bytes
				3181	is legal, but the result is undefined.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3182
				3183	<h5>Example:</h5>
				3184
				3185	<pre>
				3186	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
				3187	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3188	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
				3189	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
				3190	</pre>
				3191	</div>
				3192
				3193	<!-- _______________________________________________________________________ -->
				3194	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3195	Instruction</a> </div>
				3196	<div class="doc_text">
				3197	<h5>Syntax:</h5>
				3198	<pre> <result> = load <ty>* <pointer>[, align <alignment>]<br> <result> = volatile load <ty>* <pointer>[, align <alignment>]<br></pre>
				3199	<h5>Overview:</h5>
				3200	<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
				3201	<h5>Arguments:</h5>
				3202	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
				3203	address from which to load. The pointer must point to a <a
				3204	href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
				3205	marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
				3206	the number or order of execution of this <tt>load</tt> with other
				3207	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3208	instructions. </p>
Chris Lattner	21003c8	2008-01-06 21:04:43 +0000	[diff] [blame]	3209	<p>
Chris Lattner	10368b6	2008-04-02 00:38:26 +0000	[diff] [blame]	3210	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	21003c8	2008-01-06 21:04:43 +0000	[diff] [blame]	3211	(that is, the alignment of the memory address). A value of 0 or an
				3212	omitted "align" argument means that the operation has the preferential
				3213	alignment for the target. It is the responsibility of the code emitter
				3214	to ensure that the alignment information is correct. Overestimating
				3215	the alignment results in an undefined behavior. Underestimating the
				3216	alignment may produce less efficient code. An alignment of 1 is always
				3217	safe.
				3218	</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3219	<h5>Semantics:</h5>
				3220	<p>The location of memory pointed to is loaded.</p>
				3221	<h5>Examples:</h5>
				3222	<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
				3223	<a
				3224	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3225	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
				3226	</pre>
				3227	</div>
				3228	<!-- _______________________________________________________________________ -->
				3229	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3230	Instruction</a> </div>
				3231	<div class="doc_text">
				3232	<h5>Syntax:</h5>
				3233	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3234	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3235	</pre>
				3236	<h5>Overview:</h5>
				3237	<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
				3238	<h5>Arguments:</h5>
				3239	<p>There are two arguments to the '<tt>store</tt>' instruction: a value
				3240	to store and an address at which to store it. The type of the '<tt><pointer></tt>'
Chris Lattner	10368b6	2008-04-02 00:38:26 +0000	[diff] [blame]	3241	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3242	of the '<tt><value></tt>'
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3243	operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
				3244	optimizer is not allowed to modify the number or order of execution of
				3245	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3246	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	21003c8	2008-01-06 21:04:43 +0000	[diff] [blame]	3247	<p>
Chris Lattner	10368b6	2008-04-02 00:38:26 +0000	[diff] [blame]	3248	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	21003c8	2008-01-06 21:04:43 +0000	[diff] [blame]	3249	(that is, the alignment of the memory address). A value of 0 or an
				3250	omitted "align" argument means that the operation has the preferential
				3251	alignment for the target. It is the responsibility of the code emitter
				3252	to ensure that the alignment information is correct. Overestimating
				3253	the alignment results in an undefined behavior. Underestimating the
				3254	alignment may produce less efficient code. An alignment of 1 is always
				3255	safe.
				3256	</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3257	<h5>Semantics:</h5>
				3258	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3259	at the location specified by the '<tt><pointer></tt>' operand.</p>
				3260	<h5>Example:</h5>
				3261	<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	63ffa14	2007-10-22 05:10:05 +0000	[diff] [blame]	3262	store i32 3, i32* %ptr <i>; yields {void}</i>
				3263	%val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3264	</pre>
				3265	</div>
				3266
				3267	<!-- _______________________________________________________________________ -->
				3268	<div class="doc_subsubsection">
				3269	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3270	</div>
				3271
				3272	<div class="doc_text">
				3273	<h5>Syntax:</h5>
				3274	<pre>
				3275	<result> = getelementptr <ty>* <ptrval>{, <ty> <idx>}*
				3276	</pre>
				3277
				3278	<h5>Overview:</h5>
				3279
				3280	<p>
				3281	The '<tt>getelementptr</tt>' instruction is used to get the address of a
				3282	subelement of an aggregate data structure.</p>
				3283
				3284	<h5>Arguments:</h5>
				3285
				3286	<p>This instruction takes a list of integer operands that indicate what
				3287	elements of the aggregate object to index to. The actual types of the arguments
				3288	provided depend on the type of the first pointer argument. The
				3289	'<tt>getelementptr</tt>' instruction is used to index down through the type
				3290	levels of a structure or to a specific index in an array. When indexing into a
				3291	structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner	a7d94ba	2008-04-24 05:59:56 +0000	[diff] [blame]	3292	into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
				3293	values will be sign extended to 64-bits if required.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3294
				3295	<p>For example, let's consider a C code fragment and how it gets
				3296	compiled to LLVM:</p>
				3297
				3298	<div class="doc_code">
				3299	<pre>
				3300	struct RT {
				3301	char A;
				3302	int B[10][20];
				3303	char C;
				3304	};
				3305	struct ST {
				3306	int X;
				3307	double Y;
				3308	struct RT Z;
				3309	};
				3310
				3311	int foo(struct ST s) {
				3312	return &s[1].Z.B[5][13];
				3313	}
				3314	</pre>
				3315	</div>
				3316
				3317	<p>The LLVM code generated by the GCC frontend is:</p>
				3318
				3319	<div class="doc_code">
				3320	<pre>
				3321	%RT = type { i8 , [10 x [20 x i32]], i8 }
				3322	%ST = type { i32, double, %RT }
				3323
				3324	define i32* %foo(%ST* %s) {
				3325	entry:
				3326	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3327	ret i32* %reg
				3328	}
				3329	</pre>
				3330	</div>
				3331
				3332	<h5>Semantics:</h5>
				3333
				3334	<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
				3335	on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
				3336	and <a href="#t_array">array</a> types can use a 32-bit or 64-bit
				3337	<a href="#t_integer">integer</a> type but the value will always be sign extended
Chris Lattner	10368b6	2008-04-02 00:38:26 +0000	[diff] [blame]	3338	to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
				3339	structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3340
				3341	<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
				3342	type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
				3343	}</tt>' type, a structure. The second index indexes into the third element of
				3344	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3345	i8 }</tt>' type, another structure. The third index indexes into the second
				3346	element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
				3347	array. The two dimensions of the array are subscripted into, yielding an
				3348	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3349	to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
				3350
				3351	<p>Note that it is perfectly legal to index partially through a
				3352	structure, returning a pointer to an inner element. Because of this,
				3353	the LLVM code for the given testcase is equivalent to:</p>
				3354
				3355	<pre>
				3356	define i32* %foo(%ST* %s) {
				3357	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
				3358	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3359	%t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
				3360	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3361	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3362	ret i32* %t5
				3363	}
				3364	</pre>
				3365
				3366	<p>Note that it is undefined to access an array out of bounds: array and
				3367	pointer indexes must always be within the defined bounds of the array type.
Chris Lattner	a7d94ba	2008-04-24 05:59:56 +0000	[diff] [blame]	3368	The one exception for this rule is zero length arrays. These arrays are
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3369	defined to be accessible as variable length arrays, which requires access
				3370	beyond the zero'th element.</p>
				3371
				3372	<p>The getelementptr instruction is often confusing. For some more insight
				3373	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3374	FAQ</a>.</p>
				3375
				3376	<h5>Example:</h5>
				3377
				3378	<pre>
				3379	<i>; yields [12 x i8]*:aptr</i>
				3380	%aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
				3381	</pre>
				3382	</div>
				3383
				3384	<!-- ======================================================================= -->
				3385	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
				3386	</div>
				3387	<div class="doc_text">
				3388	<p>The instructions in this category are the conversion instructions (casting)
				3389	which all take a single operand and a type. They perform various bit conversions
				3390	on the operand.</p>
				3391	</div>
				3392
				3393	<!-- _______________________________________________________________________ -->
				3394	<div class="doc_subsubsection">
				3395	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3396	</div>
				3397	<div class="doc_text">
				3398
				3399	<h5>Syntax:</h5>
				3400	<pre>
				3401	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3402	</pre>
				3403
				3404	<h5>Overview:</h5>
				3405	<p>
				3406	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3407	</p>
				3408
				3409	<h5>Arguments:</h5>
				3410	<p>
				3411	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3412	be an <a href="#t_integer">integer</a> type, and a type that specifies the size
				3413	and type of the result, which must be an <a href="#t_integer">integer</a>
				3414	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3415	<tt>ty2</tt>. Equal sized types are not allowed.</p>
				3416
				3417	<h5>Semantics:</h5>
				3418	<p>
				3419	The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
				3420	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3421	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3422	It will always truncate bits.</p>
				3423
				3424	<h5>Example:</h5>
				3425	<pre>
				3426	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
				3427	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3428	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
				3429	</pre>
				3430	</div>
				3431
				3432	<!-- _______________________________________________________________________ -->
				3433	<div class="doc_subsubsection">
				3434	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3435	</div>
				3436	<div class="doc_text">
				3437
				3438	<h5>Syntax:</h5>
				3439	<pre>
				3440	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3441	</pre>
				3442
				3443	<h5>Overview:</h5>
				3444	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3445	<tt>ty2</tt>.</p>
				3446
				3447
				3448	<h5>Arguments:</h5>
				3449	<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
				3450	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3451	also be of <a href="#t_integer">integer</a> type. The bit size of the
				3452	<tt>value</tt> must be smaller than the bit size of the destination type,
				3453	<tt>ty2</tt>.</p>
				3454
				3455	<h5>Semantics:</h5>
				3456	<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
				3457	bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
				3458
				3459	<p>When zero extending from i1, the result will always be either 0 or 1.</p>
				3460
				3461	<h5>Example:</h5>
				3462	<pre>
				3463	%X = zext i32 257 to i64 <i>; yields i64:257</i>
				3464	%Y = zext i1 true to i32 <i>; yields i32:1</i>
				3465	</pre>
				3466	</div>
				3467
				3468	<!-- _______________________________________________________________________ -->
				3469	<div class="doc_subsubsection">
				3470	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3471	</div>
				3472	<div class="doc_text">
				3473
				3474	<h5>Syntax:</h5>
				3475	<pre>
				3476	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3477	</pre>
				3478
				3479	<h5>Overview:</h5>
				3480	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3481
				3482	<h5>Arguments:</h5>
				3483	<p>
				3484	The '<tt>sext</tt>' instruction takes a value to cast, which must be of
				3485	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3486	also be of <a href="#t_integer">integer</a> type. The bit size of the
				3487	<tt>value</tt> must be smaller than the bit size of the destination type,
				3488	<tt>ty2</tt>.</p>
				3489
				3490	<h5>Semantics:</h5>
				3491	<p>
				3492	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3493	bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
				3494	the type <tt>ty2</tt>.</p>
				3495
				3496	<p>When sign extending from i1, the extension always results in -1 or 0.</p>
				3497
				3498	<h5>Example:</h5>
				3499	<pre>
				3500	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
				3501	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
				3502	</pre>
				3503	</div>
				3504
				3505	<!-- _______________________________________________________________________ -->
				3506	<div class="doc_subsubsection">
				3507	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3508	</div>
				3509
				3510	<div class="doc_text">
				3511
				3512	<h5>Syntax:</h5>
				3513
				3514	<pre>
				3515	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3516	</pre>
				3517
				3518	<h5>Overview:</h5>
				3519	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3520	<tt>ty2</tt>.</p>
				3521
				3522
				3523	<h5>Arguments:</h5>
				3524	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3525	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3526	cast it to. The size of <tt>value</tt> must be larger than the size of
				3527	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3528	<i>no-op cast</i>.</p>
				3529
				3530	<h5>Semantics:</h5>
				3531	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3532	<a href="#t_floating">floating point</a> type to a smaller
				3533	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3534	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
				3535
				3536	<h5>Example:</h5>
				3537	<pre>
				3538	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3539	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3540	</pre>
				3541	</div>
				3542
				3543	<!-- _______________________________________________________________________ -->
				3544	<div class="doc_subsubsection">
				3545	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3546	</div>
				3547	<div class="doc_text">
				3548
				3549	<h5>Syntax:</h5>
				3550	<pre>
				3551	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3552	</pre>
				3553
				3554	<h5>Overview:</h5>
				3555	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3556	floating point value.</p>
				3557
				3558	<h5>Arguments:</h5>
				3559	<p>The '<tt>fpext</tt>' instruction takes a
				3560	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
				3561	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3562	type must be smaller than the destination type.</p>
				3563
				3564	<h5>Semantics:</h5>
				3565	<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
				3566	<a href="#t_floating">floating point</a> type to a larger
				3567	<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
				3568	used to make a <i>no-op cast</i> because it always changes bits. Use
				3569	<tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
				3570
				3571	<h5>Example:</h5>
				3572	<pre>
				3573	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3574	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3575	</pre>
				3576	</div>
				3577
				3578	<!-- _______________________________________________________________________ -->
				3579	<div class="doc_subsubsection">
				3580	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
				3581	</div>
				3582	<div class="doc_text">
				3583
				3584	<h5>Syntax:</h5>
				3585	<pre>
Reid Spencer	e6adee8	2007-07-31 14:40:14 +0000	[diff] [blame]	3586	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3587	</pre>
				3588
				3589	<h5>Overview:</h5>
Reid Spencer	e6adee8	2007-07-31 14:40:14 +0000	[diff] [blame]	3590	<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3591	unsigned integer equivalent of type <tt>ty2</tt>.
