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Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3	<html>
				4	<head>
				5	<title>LLVM Assembly Language Reference Manual</title>
Reid Spencer	3921c74	2004-08-26 20:44:00 +0000	[diff] [blame]	6	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
				7	<meta name="author" content="Chris Lattner">
				8	<meta name="description"
				9	content="LLVM Assembly Language Reference Manual.">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	10	<link rel="stylesheet" href="llvm.css" type="text/css">
				11	</head>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	12
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	13	<body>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	14
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	15	<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	16	<ol>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	17	<li><a href="#abstract">Abstract</a></li>
				18	<li><a href="#introduction">Introduction</a></li>
				19	<li><a href="#identifiers">Identifiers</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	20	<li><a href="#highlevel">High Level Structure</a>
				21	<ol>
				22	<li><a href="#modulestructure">Module Structure</a></li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	23	<li><a href="#linkage">Linkage Types</a></li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	24	<li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	25	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	26	<li><a href="#functionstructure">Functions</a></li>
Anton Korobeynikov	c6c98af	2007-04-29 18:02:48 +0000	[diff] [blame]	27	<li><a href="#aliasstructure">Aliases</a>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	28	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	29	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	30	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	31	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	32	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	33	</ol>
				34	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	35	<li><a href="#typesystem">Type System</a>
				36	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	37	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	38	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	39	<ol>
Chris Lattner	4f69f46	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>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	43	</ol>
				44	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	45	<li><a href="#t_derived">Derived Types</a>
				46	<ol>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	47	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	48	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	49	<li><a href="#t_function">Function Type</a></li>
				50	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	51	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	52	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	53	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	54	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	55	</ol>
				56	</li>
				57	</ol>
				58	</li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	59	<li><a href="#constants">Constants</a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	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>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	67	</li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	68	<li><a href="#othervalues">Other Values</a>
				69	<ol>
				70	<li><a href="#inlineasm">Inline Assembler Expressions</a>
				71	</ol>
				72	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	73	<li><a href="#instref">Instruction Reference</a>
				74	<ol>
				75	<li><a href="#terminators">Terminator Instructions</a>
				76	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	77	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				78	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	79	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				80	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	81	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	82	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	83	</ol>
				84	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	85	<li><a href="#binaryops">Binary Operations</a>
				86	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	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>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	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>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	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>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	96	</ol>
				97	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	98	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				99	<ol>
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	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>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	103	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	104	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	105	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	106	</ol>
				107	</li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	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>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	113	</ol>
				114	</li>
Dan Gohman	a334d5f	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>
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	121	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	122	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	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>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	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>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	129	</ol>
				130	</li>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	131	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	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>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	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>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	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>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	144	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	145	</ol>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	146	<li><a href="#otherops">Other Operations</a>
				147	<ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	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	ac80ade	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>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	152	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	153	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	154	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	155	<li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	156	<li><a href="#i_getresult">'<tt>getresult</tt>' Instruction</a></li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	157	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	158	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	159	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	160	</li>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	161	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	162	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	163	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				164	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	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>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	168	</ol>
				169	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	170	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				171	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	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>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	175	</ol>
				176	</li>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	177	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				178	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	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>
John Criswell	7123e27	2004-04-09 16:43:20 +0000	[diff] [blame]	186	</ol>
				187	</li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	188	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				189	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	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	91c284c	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>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	198	</ol>
				199	</li>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	200	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	201	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	202	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	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>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	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>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	208	</ol>
				209	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	210	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	211	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	212	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	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	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	215	</ol>
				216	</li>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	217	<li><a href="#int_atomics">Atomic intrinsics</a>
				218	<ol>
Andrew Lenharth	ab0b949	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	2887310	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	ab0b949	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	2887310	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	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	232	</ol>
				233	</li>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	234	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	235	<ol>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	236	<li><a href="#int_var_annotation">
Tanya Lattner	91d0b88	2007-09-22 00:01:26 +0000	[diff] [blame]	237	<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	238	<li><a href="#int_annotation">
Tanya Lattner	91d0b88	2007-09-22 00:01:26 +0000	[diff] [blame]	239	<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	4cb8618	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	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	242	</ol>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	243	</li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	244	</ol>
				245	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	246	</ol>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	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>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	251	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	252
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	253	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	254	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				255	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	256
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	257	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	258	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	837f39b	2008-08-05 22:29:16 +0000	[diff] [blame]	259	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	d3eda89	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
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	262	representation used throughout all phases of the LLVM compilation
				263	strategy.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	264	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	265
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	266	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	267	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				268	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	269
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	270	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	271
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	272	<p>The LLVM code representation is designed to be used in three
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	273	different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	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>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	281
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	282	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	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>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	292
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	293	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	294
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	295	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	296	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	297
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	298	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	299
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	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>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	304
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	305	<div class="doc_code">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	306	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	307	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	308	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	309	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	310
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	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
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	314	automatically run by the parser after parsing input assembly and by
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	315	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	316	by the verifier pass indicate bugs in transformation passes or input to
				317	the parser.</p>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	318	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	319
Chris Lattner	cc68939	2007-10-03 17:34:29 +0000	[diff] [blame]	320	<!-- Describe the typesetting conventions here. -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	321
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	322	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	323	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	324	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	325
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	326	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	327
Reid Spencer	2c45228	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:
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	332
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	333	<ol>
Reid Spencer	2c45228	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>'.
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	337	Identifiers which require other characters in their names can be surrounded
Reid Spencer	2c45228	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>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	340
Reid Spencer	2c45228	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>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	343
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	344	<li>Constants, which are described in a <a href="#constants">section about
				345	constants</a>, below.</li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	346	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	347
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	348	<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattner	e5d947b	2004-12-09 16:36:40 +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
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	354	<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	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
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	359	href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	360	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	361	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +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
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	366	<p>The easy way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	367
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	368	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	369	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	370	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	371	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	372	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	373
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	374	<p>After strength reduction:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	375
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	376	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	377	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	378	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	379	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	380	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	381
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	382	<p>And the hard way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	383
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	384	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	385	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	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
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	389	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	390	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	391
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	392	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				393	important lexical features of LLVM:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	394
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	395	<ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	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
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	403	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	404
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	405	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	406
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	407	<p>...and it also shows a convention that we follow in this document. When
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	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
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	412	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	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
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	431	<div class="doc_code">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	432	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	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>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	435
				436	<i>; External declaration of the puts function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	437	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	438
				439	<i>; Definition of main function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	440	define i32 @main() { <i>; i32()* </i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	441	<i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	442	%cast210 = <a
Chris Lattner	6c0955b	2007-06-12 17:01:15 +0000	[diff] [blame]	443	href="#i_getelementptr">getelementptr</a> [13 x i8 ]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	444
				445	<i>; Call puts function to write out the string to stdout...</i>
				446	<a
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	447	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	448	<a
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	449	href="#i_ret">ret</a> i32 0<br>}<br>
				450	</pre>
				451	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	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
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	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>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	463
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	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>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	476
				477	<dl>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	478
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	479	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +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
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	486	'<tt>static</tt>' keyword in C.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	487	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	488
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	489	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	490
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	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.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	496	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	497
Dale Johannesen	2307a7f	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
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	508	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	509
Dale Johannesen	2307a7f	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.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	514	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	515
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	516	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	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.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	523	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	524
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	525	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner	d3eda89	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.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	529	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	530
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	531	<dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	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.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	536	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	537	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	538
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	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	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	542	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	543	</p>
				544
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	545	<dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	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
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	563	</dl>
				564
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	565	<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	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
Reid Spencer	ac8d276	2007-01-05 00:59:10 +0000	[diff] [blame]	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>,
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	573	or <tt>extern_weak</tt>.</p>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	574	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
				575	linkages.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	576	</div>
				577
				578	<!-- ======================================================================= -->
				579	<div class="doc_subsection">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	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
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	597	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	598	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	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	d3eda89	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	9097d14	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.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +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
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	624	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	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>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	630	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	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">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	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	d3eda89	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
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +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
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	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>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	676	</dl>
				677
				678	</div>
				679
				680	<!-- ======================================================================= -->
				681	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	682	<a name="globalvars">Global Variables</a>
				683	</div>
				684
				685	<div class="doc_text">
				686
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	687	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	688	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	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
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	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
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	696	cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	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>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	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	284d992	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	d49e18d	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	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	718
Chris Lattner	88f6c46	2005-11-12 00:45:07 +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
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	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	284d992	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>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	730
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	731	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	732	<pre>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	733	@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	734	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	735	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	736
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	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
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	747	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				748	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	749	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	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
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	753	<a href="#paramattrs">parameter attributes</a>), an optional section, an
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	754	optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	0c46a7d	2008-10-04 18:10:21 +0000	[diff] [blame^]	755	an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	756
				757	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				758	optional <a href="#linkage">linkage type</a>, an optional
				759	<a href="#visibility">visibility style</a>, an optional
				760	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	761	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	762	name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksen	e754abe	2007-12-10 03:30:21 +0000	[diff] [blame]	763	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	764
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	765	<p>A function definition contains a list of basic blocks, forming the CFG
				766	(Control Flow Graph) for
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	767	the function. Each basic block may optionally start with a label (giving the
				768	basic block a symbol table entry), contains a list of instructions, and ends
				769	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				770	function return).</p>
				771
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	772	<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	773	executed on entrance to the function, and it is not allowed to have predecessor
				774	basic blocks (i.e. there can not be any branches to the entry block of a
				775	function). Because the block can have no predecessors, it also cannot have any
				776	<a href="#i_phi">PHI nodes</a>.</p>
				777
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	778	<p>LLVM allows an explicit section to be specified for functions. If the target
				779	supports it, it will emit functions to the section specified.</p>
				780
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	781	<p>An explicit alignment may be specified for a function. If not present, or if
				782	the alignment is set to zero, the alignment of the function is set by the target
				783	to whatever it feels convenient. If an explicit alignment is specified, the
				784	function is forced to have at least that much alignment. All alignments must be
				785	a power of 2.</p>
				786
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	787	</div>
				788
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	789
				790	<!-- ======================================================================= -->
				791	<div class="doc_subsection">
				792	<a name="aliasstructure">Aliases</a>
				793	</div>
				794	<div class="doc_text">
				795	<p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov	726d45c	2008-03-22 08:36:14 +0000	[diff] [blame]	796	function, global variable, another alias or bitcast of global value). Aliases
				797	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	798	optional <a href="#visibility">visibility style</a>.</p>
				799
				800	<h5>Syntax:</h5>
				801
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	802	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	803	<pre>
Duncan Sands	0b23ac1	2008-09-12 20:48:21 +0000	[diff] [blame]	804	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	805	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	806	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	807
				808	</div>
				809
				810
				811
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	812	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	813	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				814	<div class="doc_text">
				815	<p>The return type and each parameter of a function type may have a set of
				816	<i>parameter attributes</i> associated with them. Parameter attributes are
				817	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	818	a function. Parameter attributes are considered to be part of the function,
				819	not of the function type, so functions with different parameter attributes
				820	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	821
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	822	<p>Parameter attributes are simple keywords that follow the type specified. If
				823	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	824	example:</p>
				825
				826	<div class="doc_code">
				827	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	828	declare i32 @printf(i8* noalias , ...)
				829	declare i32 @atoi(i8 zeroext*)
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	830	</pre>
				831	</div>
				832
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	833	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				834	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	835
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	836	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	837	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	838	<dt><tt>zeroext</tt></dt>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	839	<dd>This indicates that the parameter should be zero extended just before
				840	a call to this function.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	841
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	842	<dt><tt>signext</tt></dt>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	843	<dd>This indicates that the parameter should be sign extended just before
				844	a call to this function.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	845
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	846	<dt><tt>inreg</tt></dt>
Dale Johannesen	c9c6da6	2008-09-25 20:47:45 +0000	[diff] [blame]	847	<dd>This indicates that this parameter or return value should be treated
				848	in a special target-dependent fashion during while emitting code for a
				849	function call or return (usually, by putting it in a register as opposed
				850	to memory; in some places it is used to distinguish between two different
				851	kinds of registers). Use of this attribute is target-specific</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	852
				853	<dt><tt>byval</tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	854	<dd>This indicates that the pointer parameter should really be passed by
				855	value to the function. The attribute implies that a hidden copy of the
				856	pointee is made between the caller and the callee, so the callee is unable
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	857	to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	858	pointer arguments. It is generally used to pass structs and arrays by
				859	value, but is also valid on scalars (even though this is silly).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	860
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	861	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	862	<dd>This indicates that the pointer parameter specifies the address of a
				863	structure that is the return value of the function in the source program.
Duncan Sands	b7f0c08	2008-03-17 12:17:41 +0000	[diff] [blame]	864	Loads and stores to the structure are assumed not to trap.
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	865	May only be applied to the first parameter.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	866
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	867	<dt><tt>noalias</tt></dt>
Owen Anderson	117bbd3	2008-02-18 04:09:01 +0000	[diff] [blame]	868	<dd>This indicates that the parameter does not alias any global or any other
				869	parameter. The caller is responsible for ensuring that this is the case,
				870	usually by placing the value in a stack allocation.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	871
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	872	<dt><tt>nest</tt></dt>
Duncan Sands	0789b8b	2008-07-08 09:27:25 +0000	[diff] [blame]	873	<dd>This indicates that the pointer parameter can be excised using the
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	874	<a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	875	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	876
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	877	</div>
				878
				879	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	880	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	881	<a name="gc">Garbage Collector Names</a>
				882	</div>
				883
				884	<div class="doc_text">
				885	<p>Each function may specify a garbage collector name, which is simply a
				886	string.</p>
				887
				888	<div class="doc_code"><pre
				889	>define void @f() gc "name" { ...</pre></div>
				890
				891	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				892	collector which will cause the compiler to alter its output in order to support
				893	the named garbage collection algorithm.</p>
				894	</div>
				895
				896	<!-- ======================================================================= -->
				897	<div class="doc_subsection">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	898	<a name="fnattrs">Function Attributes</a>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	899	</div>
				900
				901	<div class="doc_text">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	902
				903	<p>Function attributes are set to communicate additional information about
				904	a function. Function attributes are considered to be part of the function,
				905	not of the function type, so functions with different parameter attributes
				906	can have the same function type.</p>
				907
				908	<p>Function attributes are simple keywords that follow the type specified. If
				909	multiple attributes are needed, they are space separated. For
				910	example:</p>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	911
				912	<div class="doc_code">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	913	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	914	define void @f() noinline { ... }
				915	define void @f() alwaysinline { ... }
				916	define void @f() alwaysinline optsize { ... }
				917	define void @f() optsize
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	918	</pre>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	919	</div>
				920
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	921	<dl>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	922	<dt><tt>alwaysinline</tt></dt>
				923	<dd>This attribute requests inliner to inline this function irrespective of
				924	inlining size threshold for this function.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	925
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	926	<dt><tt>noinline</tt></dt>
				927	<dd>This attributes requests inliner to never inline this function in any
				928	situation. This attribute may not be used together with <tt>alwaysinline</tt>
				929	attribute.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	930
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	931	<dt><tt>optsize</tt></dt>
Devang Patel	66c6c65	2008-09-29 18:34:44 +0000	[diff] [blame]	932	<dd>This attribute suggests that optimization passes and code generator passes
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	933	make choices that help reduce code size.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	934
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	935	<dt><tt>noreturn</tt></dt>
				936	<dd>This function attribute indicates that the function never returns. This
Devang Patel	1260205	2008-09-29 18:16:09 +0000	[diff] [blame]	937	tells LLVM that every call to this function should be treated as if
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	938	an <tt>unreachable</tt> instruction immediately followed the call.</dd>
				939
				940	<dt><tt>nounwind</tt></dt>
				941	<dd>This function attribute indicates that no exceptions unwind out of the
				942	function. Usually this is because the function makes no use of exceptions,
				943	but it may also be that the function catches any exceptions thrown when
				944	executing it.</dd>
				945
				946	<dt><tt>readonly</tt></dt>
				947	<dd>This function attribute indicates that the function has no side-effects
				948	except for producing a return value or throwing an exception. The value
				949	returned must only depend on the function arguments and/or global variables.
				950	It may use values obtained by dereferencing pointers.</dd>
				951	<dt><tt>readnone</tt></dt>
				952	<dd>A <tt>readnone</tt> function has the same restrictions as a <tt>readonly</tt>
				953	function, but in addition it is not allowed to dereference any pointer arguments
				954	or global variables.
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	955	</dl>
				956
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	957	</div>
				958
				959	<!-- ======================================================================= -->
				960	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	961	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	962	</div>
				963
				964	<div class="doc_text">
				965	<p>
				966	Modules may contain "module-level inline asm" blocks, which corresponds to the
				967	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				968	LLVM and treated as a single unit, but may be separated in the .ll file if
				969	desired. The syntax is very simple:
				970	</p>
				971
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	972	<div class="doc_code">
				973	<pre>
				974	module asm "inline asm code goes here"
				975	module asm "more can go here"
				976	</pre>
				977	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	978
				979	<p>The strings can contain any character by escaping non-printable characters.
				980	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				981	for the number.
				982	</p>
				983
				984	<p>
				985	The inline asm code is simply printed to the machine code .s file when
				986	assembly code is generated.
				987	</p>
				988	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	989
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	990	<!-- ======================================================================= -->
				991	<div class="doc_subsection">
				992	<a name="datalayout">Data Layout</a>
				993	</div>
				994
				995	<div class="doc_text">
				996	<p>A module may specify a target specific data layout string that specifies how
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	997	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				998	<pre> target datalayout = "<i>layout specification</i>"</pre>
				999	<p>The <i>layout specification</i> consists of a list of specifications
				1000	separated by the minus sign character ('-'). Each specification starts with a
				1001	letter and may include other information after the letter to define some
				1002	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1003	<dl>
				1004	<dt><tt>E</tt></dt>
				1005	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1006	bits with the most significance have the lowest address location.</dd>
				1007	<dt><tt>e</tt></dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1008	<dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1009	the bits with the least significance have the lowest address location.</dd>
				1010	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1011	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1012	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1013	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1014	too.</dd>
				1015	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1016	<dd>This specifies the alignment for an integer type of a given bit
				1017	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1018	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1019	<dd>This specifies the alignment for a vector type of a given bit
				1020	<i>size</i>.</dd>
				1021	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1022	<dd>This specifies the alignment for a floating point type of a given bit
				1023	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1024	(double).</dd>
				1025	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1026	<dd>This specifies the alignment for an aggregate type of a given bit
				1027	<i>size</i>.</dd>
				1028	</dl>
				1029	<p>When constructing the data layout for a given target, LLVM starts with a
				1030	default set of specifications which are then (possibly) overriden by the
				1031	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1032	are given in this list:</p>
				1033	<ul>
				1034	<li><tt>E</tt> - big endian</li>
				1035	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1036	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1037	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1038	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1039	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1040	<li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1041	alignment of 64-bits</li>
				1042	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1043	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1044	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1045	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1046	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				1047	</ul>
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	1048	<p>When LLVM is determining the alignment for a given type, it uses the
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1049	following rules:
				1050	<ol>
				1051	<li>If the type sought is an exact match for one of the specifications, that
				1052	specification is used.</li>
				1053	<li>If no match is found, and the type sought is an integer type, then the
				1054	smallest integer type that is larger than the bitwidth of the sought type is
				1055	used. If none of the specifications are larger than the bitwidth then the the
				1056	largest integer type is used. For example, given the default specifications
				1057	above, the i7 type will use the alignment of i8 (next largest) while both
				1058	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1059	<li>If no match is found, and the type sought is a vector type, then the
				1060	largest vector type that is smaller than the sought vector type will be used
				1061	as a fall back. This happens because <128 x double> can be implemented in
				1062	terms of 64 <2 x double>, for example.</li>
				1063	</ol>
				1064	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1065
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1066	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1067	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1068	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1069
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1070	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1071
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1072	<p>The LLVM type system is one of the most important features of the
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1073	intermediate representation. Being typed enables a number of
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1074	optimizations to be performed on the intermediate representation directly,
				1075	without having to do
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1076	extra analyses on the side before the transformation. A strong type
				1077	system makes it easier to read the generated code and enables novel
				1078	analyses and transformations that are not feasible to perform on normal
				1079	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1080
				1081	</div>
				1082
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1083	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1084	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1085	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1086	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1087	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1088	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1089
				1090	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1091	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1092	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1093	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1094	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1095	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1096	</tr>
				1097	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1098	<td><a href="#t_floating">floating point</a></td>
				1099	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1100	</tr>
				1101	<tr>
				1102	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1103	<td><a href="#t_integer">integer</a>,
				1104	<a href="#t_floating">floating point</a>,
				1105	<a href="#t_pointer">pointer</a>,
Dan Gohman	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame]	1106	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1107	<a href="#t_struct">structure</a>,
				1108	<a href="#t_array">array</a>,
Dan Gohman	ade5faa	2008-05-23 22:50:26 +0000	[diff] [blame]	1109	<a href="#t_label">label</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1110	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1111	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1112	<tr>
				1113	<td><a href="#t_primitive">primitive</a></td>
				1114	<td><a href="#t_label">label</a>,
				1115	<a href="#t_void">void</a>,
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1116	<a href="#t_floating">floating point</a>.</td>
				1117	</tr>
				1118	<tr>
				1119	<td><a href="#t_derived">derived</a></td>
				1120	<td><a href="#t_integer">integer</a>,
				1121	<a href="#t_array">array</a>,
				1122	<a href="#t_function">function</a>,
				1123	<a href="#t_pointer">pointer</a>,
				1124	<a href="#t_struct">structure</a>,
				1125	<a href="#t_pstruct">packed structure</a>,
				1126	<a href="#t_vector">vector</a>,
				1127	<a href="#t_opaque">opaque</a>.
				1128	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1129	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1130	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1131
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1132	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1133	most important. Values of these types are the only ones which can be
				1134	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1135	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1136	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1137
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1138	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1139	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1140
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1141	<div class="doc_text">
				1142	<p>The primitive types are the fundamental building blocks of the LLVM
				1143	system.</p>
				1144
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1145	</div>
				1146
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1147	<!-- _______________________________________________________________________ -->
				1148	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1149
				1150	<div class="doc_text">
				1151	<table>
				1152	<tbody>
				1153	<tr><th>Type</th><th>Description</th></tr>
				1154	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1155	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1156	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1157	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1158	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1159	</tbody>
				1160	</table>
				1161	</div>
				1162
				1163	<!-- _______________________________________________________________________ -->
				1164	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1165
				1166	<div class="doc_text">
				1167	<h5>Overview:</h5>
				1168	<p>The void type does not represent any value and has no size.</p>
				1169
				1170	<h5>Syntax:</h5>
				1171
				1172	<pre>
				1173	void
				1174	</pre>
				1175	</div>
				1176
				1177	<!-- _______________________________________________________________________ -->
				1178	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1179
				1180	<div class="doc_text">
				1181	<h5>Overview:</h5>
				1182	<p>The label type represents code labels.</p>
				1183
				1184	<h5>Syntax:</h5>
				1185
				1186	<pre>
				1187	label
				1188	</pre>
				1189	</div>
				1190
				1191
				1192	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1193	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1194
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1195	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1196
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1197	<p>The real power in LLVM comes from the derived types in the system.
				1198	This is what allows a programmer to represent arrays, functions,
				1199	pointers, and other useful types. Note that these derived types may be
				1200	recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1201
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1202	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1203
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1204	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1205	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1206
				1207	<div class="doc_text">
				1208
				1209	<h5>Overview:</h5>
				1210	<p>The integer type is a very simple derived type that simply specifies an
				1211	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1212	2^23-1 (about 8 million) can be specified.</p>
				1213
				1214	<h5>Syntax:</h5>
				1215
				1216	<pre>
				1217	iN
				1218	</pre>
				1219
				1220	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1221	value.</p>
				1222
				1223	<h5>Examples:</h5>
				1224	<table class="layout">
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1225	<tbody>
				1226	<tr>
				1227	<td><tt>i1</tt></td>
				1228	<td>a single-bit integer.</td>
				1229	</tr><tr>
				1230	<td><tt>i32</tt></td>
				1231	<td>a 32-bit integer.</td>
				1232	</tr><tr>
				1233	<td><tt>i1942652</tt></td>
				1234	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1235	</tr>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1236	</tbody>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1237	</table>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1238	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1239
				1240	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1241	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1242
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1243	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1244
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1245	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1246
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1247	<p>The array type is a very simple derived type that arranges elements
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1248	sequentially in memory. The array type requires a size (number of
				1249	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1250
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1251	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1252
				1253	<pre>
				1254	[<# elements> x <elementtype>]
				1255	</pre>
				1256
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1257	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1258	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1259
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1260	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1261	<table class="layout">
				1262	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1263	<td class="left"><tt>[40 x i32]</tt></td>
				1264	<td class="left">Array of 40 32-bit integer values.</td>
				1265	</tr>
				1266	<tr class="layout">
				1267	<td class="left"><tt>[41 x i32]</tt></td>
				1268	<td class="left">Array of 41 32-bit integer values.</td>
				1269	</tr>
				1270	<tr class="layout">
				1271	<td class="left"><tt>[4 x i8]</tt></td>
				1272	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1273	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1274	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1275	<p>Here are some examples of multidimensional arrays:</p>
				1276	<table class="layout">
				1277	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1278	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1279	<td class="left">3x4 array of 32-bit integer values.</td>
				1280	</tr>
				1281	<tr class="layout">
				1282	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1283	<td class="left">12x10 array of single precision floating point values.</td>
				1284	</tr>
				1285	<tr class="layout">
				1286	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1287	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1288	</tr>
				1289	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1290
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1291	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1292	length array. Normally, accesses past the end of an array are undefined in
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1293	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1294	As a special case, however, zero length arrays are recognized to be variable
				1295	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1296	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1297
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1298	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1299
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1300	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1301	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1302	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1303
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1304	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1305
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1306	<p>The function type can be thought of as a function signature. It
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1307	consists of a return type and a list of formal parameter types. The
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1308	return type of a function type is a scalar type, a void type, or a struct type.
Devang Patel	7a3ad1a	2008-03-24 20:52:42 +0000	[diff] [blame]	1309	If the return type is a struct type then all struct elements must be of first
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1310	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1311
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1312	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1313
				1314	<pre>
				1315	<returntype list> (<parameter list>)
				1316	</pre>
				1317
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1318	<p>...where '<tt><parameter list></tt>' is a comma-separated list of type
Misha Brukman	c24b758	2004-08-12 20:16:08 +0000	[diff] [blame]	1319	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1320	which indicates that the function takes a variable number of arguments.
				1321	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1322	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1323	'<tt><returntype list></tt>' is a comma-separated list of
				1324	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1325
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1326	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1327	<table class="layout">
				1328	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1329	<td class="left"><tt>i32 (i32)</tt></td>
				1330	<td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1331	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1332	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1333	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1334	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1335	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1336	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1337	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1338	<tt>float</tt>.
				1339	</td>
				1340	</tr><tr class="layout">
				1341	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1342	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1343	<a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1344	which returns an integer. This is the signature for <tt>printf</tt> in
				1345	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1346	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1347	</tr><tr class="layout">
				1348	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel	3a5bff8	2008-03-24 18:10:52 +0000	[diff] [blame]	1349	<td class="left">A function taking an <tt>i32></tt>, returning two
				1350	<tt> i32 </tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1351	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1352	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1353	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1354
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1355	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1356	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1357	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1358	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1359	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1360	<p>The structure type is used to represent a collection of data members
				1361	together in memory. The packing of the field types is defined to match
				1362	the ABI of the underlying processor. The elements of a structure may
				1363	be any type that has a size.</p>
				1364	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1365	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1366	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1367	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1368	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1369	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1370	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1371	<table class="layout">
				1372	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1373	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1374	<td class="left">A triple of three <tt>i32</tt> values</td>
				1375	</tr><tr class="layout">
				1376	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1377	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1378	second element is a <a href="#t_pointer">pointer</a> to a
				1379	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1380	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1381	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1382	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1383	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1384
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1385	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1386	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1387	</div>
				1388	<div class="doc_text">
				1389	<h5>Overview:</h5>
				1390	<p>The packed structure type is used to represent a collection of data members
				1391	together in memory. There is no padding between fields. Further, the alignment
				1392	of a packed structure is 1 byte. The elements of a packed structure may
				1393	be any type that has a size.</p>
				1394	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1395	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1396	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1397	instruction.</p>
				1398	<h5>Syntax:</h5>
				1399	<pre> < { <type list> } > <br></pre>
				1400	<h5>Examples:</h5>
				1401	<table class="layout">
				1402	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1403	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1404	<td class="left">A triple of three <tt>i32</tt> values</td>
				1405	</tr><tr class="layout">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1406	<td class="left">
				1407	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1408	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1409	second element is a <a href="#t_pointer">pointer</a> to a
				1410	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1411	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1412	</tr>
				1413	</table>
				1414	</div>
				1415
				1416	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1417	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1418	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1419	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1420	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1421	reference to another object, which must live in memory. Pointer types may have
				1422	an optional address space attribute defining the target-specific numbered
				1423	address space where the pointed-to object resides. The default address space is
				1424	zero.</p>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1425	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1426	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1427	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1428	<table class="layout">
				1429	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1430	<td class="left"><tt>[4x i32]*</tt></td>
				1431	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1432	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1433	</tr>
				1434	<tr class="layout">
				1435	<td class="left"><tt>i32 (i32 ) </tt></td>
				1436	<td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1437	href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1438	<tt>i32</tt>.</td>
				1439	</tr>
				1440	<tr class="layout">
				1441	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1442	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1443	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1444	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1445	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1446	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1447
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1448	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1449	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1450	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1451
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1452	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1453
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1454	<p>A vector type is a simple derived type that represents a vector
				1455	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1456	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1457	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1458	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1459	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1460	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1461
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1462	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1463
				1464	<pre>
				1465	< <# elements> x <elementtype> >
				1466	</pre>
				1467
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1468	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1469	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1470
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1471	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1472
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1473	<table class="layout">
				1474	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1475	<td class="left"><tt><4 x i32></tt></td>
				1476	<td class="left">Vector of 4 32-bit integer values.</td>
				1477	</tr>
				1478	<tr class="layout">
				1479	<td class="left"><tt><8 x float></tt></td>
				1480	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1481	</tr>
				1482	<tr class="layout">
				1483	<td class="left"><tt><2 x i64></tt></td>
				1484	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1485	</tr>
				1486	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1487	</div>
				1488
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1489	<!-- _______________________________________________________________________ -->
				1490	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1491	<div class="doc_text">
				1492
				1493	<h5>Overview:</h5>
				1494
				1495	<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen	8ac04ff	2007-10-14 00:34:53 +0000	[diff] [blame]	1496	corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1497	In LLVM, opaque types can eventually be resolved to any type (not just a
				1498	structure type).</p>
				1499
				1500	<h5>Syntax:</h5>
				1501
				1502	<pre>
				1503	opaque
				1504	</pre>
				1505
				1506	<h5>Examples:</h5>
				1507
				1508	<table class="layout">
				1509	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1510	<td class="left"><tt>opaque</tt></td>
				1511	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1512	</tr>
				1513	</table>
				1514	</div>
				1515
				1516
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1517	<!-- *********************************************************************** -->
				1518	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1519	<!-- *********************************************************************** -->
				1520
				1521	<div class="doc_text">
				1522
				1523	<p>LLVM has several different basic types of constants. This section describes
				1524	them all and their syntax.</p>
				1525
				1526	</div>
				1527
				1528	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1529	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1530
				1531	<div class="doc_text">
				1532
				1533	<dl>
				1534	<dt><b>Boolean constants</b></dt>
				1535
				1536	<dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1537	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1538	</dd>
				1539
				1540	<dt><b>Integer constants</b></dt>
				1541
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1542	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1543	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1544	integer types.
				1545	</dd>
				1546
				1547	<dt><b>Floating point constants</b></dt>
				1548
				1549	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1550	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1551	notation (see below). The assembler requires the exact decimal value of
				1552	a floating-point constant. For example, the assembler accepts 1.25 but
				1553	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1554	constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1555
				1556	<dt><b>Null pointer constants</b></dt>
				1557
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1558	<dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1559	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1560
				1561	</dl>
				1562
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1563	<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1564	of floating point constants. For example, the form '<tt>double
				1565	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1566	4.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1567	(and the only time that they are generated by the disassembler) is when a
				1568	floating point constant must be emitted but it cannot be represented as a
				1569	decimal floating point number. For example, NaN's, infinities, and other
				1570	special values are represented in their IEEE hexadecimal format so that
				1571	assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1572
				1573	</div>
				1574
				1575	<!-- ======================================================================= -->
				1576	<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
				1577	</div>
				1578
				1579	<div class="doc_text">
Chris Lattner	d4f6b17	2005-03-07 22:13:59 +0000	[diff] [blame]	1580	<p>Aggregate constants arise from aggregation of simple constants
				1581	and smaller aggregate constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1582
				1583	<dl>
				1584	<dt><b>Structure constants</b></dt>
				1585
				1586	<dd>Structure constants are represented with notation similar to structure
				1587	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1588	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1589	where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Chris Lattner	d4f6b17	2005-03-07 22:13:59 +0000	[diff] [blame]	1590	must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1591	types of elements must match those specified by the type.
				1592	</dd>
				1593
				1594	<dt><b>Array constants</b></dt>
				1595
				1596	<dd>Array constants are represented with notation similar to array type
				1597	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1598	(<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1599	constants must have <a href="#t_array">array type</a>, and the number and
				1600	types of elements must match those specified by the type.
				1601	</dd>
				1602
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1603	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1604
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1605	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1606	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1607	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1608	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1609	href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1610	match those specified by the type.
				1611	</dd>
				1612
				1613	<dt><b>Zero initialization</b></dt>
				1614
				1615	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1616	value to zero of <em>any</em> type, including scalar and aggregate types.
				1617	This is often used to avoid having to print large zero initializers (e.g. for
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1618	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1619	initializers.