				3592	</p>
				3593
				3594	<h5>Arguments:</h5>
Reid Spencer	e6adee8	2007-07-31 14:40:14 +0000	[diff] [blame]	3595	<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begeman	78246ca	2007-11-17 03:58:34 +0000	[diff] [blame]	3596	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3597	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3598	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3599	vector integer type with the same number of elements as <tt>ty</tt></p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3600
				3601	<h5>Semantics:</h5>
Reid Spencer	e6adee8	2007-07-31 14:40:14 +0000	[diff] [blame]	3602	<p> The '<tt>fptoui</tt>' instruction converts its
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3603	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3604	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3605	the results are undefined.</p>
				3606
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3607	<h5>Example:</h5>
				3608	<pre>
Reid Spencer	e6adee8	2007-07-31 14:40:14 +0000	[diff] [blame]	3609	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	681f1e8	2007-09-22 03:17:52 +0000	[diff] [blame]	3610	%Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer	e6adee8	2007-07-31 14:40:14 +0000	[diff] [blame]	3611	%X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3612	</pre>
				3613	</div>
				3614
				3615	<!-- _______________________________________________________________________ -->
				3616	<div class="doc_subsubsection">
				3617	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
				3618	</div>
				3619	<div class="doc_text">
				3620
				3621	<h5>Syntax:</h5>
				3622	<pre>
				3623	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
				3624	</pre>
				3625
				3626	<h5>Overview:</h5>
				3627	<p>The '<tt>fptosi</tt>' instruction converts
				3628	<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
				3629	</p>
				3630
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3631	<h5>Arguments:</h5>
				3632	<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begeman	78246ca	2007-11-17 03:58:34 +0000	[diff] [blame]	3633	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3634	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3635	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3636	vector integer type with the same number of elements as <tt>ty</tt></p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3637
				3638	<h5>Semantics:</h5>
				3639	<p>The '<tt>fptosi</tt>' instruction converts its
				3640	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3641	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3642	the results are undefined.</p>
				3643
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3644	<h5>Example:</h5>
				3645	<pre>
				3646	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	681f1e8	2007-09-22 03:17:52 +0000	[diff] [blame]	3647	%Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3648	%X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
				3649	</pre>
				3650	</div>
				3651
				3652	<!-- _______________________________________________________________________ -->
				3653	<div class="doc_subsubsection">
				3654	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
				3655	</div>
				3656	<div class="doc_text">
				3657
				3658	<h5>Syntax:</h5>
				3659	<pre>
				3660	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
				3661	</pre>
				3662
				3663	<h5>Overview:</h5>
				3664	<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
				3665	integer and converts that value to the <tt>ty2</tt> type.</p>
				3666
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3667	<h5>Arguments:</h5>
Nate Begeman	78246ca	2007-11-17 03:58:34 +0000	[diff] [blame]	3668	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3669	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3670	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3671	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3672	floating point type with the same number of elements as <tt>ty</tt></p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3673
				3674	<h5>Semantics:</h5>
				3675	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
				3676	integer quantity and converts it to the corresponding floating point value. If
				3677	the value cannot fit in the floating point value, the results are undefined.</p>
				3678
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3679	<h5>Example:</h5>
				3680	<pre>
				3681	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
				3682	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
				3683	</pre>
				3684	</div>
				3685
				3686	<!-- _______________________________________________________________________ -->
				3687	<div class="doc_subsubsection">
				3688	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
				3689	</div>
				3690	<div class="doc_text">
				3691
				3692	<h5>Syntax:</h5>
				3693	<pre>
				3694	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
				3695	</pre>
				3696
				3697	<h5>Overview:</h5>
				3698	<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
				3699	integer and converts that value to the <tt>ty2</tt> type.</p>
				3700
				3701	<h5>Arguments:</h5>
Nate Begeman	78246ca	2007-11-17 03:58:34 +0000	[diff] [blame]	3702	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3703	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3704	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3705	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3706	floating point type with the same number of elements as <tt>ty</tt></p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3707
				3708	<h5>Semantics:</h5>
				3709	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
				3710	integer quantity and converts it to the corresponding floating point value. If
				3711	the value cannot fit in the floating point value, the results are undefined.</p>
				3712
				3713	<h5>Example:</h5>
				3714	<pre>
				3715	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
				3716	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
				3717	</pre>
				3718	</div>
				3719
				3720	<!-- _______________________________________________________________________ -->
				3721	<div class="doc_subsubsection">
				3722	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				3723	</div>
				3724	<div class="doc_text">
				3725
				3726	<h5>Syntax:</h5>
				3727	<pre>
				3728	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				3729	</pre>
				3730
				3731	<h5>Overview:</h5>
				3732	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				3733	the integer type <tt>ty2</tt>.</p>
				3734
				3735	<h5>Arguments:</h5>
				3736	<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
				3737	must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
				3738	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
				3739
				3740	<h5>Semantics:</h5>
				3741	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				3742	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				3743	truncating or zero extending that value to the size of the integer type. If
				3744	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				3745	<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
				3746	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				3747	change.</p>
				3748
				3749	<h5>Example:</h5>
				3750	<pre>
				3751	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				3752	%Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
				3753	</pre>
				3754	</div>
				3755
				3756	<!-- _______________________________________________________________________ -->
				3757	<div class="doc_subsubsection">
				3758	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				3759	</div>
				3760	<div class="doc_text">
				3761
				3762	<h5>Syntax:</h5>
				3763	<pre>
				3764	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				3765	</pre>
				3766
				3767	<h5>Overview:</h5>
				3768	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				3769	a pointer type, <tt>ty2</tt>.</p>
				3770
				3771	<h5>Arguments:</h5>
				3772	<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
				3773	value to cast, and a type to cast it to, which must be a
				3774	<a href="#t_pointer">pointer</a> type.
				3775
				3776	<h5>Semantics:</h5>
				3777	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				3778	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				3779	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				3780	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				3781	the size of a pointer then a zero extension is done. If they are the same size,
				3782	nothing is done (<i>no-op cast</i>).</p>
				3783
				3784	<h5>Example:</h5>
				3785	<pre>
				3786	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				3787	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				3788	%Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
				3789	</pre>
				3790	</div>
				3791
				3792	<!-- _______________________________________________________________________ -->
				3793	<div class="doc_subsubsection">
				3794	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
				3795	</div>
				3796	<div class="doc_text">
				3797
				3798	<h5>Syntax:</h5>
				3799	<pre>
				3800	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
				3801	</pre>
				3802
				3803	<h5>Overview:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	3804
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3805	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
				3806	<tt>ty2</tt> without changing any bits.</p>
				3807
				3808	<h5>Arguments:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	3809
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3810	<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
				3811	a first class value, and a type to cast it to, which must also be a <a
				3812	href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
				3813	and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	3814	type is a pointer, the destination type must also be a pointer. This
				3815	instruction supports bitwise conversion of vectors to integers and to vectors
				3816	of other types (as long as they have the same size).</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3817
				3818	<h5>Semantics:</h5>
				3819	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
				3820	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				3821	this conversion. The conversion is done as if the <tt>value</tt> had been
				3822	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				3823	converted to other pointer types with this instruction. To convert pointers to
				3824	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				3825	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
				3826
				3827	<h5>Example:</h5>
				3828	<pre>
				3829	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
				3830	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
				3831	%Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
				3832	</pre>
				3833	</div>
				3834
				3835	<!-- ======================================================================= -->
				3836	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				3837	<div class="doc_text">
				3838	<p>The instructions in this category are the "miscellaneous"
				3839	instructions, which defy better classification.</p>
				3840	</div>
				3841
				3842	<!-- _______________________________________________________________________ -->
				3843	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				3844	</div>
				3845	<div class="doc_text">
				3846	<h5>Syntax:</h5>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3847	<pre> <result> = icmp <cond> <ty> <op1>, <op2> <i>; yields {i1}:result</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3848	</pre>
				3849	<h5>Overview:</h5>
				3850	<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
Chris Lattner	10368b6	2008-04-02 00:38:26 +0000	[diff] [blame]	3851	of its two integer or pointer operands.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3852	<h5>Arguments:</h5>
				3853	<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
				3854	the condition code indicating the kind of comparison to perform. It is not
				3855	a value, just a keyword. The possible condition code are:
				3856	<ol>
				3857	<li><tt>eq</tt>: equal</li>
				3858	<li><tt>ne</tt>: not equal </li>
				3859	<li><tt>ugt</tt>: unsigned greater than</li>
				3860	<li><tt>uge</tt>: unsigned greater or equal</li>
				3861	<li><tt>ult</tt>: unsigned less than</li>
				3862	<li><tt>ule</tt>: unsigned less or equal</li>
				3863	<li><tt>sgt</tt>: signed greater than</li>
				3864	<li><tt>sge</tt>: signed greater or equal</li>
				3865	<li><tt>slt</tt>: signed less than</li>
				3866	<li><tt>sle</tt>: signed less or equal</li>
				3867	</ol>
				3868	<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
				3869	<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
				3870	<h5>Semantics:</h5>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3871	<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3872	the condition code given as <tt>cond</tt>. The comparison performed always
				3873	yields a <a href="#t_primitive">i1</a> result, as follows:
				3874	<ol>
				3875	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				3876	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3877	</li>
				3878	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
				3879	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3880	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3881	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3882	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3883	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3884	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3885	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3886	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3887	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3888	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3889	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3890	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3891	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3892	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3893	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3894	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3895	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3896	</ol>
				3897	<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
				3898	values are compared as if they were integers.</p>
				3899
				3900	<h5>Example:</h5>
				3901	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				3902	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				3903	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				3904	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				3905	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				3906	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
				3907	</pre>
				3908	</div>
				3909
				3910	<!-- _______________________________________________________________________ -->
				3911	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				3912	</div>
				3913	<div class="doc_text">
				3914	<h5>Syntax:</h5>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3915	<pre> <result> = fcmp <cond> <ty> <op1>, <op2> <i>; yields {i1}:result</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3916	</pre>
				3917	<h5>Overview:</h5>
				3918	<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
				3919	of its floating point operands.</p>
				3920	<h5>Arguments:</h5>
				3921	<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
				3922	the condition code indicating the kind of comparison to perform. It is not
				3923	a value, just a keyword. The possible condition code are:
				3924	<ol>
				3925	<li><tt>false</tt>: no comparison, always returns false</li>
				3926	<li><tt>oeq</tt>: ordered and equal</li>
				3927	<li><tt>ogt</tt>: ordered and greater than </li>
				3928	<li><tt>oge</tt>: ordered and greater than or equal</li>
				3929	<li><tt>olt</tt>: ordered and less than </li>
				3930	<li><tt>ole</tt>: ordered and less than or equal</li>
				3931	<li><tt>one</tt>: ordered and not equal</li>
				3932	<li><tt>ord</tt>: ordered (no nans)</li>
				3933	<li><tt>ueq</tt>: unordered or equal</li>
				3934	<li><tt>ugt</tt>: unordered or greater than </li>
				3935	<li><tt>uge</tt>: unordered or greater than or equal</li>
				3936	<li><tt>ult</tt>: unordered or less than </li>
				3937	<li><tt>ule</tt>: unordered or less than or equal</li>
				3938	<li><tt>une</tt>: unordered or not equal</li>
				3939	<li><tt>uno</tt>: unordered (either nans)</li>
				3940	<li><tt>true</tt>: no comparison, always returns true</li>
				3941	</ol>
				3942	<p><i>Ordered</i> means that neither operand is a QNAN while
				3943	<i>unordered</i> means that either operand may be a QNAN.</p>
				3944	<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
				3945	<a href="#t_floating">floating point</a> typed. They must have identical
				3946	types.</p>
				3947	<h5>Semantics:</h5>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3948	<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	646fa48	2008-05-12 19:01:56 +0000	[diff] [blame]	3949	according to the condition code given as <tt>cond</tt>. The comparison performed
				3950	always yields a <a href="#t_primitive">i1</a> result, as follows:
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3951	<ol>
				3952	<li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
				3953	<li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3954	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3955	<li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3956	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3957	<li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3958	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3959	<li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3960	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3961	<li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3962	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3963	<li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3964	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3965	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				3966	<li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3967	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3968	<li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3969	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3970	<li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3971	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3972	<li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3973	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3974	<li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3975	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3976	<li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3977	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	3978	<li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
				3979	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				3980	</ol>
				3981
				3982	<h5>Example:</h5>
				3983	<pre> <result> = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
				3984	<result> = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
				3985	<result> = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				3986	<result> = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
				3987	</pre>
				3988	</div>
				3989
				3990	<!-- _______________________________________________________________________ -->
Nate Begeman	646fa48	2008-05-12 19:01:56 +0000	[diff] [blame]	3991	<div class="doc_subsubsection">
				3992	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				3993	</div>
				3994	<div class="doc_text">
				3995	<h5>Syntax:</h5>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	3996	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	646fa48	2008-05-12 19:01:56 +0000	[diff] [blame]	3997	</pre>
				3998	<h5>Overview:</h5>
				3999	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4000	element-wise comparison of its two integer vector operands.</p>
				4001	<h5>Arguments:</h5>
				4002	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4003	the condition code indicating the kind of comparison to perform. It is not
				4004	a value, just a keyword. The possible condition code are:
				4005	<ol>
				4006	<li><tt>eq</tt>: equal</li>
				4007	<li><tt>ne</tt>: not equal </li>
				4008	<li><tt>ugt</tt>: unsigned greater than</li>
				4009	<li><tt>uge</tt>: unsigned greater or equal</li>
				4010	<li><tt>ult</tt>: unsigned less than</li>
				4011	<li><tt>ule</tt>: unsigned less or equal</li>
				4012	<li><tt>sgt</tt>: signed greater than</li>
				4013	<li><tt>sge</tt>: signed greater or equal</li>
				4014	<li><tt>slt</tt>: signed less than</li>
				4015	<li><tt>sle</tt>: signed less or equal</li>
				4016	</ol>
				4017	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4018	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4019	<h5>Semantics:</h5>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	4020	<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	646fa48	2008-05-12 19:01:56 +0000	[diff] [blame]	4021	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4022	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4023	identical type as the values being compared. The most significant bit in each
				4024	element is 1 if the element-wise comparison evaluates to true, and is 0
				4025	otherwise. All other bits of the result are undefined. The condition codes
				4026	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
				4027	instruction</a>.
				4028
				4029	<h5>Example:</h5>
				4030	<pre>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	4031	<result> = vicmp eq <2 x i32> < i32 4, i32 0>, < i32 5, i32 0> <i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4032	<result> = vicmp ult <2 x i8 > < i8 1, i8 2>, < i8 2, i8 2 > <i>; yields: result=<2 x i8> < i8 -1, i8 0 ></i>
Nate Begeman	646fa48	2008-05-12 19:01:56 +0000	[diff] [blame]	4033	</pre>
				4034	</div>
				4035
				4036	<!-- _______________________________________________________________________ -->
				4037	<div class="doc_subsubsection">
				4038	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4039	</div>
				4040	<div class="doc_text">
				4041	<h5>Syntax:</h5>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	4042	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	646fa48	2008-05-12 19:01:56 +0000	[diff] [blame]	4043	<h5>Overview:</h5>
				4044	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4045	element-wise comparison of its two floating point vector operands. The output
				4046	elements have the same width as the input elements.</p>
				4047	<h5>Arguments:</h5>
				4048	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4049	the condition code indicating the kind of comparison to perform. It is not
				4050	a value, just a keyword. The possible condition code are:
				4051	<ol>
				4052	<li><tt>false</tt>: no comparison, always returns false</li>
				4053	<li><tt>oeq</tt>: ordered and equal</li>
				4054	<li><tt>ogt</tt>: ordered and greater than </li>
				4055	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4056	<li><tt>olt</tt>: ordered and less than </li>
				4057	<li><tt>ole</tt>: ordered and less than or equal</li>
				4058	<li><tt>one</tt>: ordered and not equal</li>
				4059	<li><tt>ord</tt>: ordered (no nans)</li>
				4060	<li><tt>ueq</tt>: unordered or equal</li>
				4061	<li><tt>ugt</tt>: unordered or greater than </li>
				4062	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4063	<li><tt>ult</tt>: unordered or less than </li>
				4064	<li><tt>ule</tt>: unordered or less than or equal</li>
				4065	<li><tt>une</tt>: unordered or not equal</li>
				4066	<li><tt>uno</tt>: unordered (either nans)</li>
				4067	<li><tt>true</tt>: no comparison, always returns true</li>
				4068	</ol>
				4069	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4070	<a href="#t_floating">floating point</a> typed. They must also be identical
				4071	types.</p>
				4072	<h5>Semantics:</h5>
Gabor Greif	d9068fe	2008-08-07 21:46:00 +0000	[diff] [blame]	4073	<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	646fa48	2008-05-12 19:01:56 +0000	[diff] [blame]	4074	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4075	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4076	an identical number of elements as the values being compared, and each element
				4077	having identical with to the width of the floating point elements. The most
				4078	significant bit in each element is 1 if the element-wise comparison evaluates to
				4079	true, and is 0 otherwise. All other bits of the result are undefined. The
				4080	condition codes are evaluated identically to the
				4081	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
				4082
				4083	<h5>Example:</h5>
				4084	<pre>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	4085	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 > <i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4086	<result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2> <i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
Nate Begeman	646fa48	2008-05-12 19:01:56 +0000	[diff] [blame]	4087	</pre>
				4088	</div>
				4089
				4090	<!-- _______________________________________________________________________ -->
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	4091	<div class="doc_subsubsection">
				4092	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4093	</div>
				4094
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4095	<div class="doc_text">
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	4096
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4097	<h5>Syntax:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	4098
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4099	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4100	<h5>Overview:</h5>
				4101	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4102	the SSA graph representing the function.</p>
				4103	<h5>Arguments:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	4104
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4105	<p>The type of the incoming values is specified with the first type
				4106	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4107	as arguments, with one pair for each predecessor basic block of the
				4108	current block. Only values of <a href="#t_firstclass">first class</a>
				4109	type may be used as the value arguments to the PHI node. Only labels
				4110	may be used as the label arguments.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	4111
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4112	<p>There must be no non-phi instructions between the start of a basic
				4113	block and the PHI instructions: i.e. PHI instructions must be first in
				4114	a basic block.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	4115
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4116	<h5>Semantics:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	4117
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4118	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4119	specified by the pair corresponding to the predecessor basic block that executed
				4120	just prior to the current block.</p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	4121
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4122	<h5>Example:</h5>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	4123	<pre>
				4124	Loop: ; Infinite loop that counts from 0 on up...
				4125	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4126	%nextindvar = add i32 %indvar, 1
				4127	br label %Loop
				4128	</pre>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4129	</div>
				4130
				4131	<!-- _______________________________________________________________________ -->
				4132	<div class="doc_subsubsection">
				4133	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4134	</div>
				4135
				4136	<div class="doc_text">
				4137
				4138	<h5>Syntax:</h5>
				4139
				4140	<pre>
				4141	<result> = select i1 <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4142	</pre>
				4143
				4144	<h5>Overview:</h5>
				4145
				4146	<p>
				4147	The '<tt>select</tt>' instruction is used to choose one value based on a
				4148	condition, without branching.
				4149	</p>
				4150
				4151
				4152	<h5>Arguments:</h5>
				4153
				4154	<p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	4155	The '<tt>select</tt>' instruction requires an 'i1' value indicating the
				4156	condition, and two values of the same <a href="#t_firstclass">first class</a>
				4157	type. If the val1/val2 are vectors, the entire vectors are selected, not
				4158	individual elements.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4159	</p>
				4160
				4161	<h5>Semantics:</h5>
				4162
				4163	<p>
Chris Lattner	6704c21	2008-05-20 20:48:21 +0000	[diff] [blame]	4164	If the i1 condition evaluates is 1, the instruction returns the first
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4165	value argument; otherwise, it returns the second value argument.
				4166	</p>
				4167
				4168	<h5>Example:</h5>
				4169
				4170	<pre>
				4171	%X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
				4172	</pre>
				4173	</div>
				4174
				4175
				4176	<!-- _______________________________________________________________________ -->
				4177	<div class="doc_subsubsection">
				4178	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4179	</div>
				4180
				4181	<div class="doc_text">
				4182
				4183	<h5>Syntax:</h5>
				4184	<pre>
Nick Lewycky	93082fc	2007-09-08 13:57:50 +0000	[diff] [blame]	4185	<result> = [tail] call [<a href="#callingconv">cconv</a>] <ty> [<fnty>*] <fnptrval>(<param list>)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4186	</pre>
				4187
				4188	<h5>Overview:</h5>
				4189
				4190	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
				4191
				4192	<h5>Arguments:</h5>
				4193
				4194	<p>This instruction requires several arguments:</p>
				4195
				4196	<ol>
				4197	<li>
				4198	<p>The optional "tail" marker indicates whether the callee function accesses
				4199	any allocas or varargs in the caller. If the "tail" marker is present, the
				4200	function call is eligible for tail call optimization. Note that calls may
				4201	be marked "tail" even if they do not occur before a <a
				4202	href="#i_ret"><tt>ret</tt></a> instruction.
				4203	</li>
				4204	<li>
				4205	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
				4206	convention</a> the call should use. If none is specified, the call defaults
				4207	to using C calling conventions.
				4208	</li>
				4209	<li>
Nick Lewycky	93082fc	2007-09-08 13:57:50 +0000	[diff] [blame]	4210	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4211	the type of the return value. Functions that return no value are marked
				4212	<tt><a href="#t_void">void</a></tt>.</p>
				4213	</li>
				4214	<li>
				4215	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4216	value being invoked. The argument types must match the types implied by
				4217	this signature. This type can be omitted if the function is not varargs
				4218	and if the function type does not return a pointer to a function.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4219	</li>
				4220	<li>
				4221	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4222	be invoked. In most cases, this is a direct function invocation, but
				4223	indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
				4224	to function value.</p>
				4225	</li>
				4226	<li>
				4227	<p>'<tt>function args</tt>': argument list whose types match the
				4228	function signature argument types. All arguments must be of
				4229	<a href="#t_firstclass">first class</a> type. If the function signature
				4230	indicates the function accepts a variable number of arguments, the extra
				4231	arguments can be specified.</p>
				4232	</li>
				4233	</ol>
				4234
				4235	<h5>Semantics:</h5>
				4236
				4237	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4238	transfer to a specified function, with its incoming arguments bound to
				4239	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4240	instruction in the called function, control flow continues with the
				4241	instruction after the function call, and the return value of the
Chris Lattner	5e893ef	2008-03-21 17:24:17 +0000	[diff] [blame]	4242	function is bound to the result argument. If the callee returns multiple
				4243	values then the return values of the function are only accessible through
				4244	the '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4245
				4246	<h5>Example:</h5>
				4247
				4248	<pre>
Nick Lewycky	93082fc	2007-09-08 13:57:50 +0000	[diff] [blame]	4249	%retval = call i32 @test(i32 %argc)
Chris Lattner	5e893ef	2008-03-21 17:24:17 +0000	[diff] [blame]	4250	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4251	%X = tail call i32 @foo() <i>; yields i32</i>
				4252	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4253	call void %foo(i8 97 signext)
Devang Patel	a3cc537	2008-03-10 20:49:15 +0000	[diff] [blame]	4254
				4255	%struct.A = type { i32, i8 }
Chris Lattner	5e893ef	2008-03-21 17:24:17 +0000	[diff] [blame]	4256	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
				4257	%gr = getresult %struct.A %r, 0 <i>; yields i32</i>
				4258	%gr1 = getresult %struct.A %r, 1 <i>; yields i8</i>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4259	</pre>
				4260
				4261	</div>
				4262
				4263	<!-- _______________________________________________________________________ -->
				4264	<div class="doc_subsubsection">
				4265	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
				4266	</div>
				4267
				4268	<div class="doc_text">
				4269
				4270	<h5>Syntax:</h5>
				4271
				4272	<pre>
				4273	<resultval> = va_arg <va_list*> <arglist>, <argty>
				4274	</pre>
				4275
				4276	<h5>Overview:</h5>
				4277
				4278	<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
				4279	the "variable argument" area of a function call. It is used to implement the
				4280	<tt>va_arg</tt> macro in C.</p>
				4281
				4282	<h5>Arguments:</h5>
				4283
				4284	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4285	the argument. It returns a value of the specified argument type and
				4286	increments the <tt>va_list</tt> to point to the next argument. The
				4287	actual type of <tt>va_list</tt> is target specific.</p>
				4288
				4289	<h5>Semantics:</h5>
				4290
				4291	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4292	type from the specified <tt>va_list</tt> and causes the
				4293	<tt>va_list</tt> to point to the next argument. For more information,
				4294	see the variable argument handling <a href="#int_varargs">Intrinsic
				4295	Functions</a>.</p>
				4296
				4297	<p>It is legal for this instruction to be called in a function which does not
				4298	take a variable number of arguments, for example, the <tt>vfprintf</tt>
				4299	function.</p>
				4300
				4301	<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
				4302	href="#intrinsics">intrinsic function</a> because it takes a type as an
				4303	argument.</p>
				4304
				4305	<h5>Example:</h5>
				4306
				4307	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4308
				4309	</div>
				4310
Devang Patel	a3cc537	2008-03-10 20:49:15 +0000	[diff] [blame]	4311	<!-- _______________________________________________________________________ -->
				4312	<div class="doc_subsubsection">
				4313	<a name="i_getresult">'<tt>getresult</tt>' Instruction</a>
				4314	</div>
				4315
				4316	<div class="doc_text">
				4317
				4318	<h5>Syntax:</h5>
				4319	<pre>
Chris Lattner	ee9da3f	2008-03-21 17:20:51 +0000	[diff] [blame]	4320	<resultval> = getresult <type> <retval>, <index>
Devang Patel	a3cc537	2008-03-10 20:49:15 +0000	[diff] [blame]	4321	</pre>
Chris Lattner	ee9da3f	2008-03-21 17:20:51 +0000	[diff] [blame]	4322
Devang Patel	a3cc537	2008-03-10 20:49:15 +0000	[diff] [blame]	4323	<h5>Overview:</h5>
				4324
				4325	<p> The '<tt>getresult</tt>' instruction is used to extract individual values
Chris Lattner	ee9da3f	2008-03-21 17:20:51 +0000	[diff] [blame]	4326	from a '<tt><a href="#i_call">call</a></tt>'
				4327	or '<tt><a href="#i_invoke">invoke</a></tt>' instruction that returns multiple
				4328	results.</p>
Devang Patel	a3cc537	2008-03-10 20:49:15 +0000	[diff] [blame]	4329
				4330	<h5>Arguments:</h5>
				4331
Chris Lattner	ee9da3f	2008-03-21 17:20:51 +0000	[diff] [blame]	4332	<p>The '<tt>getresult</tt>' instruction takes a call or invoke value as its
Chris Lattner	d8dd352	2008-04-23 04:06:52 +0000	[diff] [blame]	4333	first argument, or an undef value. The value must have <a
				4334	href="#t_struct">structure type</a>. The second argument is a constant
				4335	unsigned index value which must be in range for the number of values returned
				4336	by the call.</p>
Devang Patel	a3cc537	2008-03-10 20:49:15 +0000	[diff] [blame]	4337
				4338	<h5>Semantics:</h5>
				4339
Chris Lattner	ee9da3f	2008-03-21 17:20:51 +0000	[diff] [blame]	4340	<p>The '<tt>getresult</tt>' instruction extracts the element identified by
				4341	'<tt>index</tt>' from the aggregate value.</p>
Devang Patel	a3cc537	2008-03-10 20:49:15 +0000	[diff] [blame]	4342
				4343	<h5>Example:</h5>
				4344
				4345	<pre>
				4346	%struct.A = type { i32, i8 }
				4347
				4348	%r = call %struct.A @foo()
Chris Lattner	ee9da3f	2008-03-21 17:20:51 +0000	[diff] [blame]	4349	%gr = getresult %struct.A %r, 0 <i>; yields i32:%gr</i>
				4350	%gr1 = getresult %struct.A %r, 1 <i>; yields i8:%gr1</i>
Devang Patel	a3cc537	2008-03-10 20:49:15 +0000	[diff] [blame]	4351	add i32 %gr, 42
				4352	add i8 %gr1, 41
				4353	</pre>
				4354
				4355	</div>
				4356
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4357	<!-- *********************************************************************** -->
				4358	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4359	<!-- *********************************************************************** -->
				4360
				4361	<div class="doc_text">
				4362
				4363	<p>LLVM supports the notion of an "intrinsic function". These functions have
				4364	well known names and semantics and are required to follow certain restrictions.