				1620	</dd>
				1621	</dl>
				1622
				1623	</div>
				1624
				1625	<!-- ======================================================================= -->
				1626	<div class="doc_subsection">
				1627	<a name="globalconstants">Global Variable and Function Addresses</a>
				1628	</div>
				1629
				1630	<div class="doc_text">
				1631
				1632	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1633	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1634	constants. These constants are explicitly referenced when the <a
				1635	href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1636	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1637	file:</p>
				1638
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1639	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1640	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1641	@X = global i32 17
				1642	@Y = global i32 42
				1643	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1644	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1645	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1646
				1647	</div>
				1648
				1649	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1650	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1651	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1652	<p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1653	no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1654	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1655
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1656	<p>Undefined values indicate to the compiler that the program is well defined
				1657	no matter what value is used, giving the compiler more freedom to optimize.
				1658	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1659	</div>
				1660
				1661	<!-- ======================================================================= -->
				1662	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1663	</div>
				1664
				1665	<div class="doc_text">
				1666
				1667	<p>Constant expressions are used to allow expressions involving other constants
				1668	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1669	href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1670	that does not have side effects (e.g. load and call are not supported). The
				1671	following is the syntax for constant expressions:</p>
				1672
				1673	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1674	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1675	<dd>Truncate a constant to another type. The bit size of CST must be larger
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1676	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1677
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1678	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1679	<dd>Zero extend a constant to another type. The bit size of CST must be
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1680	smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1681
				1682	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1683	<dd>Sign extend a constant to another type. The bit size of CST must be
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1684	smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1685
				1686	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1687	<dd>Truncate a floating point constant to another floating point type. The
				1688	size of CST must be larger than the size of TYPE. Both types must be
				1689	floating point.</dd>
				1690
				1691	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1692	<dd>Floating point extend a constant to another type. The size of CST must be
				1693	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1694
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1695	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1696	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1697	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1698	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1699	of the same number of elements. If the value won't fit in the integer type,
				1700	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1701
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1702	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1703	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1704	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1705	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1706	of the same number of elements. If the value won't fit in the integer type,
				1707	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1708
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1709	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1710	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1711	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1712	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1713	of the same number of elements. If the value won't fit in the floating point
				1714	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1715
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1716	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1717	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1718	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1719	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1720	of the same number of elements. If the value won't fit in the floating point
				1721	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1722
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1723	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1724	<dd>Convert a pointer typed constant to the corresponding integer constant
				1725	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1726	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1727
				1728	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1729	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1730	pointer type. CST must be of integer type. The CST value is zero extended,
				1731	truncated, or unchanged to make it fit in a pointer size. This one is
				1732	<i>really</i> dangerous!</dd>
				1733
				1734	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1735	<dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
				1736	identical (same number of bits). The conversion is done as if the CST value
				1737	was stored to memory and read back as TYPE. In other words, no bits change
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1738	with this operator, just the type. This can be used for conversion of
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1739	vector types to any other type, as long as they have the same bit width. For
Dan Gohman	500233a	2008-09-08 16:45:59 +0000	[diff] [blame]	1740	pointers it is only valid to cast to another pointer type. It is not valid
				1741	to bitcast to or from an aggregate type.
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1742	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1743
				1744	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1745
				1746	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1747	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1748	instruction, the index list may have zero or more indexes, which are required
				1749	to make sense for the type of "CSTPTR".</dd>
				1750
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1751	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1752
				1753	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1754	constants.</dd>
				1755
				1756	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1757	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1758
				1759	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1760	<dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1761
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	1762	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1763	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1764
				1765	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1766	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1767
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1768	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1769
				1770	<dd>Perform the <a href="#i_extractelement">extractelement
				1771	operation</a> on constants.
				1772
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1773	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				1774
				1775	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1776	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1777
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1778
				1779	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				1780
				1781	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1782	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1783
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1784	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				1785
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1786	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				1787	be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1788	binary</a> operations. The constraints on operands are the same as those for
				1789	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1790	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1791	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1792	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	1793
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1794	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1795	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				1796	<!-- *********************************************************************** -->
				1797
				1798	<!-- ======================================================================= -->
				1799	<div class="doc_subsection">
				1800	<a name="inlineasm">Inline Assembler Expressions</a>
				1801	</div>
				1802
				1803	<div class="doc_text">
				1804
				1805	<p>
				1806	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				1807	Module-Level Inline Assembly</a>) through the use of a special value. This
				1808	value represents the inline assembler as a string (containing the instructions
				1809	to emit), a list of operand constraints (stored as a string), and a flag that
				1810	indicates whether or not the inline asm expression has side effects. An example
				1811	inline assembler expression is:
				1812	</p>
				1813
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1814	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1815	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1816	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1817	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1818	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1819
				1820	<p>
				1821	Inline assembler expressions may <b>only</b> be used as the callee operand of
				1822	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				1823	</p>
				1824
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1825	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1826	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1827	%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1828	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1829	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1830
				1831	<p>
				1832	Inline asms with side effects not visible in the constraint list must be marked
				1833	as having side effects. This is done through the use of the
				1834	'<tt>sideeffect</tt>' keyword, like so:
				1835	</p>
				1836
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1837	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1838	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1839	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1840	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1841	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1842
				1843	<p>TODO: The format of the asm and constraints string still need to be
				1844	documented here. Constraints on what can be done (e.g. duplication, moving, etc
				1845	need to be documented).
				1846	</p>
				1847
				1848	</div>
				1849
				1850	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1851	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				1852	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1853
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1854	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1855
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1856	<p>The LLVM instruction set consists of several different
				1857	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1858	instructions</a>, <a href="#binaryops">binary instructions</a>,
				1859	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1860	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				1861	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1862
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1863	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1864
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1865	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1866	<div class="doc_subsection"> <a name="terminators">Terminator
				1867	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1868
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1869	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1870
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1871	<p>As mentioned <a href="#functionstructure">previously</a>, every
				1872	basic block in a program ends with a "Terminator" instruction, which
				1873	indicates which block should be executed after the current block is
				1874	finished. These terminator instructions typically yield a '<tt>void</tt>'
				1875	value: they produce control flow, not values (the one exception being
				1876	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1877	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1878	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				1879	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	1880	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				1881	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				1882	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1883
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1884	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1885
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1886	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1887	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				1888	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1889	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1890	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1891	<pre> ret <type> <value> <i>; Return a value from a non-void function</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1892	ret void <i>; Return from void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1893	ret <type> <value>, <type> <value> <i>; Return two values from a non-void function </i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1894	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1895
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1896	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1897
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1898	<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1899	value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	1900	<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1901	returns value(s) and then causes control flow, and one that just causes
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1902	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1903
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1904	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1905
				1906	<p>The '<tt>ret</tt>' instruction may return zero, one or multiple values.
				1907	The type of each return value must be a '<a href="#t_firstclass">first
				1908	class</a>' type. Note that a function is not <a href="#wellformed">well
				1909	formed</a> if there exists a '<tt>ret</tt>' instruction inside of the
				1910	function that returns values that do not match the return type of the
				1911	function.</p>
				1912
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1913	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1914
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1915	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				1916	returns back to the calling function's context. If the caller is a "<a
John Criswell	fa08187	2004-06-25 15:16:57 +0000	[diff] [blame]	1917	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1918	the instruction after the call. If the caller was an "<a
				1919	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1920	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1921	returns a value, that value shall set the call or invoke instruction's
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1922	return value. If the instruction returns multiple values then these
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	1923	values can only be accessed through a '<a href="#i_getresult"><tt>getresult</tt>
				1924	</a>' instruction.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1925
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1926	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1927
				1928	<pre>
				1929	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1930	ret void <i>; Return from a void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1931	ret i32 4, i8 2 <i>; Return two values 4 and 2 </i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1932	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1933	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1934	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1935	<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1936	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1937	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1938	<pre> br i1 <cond>, label <iftrue>, label <iffalse><br> br label <dest> <i>; Unconditional branch</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1939	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1940	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1941	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				1942	transfer to a different basic block in the current function. There are
				1943	two forms of this instruction, corresponding to a conditional branch
				1944	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1945	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1946	<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1947	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1948	unconditional form of the '<tt>br</tt>' instruction takes a single
				1949	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1950	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1951	<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1952	argument is evaluated. If the value is <tt>true</tt>, control flows
				1953	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				1954	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1955	<h5>Example:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1956	<pre>Test:<br> %cond = <a href="#i_icmp">icmp</a> eq, i32 %a, %b<br> br i1 %cond, label %IfEqual, label %IfUnequal<br>IfEqual:<br> <a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1957	href="#i_ret">ret</a> i32 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> i32 0<br></pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1958	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1959	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1960	<div class="doc_subsubsection">
				1961	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				1962	</div>
				1963
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1964	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1965	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1966
				1967	<pre>
				1968	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				1969	</pre>
				1970
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1971	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1972
				1973	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				1974	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1975	instruction, allowing a branch to occur to one of many possible
				1976	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1977
				1978
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1979	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1980
				1981	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				1982	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				1983	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				1984	table is not allowed to contain duplicate constant entries.</p>
				1985
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1986	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1987
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1988	<p>The <tt>switch</tt> instruction specifies a table of values and
				1989	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	1990	table is searched for the given value. If the value is found, control flow is
				1991	transfered to the corresponding destination; otherwise, control flow is
				1992	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1993
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1994	<h5>Implementation:</h5>
				1995
				1996	<p>Depending on properties of the target machine and the particular
				1997	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	1998	ways. For example, it could be generated as a series of chained conditional
				1999	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2000
				2001	<h5>Example:</h5>
				2002
				2003	<pre>
				2004	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2005	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2006	switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2007
				2008	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2009	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2010
				2011	<i>; Implement a jump table:</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2012	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2013	i32 1, label %onone
				2014	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2015	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2016	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2017
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2018	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2019	<div class="doc_subsubsection">
				2020	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2021	</div>
				2022
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2023	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2024
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2025	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2026
				2027	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2028	<result> = invoke [<a href="#callingconv">cconv</a>] <ptr to function ty> <function ptr val>(<function args>)
Chris Lattner	76b8a33	2006-05-14 18:23:06 +0000	[diff] [blame]	2029	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2030	</pre>
				2031
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	2032	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2033
				2034	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2035	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2036	'<tt>normal</tt>' label or the
				2037	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2038	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2039	"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2040	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	2041	continued at the dynamically nearest "exception" label. If the callee function
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	2042	returns multiple values then individual return values are only accessible through
				2043	a '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2044
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2045	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2046
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2047	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2048
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2049	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2050	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	2051	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2052	convention</a> the call should use. If none is specified, the call defaults
				2053	to using C calling conventions.
				2054	</li>
				2055	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2056	function value being invoked. In most cases, this is a direct function
				2057	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2058	an arbitrary pointer to function value.
				2059	</li>
				2060
				2061	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2062	function to be invoked. </li>
				2063
				2064	<li>'<tt>function args</tt>': argument list whose types match the function
				2065	signature argument types. If the function signature indicates the function
				2066	accepts a variable number of arguments, the extra arguments can be
				2067	specified. </li>
				2068
				2069	<li>'<tt>normal label</tt>': the label reached when the called function
				2070	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2071
				2072	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2073	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2074
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2075	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2076
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2077	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2078
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2079	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2080	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2081	difference is that it establishes an association with a label, which is used by
				2082	the runtime library to unwind the stack.</p>
				2083
				2084	<p>This instruction is used in languages with destructors to ensure that proper
				2085	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2086	exception. Additionally, this is important for implementation of
				2087	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2088
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2089	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2090	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2091	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2092	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2093	%retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2094	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2095	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2096	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2097
				2098
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2099	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2100
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2101	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2102	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2103
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2104	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2105
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2106	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2107	<pre>
				2108	unwind
				2109	</pre>
				2110
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2111	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2112
				2113	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2114	at the first callee in the dynamic call stack which used an <a
				2115	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2116	primarily used to implement exception handling.</p>
				2117
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2118	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2119
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2120	<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2121	immediately halt. The dynamic call stack is then searched for the first <a
				2122	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2123	execution continues at the "exceptional" destination block specified by the
				2124	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2125	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2126	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2127
				2128	<!-- _______________________________________________________________________ -->
				2129
				2130	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2131	Instruction</a> </div>
				2132
				2133	<div class="doc_text">
				2134
				2135	<h5>Syntax:</h5>
				2136	<pre>
				2137	unreachable
				2138	</pre>
				2139
				2140	<h5>Overview:</h5>
				2141
				2142	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2143	instruction is used to inform the optimizer that a particular portion of the
				2144	code is not reachable. This can be used to indicate that the code after a
				2145	no-return function cannot be reached, and other facts.</p>
				2146
				2147	<h5>Semantics:</h5>
				2148
				2149	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2150	</div>
				2151
				2152
				2153
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2154	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2155	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2156	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2157	<p>Binary operators are used to do most of the computation in a
Chris Lattner	5a15814	2008-04-01 18:47:32 +0000	[diff] [blame]	2158	program. They require two operands of the same type, execute an operation on them, and
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2159	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2160	multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattner	5a15814	2008-04-01 18:47:32 +0000	[diff] [blame]	2161	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2162	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2163	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2164	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2165	<div class="doc_subsubsection">
				2166	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2167	</div>
				2168
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2169	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2170
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2171	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2172
				2173	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2174	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2175	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2176
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2177	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2178
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2179	<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2180
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2181	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2182
				2183	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2184	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2185	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2186	types.</p>
				2187
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2188	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2189
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2190	<p>The value produced is the integer or floating point sum of the two
				2191	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2192
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2193	<p>If an integer sum has unsigned overflow, the result returned is the
				2194	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2195	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2196
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2197	<p>Because LLVM integers use a two's complement representation, this
				2198	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2199
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2200	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2201
				2202	<pre>
				2203	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2204	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2205	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2206	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2207	<div class="doc_subsubsection">
				2208	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2209	</div>
				2210
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2211	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2212
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2213	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2214
				2215	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2216	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2217	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2218
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2219	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2220
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2221	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2222	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2223
				2224	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2225	'<tt>neg</tt>' instruction present in most other intermediate
				2226	representations.</p>
				2227
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2228	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2229
				2230	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2231	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2232	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2233	types.</p>
				2234
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2235	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2236
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2237	<p>The value produced is the integer or floating point difference of
				2238	the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2239
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2240	<p>If an integer difference has unsigned overflow, the result returned is the
				2241	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2242	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2243
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2244	<p>Because LLVM integers use a two's complement representation, this
				2245	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2246
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2247	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2248	<pre>
				2249	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2250	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2251	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2252	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2253
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2254	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2255	<div class="doc_subsubsection">
				2256	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2257	</div>
				2258
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2259	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2260
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2261	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2262	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2263	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2264	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2265	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2266	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2267
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2268	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2269
				2270	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2271	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2272	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2273	types.</p>
				2274
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2275	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2276
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2277	<p>The value produced is the integer or floating point product of the
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2278	two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2279
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2280	<p>If the result of an integer multiplication has unsigned overflow,
				2281	the result returned is the mathematical result modulo
				2282	2<sup>n</sup>, where n is the bit width of the result.</p>
				2283	<p>Because LLVM integers use a two's complement representation, and the
				2284	result is the same width as the operands, this instruction returns the
				2285	correct result for both signed and unsigned integers. If a full product
				2286	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2287	should be sign-extended or zero-extended as appropriate to the
				2288	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2289	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2290	<pre> <result> = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2291	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2292	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2293
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2294	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2295	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2296	</a></div>
				2297	<div class="doc_text">
				2298	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2299	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2300	</pre>
				2301	<h5>Overview:</h5>
				2302	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2303	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2304
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2305	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2306
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2307	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2308	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2309	values. Both arguments must have identical types.</p>
				2310
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2311	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2312
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2313	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2314	<p>Note that unsigned integer division and signed integer division are distinct
				2315	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2316	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2317	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2318	<pre> <result> = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2319	</pre>
				2320	</div>
				2321	<!-- _______________________________________________________________________ -->
				2322	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2323	</a> </div>
				2324	<div class="doc_text">
				2325	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2326	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2327	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2328	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2329
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2330	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2331
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2332	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2333	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2334
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2335	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2336
				2337	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2338	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2339	values. Both arguments must have identical types.</p>
				2340
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2341	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2342	<p>The value produced is the signed integer quotient of the two operands rounded towards zero.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2343	<p>Note that signed integer division and unsigned integer division are distinct
				2344	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2345	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2346	undefined behavior; this is a rare case, but can occur, for example,
				2347	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2348	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2349	<pre> <result> = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2350	</pre>
				2351	</div>
				2352	<!-- _______________________________________________________________________ -->
				2353	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2354	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2355	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2356	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2357	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2358	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2359	</pre>
				2360	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2361
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2362	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2363	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2364
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2365	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2366
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2367	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2368	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2369	of floating point values. Both arguments must have identical types.</p>
				2370
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2371	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2372
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2373	<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2374
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2375	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2376
				2377	<pre>
				2378	<result> = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2379	</pre>
				2380	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2381
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2382	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2383	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2384	</div>
				2385	<div class="doc_text">
				2386	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2387	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2388	</pre>
				2389	<h5>Overview:</h5>
				2390	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2391	unsigned division of its two arguments.</p>
				2392	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2393	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2394	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2395	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2396	<h5>Semantics:</h5>
				2397	<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2398	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2399	<p>Note that unsigned integer remainder and signed integer remainder are
				2400	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2401	<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2402	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2403	<pre> <result> = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2404	</pre>
				2405
				2406	</div>
				2407	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2408	<div class="doc_subsubsection">
				2409	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2410	</div>
				2411
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2412	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2413
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2414	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2415
				2416	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2417	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2418	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2419
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2420	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2421
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2422	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2423	signed division of its two operands. This instruction can also take
				2424	<a href="#t_vector">vector</a> versions of the values in which case
				2425	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2426
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2427	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2428
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2429	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2430	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2431	values. Both arguments must have identical types.</p>
				2432
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2433	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2434
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2435	<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2436	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2437	operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2438	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2439	href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2440	Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer	64f5c6c	2007-03-24 22:40:44 +0000	[diff] [blame]	2441	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2442	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2443	<p>Note that signed integer remainder and unsigned integer remainder are
				2444	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2445	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2446	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2447	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2448	(The remainder doesn't actually overflow, but this rule lets srem be
				2449	implemented using instructions that return both the result of the division
				2450	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2451	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2452	<pre> <result> = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2453	</pre>
				2454
				2455	</div>
				2456	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2457	<div class="doc_subsubsection">
				2458	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2459
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2460	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2461
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2462	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2463	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2464	</pre>
				2465	<h5>Overview:</h5>
				2466	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2467	division of its two operands.</p>
				2468	<h5>Arguments:</h5>
				2469	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2470	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2471	of floating point values. Both arguments must have identical types.</p>
				2472
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2473	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2474
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2475	<p>This instruction returns the <i>remainder</i> of a division.