				4365	Overall, these intrinsics represent an extension mechanism for the LLVM
				4366	language that does not require changing all of the transformations in LLVM when
				4367	adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
				4368
				4369	<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
				4370	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4371	begin with this prefix. Intrinsic functions must always be external functions:
				4372	you cannot define the body of intrinsic functions. Intrinsic functions may
				4373	only be used in call or invoke instructions: it is illegal to take the address
				4374	of an intrinsic function. Additionally, because intrinsic functions are part
				4375	of the LLVM language, it is required if any are added that they be documented
				4376	here.</p>
				4377
Chandler Carruth	a228e39	2007-08-04 01:51:18 +0000	[diff] [blame]	4378	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4379	a family of functions that perform the same operation but on different data
				4380	types. Because LLVM can represent over 8 million different integer types,
				4381	overloading is used commonly to allow an intrinsic function to operate on any
				4382	integer type. One or more of the argument types or the result type can be
				4383	overloaded to accept any integer type. Argument types may also be defined as
				4384	exactly matching a previous argument's type or the result type. This allows an
				4385	intrinsic function which accepts multiple arguments, but needs all of them to
				4386	be of the same type, to only be overloaded with respect to a single argument or
				4387	the result.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4388
Chandler Carruth	a228e39	2007-08-04 01:51:18 +0000	[diff] [blame]	4389	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4390	encoded into its function name, each preceded by a period. Only those types
				4391	which are overloaded result in a name suffix. Arguments whose type is matched
				4392	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4393	take an integer of any width and returns an integer of exactly the same integer
				4394	width. This leads to a family of functions such as
				4395	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4396	Only one type, the return type, is overloaded, and only one type suffix is
				4397	required. Because the argument's type is matched against the return type, it
				4398	does not require its own name suffix.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4399
				4400	<p>To learn how to add an intrinsic function, please see the
				4401	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
				4402	</p>
				4403
				4404	</div>
				4405
				4406	<!-- ======================================================================= -->
				4407	<div class="doc_subsection">
				4408	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4409	</div>
				4410
				4411	<div class="doc_text">
				4412
				4413	<p>Variable argument support is defined in LLVM with the <a
				4414	href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
				4415	intrinsic functions. These functions are related to the similarly
				4416	named macros defined in the <tt><stdarg.h></tt> header file.</p>
				4417
				4418	<p>All of these functions operate on arguments that use a
				4419	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4420	language reference manual does not define what this type is, so all
				4421	transformations should be prepared to handle these functions regardless of
				4422	the type used.</p>
				4423
				4424	<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
				4425	instruction and the variable argument handling intrinsic functions are
				4426	used.</p>
				4427
				4428	<div class="doc_code">
				4429	<pre>
				4430	define i32 @test(i32 %X, ...) {
				4431	; Initialize variable argument processing
				4432	%ap = alloca i8*
				4433	%ap2 = bitcast i8** %ap to i8*
				4434	call void @llvm.va_start(i8* %ap2)
				4435
				4436	; Read a single integer argument
				4437	%tmp = va_arg i8** %ap, i32
				4438
				4439	; Demonstrate usage of llvm.va_copy and llvm.va_end
				4440	%aq = alloca i8*
				4441	%aq2 = bitcast i8** %aq to i8*
				4442	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
				4443	call void @llvm.va_end(i8* %aq2)
				4444
				4445	; Stop processing of arguments.
				4446	call void @llvm.va_end(i8* %ap2)
				4447	ret i32 %tmp
				4448	}
				4449
				4450	declare void @llvm.va_start(i8*)
				4451	declare void @llvm.va_copy(i8, i8)
				4452	declare void @llvm.va_end(i8*)
				4453	</pre>
				4454	</div>
				4455
				4456	</div>
				4457
				4458	<!-- _______________________________________________________________________ -->
				4459	<div class="doc_subsubsection">
				4460	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
				4461	</div>
				4462
				4463
				4464	<div class="doc_text">
				4465	<h5>Syntax:</h5>
				4466	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
				4467	<h5>Overview:</h5>
				4468	<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
				4469	<tt>*<arglist></tt> for subsequent use by <tt><a
				4470	href="#i_va_arg">va_arg</a></tt>.</p>
				4471
				4472	<h5>Arguments:</h5>
				4473
				4474	<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
				4475
				4476	<h5>Semantics:</h5>
				4477
				4478	<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
				4479	macro available in C. In a target-dependent way, it initializes the
				4480	<tt>va_list</tt> element to which the argument points, so that the next call to
				4481	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4482	Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
				4483	last argument of the function as the compiler can figure that out.</p>
				4484
				4485	</div>
				4486
				4487	<!-- _______________________________________________________________________ -->
				4488	<div class="doc_subsubsection">
				4489	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
				4490	</div>
				4491
				4492	<div class="doc_text">
				4493	<h5>Syntax:</h5>
				4494	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
				4495	<h5>Overview:</h5>
				4496
				4497	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
				4498	which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
				4499	or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
				4500
				4501	<h5>Arguments:</h5>
				4502
				4503	<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
				4504
				4505	<h5>Semantics:</h5>
				4506
				4507	<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
				4508	macro available in C. In a target-dependent way, it destroys the
				4509	<tt>va_list</tt> element to which the argument points. Calls to <a
				4510	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4511	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4512	<tt>llvm.va_end</tt>.</p>
				4513
				4514	</div>
				4515
				4516	<!-- _______________________________________________________________________ -->
				4517	<div class="doc_subsubsection">
				4518	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
				4519	</div>
				4520
				4521	<div class="doc_text">
				4522
				4523	<h5>Syntax:</h5>
				4524
				4525	<pre>
				4526	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
				4527	</pre>
				4528
				4529	<h5>Overview:</h5>
				4530
				4531	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4532	from the source argument list to the destination argument list.</p>
				4533
				4534	<h5>Arguments:</h5>
				4535
				4536	<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
				4537	The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
				4538
				4539
				4540	<h5>Semantics:</h5>
				4541
				4542	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4543	macro available in C. In a target-dependent way, it copies the source
				4544	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4545	intrinsic is necessary because the <tt><a href="#int_va_start">
				4546	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4547	example, memory allocation.</p>
				4548
				4549	</div>
				4550
				4551	<!-- ======================================================================= -->
				4552	<div class="doc_subsection">
				4553	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4554	</div>
				4555
				4556	<div class="doc_text">
				4557
				4558	<p>
				4559	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	9645148	2008-08-05 18:29:16 +0000	[diff] [blame]	4560	Collection</a> (GC) requires the implementation and generation of these
				4561	intrinsics.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4562	These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
				4563	stack</a>, as well as garbage collector implementations that require <a
				4564	href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
				4565	Front-ends for type-safe garbage collected languages should generate these
				4566	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4567	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4568	</p>
Christopher Lamb	cfe0096	2007-12-17 01:00:21 +0000	[diff] [blame]	4569
				4570	<p>The garbage collection intrinsics only operate on objects in the generic
				4571	address space (address space zero).</p>
				4572
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4573	</div>
				4574
				4575	<!-- _______________________________________________________________________ -->
				4576	<div class="doc_subsubsection">
				4577	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
				4578	</div>
				4579
				4580	<div class="doc_text">
				4581
				4582	<h5>Syntax:</h5>
				4583
				4584	<pre>
Chris Lattner	38bd5dd	2007-09-21 17:30:40 +0000	[diff] [blame]	4585	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4586	</pre>
				4587
				4588	<h5>Overview:</h5>
				4589
				4590	<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
				4591	the code generator, and allows some metadata to be associated with it.</p>
				4592
				4593	<h5>Arguments:</h5>
				4594
				4595	<p>The first argument specifies the address of a stack object that contains the
				4596	root pointer. The second pointer (which must be either a constant or a global
				4597	value address) contains the meta-data to be associated with the root.</p>
				4598
				4599	<h5>Semantics:</h5>
				4600
Chris Lattner	a7d94ba	2008-04-24 05:59:56 +0000	[diff] [blame]	4601	<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4602	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	4039354	2007-12-25 02:31:26 +0000	[diff] [blame]	4603	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4604	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4605	algorithm</a>.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4606
				4607	</div>
				4608
				4609
				4610	<!-- _______________________________________________________________________ -->
				4611	<div class="doc_subsubsection">
				4612	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
				4613	</div>
				4614
				4615	<div class="doc_text">
				4616
				4617	<h5>Syntax:</h5>
				4618
				4619	<pre>
Chris Lattner	38bd5dd	2007-09-21 17:30:40 +0000	[diff] [blame]	4620	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4621	</pre>
				4622
				4623	<h5>Overview:</h5>
				4624
				4625	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4626	locations, allowing garbage collector implementations that require read
				4627	barriers.</p>
				4628
				4629	<h5>Arguments:</h5>
				4630
				4631	<p>The second argument is the address to read from, which should be an address
				4632	allocated from the garbage collector. The first object is a pointer to the
				4633	start of the referenced object, if needed by the language runtime (otherwise
				4634	null).</p>
				4635
				4636	<h5>Semantics:</h5>
				4637
				4638	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4639	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	4039354	2007-12-25 02:31:26 +0000	[diff] [blame]	4640	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4641	may only be used in a function which <a href="#gc">specifies a GC
				4642	algorithm</a>.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4643
				4644	</div>
				4645
				4646
				4647	<!-- _______________________________________________________________________ -->
				4648	<div class="doc_subsubsection">
				4649	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
				4650	</div>
				4651
				4652	<div class="doc_text">
				4653
				4654	<h5>Syntax:</h5>
				4655
				4656	<pre>
Chris Lattner	38bd5dd	2007-09-21 17:30:40 +0000	[diff] [blame]	4657	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4658	</pre>
				4659
				4660	<h5>Overview:</h5>
				4661
				4662	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4663	locations, allowing garbage collector implementations that require write
				4664	barriers (such as generational or reference counting collectors).</p>
				4665
				4666	<h5>Arguments:</h5>
				4667
				4668	<p>The first argument is the reference to store, the second is the start of the
				4669	object to store it to, and the third is the address of the field of Obj to
				4670	store to. If the runtime does not require a pointer to the object, Obj may be
				4671	null.</p>
				4672
				4673	<h5>Semantics:</h5>
				4674
				4675	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4676	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	4039354	2007-12-25 02:31:26 +0000	[diff] [blame]	4677	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4678	may only be used in a function which <a href="#gc">specifies a GC
				4679	algorithm</a>.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4680
				4681	</div>
				4682
				4683
				4684
				4685	<!-- ======================================================================= -->
				4686	<div class="doc_subsection">
				4687	<a name="int_codegen">Code Generator Intrinsics</a>
				4688	</div>
				4689
				4690	<div class="doc_text">
				4691	<p>
				4692	These intrinsics are provided by LLVM to expose special features that may only
				4693	be implemented with code generator support.
				4694	</p>
				4695
				4696	</div>
				4697
				4698	<!-- _______________________________________________________________________ -->
				4699	<div class="doc_subsubsection">
				4700	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
				4701	</div>
				4702
				4703	<div class="doc_text">
				4704
				4705	<h5>Syntax:</h5>
				4706	<pre>
				4707	declare i8 *@llvm.returnaddress(i32 <level>)
				4708	</pre>
				4709
				4710	<h5>Overview:</h5>
				4711
				4712	<p>
				4713	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				4714	target-specific value indicating the return address of the current function
				4715	or one of its callers.