				2476	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2477
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2478	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2479
				2480	<pre>
				2481	<result> = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2482	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2483	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2484
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2485	<!-- ======================================================================= -->
				2486	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2487	Operations</a> </div>
				2488	<div class="doc_text">
				2489	<p>Bitwise binary operators are used to do various forms of
				2490	bit-twiddling in a program. They are generally very efficient
				2491	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2492	instructions. They require two operands of the same type, execute an operation on them,
				2493	and produce a single value. The resulting value is the same type as its operands.</p>
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2494	</div>
				2495
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2496	<!-- _______________________________________________________________________ -->
				2497	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2498	Instruction</a> </div>
				2499	<div class="doc_text">
				2500	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2501	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2502	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2503
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2504	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2505
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2506	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2507	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2508
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2509	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2510
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2511	<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman	5bc1ea0	2008-07-29 15:49:41 +0000	[diff] [blame]	2512	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2513	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2514
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2515	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2516
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2517	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2518	where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
				2519	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2520
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2521	<h5>Example:</h5><pre>
				2522	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2523	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2524	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2525	<result> = shl i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2526	</pre>
				2527	</div>
				2528	<!-- _______________________________________________________________________ -->
				2529	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2530	Instruction</a> </div>
				2531	<div class="doc_text">
				2532	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2533	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2534	</pre>
				2535
				2536	<h5>Overview:</h5>
				2537	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2538	operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2539
				2540	<h5>Arguments:</h5>
				2541	<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman	5bc1ea0	2008-07-29 15:49:41 +0000	[diff] [blame]	2542	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2543	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2544
				2545	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2546
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2547	<p>This instruction always performs a logical shift right operation. The most
				2548	significant bits of the result will be filled with zero bits after the
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2549	shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
				2550	the number of bits in <tt>op1</tt>, the result is undefined.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2551
				2552	<h5>Example:</h5>
				2553	<pre>
				2554	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2555	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2556	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2557	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2558	<result> = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2559	</pre>
				2560	</div>
				2561
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2562	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2563	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2564	Instruction</a> </div>
				2565	<div class="doc_text">
				2566
				2567	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2568	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2569	</pre>
				2570
				2571	<h5>Overview:</h5>
				2572	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2573	operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2574
				2575	<h5>Arguments:</h5>
				2576	<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman	5bc1ea0	2008-07-29 15:49:41 +0000	[diff] [blame]	2577	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2578	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2579
				2580	<h5>Semantics:</h5>
				2581	<p>This instruction always performs an arithmetic shift right operation,
				2582	The most significant bits of the result will be filled with the sign bit
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2583	of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
				2584	larger than the number of bits in <tt>op1</tt>, the result is undefined.
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2585	</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2586
				2587	<h5>Example:</h5>
				2588	<pre>
				2589	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2590	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2591	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2592	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2593	<result> = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2594	</pre>
				2595	</div>
				2596
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2597	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2598	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2599	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2600
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2601	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2602
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2603	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2604
				2605	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2606	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2607	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2608
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2609	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2610
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2611	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2612	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2613
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2614	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2615
				2616	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2617	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2618	values. Both arguments must have identical types.</p>
				2619
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2620	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2621	<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2622	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2623	<div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2624	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2625	<tbody>
				2626	<tr>
				2627	<td>In0</td>
				2628	<td>In1</td>
				2629	<td>Out</td>
				2630	</tr>
				2631	<tr>
				2632	<td>0</td>
				2633	<td>0</td>
				2634	<td>0</td>
				2635	</tr>
				2636	<tr>
				2637	<td>0</td>
				2638	<td>1</td>
				2639	<td>0</td>
				2640	</tr>
				2641	<tr>
				2642	<td>1</td>
				2643	<td>0</td>
				2644	<td>0</td>
				2645	</tr>
				2646	<tr>
				2647	<td>1</td>
				2648	<td>1</td>
				2649	<td>1</td>
				2650	</tr>
				2651	</tbody>
				2652	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2653	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2654	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2655	<pre>
				2656	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2657	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2658	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2659	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2660	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2661	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2662	<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2663	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2664	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2665	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2666	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2667	<h5>Overview:</h5>
				2668	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2669	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2670	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2671
				2672	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2673	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2674	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2675	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2676	<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2677	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2678	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2679	<table border="1" cellspacing="0" cellpadding="4">
				2680	<tbody>
				2681	<tr>
				2682	<td>In0</td>
				2683	<td>In1</td>
				2684	<td>Out</td>
				2685	</tr>
				2686	<tr>
				2687	<td>0</td>
				2688	<td>0</td>
				2689	<td>0</td>
				2690	</tr>
				2691	<tr>
				2692	<td>0</td>
				2693	<td>1</td>
				2694	<td>1</td>
				2695	</tr>
				2696	<tr>
				2697	<td>1</td>
				2698	<td>0</td>
				2699	<td>1</td>
				2700	</tr>
				2701	<tr>
				2702	<td>1</td>
				2703	<td>1</td>
				2704	<td>1</td>
				2705	</tr>
				2706	</tbody>
				2707	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2708	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2709	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2710	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2711	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2712	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2713	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2714	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2715	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2716	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2717	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2718	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2719	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2720	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2721	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2722	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2723	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2724	or of its two operands. The <tt>xor</tt> is used to implement the
				2725	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2726	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2727	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				2728	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2729	values. Both arguments must have identical types.</p>
				2730
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2731	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2732
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2733	<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2734	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2735	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2736	<table border="1" cellspacing="0" cellpadding="4">
				2737	<tbody>
				2738	<tr>
				2739	<td>In0</td>
				2740	<td>In1</td>
				2741	<td>Out</td>
				2742	</tr>
				2743	<tr>
				2744	<td>0</td>
				2745	<td>0</td>
				2746	<td>0</td>
				2747	</tr>
				2748	<tr>
				2749	<td>0</td>
				2750	<td>1</td>
				2751	<td>1</td>
				2752	</tr>
				2753	<tr>
				2754	<td>1</td>
				2755	<td>0</td>
				2756	<td>1</td>
				2757	</tr>
				2758	<tr>
				2759	<td>1</td>
				2760	<td>1</td>
				2761	<td>0</td>
				2762	</tr>
				2763	</tbody>
				2764	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2765	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2766	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2767	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2768	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				2769	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				2770	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				2771	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2772	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2773	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2774
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2775	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2776	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2777	<a name="vectorops">Vector Operations</a>
				2778	</div>
				2779
				2780	<div class="doc_text">
				2781
				2782	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2783	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2784	vector-specific operations needed to process vectors effectively. While LLVM
				2785	does directly support these vector operations, many sophisticated algorithms
				2786	will want to use target-specific intrinsics to take full advantage of a specific
				2787	target.</p>
				2788
				2789	</div>
				2790
				2791	<!-- _______________________________________________________________________ -->
				2792	<div class="doc_subsubsection">
				2793	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				2794	</div>
				2795
				2796	<div class="doc_text">
				2797
				2798	<h5>Syntax:</h5>
				2799
				2800	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2801	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2802	</pre>
				2803
				2804	<h5>Overview:</h5>
				2805
				2806	<p>
				2807	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2808	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2809	</p>
				2810
				2811
				2812	<h5>Arguments:</h5>
				2813
				2814	<p>
				2815	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2816	value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2817	an index indicating the position from which to extract the element.
				2818	The index may be a variable.</p>
				2819
				2820	<h5>Semantics:</h5>
				2821
				2822	<p>
				2823	The result is a scalar of the same type as the element type of
				2824	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				2825	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				2826	results are undefined.
				2827	</p>
				2828
				2829	<h5>Example:</h5>
				2830
				2831	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2832	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2833	</pre>
				2834	</div>
				2835
				2836
				2837	<!-- _______________________________________________________________________ -->
				2838	<div class="doc_subsubsection">
				2839	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				2840	</div>
				2841
				2842	<div class="doc_text">
				2843
				2844	<h5>Syntax:</h5>
				2845
				2846	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	2847	<result> = insertelement <n x <ty>> <val>, <ty> <elt>, i32 <idx> <i>; yields <n x <ty>></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2848	</pre>
				2849
				2850	<h5>Overview:</h5>
				2851
				2852	<p>
				2853	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2854	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2855	</p>
				2856
				2857
				2858	<h5>Arguments:</h5>
				2859
				2860	<p>
				2861	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2862	value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2863	scalar value whose type must equal the element type of the first
				2864	operand. The third operand is an index indicating the position at
				2865	which to insert the value. The index may be a variable.</p>
				2866
				2867	<h5>Semantics:</h5>
				2868
				2869	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2870	The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2871	element values are those of <tt>val</tt> except at position
				2872	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				2873	exceeds the length of <tt>val</tt>, the results are undefined.
				2874	</p>
				2875
				2876	<h5>Example:</h5>
				2877
				2878	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2879	%result = insertelement <4 x i32> %vec, i32 1, i32 0 <i>; yields <4 x i32></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2880	</pre>
				2881	</div>
				2882
				2883	<!-- _______________________________________________________________________ -->
				2884	<div class="doc_subsubsection">
				2885	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				2886	</div>
				2887
				2888	<div class="doc_text">
				2889
				2890	<h5>Syntax:</h5>
				2891
				2892	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2893	<result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <n x i32> <mask> <i>; yields <n x <ty>></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2894	</pre>
				2895
				2896	<h5>Overview:</h5>
				2897
				2898	<p>
				2899	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
				2900	from two input vectors, returning a vector of the same type.
				2901	</p>
				2902
				2903	<h5>Arguments:</h5>
				2904
				2905	<p>
				2906	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				2907	with types that match each other and types that match the result of the
				2908	instruction. The third argument is a shuffle mask, which has the same number
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2909	of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2910	</p>
				2911
				2912	<p>
				2913	The shuffle mask operand is required to be a constant vector with either
				2914	constant integer or undef values.
				2915	</p>
				2916
				2917	<h5>Semantics:</h5>
				2918
				2919	<p>
				2920	The elements of the two input vectors are numbered from left to right across
				2921	both of the vectors. The shuffle mask operand specifies, for each element of
				2922	the result vector, which element of the two input registers the result element
				2923	gets. The element selector may be undef (meaning "don't care") and the second
				2924	operand may be undef if performing a shuffle from only one vector.
				2925	</p>
				2926
				2927	<h5>Example:</h5>
				2928
				2929	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2930	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2931	<4 x i32> <i32 0, i32 4, i32 1, i32 5> <i>; yields <4 x i32></i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2932	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				2933	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> - Identity shuffle.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2934	</pre>
				2935	</div>
				2936
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	2937
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2938	<!-- ======================================================================= -->
				2939	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2940	<a name="aggregateops">Aggregate Operations</a>
				2941	</div>
				2942
				2943	<div class="doc_text">
				2944
				2945	<p>LLVM supports several instructions for working with aggregate values.
				2946	</p>
				2947
				2948	</div>
				2949
				2950	<!-- _______________________________________________________________________ -->
				2951	<div class="doc_subsubsection">
				2952	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				2953	</div>
				2954
				2955	<div class="doc_text">
				2956
				2957	<h5>Syntax:</h5>
				2958
				2959	<pre>
				2960	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				2961	</pre>
				2962
				2963	<h5>Overview:</h5>
				2964
				2965	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2966	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				2967	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2968	</p>
				2969
				2970
				2971	<h5>Arguments:</h5>
				2972
				2973	<p>
				2974	The first operand of an '<tt>extractvalue</tt>' instruction is a
				2975	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2976	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2977	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2978	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2979	</p>
				2980
				2981	<h5>Semantics:</h5>
				2982
				2983	<p>
				2984	The result is the value at the position in the aggregate specified by
				2985	the index operands.
				2986	</p>
				2987
				2988	<h5>Example:</h5>
				2989
				2990	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2991	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2992	</pre>
				2993	</div>
				2994
				2995
				2996	<!-- _______________________________________________________________________ -->
				2997	<div class="doc_subsubsection">
				2998	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				2999	</div>
				3000
				3001	<div class="doc_text">
				3002
				3003	<h5>Syntax:</h5>
				3004
				3005	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3006	<result> = insertvalue <aggregate type> <val>, <ty> <val>, <idx> <i>; yields <n x <ty>></i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3007	</pre>
				3008
				3009	<h5>Overview:</h5>
				3010
				3011	<p>
				3012	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3013	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3014	</p>
				3015
				3016
				3017	<h5>Arguments:</h5>
				3018
				3019	<p>
				3020	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3021	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3022	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	3023	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3024	indicating the position at which to insert the value in a similar manner as
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3025	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3026	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3027	The value to insert must have the same type as the value identified
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3028	by the indices.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3029
				3030	<h5>Semantics:</h5>
				3031
				3032	<p>
				3033	The result is an aggregate of the same type as <tt>val</tt>. Its
				3034	value is that of <tt>val</tt> except that the value at the position
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3035	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3036	</p>
				3037
				3038	<h5>Example:</h5>
				3039
				3040	<pre>
Dan Gohman	52bb2db	2008-06-23 15:26:37 +0000	[diff] [blame]	3041	%result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3042	</pre>
				3043	</div>
				3044
				3045
				3046	<!-- ======================================================================= -->
				3047	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3048	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3049	</div>
				3050
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3051	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3052
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3053	<p>A key design point of an SSA-based representation is how it
				3054	represents memory. In LLVM, no memory locations are in SSA form, which
				3055	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3056	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3057
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3058	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3059
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3060	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3061	<div class="doc_subsubsection">
				3062	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3063	</div>
				3064
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3065	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3066
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3067	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3068
				3069	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3070	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3071	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3072
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3073	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3074
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3075	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3076	heap and returns a pointer to it. The object is always allocated in the generic
				3077	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3078
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3079	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3080
				3081	<p>The '<tt>malloc</tt>' instruction allocates
				3082	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3083	bytes of memory from the operating system and returns a pointer of the
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3084	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3085	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3086	If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3087	be aligned to at least that boundary. If not specified, or if zero, the target can
				3088	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3089
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3090	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3091
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3092	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3093
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3094	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3095	a pointer is returned. The result of a zero byte allocattion is undefined. The
				3096	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3097
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3098	<h5>Example:</h5>
				3099
				3100	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3101	%array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3102
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3103	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3104	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3105	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3106	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3107	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3108	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3109	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3110
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3111	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3112	<div class="doc_subsubsection">
				3113	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3114	</div>
				3115
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3116	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3117
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3118	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3119
				3120	<pre>
				3121	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3122	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3123
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3124	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3125
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3126	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3127	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3128
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3129	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3130
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3131	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3132	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3133	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3134
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3135	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3136
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3137	<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner	e0db56d	2008-04-19 22:41:32 +0000	[diff] [blame]	3138	after this instruction executes. If the pointer is null, the operation
				3139	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3140
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3141	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3142
				3143	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3144	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
				3145	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3146	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3147	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3148
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3149	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3150	<div class="doc_subsubsection">
				3151	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3152	</div>
				3153
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3154	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3155
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3156	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3157
				3158	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3159	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3160	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3161
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3162	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3163
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3164	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3165	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3166	returns to its caller. The object is always allocated in the generic address
				3167	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3168
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3169	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3170
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3171	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3172	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3173	appropriate type to the program. If "NumElements" is specified, it is the
				3174	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3175	If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3176	to be aligned to at least that boundary. If not specified, or if zero, the target
				3177	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3178
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3179	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3180
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3181	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3182
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3183	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3184	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3185	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3186	instruction is commonly used to represent automatic variables that must
				3187	have an address available. When the function returns (either with the <tt><a
John Criswell	dae2e93	2005-05-12 16:55:34 +0000	[diff] [blame]	3188	href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3189	instructions), the memory is reclaimed. Allocating zero bytes
				3190	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3191
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3192	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3193
				3194	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3195	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3196	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3197	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3198	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3199	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3200	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3201
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3202	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3203	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3204	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3205	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3206	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3207	<pre> <result> = load <ty>* <pointer>[, align <alignment>]<br> <result> = volatile load <ty>* <pointer>[, align <alignment>]<br></pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3208	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3209	<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3210	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3211	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3212	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3213	href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3214	marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3215	the number or order of execution of this <tt>load</tt> with other
				3216	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3217	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3218	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3219	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3220	(that is, the alignment of the memory address). A value of 0 or an
				3221	omitted "align" argument means that the operation has the preferential
				3222	alignment for the target. It is the responsibility of the code emitter
				3223	to ensure that the alignment information is correct. Overestimating
				3224	the alignment results in an undefined behavior. Underestimating the
				3225	alignment may produce less efficient code. An alignment of 1 is always
				3226	safe.