				4716	</p>
				4717
				4718	<h5>Arguments:</h5>
				4719
				4720	<p>
				4721	The argument to this intrinsic indicates which function to return the address
				4722	for. Zero indicates the calling function, one indicates its caller, etc. The
				4723	argument is <b>required</b> to be a constant integer value.
				4724	</p>
				4725
				4726	<h5>Semantics:</h5>
				4727
				4728	<p>
				4729	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				4730	the return address of the specified call frame, or zero if it cannot be
				4731	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4732	for arguments other than zero, so it should only be used for debugging purposes.
				4733	</p>
				4734
				4735	<p>
				4736	Note that calling this intrinsic does not prevent function inlining or other
				4737	aggressive transformations, so the value returned may not be that of the obvious
				4738	source-language caller.
				4739	</p>
				4740	</div>
				4741
				4742
				4743	<!-- _______________________________________________________________________ -->
				4744	<div class="doc_subsubsection">
				4745	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
				4746	</div>
				4747
				4748	<div class="doc_text">
				4749
				4750	<h5>Syntax:</h5>
				4751	<pre>
Chris Lattner	38bd5dd	2007-09-21 17:30:40 +0000	[diff] [blame]	4752	declare i8 *@llvm.frameaddress(i32 <level>)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4753	</pre>
				4754
				4755	<h5>Overview:</h5>
				4756
				4757	<p>
				4758	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				4759	target-specific frame pointer value for the specified stack frame.
				4760	</p>
				4761
				4762	<h5>Arguments:</h5>
				4763
				4764	<p>
				4765	The argument to this intrinsic indicates which function to return the frame
				4766	pointer for. Zero indicates the calling function, one indicates its caller,
				4767	etc. The argument is <b>required</b> to be a constant integer value.
				4768	</p>
				4769
				4770	<h5>Semantics:</h5>
				4771
				4772	<p>
				4773	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				4774	the frame address of the specified call frame, or zero if it cannot be
				4775	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4776	for arguments other than zero, so it should only be used for debugging purposes.
				4777	</p>
				4778
				4779	<p>
				4780	Note that calling this intrinsic does not prevent function inlining or other
				4781	aggressive transformations, so the value returned may not be that of the obvious
				4782	source-language caller.
				4783	</p>
				4784	</div>
				4785
				4786	<!-- _______________________________________________________________________ -->
				4787	<div class="doc_subsubsection">
				4788	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
				4789	</div>
				4790
				4791	<div class="doc_text">
				4792
				4793	<h5>Syntax:</h5>
				4794	<pre>
Chris Lattner	38bd5dd	2007-09-21 17:30:40 +0000	[diff] [blame]	4795	declare i8 *@llvm.stacksave()
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4796	</pre>
				4797
				4798	<h5>Overview:</h5>
				4799
				4800	<p>
				4801	The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
				4802	the function stack, for use with <a href="#int_stackrestore">
				4803	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				4804	features like scoped automatic variable sized arrays in C99.
				4805	</p>
				4806
				4807	<h5>Semantics:</h5>
				4808
				4809	<p>
				4810	This intrinsic returns a opaque pointer value that can be passed to <a
				4811	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
				4812	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				4813	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				4814	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				4815	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				4816	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				4817	</p>
				4818
				4819	</div>
				4820
				4821	<!-- _______________________________________________________________________ -->
				4822	<div class="doc_subsubsection">
				4823	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
				4824	</div>
				4825
				4826	<div class="doc_text">
				4827
				4828	<h5>Syntax:</h5>
				4829	<pre>
				4830	declare void @llvm.stackrestore(i8 * %ptr)
				4831	</pre>
				4832
				4833	<h5>Overview:</h5>
				4834
				4835	<p>
				4836	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				4837	the function stack to the state it was in when the corresponding <a
				4838	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
				4839	useful for implementing language features like scoped automatic variable sized
				4840	arrays in C99.
				4841	</p>
				4842
				4843	<h5>Semantics:</h5>
				4844
				4845	<p>
				4846	See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
				4847	</p>
				4848
				4849	</div>
				4850
				4851
				4852	<!-- _______________________________________________________________________ -->
				4853	<div class="doc_subsubsection">
				4854	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
				4855	</div>
				4856
				4857	<div class="doc_text">
				4858
				4859	<h5>Syntax:</h5>
				4860	<pre>
Chris Lattner	38bd5dd	2007-09-21 17:30:40 +0000	[diff] [blame]	4861	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4862	</pre>
				4863
				4864	<h5>Overview:</h5>
				4865
				4866
				4867	<p>
				4868	The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
				4869	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				4870	no
				4871	effect on the behavior of the program but can change its performance
				4872	characteristics.
				4873	</p>
				4874
				4875	<h5>Arguments:</h5>
				4876
				4877	<p>
				4878	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				4879	determining if the fetch should be for a read (0) or write (1), and
				4880	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
				4881	locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
				4882	<tt>locality</tt> arguments must be constant integers.
				4883	</p>
				4884
				4885	<h5>Semantics:</h5>
				4886
				4887	<p>
				4888	This intrinsic does not modify the behavior of the program. In particular,
				4889	prefetches cannot trap and do not produce a value. On targets that support this
				4890	intrinsic, the prefetch can provide hints to the processor cache for better
				4891	performance.
				4892	</p>
				4893
				4894	</div>
				4895
				4896	<!-- _______________________________________________________________________ -->
				4897	<div class="doc_subsubsection">
				4898	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
				4899	</div>
				4900
				4901	<div class="doc_text">
				4902
				4903	<h5>Syntax:</h5>
				4904	<pre>
Chris Lattner	38bd5dd	2007-09-21 17:30:40 +0000	[diff] [blame]	4905	declare void @llvm.pcmarker(i32 <id>)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4906	</pre>
				4907
				4908	<h5>Overview:</h5>
				4909
				4910
				4911	<p>
				4912	The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner	9645148	2008-08-05 18:29:16 +0000	[diff] [blame]	4913	(PC) in a region of
				4914	code to simulators and other tools. The method is target specific, but it is
				4915	expected that the marker will use exported symbols to transmit the PC of the
				4916	marker.
				4917	The marker makes no guarantees that it will remain with any specific instruction
				4918	after optimizations. It is possible that the presence of a marker will inhibit
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	4919	optimizations. The intended use is to be inserted after optimizations to allow
				4920	correlations of simulation runs.
				4921	</p>
				4922
				4923	<h5>Arguments:</h5>
				4924
				4925	<p>
				4926	<tt>id</tt> is a numerical id identifying the marker.
				4927	</p>
				4928
				4929	<h5>Semantics:</h5>
				4930
				4931	<p>
				4932	This intrinsic does not modify the behavior of the program. Backends that do not
				4933	support this intrinisic may ignore it.
				4934	</p>
				4935
				4936	</div>
				4937
				4938	<!-- _______________________________________________________________________ -->
				4939	<div class="doc_subsubsection">
				4940	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
				4941	</div>
				4942
				4943	<div class="doc_text">
				4944
				4945	<h5>Syntax:</h5>
				4946	<pre>
				4947	declare i64 @llvm.readcyclecounter( )
				4948	</pre>
				4949
				4950	<h5>Overview:</h5>
				4951
				4952
				4953	<p>
				4954	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				4955	counter register (or similar low latency, high accuracy clocks) on those targets
				4956	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				4957	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				4958	should only be used for small timings.
				4959	</p>
				4960
				4961	<h5>Semantics:</h5>
				4962
				4963	<p>
				4964	When directly supported, reading the cycle counter should not modify any memory.
				4965	Implementations are allowed to either return a application specific value or a
				4966	system wide value. On backends without support, this is lowered to a constant 0.
				4967	</p>
				4968
				4969	</div>
				4970
				4971	<!-- ======================================================================= -->
				4972	<div class="doc_subsection">
				4973	<a name="int_libc">Standard C Library Intrinsics</a>
				4974	</div>
				4975
				4976	<div class="doc_text">
				4977	<p>
				4978	LLVM provides intrinsics for a few important standard C library functions.
				4979	These intrinsics allow source-language front-ends to pass information about the
				4980	alignment of the pointer arguments to the code generator, providing opportunity
				4981	for more efficient code generation.
				4982	</p>
				4983
				4984	</div>
				4985
				4986	<!-- _______________________________________________________________________ -->
				4987	<div class="doc_subsubsection">
				4988	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
				4989	</div>
				4990
				4991	<div class="doc_text">
				4992
				4993	<h5>Syntax:</h5>
				4994	<pre>
				4995	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
				4996	i32 <len>, i32 <align>)
				4997	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
				4998	i64 <len>, i32 <align>)
				4999	</pre>
				5000
				5001	<h5>Overview:</h5>
				5002
				5003	<p>
				5004	The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
				5005	location to the destination location.
				5006	</p>
				5007
				5008	<p>
				5009	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5010	intrinsics do not return a value, and takes an extra alignment argument.
				5011	</p>
				5012
				5013	<h5>Arguments:</h5>
				5014
				5015	<p>
				5016	The first argument is a pointer to the destination, the second is a pointer to
				5017	the source. The third argument is an integer argument
				5018	specifying the number of bytes to copy, and the fourth argument is the alignment
				5019	of the source and destination locations.
				5020	</p>
				5021
				5022	<p>
				5023	If the call to this intrinisic has an alignment value that is not 0 or 1, then
				5024	the caller guarantees that both the source and destination pointers are aligned
				5025	to that boundary.
				5026	</p>
				5027
				5028	<h5>Semantics:</h5>
				5029
				5030	<p>
				5031	The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
				5032	location to the destination location, which are not allowed to overlap. It
				5033	copies "len" bytes of memory over. If the argument is known to be aligned to
				5034	some boundary, this can be specified as the fourth argument, otherwise it should
				5035	be set to 0 or 1.
				5036	</p>
				5037	</div>
				5038
				5039
				5040	<!-- _______________________________________________________________________ -->
				5041	<div class="doc_subsubsection">
				5042	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
				5043	</div>
				5044
				5045	<div class="doc_text">
				5046
				5047	<h5>Syntax:</h5>
				5048	<pre>
				5049	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
				5050	i32 <len>, i32 <align>)
				5051	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
				5052	i64 <len>, i32 <align>)
				5053	</pre>
				5054
				5055	<h5>Overview:</h5>
				5056
				5057	<p>
				5058	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5059	location to the destination location. It is similar to the
Chris Lattner	dba16ea	2008-01-06 19:51:52 +0000	[diff] [blame]	5060	'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5061	</p>
				5062
				5063	<p>
				5064	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5065	intrinsics do not return a value, and takes an extra alignment argument.
				5066	</p>
				5067
				5068	<h5>Arguments:</h5>
				5069
				5070	<p>
				5071	The first argument is a pointer to the destination, the second is a pointer to
				5072	the source. The third argument is an integer argument
				5073	specifying the number of bytes to copy, and the fourth argument is the alignment
				5074	of the source and destination locations.
				5075	</p>
				5076
				5077	<p>
				5078	If the call to this intrinisic has an alignment value that is not 0 or 1, then
				5079	the caller guarantees that the source and destination pointers are aligned to
				5080	that boundary.
				5081	</p>
				5082
				5083	<h5>Semantics:</h5>
				5084
				5085	<p>
				5086	The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
				5087	location to the destination location, which may overlap. It
				5088	copies "len" bytes of memory over. If the argument is known to be aligned to
				5089	some boundary, this can be specified as the fourth argument, otherwise it should
				5090	be set to 0 or 1.
				5091	</p>
				5092	</div>
				5093
				5094
				5095	<!-- _______________________________________________________________________ -->
				5096	<div class="doc_subsubsection">
				5097	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
				5098	</div>
				5099
				5100	<div class="doc_text">
				5101
				5102	<h5>Syntax:</h5>
				5103	<pre>
				5104	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
				5105	i32 <len>, i32 <align>)
				5106	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
				5107	i64 <len>, i32 <align>)
				5108	</pre>
				5109
				5110	<h5>Overview:</h5>
				5111
				5112	<p>
				5113	The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
				5114	byte value.
				5115	</p>
				5116
				5117	<p>
				5118	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5119	does not return a value, and takes an extra alignment argument.
				5120	</p>
				5121
				5122	<h5>Arguments:</h5>
				5123
				5124	<p>
				5125	The first argument is a pointer to the destination to fill, the second is the
				5126	byte value to fill it with, the third argument is an integer
				5127	argument specifying the number of bytes to fill, and the fourth argument is the
				5128	known alignment of destination location.
				5129	</p>
				5130
				5131	<p>
				5132	If the call to this intrinisic has an alignment value that is not 0 or 1, then
				5133	the caller guarantees that the destination pointer is aligned to that boundary.
				5134	</p>
				5135
				5136	<h5>Semantics:</h5>
				5137
				5138	<p>
				5139	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5140	the
				5141	destination location. If the argument is known to be aligned to some boundary,
				5142	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5143	1.