				3227	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3228	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3229	<p>The location of memory pointed to is loaded.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3230	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3231	<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3232	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3233	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3234	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3235	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3236	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3237	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3238	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3239	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3240	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3241	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3242	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3243	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3244	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3245	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3246	<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3247	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3248	<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3249	to store and an address at which to store it. The type of the '<tt><pointer></tt>'
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3250	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3251	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3252	operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3253	optimizer is not allowed to modify the number or order of execution of
				3254	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3255	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3256	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3257	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3258	(that is, the alignment of the memory address). A value of 0 or an
				3259	omitted "align" argument means that the operation has the preferential
				3260	alignment for the target. It is the responsibility of the code emitter
				3261	to ensure that the alignment information is correct. Overestimating
				3262	the alignment results in an undefined behavior. Underestimating the
				3263	alignment may produce less efficient code. An alignment of 1 is always
				3264	safe.
				3265	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3266	<h5>Semantics:</h5>
				3267	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3268	at the location specified by the '<tt><pointer></tt>' operand.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3269	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3270	<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	8c6c72d	2007-10-22 05:10:05 +0000	[diff] [blame]	3271	store i32 3, i32* %ptr <i>; yields {void}</i>
				3272	%val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3273	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3274	</div>
				3275
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3276	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3277	<div class="doc_subsubsection">
				3278	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3279	</div>
				3280
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3281	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3282	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3283	<pre>
				3284	<result> = getelementptr <ty>* <ptrval>{, <ty> <idx>}*
				3285	</pre>
				3286
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3287	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3288
				3289	<p>
				3290	The '<tt>getelementptr</tt>' instruction is used to get the address of a
				3291	subelement of an aggregate data structure.</p>
				3292
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3293	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3294
Reid Spencer	85f5b5b	2006-12-04 21:29:24 +0000	[diff] [blame]	3295	<p>This instruction takes a list of integer operands that indicate what
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3296	elements of the aggregate object to index to. The actual types of the arguments
				3297	provided depend on the type of the first pointer argument. The
				3298	'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	3299	levels of a structure or to a specific index in an array. When indexing into a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3300	structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	3301	into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
				3302	values will be sign extended to 64-bits if required.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3303
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3304	<p>For example, let's consider a C code fragment and how it gets
				3305	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3306
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3307	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3308	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3309	struct RT {
				3310	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3311	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3312	char C;
				3313	};
				3314	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3315	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3316	double Y;
				3317	struct RT Z;
				3318	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3319
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3320	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3321	return &s[1].Z.B[5][13];
				3322	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3323	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3324	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3325
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3326	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3327
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3328	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3329	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3330	%RT = type { i8 , [10 x [20 x i32]], i8 }
				3331	%ST = type { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3332
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3333	define i32* %foo(%ST* %s) {
				3334	entry:
				3335	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3336	ret i32* %reg
				3337	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3338	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3339	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3340
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3341	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3342
				3343	<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3344	on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencer	85f5b5b	2006-12-04 21:29:24 +0000	[diff] [blame]	3345	and <a href="#t_array">array</a> types can use a 32-bit or 64-bit
Reid Spencer	42ddd84	2006-12-03 16:53:48 +0000	[diff] [blame]	3346	<a href="#t_integer">integer</a> type but the value will always be sign extended
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3347	to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
				3348	structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3349
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3350	<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3351	type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3352	}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3353	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3354	i8 }</tt>' type, another structure. The third index indexes into the second
				3355	element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3356	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3357	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3358	to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3359
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3360	<p>Note that it is perfectly legal to index partially through a
				3361	structure, returning a pointer to an inner element. Because of this,
				3362	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3363
				3364	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3365	define i32* %foo(%ST* %s) {
				3366	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3367	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3368	%t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3369	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3370	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3371	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3372	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3373	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3374
				3375	<p>Note that it is undefined to access an array out of bounds: array and
				3376	pointer indexes must always be within the defined bounds of the array type.
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	3377	The one exception for this rule is zero length arrays. These arrays are
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3378	defined to be accessible as variable length arrays, which requires access
				3379	beyond the zero'th element.</p>
				3380
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3381	<p>The getelementptr instruction is often confusing. For some more insight
				3382	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3383	FAQ</a>.</p>
				3384
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3385	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3386
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3387	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3388	<i>; yields [12 x i8]*:aptr</i>
				3389	%aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3390	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3391	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3392
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3393	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3394	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3395	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3396	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3397	<p>The instructions in this category are the conversion instructions (casting)
				3398	which all take a single operand and a type. They perform various bit conversions
				3399	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3400	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3401
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3402	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3403	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3404	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3405	</div>
				3406	<div class="doc_text">
				3407
				3408	<h5>Syntax:</h5>
				3409	<pre>
				3410	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3411	</pre>
				3412
				3413	<h5>Overview:</h5>
				3414	<p>
				3415	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3416	</p>
				3417
				3418	<h5>Arguments:</h5>
				3419	<p>
				3420	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3421	be an <a href="#t_integer">integer</a> type, and a type that specifies the size
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3422	and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3423	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3424	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3425
				3426	<h5>Semantics:</h5>
				3427	<p>
				3428	The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3429	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3430	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3431	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3432
				3433	<h5>Example:</h5>
				3434	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3435	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3436	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3437	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3438	</pre>
				3439	</div>
				3440
				3441	<!-- _______________________________________________________________________ -->
				3442	<div class="doc_subsubsection">
				3443	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3444	</div>
				3445	<div class="doc_text">
				3446
				3447	<h5>Syntax:</h5>
				3448	<pre>
				3449	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3450	</pre>
				3451
				3452	<h5>Overview:</h5>
				3453	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3454	<tt>ty2</tt>.</p>
				3455
				3456
				3457	<h5>Arguments:</h5>
				3458	<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3459	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3460	also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3461	<tt>value</tt> must be smaller than the bit size of the destination type,
				3462	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3463
				3464	<h5>Semantics:</h5>
				3465	<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Chris Lattner	d1d2517	2007-05-24 19:13:27 +0000	[diff] [blame]	3466	bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3467
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3468	<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3469
				3470	<h5>Example:</h5>
				3471	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3472	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3473	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3474	</pre>
				3475	</div>
				3476
				3477	<!-- _______________________________________________________________________ -->
				3478	<div class="doc_subsubsection">
				3479	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3480	</div>
				3481	<div class="doc_text">
				3482
				3483	<h5>Syntax:</h5>
				3484	<pre>
				3485	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3486	</pre>
				3487
				3488	<h5>Overview:</h5>
				3489	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3490
				3491	<h5>Arguments:</h5>
				3492	<p>
				3493	The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3494	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3495	also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3496	<tt>value</tt> must be smaller than the bit size of the destination type,
				3497	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3498
				3499	<h5>Semantics:</h5>
				3500	<p>
				3501	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3502	bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
Chris Lattner	d1d2517	2007-05-24 19:13:27 +0000	[diff] [blame]	3503	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3504
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3505	<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3506
				3507	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3508	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3509	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3510	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3511	</pre>
				3512	</div>
				3513
				3514	<!-- _______________________________________________________________________ -->
				3515	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3516	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3517	</div>
				3518
				3519	<div class="doc_text">
				3520
				3521	<h5>Syntax:</h5>
				3522
				3523	<pre>
				3524	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3525	</pre>
				3526
				3527	<h5>Overview:</h5>
				3528	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3529	<tt>ty2</tt>.</p>
				3530
				3531
				3532	<h5>Arguments:</h5>
				3533	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3534	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3535	cast it to. The size of <tt>value</tt> must be larger than the size of
				3536	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3537	<i>no-op cast</i>.</p>
				3538
				3539	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3540	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3541	<a href="#t_floating">floating point</a> type to a smaller
				3542	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3543	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3544
				3545	<h5>Example:</h5>
				3546	<pre>
				3547	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3548	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3549	</pre>
				3550	</div>
				3551
				3552	<!-- _______________________________________________________________________ -->
				3553	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3554	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3555	</div>
				3556	<div class="doc_text">
				3557
				3558	<h5>Syntax:</h5>
				3559	<pre>
				3560	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3561	</pre>
				3562
				3563	<h5>Overview:</h5>
				3564	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3565	floating point value.</p>
				3566
				3567	<h5>Arguments:</h5>
				3568	<p>The '<tt>fpext</tt>' instruction takes a
				3569	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3570	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3571	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3572
				3573	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3574	<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	3575	<a href="#t_floating">floating point</a> type to a larger
				3576	<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3577	used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3578	<tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3579
				3580	<h5>Example:</h5>
				3581	<pre>
				3582	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3583	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3584	</pre>
				3585	</div>
				3586
				3587	<!-- _______________________________________________________________________ -->
				3588	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	3589	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3590	</div>
				3591	<div class="doc_text">
				3592
				3593	<h5>Syntax:</h5>
				3594	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3595	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3596	</pre>
				3597
				3598	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3599	<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3600	unsigned integer equivalent of type <tt>ty2</tt>.
				3601	</p>
				3602
				3603	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3604	<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3605	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3606	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3607	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3608	vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3609
				3610	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3611	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3612	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3613	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3614	the results are undefined.</p>
				3615
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3616	<h5>Example:</h5>
				3617	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3618	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3619	%Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3620	%X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3621	</pre>
				3622	</div>
				3623
				3624	<!-- _______________________________________________________________________ -->
				3625	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3626	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3627	</div>
				3628	<div class="doc_text">
				3629
				3630	<h5>Syntax:</h5>
				3631	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3632	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3633	</pre>
				3634
				3635	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3636	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3637	<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3638	</p>
				3639
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3640	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3641	<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3642	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3643	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3644	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3645	vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3646
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3647	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3648	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3649	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3650	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3651	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3652
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3653	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3654	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3655	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3656	%Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3657	%X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3658	</pre>
				3659	</div>
				3660
				3661	<!-- _______________________________________________________________________ -->
				3662	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3663	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3664	</div>
				3665	<div class="doc_text">
				3666
				3667	<h5>Syntax:</h5>
				3668	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3669	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3670	</pre>
				3671
				3672	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3673	<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3674	integer and converts that value to the <tt>ty2</tt> type.</p>
				3675
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3676	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3677	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3678	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3679	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3680	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3681	floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3682
				3683	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3684	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3685	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3686	the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3687
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3688	<h5>Example:</h5>
				3689	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3690	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3691	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3692	</pre>
				3693	</div>
				3694
				3695	<!-- _______________________________________________________________________ -->
				3696	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3697	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3698	</div>
				3699	<div class="doc_text">
				3700
				3701	<h5>Syntax:</h5>
				3702	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3703	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3704	</pre>
				3705
				3706	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3707	<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3708	integer and converts that value to the <tt>ty2</tt> type.</p>
				3709
				3710	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3711	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3712	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3713	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3714	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3715	floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3716
				3717	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3718	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3719	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3720	the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3721
				3722	<h5>Example:</h5>
				3723	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3724	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3725	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3726	</pre>
				3727	</div>
				3728
				3729	<!-- _______________________________________________________________________ -->
				3730	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3731	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				3732	</div>
				3733	<div class="doc_text">
				3734
				3735	<h5>Syntax:</h5>
				3736	<pre>
				3737	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				3738	</pre>
				3739
				3740	<h5>Overview:</h5>
				3741	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				3742	the integer type <tt>ty2</tt>.</p>
				3743
				3744	<h5>Arguments:</h5>
				3745	<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	3746	must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3747	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
				3748
				3749	<h5>Semantics:</h5>
				3750	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				3751	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				3752	truncating or zero extending that value to the size of the integer type. If
				3753	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				3754	<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3755	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				3756	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3757
				3758	<h5>Example:</h5>
				3759	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3760	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				3761	%Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3762	</pre>
				3763	</div>
				3764
				3765	<!-- _______________________________________________________________________ -->
				3766	<div class="doc_subsubsection">
				3767	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				3768	</div>
				3769	<div class="doc_text">
				3770
				3771	<h5>Syntax:</h5>
				3772	<pre>
				3773	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				3774	</pre>
				3775
				3776	<h5>Overview:</h5>
				3777	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				3778	a pointer type, <tt>ty2</tt>.</p>
				3779
				3780	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	3781	<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3782	value to cast, and a type to cast it to, which must be a
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	3783	<a href="#t_pointer">pointer</a> type.
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3784
				3785	<h5>Semantics:</h5>
				3786	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				3787	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				3788	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				3789	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				3790	the size of a pointer then a zero extension is done. If they are the same size,
				3791	nothing is done (<i>no-op cast</i>).</p>
				3792
				3793	<h5>Example:</h5>
				3794	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3795	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				3796	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				3797	%Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3798	</pre>
				3799	</div>
				3800
				3801	<!-- _______________________________________________________________________ -->
				3802	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3803	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3804	</div>
				3805	<div class="doc_text">
				3806
				3807	<h5>Syntax:</h5>
				3808	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3809	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3810	</pre>
				3811
				3812	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3813
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3814	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3815	<tt>ty2</tt> without changing any bits.</p>
				3816
				3817	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3818
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3819	<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman	500233a	2008-09-08 16:45:59 +0000	[diff] [blame]	3820	a non-aggregate first class value, and a type to cast it to, which must also be
				3821	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				3822	<tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	3823	and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3824	type is a pointer, the destination type must also be a pointer. This
				3825	instruction supports bitwise conversion of vectors to integers and to vectors
				3826	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3827
				3828	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3829	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3830	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				3831	this conversion. The conversion is done as if the <tt>value</tt> had been
				3832	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				3833	converted to other pointer types with this instruction. To convert pointers to
				3834	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				3835	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3836
				3837	<h5>Example:</h5>
				3838	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3839	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3840	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
				3841	%Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3842	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3843	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3844
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3845	<!-- ======================================================================= -->
				3846	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				3847	<div class="doc_text">
				3848	<p>The instructions in this category are the "miscellaneous"
				3849	instructions, which defy better classification.</p>
				3850	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3851
				3852	<!-- _______________________________________________________________________ -->
				3853	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				3854	</div>
				3855	<div class="doc_text">
				3856	<h5>Syntax:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3857	<pre> <result> = icmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1&gt}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3858	</pre>
				3859	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3860	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				3861	a vector of boolean values based on comparison
				3862	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3863	<h5>Arguments:</h5>
				3864	<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3865	the condition code indicating the kind of comparison to perform. It is not
				3866	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3867	<ol>
				3868	<li><tt>eq</tt>: equal</li>
				3869	<li><tt>ne</tt>: not equal </li>
				3870	<li><tt>ugt</tt>: unsigned greater than</li>
				3871	<li><tt>uge</tt>: unsigned greater or equal</li>
				3872	<li><tt>ult</tt>: unsigned less than</li>
				3873	<li><tt>ule</tt>: unsigned less or equal</li>
				3874	<li><tt>sgt</tt>: signed greater than</li>
				3875	<li><tt>sge</tt>: signed greater or equal</li>
				3876	<li><tt>slt</tt>: signed less than</li>
				3877	<li><tt>sle</tt>: signed less or equal</li>
				3878	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3879	<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3880	<a href="#t_pointer">pointer</a>
				3881	or integer <a href="#t_vector">vector</a> typed.
				3882	They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3883	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3884	<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3885	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3886	yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3887	<ol>
				3888	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				3889	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3890	</li>
				3891	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
				3892	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3893	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3894	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3895	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3896	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3897	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3898	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3899	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3900	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3901	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3902	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3903	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3904	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3905	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3906	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3907	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3908	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3909	</ol>
				3910	<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3911	values are compared as if they were integers.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3912	<p>If the operands are integer vectors, then they are compared
				3913	element by element. The result is an <tt>i1</tt> vector with
				3914	the same number of elements as the values being compared.