				5144	</p>
				5145	</div>
				5146
				5147
				5148	<!-- _______________________________________________________________________ -->
				5149	<div class="doc_subsubsection">
				5150	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
				5151	</div>
				5152
				5153	<div class="doc_text">
				5154
				5155	<h5>Syntax:</h5>
Dale Johannesen	f9adbb6	2007-10-02 17:47:38 +0000	[diff] [blame]	5156	<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohman	361079c	2007-10-15 20:30:11 +0000	[diff] [blame]	5157	floating point or vector of floating point type. Not all targets support all
				5158	types however.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5159	<pre>
Dale Johannesen	f9adbb6	2007-10-02 17:47:38 +0000	[diff] [blame]	5160	declare float @llvm.sqrt.f32(float %Val)
				5161	declare double @llvm.sqrt.f64(double %Val)
				5162	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5163	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5164	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5165	</pre>
				5166
				5167	<h5>Overview:</h5>
				5168
				5169	<p>
				5170	The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman	361079c	2007-10-15 20:30:11 +0000	[diff] [blame]	5171	returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5172	<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner	f914a00	2008-01-29 07:00:44 +0000	[diff] [blame]	5173	negative numbers other than -0.0 (which allows for better optimization, because
				5174	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5175	defined to return -0.0 like IEEE sqrt.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5176	</p>
				5177
				5178	<h5>Arguments:</h5>
				5179
				5180	<p>
				5181	The argument and return value are floating point numbers of the same type.
				5182	</p>
				5183
				5184	<h5>Semantics:</h5>
				5185
				5186	<p>
				5187	This function returns the sqrt of the specified operand if it is a nonnegative
				5188	floating point number.
				5189	</p>
				5190	</div>
				5191
				5192	<!-- _______________________________________________________________________ -->
				5193	<div class="doc_subsubsection">
				5194	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
				5195	</div>
				5196
				5197	<div class="doc_text">
				5198
				5199	<h5>Syntax:</h5>
Dale Johannesen	f9adbb6	2007-10-02 17:47:38 +0000	[diff] [blame]	5200	<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohman	361079c	2007-10-15 20:30:11 +0000	[diff] [blame]	5201	floating point or vector of floating point type. Not all targets support all
				5202	types however.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5203	<pre>
Dale Johannesen	f9adbb6	2007-10-02 17:47:38 +0000	[diff] [blame]	5204	declare float @llvm.powi.f32(float %Val, i32 %power)
				5205	declare double @llvm.powi.f64(double %Val, i32 %power)
				5206	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5207	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5208	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5209	</pre>
				5210
				5211	<h5>Overview:</h5>
				5212
				5213	<p>
				5214	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5215	specified (positive or negative) power. The order of evaluation of
Dan Gohman	361079c	2007-10-15 20:30:11 +0000	[diff] [blame]	5216	multiplications is not defined. When a vector of floating point type is
				5217	used, the second argument remains a scalar integer value.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5218	</p>
				5219
				5220	<h5>Arguments:</h5>
				5221
				5222	<p>
				5223	The second argument is an integer power, and the first is a value to raise to
				5224	that power.
				5225	</p>
				5226
				5227	<h5>Semantics:</h5>
				5228
				5229	<p>
				5230	This function returns the first value raised to the second power with an
				5231	unspecified sequence of rounding operations.</p>
				5232	</div>
				5233
Dan Gohman	361079c	2007-10-15 20:30:11 +0000	[diff] [blame]	5234	<!-- _______________________________________________________________________ -->
				5235	<div class="doc_subsubsection">
				5236	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5237	</div>
				5238
				5239	<div class="doc_text">
				5240
				5241	<h5>Syntax:</h5>
				5242	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5243	floating point or vector of floating point type. Not all targets support all
				5244	types however.
				5245	<pre>
				5246	declare float @llvm.sin.f32(float %Val)
				5247	declare double @llvm.sin.f64(double %Val)
				5248	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5249	declare fp128 @llvm.sin.f128(fp128 %Val)
				5250	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5251	</pre>
				5252
				5253	<h5>Overview:</h5>
				5254
				5255	<p>
				5256	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5257	</p>
				5258
				5259	<h5>Arguments:</h5>
				5260
				5261	<p>
				5262	The argument and return value are floating point numbers of the same type.
				5263	</p>
				5264
				5265	<h5>Semantics:</h5>
				5266
				5267	<p>
				5268	This function returns the sine of the specified operand, returning the
				5269	same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohman	eaba92e	2007-10-17 18:05:13 +0000	[diff] [blame]	5270	conditions in the same way.</p>
Dan Gohman	361079c	2007-10-15 20:30:11 +0000	[diff] [blame]	5271	</div>
				5272
				5273	<!-- _______________________________________________________________________ -->
				5274	<div class="doc_subsubsection">
				5275	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5276	</div>
				5277
				5278	<div class="doc_text">
				5279
				5280	<h5>Syntax:</h5>
				5281	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5282	floating point or vector of floating point type. Not all targets support all
				5283	types however.
				5284	<pre>
				5285	declare float @llvm.cos.f32(float %Val)
				5286	declare double @llvm.cos.f64(double %Val)
				5287	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5288	declare fp128 @llvm.cos.f128(fp128 %Val)
				5289	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5290	</pre>
				5291
				5292	<h5>Overview:</h5>
				5293
				5294	<p>
				5295	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5296	</p>
				5297
				5298	<h5>Arguments:</h5>
				5299
				5300	<p>
				5301	The argument and return value are floating point numbers of the same type.
				5302	</p>
				5303
				5304	<h5>Semantics:</h5>
				5305
				5306	<p>
				5307	This function returns the cosine of the specified operand, returning the
				5308	same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohman	eaba92e	2007-10-17 18:05:13 +0000	[diff] [blame]	5309	conditions in the same way.</p>
Dan Gohman	361079c	2007-10-15 20:30:11 +0000	[diff] [blame]	5310	</div>
				5311
				5312	<!-- _______________________________________________________________________ -->
				5313	<div class="doc_subsubsection">
				5314	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5315	</div>
				5316
				5317	<div class="doc_text">
				5318
				5319	<h5>Syntax:</h5>
				5320	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5321	floating point or vector of floating point type. Not all targets support all
				5322	types however.
				5323	<pre>
				5324	declare float @llvm.pow.f32(float %Val, float %Power)
				5325	declare double @llvm.pow.f64(double %Val, double %Power)
				5326	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5327	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5328	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5329	</pre>
				5330
				5331	<h5>Overview:</h5>
				5332
				5333	<p>
				5334	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5335	specified (positive or negative) power.
				5336	</p>
				5337
				5338	<h5>Arguments:</h5>
				5339
				5340	<p>
				5341	The second argument is a floating point power, and the first is a value to
				5342	raise to that power.
				5343	</p>
				5344
				5345	<h5>Semantics:</h5>
				5346
				5347	<p>
				5348	This function returns the first value raised to the second power,
				5349	returning the
				5350	same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohman	eaba92e	2007-10-17 18:05:13 +0000	[diff] [blame]	5351	conditions in the same way.</p>
Dan Gohman	361079c	2007-10-15 20:30:11 +0000	[diff] [blame]	5352	</div>
				5353
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5354
				5355	<!-- ======================================================================= -->
				5356	<div class="doc_subsection">
				5357	<a name="int_manip">Bit Manipulation Intrinsics</a>
				5358	</div>
				5359
				5360	<div class="doc_text">
				5361	<p>
				5362	LLVM provides intrinsics for a few important bit manipulation operations.
				5363	These allow efficient code generation for some algorithms.
				5364	</p>
				5365
				5366	</div>
				5367
				5368	<!-- _______________________________________________________________________ -->
				5369	<div class="doc_subsubsection">
				5370	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
				5371	</div>
				5372
				5373	<div class="doc_text">
				5374
				5375	<h5>Syntax:</h5>
				5376	<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth	a228e39	2007-08-04 01:51:18 +0000	[diff] [blame]	5377	type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5378	<pre>
Chandler Carruth	a228e39	2007-08-04 01:51:18 +0000	[diff] [blame]	5379	declare i16 @llvm.bswap.i16(i16 <id>)
				5380	declare i32 @llvm.bswap.i32(i32 <id>)
				5381	declare i64 @llvm.bswap.i64(i64 <id>)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5382	</pre>
				5383
				5384	<h5>Overview:</h5>
				5385
				5386	<p>
				5387	The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
				5388	values with an even number of bytes (positive multiple of 16 bits). These are
				5389	useful for performing operations on data that is not in the target's native
				5390	byte order.
				5391	</p>
				5392
				5393	<h5>Semantics:</h5>
				5394
				5395	<p>
Chandler Carruth	a228e39	2007-08-04 01:51:18 +0000	[diff] [blame]	5396	The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5397	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5398	intrinsic returns an i32 value that has the four bytes of the input i32
				5399	swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth	a228e39	2007-08-04 01:51:18 +0000	[diff] [blame]	5400	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5401	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5402	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
				5403	</p>
				5404
				5405	</div>
				5406
				5407	<!-- _______________________________________________________________________ -->
				5408	<div class="doc_subsubsection">
				5409	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
				5410	</div>
				5411
				5412	<div class="doc_text">
				5413
				5414	<h5>Syntax:</h5>
				5415	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
				5416	width. Not all targets support all bit widths however.
				5417	<pre>
Chandler Carruth	a228e39	2007-08-04 01:51:18 +0000	[diff] [blame]	5418	declare i8 @llvm.ctpop.i8 (i8 <src>)
				5419	declare i16 @llvm.ctpop.i16(i16 <src>)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5420	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	a228e39	2007-08-04 01:51:18 +0000	[diff] [blame]	5421	declare i64 @llvm.ctpop.i64(i64 <src>)
				5422	declare i256 @llvm.ctpop.i256(i256 <src>)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5423	</pre>
				5424
				5425	<h5>Overview:</h5>
				5426
				5427	<p>
				5428	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5429	value.
				5430	</p>
				5431
				5432	<h5>Arguments:</h5>
				5433
				5434	<p>
				5435	The only argument is the value to be counted. The argument may be of any
				5436	integer type. The return type must match the argument type.
				5437	</p>
				5438
				5439	<h5>Semantics:</h5>
				5440
				5441	<p>
				5442	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5443	</p>
				5444	</div>
				5445
				5446	<!-- _______________________________________________________________________ -->
				5447	<div class="doc_subsubsection">
				5448	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
				5449	</div>
				5450
				5451	<div class="doc_text">
				5452
				5453	<h5>Syntax:</h5>
				5454	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
				5455	integer bit width. Not all targets support all bit widths however.
				5456	<pre>
Chandler Carruth	a228e39	2007-08-04 01:51:18 +0000	[diff] [blame]	5457	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5458	declare i16 @llvm.ctlz.i16(i16 <src>)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5459	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	a228e39	2007-08-04 01:51:18 +0000	[diff] [blame]	5460	declare i64 @llvm.ctlz.i64(i64 <src>)
				5461	declare i256 @llvm.ctlz.i256(i256 <src>)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5462	</pre>
				5463
				5464	<h5>Overview:</h5>
				5465
				5466	<p>
				5467	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5468	leading zeros in a variable.
				5469	</p>
				5470
				5471	<h5>Arguments:</h5>
				5472
				5473	<p>
				5474	The only argument is the value to be counted. The argument may be of any
				5475	integer type. The return type must match the argument type.
				5476	</p>
				5477
				5478	<h5>Semantics:</h5>
				5479
				5480	<p>
				5481	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5482	in a variable. If the src == 0 then the result is the size in bits of the type
				5483	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
				5484	</p>
				5485	</div>
				5486
				5487
				5488
				5489	<!-- _______________________________________________________________________ -->
				5490	<div class="doc_subsubsection">
				5491	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
				5492	</div>
				5493
				5494	<div class="doc_text">
				5495
				5496	<h5>Syntax:</h5>
				5497	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
				5498	integer bit width. Not all targets support all bit widths however.
				5499	<pre>
Chandler Carruth	a228e39	2007-08-04 01:51:18 +0000	[diff] [blame]	5500	declare i8 @llvm.cttz.i8 (i8 <src>)
				5501	declare i16 @llvm.cttz.i16(i16 <src>)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5502	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	a228e39	2007-08-04 01:51:18 +0000	[diff] [blame]	5503	declare i64 @llvm.cttz.i64(i64 <src>)
				5504	declare i256 @llvm.cttz.i256(i256 <src>)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5505	</pre>
				5506
				5507	<h5>Overview:</h5>
				5508
				5509	<p>
				5510	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5511	trailing zeros.
				5512	</p>
				5513
				5514	<h5>Arguments:</h5>
				5515
				5516	<p>
				5517	The only argument is the value to be counted. The argument may be of any
				5518	integer type. The return type must match the argument type.
				5519	</p>
				5520
				5521	<h5>Semantics:</h5>
				5522
				5523	<p>
				5524	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5525	in a variable. If the src == 0 then the result is the size in bits of the type
				5526	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5527	</p>
				5528	</div>
				5529
				5530	<!-- _______________________________________________________________________ -->
				5531	<div class="doc_subsubsection">
				5532	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
				5533	</div>
				5534
				5535	<div class="doc_text">
				5536
				5537	<h5>Syntax:</h5>
				5538	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
				5539	on any integer bit width.