				3915	Otherwise, the result is an <tt>i1</tt>.
				3916	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3917
				3918	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3919	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				3920	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				3921	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				3922	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				3923	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				3924	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3925	</pre>
				3926	</div>
				3927
				3928	<!-- _______________________________________________________________________ -->
				3929	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				3930	</div>
				3931	<div class="doc_text">
				3932	<h5>Syntax:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3933	<pre> <result> = fcmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1&gt}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3934	</pre>
				3935	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3936	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				3937	or vector of boolean values based on comparison
				3938	of its operands.
				3939	<p>
				3940	If the operands are floating point scalars, then the result
				3941	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				3942	</p>
				3943	<p>If the operands are floating point vectors, then the result type
				3944	is a vector of boolean with the same number of elements as the
				3945	operands being compared.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3946	<h5>Arguments:</h5>
				3947	<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3948	the condition code indicating the kind of comparison to perform. It is not
				3949	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3950	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3951	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3952	<li><tt>oeq</tt>: ordered and equal</li>
				3953	<li><tt>ogt</tt>: ordered and greater than </li>
				3954	<li><tt>oge</tt>: ordered and greater than or equal</li>
				3955	<li><tt>olt</tt>: ordered and less than </li>
				3956	<li><tt>ole</tt>: ordered and less than or equal</li>
				3957	<li><tt>one</tt>: ordered and not equal</li>
				3958	<li><tt>ord</tt>: ordered (no nans)</li>
				3959	<li><tt>ueq</tt>: unordered or equal</li>
				3960	<li><tt>ugt</tt>: unordered or greater than </li>
				3961	<li><tt>uge</tt>: unordered or greater than or equal</li>
				3962	<li><tt>ult</tt>: unordered or less than </li>
				3963	<li><tt>ule</tt>: unordered or less than or equal</li>
				3964	<li><tt>une</tt>: unordered or not equal</li>
				3965	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3966	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3967	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3968	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	3969	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3970	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				3971	either a <a href="#t_floating">floating point</a> type
				3972	or a <a href="#t_vector">vector</a> of floating point type.
				3973	They must have identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3974	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3975	<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3976	according to the condition code given as <tt>cond</tt>.
				3977	If the operands are vectors, then the vectors are compared
				3978	element by element.
				3979	Each comparison performed
				3980	always yields an <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3981	<ol>
				3982	<li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3983	<li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3984	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3985	<li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3986	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3987	<li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3988	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3989	<li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3990	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3991	<li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3992	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3993	<li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3994	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3995	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				3996	<li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3997	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3998	<li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3999	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4000	<li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4001	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4002	<li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4003	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4004	<li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4005	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4006	<li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4007	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4008	<li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4009	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4010	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4011
				4012	<h5>Example:</h5>
				4013	<pre> <result> = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4014	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4015	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4016	<result> = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4017	</pre>
				4018	</div>
				4019
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4020	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4021	<div class="doc_subsubsection">
				4022	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4023	</div>
				4024	<div class="doc_text">
				4025	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4026	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4027	</pre>
				4028	<h5>Overview:</h5>
				4029	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4030	element-wise comparison of its two integer vector operands.</p>
				4031	<h5>Arguments:</h5>
				4032	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4033	the condition code indicating the kind of comparison to perform. It is not
				4034	a value, just a keyword. The possible condition code are:
				4035	<ol>
				4036	<li><tt>eq</tt>: equal</li>
				4037	<li><tt>ne</tt>: not equal </li>
				4038	<li><tt>ugt</tt>: unsigned greater than</li>
				4039	<li><tt>uge</tt>: unsigned greater or equal</li>
				4040	<li><tt>ult</tt>: unsigned less than</li>
				4041	<li><tt>ule</tt>: unsigned less or equal</li>
				4042	<li><tt>sgt</tt>: signed greater than</li>
				4043	<li><tt>sge</tt>: signed greater or equal</li>
				4044	<li><tt>slt</tt>: signed less than</li>
				4045	<li><tt>sle</tt>: signed less or equal</li>
				4046	</ol>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4047	<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4048	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4049	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4050	<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4051	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4052	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4053	identical type as the values being compared. The most significant bit in each
				4054	element is 1 if the element-wise comparison evaluates to true, and is 0
				4055	otherwise. All other bits of the result are undefined. The condition codes
				4056	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
				4057	instruction</a>.
				4058
				4059	<h5>Example:</h5>
				4060	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4061	<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>
				4062	<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	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4063	</pre>
				4064	</div>
				4065
				4066	<!-- _______________________________________________________________________ -->
				4067	<div class="doc_subsubsection">
				4068	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4069	</div>
				4070	<div class="doc_text">
				4071	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4072	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4073	<h5>Overview:</h5>
				4074	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4075	element-wise comparison of its two floating point vector operands. The output
				4076	elements have the same width as the input elements.</p>
				4077	<h5>Arguments:</h5>
				4078	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4079	the condition code indicating the kind of comparison to perform. It is not
				4080	a value, just a keyword. The possible condition code are:
				4081	<ol>
				4082	<li><tt>false</tt>: no comparison, always returns false</li>
				4083	<li><tt>oeq</tt>: ordered and equal</li>
				4084	<li><tt>ogt</tt>: ordered and greater than </li>
				4085	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4086	<li><tt>olt</tt>: ordered and less than </li>
				4087	<li><tt>ole</tt>: ordered and less than or equal</li>
				4088	<li><tt>one</tt>: ordered and not equal</li>
				4089	<li><tt>ord</tt>: ordered (no nans)</li>
				4090	<li><tt>ueq</tt>: unordered or equal</li>
				4091	<li><tt>ugt</tt>: unordered or greater than </li>
				4092	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4093	<li><tt>ult</tt>: unordered or less than </li>
				4094	<li><tt>ule</tt>: unordered or less than or equal</li>
				4095	<li><tt>une</tt>: unordered or not equal</li>
				4096	<li><tt>uno</tt>: unordered (either nans)</li>
				4097	<li><tt>true</tt>: no comparison, always returns true</li>
				4098	</ol>
				4099	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4100	<a href="#t_floating">floating point</a> typed. They must also be identical
				4101	types.</p>
				4102	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4103	<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4104	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4105	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4106	an identical number of elements as the values being compared, and each element
				4107	having identical with to the width of the floating point elements. The most
				4108	significant bit in each element is 1 if the element-wise comparison evaluates to
				4109	true, and is 0 otherwise. All other bits of the result are undefined. The
				4110	condition codes are evaluated identically to the
				4111	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
				4112
				4113	<h5>Example:</h5>
				4114	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4115	<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>
				4116	<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	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4117	</pre>
				4118	</div>
				4119
				4120	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4121	<div class="doc_subsubsection">
				4122	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4123	</div>
				4124
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4125	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4126
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4127	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4128
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4129	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4130	<h5>Overview:</h5>
				4131	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4132	the SSA graph representing the function.</p>
				4133	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4134
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4135	<p>The type of the incoming values is specified with the first type
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4136	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4137	as arguments, with one pair for each predecessor basic block of the
				4138	current block. Only values of <a href="#t_firstclass">first class</a>
				4139	type may be used as the value arguments to the PHI node. Only labels
				4140	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4141
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4142	<p>There must be no non-phi instructions between the start of a basic
				4143	block and the PHI instructions: i.e. PHI instructions must be first in
				4144	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4145
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4146	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4147
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4148	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4149	specified by the pair corresponding to the predecessor basic block that executed
				4150	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4151
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4152	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4153	<pre>
				4154	Loop: ; Infinite loop that counts from 0 on up...
				4155	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4156	%nextindvar = add i32 %indvar, 1
				4157	br label %Loop
				4158	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4159	</div>
				4160
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4161	<!-- _______________________________________________________________________ -->
				4162	<div class="doc_subsubsection">
				4163	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4164	</div>
				4165
				4166	<div class="doc_text">
				4167
				4168	<h5>Syntax:</h5>
				4169
				4170	<pre>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4171	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4172
				4173	<i>selty</i> is either i1 or {<N x i1&gt}
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4174	</pre>
				4175
				4176	<h5>Overview:</h5>
				4177
				4178	<p>
				4179	The '<tt>select</tt>' instruction is used to choose one value based on a
				4180	condition, without branching.
				4181	</p>
				4182
				4183
				4184	<h5>Arguments:</h5>
				4185
				4186	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4187	The '<tt>select</tt>' instruction requires an 'i1' value or
				4188	a vector of 'i1' values indicating the
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4189	condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4190	type. If the val1/val2 are vectors and
				4191	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4192	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4193	</p>
				4194
				4195	<h5>Semantics:</h5>
				4196
				4197	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4198	If the condition is an i1 and it evaluates to 1, the instruction returns the first
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4199	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4200	</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4201	<p>
				4202	If the condition is a vector of i1, then the value arguments must
				4203	be vectors of the same size, and the selection is done element
				4204	by element.
				4205	</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4206
				4207	<h5>Example:</h5>
				4208
				4209	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4210	%X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4211	</pre>
				4212	</div>
				4213
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4214
				4215	<!-- _______________________________________________________________________ -->
				4216	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4217	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4218	</div>
				4219
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4220	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4221
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4222	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4223	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4224	<result> = [tail] call [<a href="#callingconv">cconv</a>] <ty> [<fnty>*] <fnptrval>(<param list>)
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4225	</pre>
				4226
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4227	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4228
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4229	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4230
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4231	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4232
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4233	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4234
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4235	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4236	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4237	<p>The optional "tail" marker indicates whether the callee function accesses
				4238	any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4239	function call is eligible for tail call optimization. Note that calls may
				4240	be marked "tail" even if they do not occur before a <a
				4241	href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4242	</li>
				4243	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4244	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4245	convention</a> the call should use. If none is specified, the call defaults
				4246	to using C calling conventions.
				4247	</li>
				4248	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4249	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4250	the type of the return value. Functions that return no value are marked
				4251	<tt><a href="#t_void">void</a></tt>.</p>
				4252	</li>
				4253	<li>
				4254	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4255	value being invoked. The argument types must match the types implied by
				4256	this signature. This type can be omitted if the function is not varargs
				4257	and if the function type does not return a pointer to a function.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4258	</li>
				4259	<li>
				4260	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4261	be invoked. In most cases, this is a direct function invocation, but
				4262	indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4263	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4264	</li>
				4265	<li>
				4266	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4267	function signature argument types. All arguments must be of
				4268	<a href="#t_firstclass">first class</a> type. If the function signature
				4269	indicates the function accepts a variable number of arguments, the extra
				4270	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4271	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4272	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4273
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4274	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4275
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4276	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4277	transfer to a specified function, with its incoming arguments bound to
				4278	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4279	instruction in the called function, control flow continues with the
				4280	instruction after the function call, and the return value of the
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4281	function is bound to the result argument. If the callee returns multiple
				4282	values then the return values of the function are only accessible through
				4283	the '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4284
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4285	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4286
				4287	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4288	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4289	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4290	%X = tail call i32 @foo() <i>; yields i32</i>
				4291	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4292	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4293
				4294	%struct.A = type { i32, i8 }
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4295	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
				4296	%gr = getresult %struct.A %r, 0 <i>; yields i32</i>
				4297	%gr1 = getresult %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4298	</pre>
				4299
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4300	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4301
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4302	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4303	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4304	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4305	</div>
				4306
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4307	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4308
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4309	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4310
				4311	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4312	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4313	</pre>
				4314
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4315	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4316
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4317	<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4318	the "variable argument" area of a function call. It is used to implement the
				4319	<tt>va_arg</tt> macro in C.</p>
				4320
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4321	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4322
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4323	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4324	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4325	increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4326	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4327
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4328	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4329
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4330	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4331	type from the specified <tt>va_list</tt> and causes the
				4332	<tt>va_list</tt> to point to the next argument. For more information,
				4333	see the variable argument handling <a href="#int_varargs">Intrinsic
				4334	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4335
				4336	<p>It is legal for this instruction to be called in a function which does not
				4337	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4338	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4339
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4340	<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4341	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4342	argument.</p>
				4343
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4344	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4345
				4346	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4347
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4348	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4349
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4350	<!-- _______________________________________________________________________ -->
				4351	<div class="doc_subsubsection">
				4352	<a name="i_getresult">'<tt>getresult</tt>' Instruction</a>
				4353	</div>
				4354
				4355	<div class="doc_text">
				4356
				4357	<h5>Syntax:</h5>
				4358	<pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4359	<resultval> = getresult <type> <retval>, <index>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4360	</pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4361
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4362	<h5>Overview:</h5>
				4363
				4364	<p> The '<tt>getresult</tt>' instruction is used to extract individual values
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4365	from a '<tt><a href="#i_call">call</a></tt>'
				4366	or '<tt><a href="#i_invoke">invoke</a></tt>' instruction that returns multiple
				4367	results.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4368
				4369	<h5>Arguments:</h5>
				4370
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4371	<p>The '<tt>getresult</tt>' instruction takes a call or invoke value as its
Chris Lattner	1c406d7	2008-04-23 04:06:52 +0000	[diff] [blame]	4372	first argument, or an undef value. The value must have <a
				4373	href="#t_struct">structure type</a>. The second argument is a constant
				4374	unsigned index value which must be in range for the number of values returned
				4375	by the call.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4376
				4377	<h5>Semantics:</h5>
				4378
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4379	<p>The '<tt>getresult</tt>' instruction extracts the element identified by
				4380	'<tt>index</tt>' from the aggregate value.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4381
				4382	<h5>Example:</h5>
				4383
				4384	<pre>
				4385	%struct.A = type { i32, i8 }
				4386
				4387	%r = call %struct.A @foo()
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4388	%gr = getresult %struct.A %r, 0 <i>; yields i32:%gr</i>
				4389	%gr1 = getresult %struct.A %r, 1 <i>; yields i8:%gr1</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4390	add i32 %gr, 42
				4391	add i8 %gr1, 41
				4392	</pre>
				4393
				4394	</div>
				4395
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4396	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4397	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4398	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4399
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4400	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4401
				4402	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4403	well known names and semantics and are required to follow certain restrictions.
				4404	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4405	language that does not require changing all of the transformations in LLVM when
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	4406	adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4407
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4408	<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4409	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4410	begin with this prefix. Intrinsic functions must always be external functions:
				4411	you cannot define the body of intrinsic functions. Intrinsic functions may
				4412	only be used in call or invoke instructions: it is illegal to take the address
				4413	of an intrinsic function. Additionally, because intrinsic functions are part
				4414	of the LLVM language, it is required if any are added that they be documented
				4415	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4416
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4417	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4418	a family of functions that perform the same operation but on different data
				4419	types. Because LLVM can represent over 8 million different integer types,
				4420	overloading is used commonly to allow an intrinsic function to operate on any
				4421	integer type. One or more of the argument types or the result type can be
				4422	overloaded to accept any integer type. Argument types may also be defined as
				4423	exactly matching a previous argument's type or the result type. This allows an
				4424	intrinsic function which accepts multiple arguments, but needs all of them to
				4425	be of the same type, to only be overloaded with respect to a single argument or
				4426	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4427
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4428	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4429	encoded into its function name, each preceded by a period. Only those types
				4430	which are overloaded result in a name suffix. Arguments whose type is matched
				4431	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4432	take an integer of any width and returns an integer of exactly the same integer
				4433	width. This leads to a family of functions such as
				4434	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4435	Only one type, the return type, is overloaded, and only one type suffix is
				4436	required. Because the argument's type is matched against the return type, it
				4437	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4438
				4439	<p>To learn how to add an intrinsic function, please see the
				4440	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4441	</p>
				4442
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4443	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4444
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4445	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4446	<div class="doc_subsection">
				4447	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4448	</div>
				4449
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4450	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4451
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4452	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4453	href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4454	intrinsic functions. These functions are related to the similarly
				4455	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4456
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4457	<p>All of these functions operate on arguments that use a
				4458	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4459	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4460	transformations should be prepared to handle these functions regardless of
				4461	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4462
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4463	<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4464	instruction and the variable argument handling intrinsic functions are
				4465	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4466
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4467	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4468	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4469	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4470	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4471	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4472	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4473	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4474
				4475	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4476	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4477
				4478	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4479	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4480	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4481	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4482	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4483
				4484	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4485	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4486	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4487	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4488
				4489	declare void @llvm.va_start(i8*)
				4490	declare void @llvm.va_copy(i8, i8)
				4491	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4492	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4493	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4494
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4495	</div>
				4496
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4497	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4498	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4499	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4500	</div>
				4501
				4502
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4503	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4504	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4505	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4506	<h5>Overview:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4507	<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
				4508	<tt>*<arglist></tt> for subsequent use by <tt><a
				4509	href="#i_va_arg">va_arg</a></tt>.</p>
				4510
				4511	<h5>Arguments:</h5>
				4512
				4513	<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
				4514
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4515	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4516
				4517	<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
				4518	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4519	<tt>va_list</tt> element to which the argument points, so that the next call to
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4520	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4521	Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4522	last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4523
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4524	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4525
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4526	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4527	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4528	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4529	</div>
				4530
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4531	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4532	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4533	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4534	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4535
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4536	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4537	which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4538	or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4539
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4540	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4541
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4542	<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4543
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4544	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4545
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4546	<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4547	macro available in C. In a target-dependent way, it destroys the
				4548	<tt>va_list</tt> element to which the argument points. Calls to <a
				4549	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4550	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4551	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4552
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4553	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4554
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4555	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4556	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4557	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4558	</div>
				4559
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4560	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4561
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4562	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4563
				4564	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4565	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4566	</pre>
				4567
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4568	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4569
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4570	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4571	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4572
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4573	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4574
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4575	<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Andrew Lenharth	d0a4c62	2005-06-22 20:38:11 +0000	[diff] [blame]	4576	The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4577
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4578
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4579	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4580
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4581	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4582	macro available in C. In a target-dependent way, it copies the source
				4583	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4584	intrinsic is necessary because the <tt><a href="#int_va_start">
				4585	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4586	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4587
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4588	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4589
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4590	<!-- ======================================================================= -->
				4591	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4592	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4593	</div>
				4594
				4595	<div class="doc_text">
				4596
				4597	<p>
				4598	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	4599	Collection</a> (GC) requires the implementation and generation of these
				4600	intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4601	These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4602	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4603	href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4604	Front-ends for type-safe garbage collected languages should generate these
				4605	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4606	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4607	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4608
				4609	<p>The garbage collection intrinsics only operate on objects in the generic
				4610	address space (address space zero).</p>
				4611
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4612	</div>
				4613
				4614	<!-- _______________________________________________________________________ -->
				4615	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4616	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4617	</div>
				4618
				4619	<div class="doc_text">
				4620
				4621	<h5>Syntax:</h5>
				4622
				4623	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4624	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4625	</pre>
				4626
				4627	<h5>Overview:</h5>
				4628
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4629	<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4630	the code generator, and allows some metadata to be associated with it.</p>
				4631
				4632	<h5>Arguments:</h5>
				4633
				4634	<p>The first argument specifies the address of a stack object that contains the
				4635	root pointer. The second pointer (which must be either a constant or a global
				4636	value address) contains the meta-data to be associated with the root.</p>
				4637
				4638	<h5>Semantics:</h5>
				4639
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	4640	<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4641	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4642	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4643	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4644	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4645
				4646	</div>
				4647
				4648
				4649	<!-- _______________________________________________________________________ -->
				4650	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4651	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4652	</div>
				4653
				4654	<div class="doc_text">
				4655
				4656	<h5>Syntax:</h5>
				4657
				4658	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4659	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4660	</pre>
				4661
				4662	<h5>Overview:</h5>
				4663
				4664	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4665	locations, allowing garbage collector implementations that require read
				4666	barriers.</p>
				4667
				4668	<h5>Arguments:</h5>
				4669
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4670	<p>The second argument is the address to read from, which should be an address
				4671	allocated from the garbage collector. The first object is a pointer to the
				4672	start of the referenced object, if needed by the language runtime (otherwise
				4673	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4674
				4675	<h5>Semantics:</h5>
				4676
				4677	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4678	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4679	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4680	may only be used in a function which <a href="#gc">specifies a GC
				4681	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4682
				4683	</div>
				4684
				4685
				4686	<!-- _______________________________________________________________________ -->
				4687	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4688	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4689	</div>
				4690
				4691	<div class="doc_text">
				4692
				4693	<h5>Syntax:</h5>
				4694
				4695	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4696	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4697	</pre>
				4698
				4699	<h5>Overview:</h5>
				4700
				4701	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4702	locations, allowing garbage collector implementations that require write
				4703	barriers (such as generational or reference counting collectors).</p>
				4704
				4705	<h5>Arguments:</h5>
				4706
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4707	<p>The first argument is the reference to store, the second is the start of the
				4708	object to store it to, and the third is the address of the field of Obj to
				4709	store to. If the runtime does not require a pointer to the object, Obj may be
				4710	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4711
				4712	<h5>Semantics:</h5>
				4713
				4714	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4715	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4716	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4717	may only be used in a function which <a href="#gc">specifies a GC
				4718	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4719
				4720	</div>
				4721
				4722
				4723
				4724	<!-- ======================================================================= -->
				4725	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4726	<a name="int_codegen">Code Generator Intrinsics</a>
				4727	</div>
				4728
				4729	<div class="doc_text">
				4730	<p>
				4731	These intrinsics are provided by LLVM to expose special features that may only
				4732	be implemented with code generator support.
				4733	</p>
				4734
				4735	</div>
				4736
				4737	<!-- _______________________________________________________________________ -->
				4738	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4739	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4740	</div>
				4741
				4742	<div class="doc_text">
				4743
				4744	<h5>Syntax:</h5>
				4745	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4746	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4747	</pre>
				4748
				4749	<h5>Overview:</h5>
				4750
				4751	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4752	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				4753	target-specific value indicating the return address of the current function
				4754	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4755	</p>
				4756
				4757	<h5>Arguments:</h5>
				4758
				4759	<p>
				4760	The argument to this intrinsic indicates which function to return the address
				4761	for. Zero indicates the calling function, one indicates its caller, etc. The
				4762	argument is <b>required</b> to be a constant integer value.
				4763	</p>
				4764
				4765	<h5>Semantics:</h5>
				4766
				4767	<p>
				4768	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				4769	the return address of the specified call frame, or zero if it cannot be
				4770	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4771	for arguments other than zero, so it should only be used for debugging purposes.
				4772	</p>
				4773
				4774	<p>
				4775	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4776	aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4777	source-language caller.
				4778	</p>
				4779	</div>
				4780
				4781
				4782	<!-- _______________________________________________________________________ -->
				4783	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4784	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4785	</div>
				4786
				4787	<div class="doc_text">
				4788
				4789	<h5>Syntax:</h5>
				4790	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4791	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4792	</pre>
				4793
				4794	<h5>Overview:</h5>
				4795
				4796	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4797	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				4798	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4799	</p>
				4800
				4801	<h5>Arguments:</h5>
				4802
				4803	<p>
				4804	The argument to this intrinsic indicates which function to return the frame
				4805	pointer for. Zero indicates the calling function, one indicates its caller,
				4806	etc. The argument is <b>required</b> to be a constant integer value.
				4807	</p>
				4808
				4809	<h5>Semantics:</h5>
				4810
				4811	<p>
				4812	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				4813	the frame address of the specified call frame, or zero if it cannot be
				4814	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4815	for arguments other than zero, so it should only be used for debugging purposes.
				4816	</p>
				4817
				4818	<p>
				4819	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4820	aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4821	source-language caller.
				4822	</p>
				4823	</div>
				4824
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4825	<!-- _______________________________________________________________________ -->
				4826	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4827	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4828	</div>
				4829
				4830	<div class="doc_text">
				4831
				4832	<h5>Syntax:</h5>
				4833	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4834	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4835	</pre>
				4836
				4837	<h5>Overview:</h5>
				4838
				4839	<p>
				4840	The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4841	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4842	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				4843	features like scoped automatic variable sized arrays in C99.
				4844	</p>
				4845
				4846	<h5>Semantics:</h5>
				4847
				4848	<p>
				4849	This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4850	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4851	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				4852	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				4853	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				4854	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				4855	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				4856	</p>
				4857
				4858	</div>
				4859
				4860	<!-- _______________________________________________________________________ -->
				4861	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4862	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4863	</div>
				4864
				4865	<div class="doc_text">
				4866
				4867	<h5>Syntax:</h5>
				4868	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4869	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4870	</pre>
				4871
				4872	<h5>Overview:</h5>
				4873
				4874	<p>
				4875	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				4876	the function stack to the state it was in when the corresponding <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4877	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4878	useful for implementing language features like scoped automatic variable sized
				4879	arrays in C99.
				4880	</p>
				4881
				4882	<h5>Semantics:</h5>
				4883
				4884	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4885	See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4886	</p>
				4887
				4888	</div>
				4889
				4890
				4891	<!-- _______________________________________________________________________ -->
				4892	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4893	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4894	</div>
				4895
				4896	<div class="doc_text">
				4897
				4898	<h5>Syntax:</h5>
				4899	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4900	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4901	</pre>
				4902
				4903	<h5>Overview:</h5>
				4904
				4905
				4906	<p>
				4907	The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4908	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				4909	no
				4910	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	4911	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4912	</p>
				4913
				4914	<h5>Arguments:</h5>
				4915
				4916	<p>
				4917	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				4918	determining if the fetch should be for a read (0) or write (1), and
				4919	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	4920	locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4921	<tt>locality</tt> arguments must be constant integers.
				4922	</p>
				4923
				4924	<h5>Semantics:</h5>
				4925
				4926	<p>
				4927	This intrinsic does not modify the behavior of the program. In particular,
				4928	prefetches cannot trap and do not produce a value. On targets that support this
				4929	intrinsic, the prefetch can provide hints to the processor cache for better
				4930	performance.
				4931	</p>
				4932
				4933	</div>
				4934
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4935	<!-- _______________________________________________________________________ -->
				4936	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4937	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4938	</div>
				4939
				4940	<div class="doc_text">
				4941
				4942	<h5>Syntax:</h5>
				4943	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4944	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4945	</pre>
				4946
				4947	<h5>Overview:</h5>
				4948
				4949
				4950	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4951	The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	4952	(PC) in a region of
				4953	code to simulators and other tools. The method is target specific, but it is
				4954	expected that the marker will use exported symbols to transmit the PC of the
				4955	marker.
				4956	The marker makes no guarantees that it will remain with any specific instruction
				4957	after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattner	b3e7afd	2006-03-24 07:16:10 +0000	[diff] [blame]	4958	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4959	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4960	</p>
				4961
				4962	<h5>Arguments:</h5>
				4963
				4964	<p>
				4965	<tt>id</tt> is a numerical id identifying the marker.
				4966	</p>
				4967
				4968	<h5>Semantics:</h5>
				4969
				4970	<p>
				4971	This intrinsic does not modify the behavior of the program. Backends that do not
				4972	support this intrinisic may ignore it.
				4973	</p>
				4974
				4975	</div>
				4976
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4977	<!-- _______________________________________________________________________ -->
				4978	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4979	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4980	</div>
				4981
				4982	<div class="doc_text">
				4983
				4984	<h5>Syntax:</h5>
				4985	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4986	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4987	</pre>
				4988
				4989	<h5>Overview:</h5>
				4990
				4991
				4992	<p>
				4993	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				4994	counter register (or similar low latency, high accuracy clocks) on those targets
				4995	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				4996	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				4997	should only be used for small timings.
				4998	</p>
				4999
				5000	<h5>Semantics:</h5>
				5001
				5002	<p>
				5003	When directly supported, reading the cycle counter should not modify any memory.
				5004	Implementations are allowed to either return a application specific value or a
				5005	system wide value. On backends without support, this is lowered to a constant 0.
				5006	</p>
				5007
				5008	</div>
				5009
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5010	<!-- ======================================================================= -->
				5011	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5012	<a name="int_libc">Standard C Library Intrinsics</a>
				5013	</div>
				5014
				5015	<div class="doc_text">
				5016	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5017	LLVM provides intrinsics for a few important standard C library functions.
				5018	These intrinsics allow source-language front-ends to pass information about the
				5019	alignment of the pointer arguments to the code generator, providing opportunity
				5020	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5021	</p>
				5022
				5023	</div>
				5024
				5025	<!-- _______________________________________________________________________ -->
				5026	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5027	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5028	</div>
				5029
				5030	<div class="doc_text">
				5031
				5032	<h5>Syntax:</h5>
				5033	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5034	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5035	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5036	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5037	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5038	</pre>
				5039
				5040	<h5>Overview:</h5>
				5041
				5042	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5043	The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5044	location to the destination location.
				5045	</p>
				5046
				5047	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5048	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5049	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5050	</p>
				5051
				5052	<h5>Arguments:</h5>
				5053
				5054	<p>
				5055	The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5056	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5057	specifying the number of bytes to copy, and the fourth argument is the alignment
				5058	of the source and destination locations.
				5059	</p>
				5060
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5061	<p>
				5062	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	f0afc2c	2006-03-04 00:02:10 +0000	[diff] [blame]	5063	the caller guarantees that both the source and destination pointers are aligned
				5064	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5065	</p>
				5066
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5067	<h5>Semantics:</h5>
				5068
				5069	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5070	The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5071	location to the destination location, which are not allowed to overlap. It
				5072	copies "len" bytes of memory over. If the argument is known to be aligned to
				5073	some boundary, this can be specified as the fourth argument, otherwise it should
				5074	be set to 0 or 1.
				5075	</p>
				5076	</div>
				5077
				5078
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5079	<!-- _______________________________________________________________________ -->
				5080	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5081	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5082	</div>
				5083
				5084	<div class="doc_text">
				5085
				5086	<h5>Syntax:</h5>
				5087	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5088	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5089	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5090	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5091	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5092	</pre>
				5093
				5094	<h5>Overview:</h5>
				5095
				5096	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5097	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5098	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5099	'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5100	</p>
				5101
				5102	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5103	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5104	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5105	</p>
				5106
				5107	<h5>Arguments:</h5>
				5108
				5109	<p>
				5110	The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5111	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5112	specifying the number of bytes to copy, and the fourth argument is the alignment
				5113	of the source and destination locations.
				5114	</p>
				5115
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5116	<p>
				5117	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	f0afc2c	2006-03-04 00:02:10 +0000	[diff] [blame]	5118	the caller guarantees that the source and destination pointers are aligned to
				5119	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5120	</p>
				5121
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5122	<h5>Semantics:</h5>
				5123
				5124	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5125	The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5126	location to the destination location, which may overlap. It
				5127	copies "len" bytes of memory over. If the argument is known to be aligned to
				5128	some boundary, this can be specified as the fourth argument, otherwise it should
				5129	be set to 0 or 1.
				5130	</p>
				5131	</div>
				5132
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5133
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5134	<!-- _______________________________________________________________________ -->
				5135	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5136	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5137	</div>
				5138
				5139	<div class="doc_text">
				5140
				5141	<h5>Syntax:</h5>
				5142	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5143	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5144	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5145	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5146	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5147	</pre>
				5148
				5149	<h5>Overview:</h5>
				5150
				5151	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5152	The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5153	byte value.
				5154	</p>
				5155
				5156	<p>
				5157	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5158	does not return a value, and takes an extra alignment argument.
				5159	</p>
				5160
				5161	<h5>Arguments:</h5>
				5162
				5163	<p>
				5164	The first argument is a pointer to the destination to fill, the second is the
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5165	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5166	argument specifying the number of bytes to fill, and the fourth argument is the
				5167	known alignment of destination location.
				5168	</p>
				5169
				5170	<p>
				5171	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	f0afc2c	2006-03-04 00:02:10 +0000	[diff] [blame]	5172	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5173	</p>
				5174
				5175	<h5>Semantics:</h5>
				5176
				5177	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5178	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5179	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5180	destination location. If the argument is known to be aligned to some boundary,
				5181	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5182	1.
				5183	</p>
				5184	</div>
				5185
				5186
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5187	<!-- _______________________________________________________________________ -->
				5188	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5189	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5190	</div>
				5191
				5192	<div class="doc_text">
				5193
				5194	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5195	<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5196	floating point or vector of floating point type. Not all targets support all
				5197	types however.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5198	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5199	declare float @llvm.sqrt.f32(float %Val)
				5200	declare double @llvm.sqrt.f64(double %Val)
				5201	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5202	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5203	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5204	</pre>
				5205
				5206	<h5>Overview:</h5>
				5207
				5208	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5209	The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5210	returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5211	<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner	103e2d7	2008-01-29 07:00:44 +0000	[diff] [blame]	5212	negative numbers other than -0.0 (which allows for better optimization, because
				5213	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5214	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5215	</p>
				5216
				5217	<h5>Arguments:</h5>
				5218
				5219	<p>
				5220	The argument and return value are floating point numbers of the same type.
				5221	</p>
				5222
				5223	<h5>Semantics:</h5>
				5224
				5225	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5226	This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5227	floating point number.
				5228	</p>
				5229	</div>
				5230
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5231	<!-- _______________________________________________________________________ -->
				5232	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5233	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5234	</div>
				5235
				5236	<div class="doc_text">
				5237
				5238	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5239	<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5240	floating point or vector of floating point type. Not all targets support all
				5241	types however.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5242	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5243	declare float @llvm.powi.f32(float %Val, i32 %power)
				5244	declare double @llvm.powi.f64(double %Val, i32 %power)
				5245	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5246	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5247	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5248	</pre>
				5249
				5250	<h5>Overview:</h5>
				5251
				5252	<p>
				5253	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5254	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5255	multiplications is not defined. When a vector of floating point type is
				5256	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5257	</p>
				5258
				5259	<h5>Arguments:</h5>
				5260
				5261	<p>
				5262	The second argument is an integer power, and the first is a value to raise to
				5263	that power.