				5540	<pre>
Chandler Carruth	a228e39	2007-08-04 01:51:18 +0000	[diff] [blame]	5541	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5542	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5543	</pre>
				5544
				5545	<h5>Overview:</h5>
				5546	<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
				5547	range of bits from an integer value and returns them in the same bit width as
				5548	the original value.</p>
				5549
				5550	<h5>Arguments:</h5>
				5551	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5552	any bit width but they must have the same bit width. The second and third
				5553	arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
				5554
				5555	<h5>Semantics:</h5>
				5556	<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
				5557	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5558	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5559	operates in forward mode.</p>
				5560	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5561	right by <tt>%loBit</tt> bits and then ANDing it with a mask with
				5562	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5563	<ol>
				5564	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5565	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5566	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5567	to determine the number of bits to retain.</li>
				5568	<li>A mask of the retained bits is created by shifting a -1 value.</li>
				5569	<li>The mask is ANDed with <tt>%val</tt> to produce the result.
				5570	</ol>
				5571	<p>In reverse mode, a similar computation is made except that the bits are
				5572	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5573	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5574	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5575	<tt>i16 0x0026 (000000100110)</tt>.</p>
				5576	</div>
				5577
				5578	<div class="doc_subsubsection">
				5579	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5580	</div>
				5581
				5582	<div class="doc_text">
				5583
				5584	<h5>Syntax:</h5>
				5585	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
				5586	on any integer bit width.
				5587	<pre>
Chandler Carruth	a228e39	2007-08-04 01:51:18 +0000	[diff] [blame]	5588	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5589	declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	5590	</pre>
				5591
				5592	<h5>Overview:</h5>
				5593	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5594	of bits in an integer value with another integer value. It returns the integer
				5595	with the replaced bits.</p>
				5596
				5597	<h5>Arguments:</h5>
				5598	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5599	any bit width but they must have the same bit width. <tt>%val</tt> is the value
				5600	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5601	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5602	type since they specify only a bit index.</p>
				5603
				5604	<h5>Semantics:</h5>
				5605	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5606	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5607	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5608	operates in forward mode.</p>
				5609	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5610	truncating it down to the size of the replacement area or zero extending it
				5611	up to that size.</p>
				5612	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5613	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5614	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
				5615	to the <tt>%hi</tt>th bit.
				5616	<p>In reverse mode, a similar computation is made except that the bits are
				5617	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
				5618	<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.
				5619	<h5>Examples:</h5>
				5620	<pre>
				5621	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
				5622	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5623	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5624	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
				5625	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
				5626	</pre>
				5627	</div>
				5628
				5629	<!-- ======================================================================= -->
				5630	<div class="doc_subsection">
				5631	<a name="int_debugger">Debugger Intrinsics</a>
				5632	</div>
				5633
				5634	<div class="doc_text">
				5635	<p>
				5636	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				5637	are described in the <a
				5638	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				5639	Debugging</a> document.
				5640	</p>
				5641	</div>
				5642
				5643
				5644	<!-- ======================================================================= -->
				5645	<div class="doc_subsection">
				5646	<a name="int_eh">Exception Handling Intrinsics</a>
				5647	</div>
				5648
				5649	<div class="doc_text">
				5650	<p> The LLVM exception handling intrinsics (which all start with
				5651	<tt>llvm.eh.</tt> prefix), are described in the <a
				5652	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				5653	Handling</a> document. </p>
				5654	</div>
				5655
				5656	<!-- ======================================================================= -->
				5657	<div class="doc_subsection">
Duncan Sands	7407a9f	2007-09-11 14:10:23 +0000	[diff] [blame]	5658	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	38947cd	2007-07-27 12:58:54 +0000	[diff] [blame]	5659	</div>
				5660
				5661	<div class="doc_text">
				5662	<p>
Duncan Sands	7407a9f	2007-09-11 14:10:23 +0000	[diff] [blame]	5663	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	38947cd	2007-07-27 12:58:54 +0000	[diff] [blame]	5664	the <tt>nest</tt> attribute, from a function. The result is a callable
				5665	function pointer lacking the nest parameter - the caller does not need
				5666	to provide a value for it. Instead, the value to use is stored in
				5667	advance in a "trampoline", a block of memory usually allocated
				5668	on the stack, which also contains code to splice the nest value into the
				5669	argument list. This is used to implement the GCC nested function address
				5670	extension.
				5671	</p>
				5672	<p>
				5673	For example, if the function is
				5674	<tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling	e262b4c	2007-09-22 09:23:55 +0000	[diff] [blame]	5675	pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands	38947cd	2007-07-27 12:58:54 +0000	[diff] [blame]	5676	<pre>
Duncan Sands	7407a9f	2007-09-11 14:10:23 +0000	[diff] [blame]	5677	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				5678	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				5679	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				5680	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	38947cd	2007-07-27 12:58:54 +0000	[diff] [blame]	5681	</pre>
Bill Wendling	e262b4c	2007-09-22 09:23:55 +0000	[diff] [blame]	5682	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				5683	to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands	38947cd	2007-07-27 12:58:54 +0000	[diff] [blame]	5684	</div>
				5685
				5686	<!-- _______________________________________________________________________ -->
				5687	<div class="doc_subsubsection">
				5688	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				5689	</div>
				5690	<div class="doc_text">
				5691	<h5>Syntax:</h5>
				5692	<pre>
Duncan Sands	7407a9f	2007-09-11 14:10:23 +0000	[diff] [blame]	5693	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	38947cd	2007-07-27 12:58:54 +0000	[diff] [blame]	5694	</pre>
				5695	<h5>Overview:</h5>
				5696	<p>
Duncan Sands	7407a9f	2007-09-11 14:10:23 +0000	[diff] [blame]	5697	This fills the memory pointed to by <tt>tramp</tt> with code
				5698	and returns a function pointer suitable for executing it.
Duncan Sands	38947cd	2007-07-27 12:58:54 +0000	[diff] [blame]	5699	</p>
				5700	<h5>Arguments:</h5>
				5701	<p>
				5702	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				5703	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				5704	and sufficiently aligned block of memory; this memory is written to by the
Duncan Sands	3501221	2007-08-22 23:39:54 +0000	[diff] [blame]	5705	intrinsic. Note that the size and the alignment are target-specific - LLVM
				5706	currently provides no portable way of determining them, so a front-end that
				5707	generates this intrinsic needs to have some target-specific knowledge.
				5708	The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands	38947cd	2007-07-27 12:58:54 +0000	[diff] [blame]	5709	</p>
				5710	<h5>Semantics:</h5>
				5711	<p>
				5712	The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands	7407a9f	2007-09-11 14:10:23 +0000	[diff] [blame]	5713	dependent code, turning it into a function. A pointer to this function is
				5714	returned, but needs to be bitcast to an
Duncan Sands	38947cd	2007-07-27 12:58:54 +0000	[diff] [blame]	5715	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	7407a9f	2007-09-11 14:10:23 +0000	[diff] [blame]	5716	before being called. The new function's signature is the same as that of
				5717	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				5718	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				5719	of pointer type. Calling the new function is equivalent to calling
				5720	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				5721	missing <tt>nest</tt> argument. If, after calling
				5722	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				5723	modified, then the effect of any later call to the returned function pointer is
				5724	undefined.
Duncan Sands	38947cd	2007-07-27 12:58:54 +0000	[diff] [blame]	5725	</p>
				5726	</div>
				5727
				5728	<!-- ======================================================================= -->
				5729	<div class="doc_subsection">
Andrew Lenharth	785610d	2008-02-16 01:24:58 +0000	[diff] [blame]	5730	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				5731	</div>
				5732
				5733	<div class="doc_text">
				5734	<p>
				5735	These intrinsic functions expand the "universal IR" of LLVM to represent
				5736	hardware constructs for atomic operations and memory synchronization. This
				5737	provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner	9645148	2008-08-05 18:29:16 +0000	[diff] [blame]	5738	is aimed at a low enough level to allow any programming models or APIs
				5739	(Application Programming Interfaces) which
Andrew Lenharth	785610d	2008-02-16 01:24:58 +0000	[diff] [blame]	5740	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				5741	hardware behavior. Just as hardware provides a "universal IR" for source
				5742	languages, it also provides a starting point for developing a "universal"
				5743	atomic operation and synchronization IR.
				5744	</p>
				5745	<p>
				5746	These do <em>not</em> form an API such as high-level threading libraries,
				5747	software transaction memory systems, atomic primitives, and intrinsic
				5748	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				5749	application libraries. The hardware interface provided by LLVM should allow
				5750	a clean implementation of all of these APIs and parallel programming models.
				5751	No one model or paradigm should be selected above others unless the hardware
				5752	itself ubiquitously does so.
				5753
				5754	</p>
				5755	</div>
				5756
				5757	<!-- _______________________________________________________________________ -->
				5758	<div class="doc_subsubsection">
				5759	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				5760	</div>
				5761	<div class="doc_text">
				5762	<h5>Syntax:</h5>
				5763	<pre>
				5764	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				5765	i1 <device> )
				5766
				5767	</pre>
				5768	<h5>Overview:</h5>
				5769	<p>
				5770	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				5771	specific pairs of memory access types.
				5772	</p>
				5773	<h5>Arguments:</h5>
				5774	<p>
				5775	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				5776	The first four arguments enables a specific barrier as listed below. The fith
				5777	argument specifies that the barrier applies to io or device or uncached memory.
				5778
				5779	</p>
				5780	<ul>
				5781	<li><tt>ll</tt>: load-load barrier</li>
				5782	<li><tt>ls</tt>: load-store barrier</li>
				5783	<li><tt>sl</tt>: store-load barrier</li>
				5784	<li><tt>ss</tt>: store-store barrier</li>
				5785	<li><tt>device</tt>: barrier applies to device and uncached memory also.
				5786	</ul>
				5787	<h5>Semantics:</h5>
				5788	<p>
				5789	This intrinsic causes the system to enforce some ordering constraints upon
				5790	the loads and stores of the program. This barrier does not indicate
				5791	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				5792	which they occur. For any of the specified pairs of load and store operations
				5793	(f.ex. load-load, or store-load), all of the first operations preceding the
				5794	barrier will complete before any of the second operations succeeding the
				5795	barrier begin. Specifically the semantics for each pairing is as follows:
				5796	</p>
				5797	<ul>
				5798	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				5799	after the barrier begins.</li>
				5800
				5801	<li><tt>ls</tt>: All loads before the barrier must complete before any
				5802	store after the barrier begins.</li>
				5803	<li><tt>ss</tt>: All stores before the barrier must complete before any
				5804	store after the barrier begins.</li>
				5805	<li><tt>sl</tt>: All stores before the barrier must complete before any
				5806	load after the barrier begins.</li>
				5807	</ul>
				5808	<p>
				5809	These semantics are applied with a logical "and" behavior when more than one
				5810	is enabled in a single memory barrier intrinsic.
				5811	</p>
				5812	<p>
				5813	Backends may implement stronger barriers than those requested when they do not
				5814	support as fine grained a barrier as requested. Some architectures do not
				5815	need all types of barriers and on such architectures, these become noops.
				5816	</p>
				5817	<h5>Example:</h5>
				5818	<pre>
				5819	%ptr = malloc i32
				5820	store i32 4, %ptr
				5821
				5822	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				5823	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				5824	<i>; guarantee the above finishes</i>
				5825	store i32 8, %ptr <i>; before this begins</i>
				5826	</pre>
				5827	</div>
				5828
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5829	<!-- _______________________________________________________________________ -->
				5830	<div class="doc_subsubsection">
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	5831	<a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5832	</div>
				5833	<div class="doc_text">
				5834	<h5>Syntax:</h5>
				5835	<p>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	5836	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				5837	any integer bit width and for different address spaces. Not all targets
				5838	support all bit widths however.</p>
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5839
				5840	<pre>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	5841	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				5842	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				5843	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				5844	declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* <ptr>, i64 <cmp>, i64 <val> )
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5845
				5846	</pre>
				5847	<h5>Overview:</h5>
				5848	<p>
				5849	This loads a value in memory and compares it to a given value. If they are
				5850	equal, it stores a new value into the memory.
				5851	</p>
				5852	<h5>Arguments:</h5>
				5853	<p>
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	5854	The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5855	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				5856	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				5857	this integer type. While any bit width integer may be used, targets may only
				5858	lower representations they support in hardware.
				5859
				5860	</p>
				5861	<h5>Semantics:</h5>
				5862	<p>
				5863	This entire intrinsic must be executed atomically. It first loads the value
				5864	in memory pointed to by <tt>ptr</tt> and compares it with the value
				5865	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				5866	loaded value is yielded in all cases. This provides the equivalent of an
				5867	atomic compare-and-swap operation within the SSA framework.
				5868	</p>
				5869	<h5>Examples:</h5>
				5870
				5871	<pre>
				5872	%ptr = malloc i32
				5873	store i32 4, %ptr
				5874
				5875	%val1 = add i32 4, 4
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	5876	%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5877	<i>; yields {i32}:result1 = 4</i>
				5878	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5879	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5880
				5881	%val2 = add i32 1, 1
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	5882	%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5883	<i>; yields {i32}:result2 = 8</i>
				5884	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				5885
				5886	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				5887	</pre>
				5888	</div>
				5889
				5890	<!-- _______________________________________________________________________ -->
				5891	<div class="doc_subsubsection">
				5892	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				5893	</div>
				5894	<div class="doc_text">
				5895	<h5>Syntax:</h5>
				5896
				5897	<p>
				5898	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				5899	integer bit width. Not all targets support all bit widths however.</p>
				5900	<pre>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	5901	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				5902	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				5903	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				5904	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5905
				5906	</pre>
				5907	<h5>Overview:</h5>
				5908	<p>
				5909	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				5910	the value from memory. It then stores the value in <tt>val</tt> in the memory
				5911	at <tt>ptr</tt>.
				5912	</p>
				5913	<h5>Arguments:</h5>
				5914
				5915	<p>
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	5916	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5917	<tt>val</tt> argument and the result must be integers of the same bit width.
				5918	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				5919	integer type. The targets may only lower integer representations they
				5920	support.
				5921	</p>
				5922	<h5>Semantics:</h5>
				5923	<p>
				5924	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				5925	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				5926	equivalent of an atomic swap operation within the SSA framework.
				5927
				5928	</p>
				5929	<h5>Examples:</h5>
				5930	<pre>
				5931	%ptr = malloc i32
				5932	store i32 4, %ptr
				5933
				5934	%val1 = add i32 4, 4
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	5935	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5936	<i>; yields {i32}:result1 = 4</i>
				5937	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5938	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5939
				5940	%val2 = add i32 1, 1
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	5941	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5942	<i>; yields {i32}:result2 = 8</i>
				5943
				5944	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				5945	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				5946	</pre>
				5947	</div>
				5948
				5949	<!-- _______________________________________________________________________ -->
				5950	<div class="doc_subsubsection">
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	5951	<a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5952
				5953	</div>
				5954	<div class="doc_text">
				5955	<h5>Syntax:</h5>
				5956	<p>
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	5957	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on any
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5958	integer bit width. Not all targets support all bit widths however.</p>
				5959	<pre>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	5960	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				5961	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				5962	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				5963	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5964
				5965	</pre>
				5966	<h5>Overview:</h5>
				5967	<p>
				5968	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				5969	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				5970	</p>
				5971	<h5>Arguments:</h5>
				5972	<p>
				5973
				5974	The intrinsic takes two arguments, the first a pointer to an integer value
				5975	and the second an integer value. The result is also an integer value. These
				5976	integer types can have any bit width, but they must all have the same bit
				5977	width. The targets may only lower integer representations they support.
				5978	</p>
				5979	<h5>Semantics:</h5>
				5980	<p>
				5981	This intrinsic does a series of operations atomically. It first loads the
				5982	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				5983	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				5984	</p>
				5985
				5986	<h5>Examples:</h5>
				5987	<pre>
				5988	%ptr = malloc i32
				5989	store i32 4, %ptr
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	5990	%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5991	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	5992	%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5993	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	5994	%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5995	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	5996	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	e44f390	2008-02-21 06:45:13 +0000	[diff] [blame]	5997	</pre>
				5998	</div>
				5999
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6000	<!-- _______________________________________________________________________ -->
				6001	<div class="doc_subsubsection">
				6002	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6003
				6004	</div>
				6005	<div class="doc_text">
				6006	<h5>Syntax:</h5>
				6007	<p>
				6008	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6009	any integer bit width and for different address spaces. Not all targets
				6010	support all bit widths however.</p>
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6011	<pre>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6012	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6013	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6014	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6015	declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6016
				6017	</pre>
				6018	<h5>Overview:</h5>
				6019	<p>
				6020	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6021	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6022	</p>
				6023	<h5>Arguments:</h5>
				6024	<p>
				6025
				6026	The intrinsic takes two arguments, the first a pointer to an integer value
				6027	and the second an integer value. The result is also an integer value. These
				6028	integer types can have any bit width, but they must all have the same bit
				6029	width. The targets may only lower integer representations they support.
				6030	</p>
				6031	<h5>Semantics:</h5>
				6032	<p>
				6033	This intrinsic does a series of operations atomically. It first loads the
				6034	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6035	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6036	</p>
				6037
				6038	<h5>Examples:</h5>
				6039	<pre>
				6040	%ptr = malloc i32
				6041	store i32 8, %ptr
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6042	%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6043	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6044	%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6045	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6046	%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6047	<i>; yields {i32}:result3 = 2</i>
				6048	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6049	</pre>
				6050	</div>
				6051
				6052	<!-- _______________________________________________________________________ -->
				6053	<div class="doc_subsubsection">
				6054	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6055	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6056	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6057	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6058
				6059	</div>
				6060	<div class="doc_text">
				6061	<h5>Syntax:</h5>
				6062	<p>
				6063	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6064	<tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6065	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6066	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6067	<pre>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6068	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6069	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6070	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6071	declare i64 @llvm.atomic.load.and.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6072
				6073	</pre>
				6074
				6075	<pre>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6076	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6077	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6078	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6079	declare i64 @llvm.atomic.load.or.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6080
				6081	</pre>
				6082
				6083	<pre>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6084	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6085	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6086	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6087	declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6088
				6089	</pre>
				6090
				6091	<pre>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6092	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6093	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6094	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6095	declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6096
				6097	</pre>
				6098	<h5>Overview:</h5>
				6099	<p>
				6100	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6101	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6102	at <tt>ptr</tt>.
				6103	</p>
				6104	<h5>Arguments:</h5>
				6105	<p>
				6106
				6107	These intrinsics take two arguments, the first a pointer to an integer value
				6108	and the second an integer value. The result is also an integer value. These
				6109	integer types can have any bit width, but they must all have the same bit
				6110	width. The targets may only lower integer representations they support.
				6111	</p>
				6112	<h5>Semantics:</h5>
				6113	<p>
				6114	These intrinsics does a series of operations atomically. They first load the
				6115	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6116	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6117	value stored at <tt>ptr</tt>.
				6118	</p>
				6119
				6120	<h5>Examples:</h5>
				6121	<pre>
				6122	%ptr = malloc i32
				6123	store i32 0x0F0F, %ptr
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6124	%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6125	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6126	%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6127	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6128	%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6129	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6130	%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6131	<i>; yields {i32}:result3 = FF</i>
				6132	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6133	</pre>
				6134	</div>
				6135
				6136
				6137	<!-- _______________________________________________________________________ -->
				6138	<div class="doc_subsubsection">
				6139	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6140	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6141	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6142	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6143
				6144	</div>
				6145	<div class="doc_text">
				6146	<h5>Syntax:</h5>
				6147	<p>
				6148	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6149	<tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6150	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6151	address spaces. Not all targets
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6152	support all bit widths however.</p>
				6153	<pre>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6154	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6155	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6156	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6157	declare i64 @llvm.atomic.load.max.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6158
				6159	</pre>
				6160
				6161	<pre>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6162	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6163	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6164	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6165	declare i64 @llvm.atomic.load.min.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6166
				6167	</pre>
				6168
				6169	<pre>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6170	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6171	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6172	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6173	declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6174
				6175	</pre>
				6176
				6177	<pre>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6178	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6179	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6180	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6181	declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6182
				6183	</pre>
				6184	<h5>Overview:</h5>
				6185	<p>
				6186	These intrinsics takes the signed or unsigned minimum or maximum of
				6187	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6188	original value at <tt>ptr</tt>.
				6189	</p>
				6190	<h5>Arguments:</h5>
				6191	<p>
				6192
				6193	These intrinsics take two arguments, the first a pointer to an integer value
				6194	and the second an integer value. The result is also an integer value. These
				6195	integer types can have any bit width, but they must all have the same bit
				6196	width. The targets may only lower integer representations they support.
				6197	</p>
				6198	<h5>Semantics:</h5>
				6199	<p>
				6200	These intrinsics does a series of operations atomically. They first load the
				6201	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6202	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6203	the original value stored at <tt>ptr</tt>.
				6204	</p>
				6205
				6206	<h5>Examples:</h5>
				6207	<pre>
				6208	%ptr = malloc i32
				6209	store i32 7, %ptr
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6210	%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6211	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6212	%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6213	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6214	%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6215	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	ce3ac89	2008-07-30 04:36:53 +0000	[diff] [blame]	6216	%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang	6bde9ec	2008-06-25 08:15:39 +0000	[diff] [blame]	6217	<i>; yields {i32}:result3 = 8</i>
				6218	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6219	</pre>
				6220	</div>
Andrew Lenharth	785610d	2008-02-16 01:24:58 +0000	[diff] [blame]	6221
				6222	<!-- ======================================================================= -->
				6223	<div class="doc_subsection">
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	6224	<a name="int_general">General Intrinsics</a>
				6225	</div>
				6226
				6227	<div class="doc_text">
				6228	<p> This class of intrinsics is designed to be generic and has
				6229	no specific purpose. </p>
				6230	</div>
				6231
				6232	<!-- _______________________________________________________________________ -->
				6233	<div class="doc_subsubsection">
				6234	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6235	</div>
				6236
				6237	<div class="doc_text">
				6238
				6239	<h5>Syntax:</h5>
				6240	<pre>
				6241	declare void @llvm.var.annotation(i8* <val>, i8* <str>, i8* <str>, i32 <int> )
				6242	</pre>
				6243
				6244	<h5>Overview:</h5>
				6245
				6246	<p>
				6247	The '<tt>llvm.var.annotation</tt>' intrinsic
				6248	</p>
				6249
				6250	<h5>Arguments:</h5>
				6251
				6252	<p>
				6253	The first argument is a pointer to a value, the second is a pointer to a
				6254	global string, the third is a pointer to a global string which is the source
				6255	file name, and the last argument is the line number.
				6256	</p>
				6257
				6258	<h5>Semantics:</h5>
				6259
				6260	<p>
Anton Korobeynikov	e6e764f	2008-01-15 22:31:34 +0000	[diff] [blame]	6261	This intrinsic allows annotation of local variables with arbitrary strings.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	6262	This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov	e6e764f	2008-01-15 22:31:34 +0000	[diff] [blame]	6263	annotations. These have no other defined use, they are ignored by code
				6264	generation and optimization.
				6265	</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	6266	</div>
				6267
Tanya Lattner	b306a9e	2007-09-21 22:59:12 +0000	[diff] [blame]	6268	<!-- _______________________________________________________________________ -->
				6269	<div class="doc_subsubsection">
Tanya Lattner	c9869b1	2007-09-21 23:57:59 +0000	[diff] [blame]	6270	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b306a9e	2007-09-21 22:59:12 +0000	[diff] [blame]	6271	</div>
				6272
				6273	<div class="doc_text">
				6274
				6275	<h5>Syntax:</h5>
Tanya Lattner	e545be7	2007-09-21 23:56:27 +0000	[diff] [blame]	6276	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6277	any integer bit width.
				6278	</p>
Tanya Lattner	b306a9e	2007-09-21 22:59:12 +0000	[diff] [blame]	6279	<pre>
Tanya Lattner	09161fe	2007-09-22 00:03:01 +0000	[diff] [blame]	6280	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6281	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6282	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6283	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6284	declare i256 @llvm.annotation.i256(i256 <val>, i8* <str>, i8* <str>, i32 <int> )
Tanya Lattner	b306a9e	2007-09-21 22:59:12 +0000	[diff] [blame]	6285	</pre>
				6286
				6287	<h5>Overview:</h5>
Tanya Lattner	e545be7	2007-09-21 23:56:27 +0000	[diff] [blame]	6288
				6289	<p>
				6290	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b306a9e	2007-09-21 22:59:12 +0000	[diff] [blame]	6291	</p>
				6292
				6293	<h5>Arguments:</h5>
				6294
				6295	<p>
				6296	The first argument is an integer value (result of some expression),
				6297	the second is a pointer to a global string, the third is a pointer to a global
				6298	string which is the source file name, and the last argument is the line number.
Tanya Lattner	e545be7	2007-09-21 23:56:27 +0000	[diff] [blame]	6299	It returns the value of the first argument.
Tanya Lattner	b306a9e	2007-09-21 22:59:12 +0000	[diff] [blame]	6300	</p>
				6301
				6302	<h5>Semantics:</h5>
				6303
				6304	<p>
				6305	This intrinsic allows annotations to be put on arbitrary expressions
				6306	with arbitrary strings. This can be useful for special purpose optimizations
				6307	that want to look for these annotations. These have no other defined use, they
				6308	are ignored by code generation and optimization.
				6309	</div>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	6310
Anton Korobeynikov	e6e764f	2008-01-15 22:31:34 +0000	[diff] [blame]	6311	<!-- _______________________________________________________________________ -->
				6312	<div class="doc_subsubsection">
				6313	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6314	</div>
				6315
				6316	<div class="doc_text">
				6317
				6318	<h5>Syntax:</h5>
				6319	<pre>
				6320	declare void @llvm.trap()
				6321	</pre>
				6322
				6323	<h5>Overview:</h5>
				6324
				6325	<p>
				6326	The '<tt>llvm.trap</tt>' intrinsic
				6327	</p>
				6328
				6329	<h5>Arguments:</h5>
				6330
				6331	<p>
				6332	None
				6333	</p>
				6334
				6335	<h5>Semantics:</h5>
				6336
				6337	<p>
				6338	This intrinsics is lowered to the target dependent trap instruction. If the
				6339	target does not have a trap instruction, this intrinsic will be lowered to the
				6340	call of the abort() function.
				6341	</p>
				6342	</div>
				6343
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	6344	<!-- *********************************************************************** -->
				6345	<hr>
				6346	<address>
				6347	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
				6348	src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
				6349	<a href="http://validator.w3.org/check/referer"><img
Chris Lattner	08497ce	2008-01-04 04:33:49 +0000	[diff] [blame]	6350	src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	6351
				6352	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
				6353	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
				6354	Last modified: $Date$
				6355	</address>
Chris Lattner	08497ce	2008-01-04 04:33:49 +0000	[diff] [blame]	6356
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	6357	</body>
				6358	</html>