				5264	</p>
				5265
				5266	<h5>Semantics:</h5>
				5267
				5268	<p>
				5269	This function returns the first value raised to the second power with an
				5270	unspecified sequence of rounding operations.</p>
				5271	</div>
				5272
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5273	<!-- _______________________________________________________________________ -->
				5274	<div class="doc_subsubsection">
				5275	<a name="int_sin">'<tt>llvm.sin.*</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.sin</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.sin.f32(float %Val)
				5286	declare double @llvm.sin.f64(double %Val)
				5287	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5288	declare fp128 @llvm.sin.f128(fp128 %Val)
				5289	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5290	</pre>
				5291
				5292	<h5>Overview:</h5>
				5293
				5294	<p>
				5295	The '<tt>llvm.sin.*</tt>' intrinsics return the sine 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 sine of the specified operand, returning the
				5308	same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohman	ba83b7e	2007-10-17 18:05:13 +0000	[diff] [blame]	5309	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5310	</div>
				5311
				5312	<!-- _______________________________________________________________________ -->
				5313	<div class="doc_subsubsection">
				5314	<a name="int_cos">'<tt>llvm.cos.*</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.cos</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.cos.f32(float %Val)
				5325	declare double @llvm.cos.f64(double %Val)
				5326	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5327	declare fp128 @llvm.cos.f128(fp128 %Val)
				5328	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5329	</pre>
				5330
				5331	<h5>Overview:</h5>
				5332
				5333	<p>
				5334	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5335	</p>
				5336
				5337	<h5>Arguments:</h5>
				5338
				5339	<p>
				5340	The argument and return value are floating point numbers of the same type.
				5341	</p>
				5342
				5343	<h5>Semantics:</h5>
				5344
				5345	<p>
				5346	This function returns the cosine of the specified operand, returning the
				5347	same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohman	ba83b7e	2007-10-17 18:05:13 +0000	[diff] [blame]	5348	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5349	</div>
				5350
				5351	<!-- _______________________________________________________________________ -->
				5352	<div class="doc_subsubsection">
				5353	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5354	</div>
				5355
				5356	<div class="doc_text">
				5357
				5358	<h5>Syntax:</h5>
				5359	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5360	floating point or vector of floating point type. Not all targets support all
				5361	types however.
				5362	<pre>
				5363	declare float @llvm.pow.f32(float %Val, float %Power)
				5364	declare double @llvm.pow.f64(double %Val, double %Power)
				5365	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5366	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5367	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5368	</pre>
				5369
				5370	<h5>Overview:</h5>
				5371
				5372	<p>
				5373	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5374	specified (positive or negative) power.
				5375	</p>
				5376
				5377	<h5>Arguments:</h5>
				5378
				5379	<p>
				5380	The second argument is a floating point power, and the first is a value to
				5381	raise to that power.
				5382	</p>
				5383
				5384	<h5>Semantics:</h5>
				5385
				5386	<p>
				5387	This function returns the first value raised to the second power,
				5388	returning the
				5389	same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohman	ba83b7e	2007-10-17 18:05:13 +0000	[diff] [blame]	5390	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5391	</div>
				5392
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5393
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5394	<!-- ======================================================================= -->
				5395	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5396	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5397	</div>
				5398
				5399	<div class="doc_text">
				5400	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5401	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5402	These allow efficient code generation for some algorithms.
				5403	</p>
				5404
				5405	</div>
				5406
				5407	<!-- _______________________________________________________________________ -->
				5408	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5409	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5410	</div>
				5411
				5412	<div class="doc_text">
				5413
				5414	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5415	<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5416	type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5417	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5418	declare i16 @llvm.bswap.i16(i16 <id>)
				5419	declare i32 @llvm.bswap.i32(i32 <id>)
				5420	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5421	</pre>
				5422
				5423	<h5>Overview:</h5>
				5424
				5425	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5426	The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5427	values with an even number of bytes (positive multiple of 16 bits). These are
				5428	useful for performing operations on data that is not in the target's native
				5429	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5430	</p>
				5431
				5432	<h5>Semantics:</h5>
				5433
				5434	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5435	The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5436	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5437	intrinsic returns an i32 value that has the four bytes of the input i32
				5438	swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5439	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5440	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5441	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5442	</p>
				5443
				5444	</div>
				5445
				5446	<!-- _______________________________________________________________________ -->
				5447	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5448	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5449	</div>
				5450
				5451	<div class="doc_text">
				5452
				5453	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5454	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
				5455	width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5456	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5457	declare i8 @llvm.ctpop.i8 (i8 <src>)
				5458	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5459	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5460	declare i64 @llvm.ctpop.i64(i64 <src>)
				5461	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5462	</pre>
				5463
				5464	<h5>Overview:</h5>
				5465
				5466	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5467	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5468	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5469	</p>
				5470
				5471	<h5>Arguments:</h5>
				5472
				5473	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5474	The only argument is the value to be counted. The argument may be of any
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	5475	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5476	</p>
				5477
				5478	<h5>Semantics:</h5>
				5479
				5480	<p>
				5481	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5482	</p>
				5483	</div>
				5484
				5485	<!-- _______________________________________________________________________ -->
				5486	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5487	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5488	</div>
				5489
				5490	<div class="doc_text">
				5491
				5492	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5493	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
				5494	integer bit width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5495	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5496	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5497	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5498	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5499	declare i64 @llvm.ctlz.i64(i64 <src>)
				5500	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5501	</pre>
				5502
				5503	<h5>Overview:</h5>
				5504
				5505	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5506	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5507	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5508	</p>
				5509
				5510	<h5>Arguments:</h5>
				5511
				5512	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5513	The only argument is the value to be counted. The argument may be of any
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	5514	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5515	</p>
				5516
				5517	<h5>Semantics:</h5>
				5518
				5519	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5520	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5521	in a variable. If the src == 0 then the result is the size in bits of the type
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5522	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5523	</p>
				5524	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5525
				5526
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5527
				5528	<!-- _______________________________________________________________________ -->
				5529	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5530	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5531	</div>
				5532
				5533	<div class="doc_text">
				5534
				5535	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5536	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
				5537	integer bit width. Not all targets support all bit widths however.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5538	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5539	declare i8 @llvm.cttz.i8 (i8 <src>)
				5540	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5541	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5542	declare i64 @llvm.cttz.i64(i64 <src>)
				5543	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5544	</pre>
				5545
				5546	<h5>Overview:</h5>
				5547
				5548	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5549	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5550	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5551	</p>
				5552
				5553	<h5>Arguments:</h5>
				5554
				5555	<p>
				5556	The only argument is the value to be counted. The argument may be of any
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	5557	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5558	</p>
				5559
				5560	<h5>Semantics:</h5>
				5561
				5562	<p>
				5563	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5564	in a variable. If the src == 0 then the result is the size in bits of the type
				5565	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5566	</p>
				5567	</div>
				5568
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	5569	<!-- _______________________________________________________________________ -->
				5570	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5571	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5572	</div>
				5573
				5574	<div class="doc_text">
				5575
				5576	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5577	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5578	on any integer bit width.
				5579	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5580	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5581	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5582	</pre>
				5583
				5584	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5585	<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5586	range of bits from an integer value and returns them in the same bit width as
				5587	the original value.</p>
				5588
				5589	<h5>Arguments:</h5>
				5590	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5591	any bit width but they must have the same bit width. The second and third
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5592	arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5593
				5594	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5595	<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5596	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5597	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5598	operates in forward mode.</p>
				5599	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5600	right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5601	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5602	<ol>
				5603	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5604	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5605	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5606	to determine the number of bits to retain.</li>
				5607	<li>A mask of the retained bits is created by shifting a -1 value.</li>
				5608	<li>The mask is ANDed with <tt>%val</tt> to produce the result.
				5609	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	5610	<p>In reverse mode, a similar computation is made except that the bits are
				5611	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5612	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5613	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5614	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5615	</div>
				5616
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5617	<div class="doc_subsubsection">
				5618	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5619	</div>
				5620
				5621	<div class="doc_text">
				5622
				5623	<h5>Syntax:</h5>
				5624	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
				5625	on any integer bit width.
				5626	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5627	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5628	declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5629	</pre>
				5630
				5631	<h5>Overview:</h5>
				5632	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5633	of bits in an integer value with another integer value. It returns the integer
				5634	with the replaced bits.</p>
				5635
				5636	<h5>Arguments:</h5>
				5637	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5638	any bit width but they must have the same bit width. <tt>%val</tt> is the value
				5639	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5640	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5641	type since they specify only a bit index.</p>
				5642
				5643	<h5>Semantics:</h5>
				5644	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5645	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5646	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5647	operates in forward mode.</p>
				5648	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5649	truncating it down to the size of the replacement area or zero extending it
				5650	up to that size.</p>
				5651	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5652	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5653	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
				5654	to the <tt>%hi</tt>th bit.
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5655	<p>In reverse mode, a similar computation is made except that the bits are
				5656	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
				5657	<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5658	<h5>Examples:</h5>
				5659	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5660	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5661	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5662	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5663	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5664	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	5665	</pre>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5666	</div>
				5667
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5668	<!-- ======================================================================= -->
				5669	<div class="doc_subsection">
				5670	<a name="int_debugger">Debugger Intrinsics</a>
				5671	</div>
				5672
				5673	<div class="doc_text">
				5674	<p>
				5675	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				5676	are described in the <a
				5677	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				5678	Debugging</a> document.
				5679	</p>
				5680	</div>
				5681
				5682
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	5683	<!-- ======================================================================= -->
				5684	<div class="doc_subsection">
				5685	<a name="int_eh">Exception Handling Intrinsics</a>
				5686	</div>
				5687
				5688	<div class="doc_text">
				5689	<p> The LLVM exception handling intrinsics (which all start with
				5690	<tt>llvm.eh.</tt> prefix), are described in the <a
				5691	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				5692	Handling</a> document. </p>
				5693	</div>
				5694
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5695	<!-- ======================================================================= -->
				5696	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5697	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5698	</div>
				5699
				5700	<div class="doc_text">
				5701	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5702	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5703	the <tt>nest</tt> attribute, from a function. The result is a callable
				5704	function pointer lacking the nest parameter - the caller does not need
				5705	to provide a value for it. Instead, the value to use is stored in
				5706	advance in a "trampoline", a block of memory usually allocated
				5707	on the stack, which also contains code to splice the nest value into the
				5708	argument list. This is used to implement the GCC nested function address
				5709	extension.
				5710	</p>
				5711	<p>
				5712	For example, if the function is
				5713	<tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	5714	pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5715	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5716	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				5717	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				5718	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				5719	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5720	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	5721	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				5722	to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5723	</div>
				5724
				5725	<!-- _______________________________________________________________________ -->
				5726	<div class="doc_subsubsection">
				5727	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				5728	</div>
				5729	<div class="doc_text">
				5730	<h5>Syntax:</h5>
				5731	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5732	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5733	</pre>
				5734	<h5>Overview:</h5>
				5735	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5736	This fills the memory pointed to by <tt>tramp</tt> with code
				5737	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5738	</p>
				5739	<h5>Arguments:</h5>
				5740	<p>
				5741	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				5742	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				5743	and sufficiently aligned block of memory; this memory is written to by the
Duncan Sands	c00c2ba	2007-08-22 23:39:54 +0000	[diff] [blame]	5744	intrinsic. Note that the size and the alignment are target-specific - LLVM
				5745	currently provides no portable way of determining them, so a front-end that
				5746	generates this intrinsic needs to have some target-specific knowledge.
				5747	The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5748	</p>
				5749	<h5>Semantics:</h5>
				5750	<p>
				5751	The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5752	dependent code, turning it into a function. A pointer to this function is
				5753	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5754	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5755	before being called. The new function's signature is the same as that of
				5756	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				5757	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				5758	of pointer type. Calling the new function is equivalent to calling
				5759	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				5760	missing <tt>nest</tt> argument. If, after calling
				5761	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				5762	modified, then the effect of any later call to the returned function pointer is
				5763	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5764	</p>
				5765	</div>
				5766
				5767	<!-- ======================================================================= -->
				5768	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5769	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				5770	</div>
				5771
				5772	<div class="doc_text">
				5773	<p>
				5774	These intrinsic functions expand the "universal IR" of LLVM to represent
				5775	hardware constructs for atomic operations and memory synchronization. This
				5776	provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	5777	is aimed at a low enough level to allow any programming models or APIs
				5778	(Application Programming Interfaces) which
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5779	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				5780	hardware behavior. Just as hardware provides a "universal IR" for source
				5781	languages, it also provides a starting point for developing a "universal"
				5782	atomic operation and synchronization IR.
				5783	</p>
				5784	<p>
				5785	These do <em>not</em> form an API such as high-level threading libraries,
				5786	software transaction memory systems, atomic primitives, and intrinsic
				5787	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				5788	application libraries. The hardware interface provided by LLVM should allow
				5789	a clean implementation of all of these APIs and parallel programming models.
				5790	No one model or paradigm should be selected above others unless the hardware
				5791	itself ubiquitously does so.
				5792
				5793	</p>
				5794	</div>
				5795
				5796	<!-- _______________________________________________________________________ -->
				5797	<div class="doc_subsubsection">
				5798	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				5799	</div>
				5800	<div class="doc_text">
				5801	<h5>Syntax:</h5>
				5802	<pre>
				5803	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				5804	i1 <device> )
				5805
				5806	</pre>
				5807	<h5>Overview:</h5>
				5808	<p>
				5809	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				5810	specific pairs of memory access types.
				5811	</p>
				5812	<h5>Arguments:</h5>
				5813	<p>
				5814	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				5815	The first four arguments enables a specific barrier as listed below. The fith
				5816	argument specifies that the barrier applies to io or device or uncached memory.
				5817
				5818	</p>
				5819	<ul>
				5820	<li><tt>ll</tt>: load-load barrier</li>
				5821	<li><tt>ls</tt>: load-store barrier</li>
				5822	<li><tt>sl</tt>: store-load barrier</li>
				5823	<li><tt>ss</tt>: store-store barrier</li>
				5824	<li><tt>device</tt>: barrier applies to device and uncached memory also.
				5825	</ul>
				5826	<h5>Semantics:</h5>
				5827	<p>
				5828	This intrinsic causes the system to enforce some ordering constraints upon
				5829	the loads and stores of the program. This barrier does not indicate
				5830	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				5831	which they occur. For any of the specified pairs of load and store operations
				5832	(f.ex. load-load, or store-load), all of the first operations preceding the
				5833	barrier will complete before any of the second operations succeeding the
				5834	barrier begin. Specifically the semantics for each pairing is as follows:
				5835	</p>
				5836	<ul>
				5837	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				5838	after the barrier begins.</li>
				5839
				5840	<li><tt>ls</tt>: All loads before the barrier must complete before any
				5841	store after the barrier begins.</li>
				5842	<li><tt>ss</tt>: All stores before the barrier must complete before any
				5843	store after the barrier begins.</li>
				5844	<li><tt>sl</tt>: All stores before the barrier must complete before any
				5845	load after the barrier begins.</li>
				5846	</ul>
				5847	<p>
				5848	These semantics are applied with a logical "and" behavior when more than one
				5849	is enabled in a single memory barrier intrinsic.
				5850	</p>
				5851	<p>
				5852	Backends may implement stronger barriers than those requested when they do not
				5853	support as fine grained a barrier as requested. Some architectures do not
				5854	need all types of barriers and on such architectures, these become noops.
				5855	</p>
				5856	<h5>Example:</h5>
				5857	<pre>
				5858	%ptr = malloc i32
				5859	store i32 4, %ptr
				5860
				5861	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				5862	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				5863	<i>; guarantee the above finishes</i>
				5864	store i32 8, %ptr <i>; before this begins</i>
				5865	</pre>
				5866	</div>
				5867
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5868	<!-- _______________________________________________________________________ -->
				5869	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5870	<a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5871	</div>
				5872	<div class="doc_text">
				5873	<h5>Syntax:</h5>
				5874	<p>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5875	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				5876	any integer bit width and for different address spaces. Not all targets
				5877	support all bit widths however.</p>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5878
				5879	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5880	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				5881	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				5882	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				5883	declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* <ptr>, i64 <cmp>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5884
				5885	</pre>
				5886	<h5>Overview:</h5>
				5887	<p>
				5888	This loads a value in memory and compares it to a given value. If they are
				5889	equal, it stores a new value into the memory.
				5890	</p>
				5891	<h5>Arguments:</h5>
				5892	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5893	The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5894	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				5895	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				5896	this integer type. While any bit width integer may be used, targets may only
				5897	lower representations they support in hardware.
				5898
				5899	</p>
				5900	<h5>Semantics:</h5>
				5901	<p>
				5902	This entire intrinsic must be executed atomically. It first loads the value
				5903	in memory pointed to by <tt>ptr</tt> and compares it with the value
				5904	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				5905	loaded value is yielded in all cases. This provides the equivalent of an
				5906	atomic compare-and-swap operation within the SSA framework.
				5907	</p>
				5908	<h5>Examples:</h5>
				5909
				5910	<pre>
				5911	%ptr = malloc i32
				5912	store i32 4, %ptr
				5913
				5914	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5915	%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5916	<i>; yields {i32}:result1 = 4</i>
				5917	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5918	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5919
				5920	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5921	%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5922	<i>; yields {i32}:result2 = 8</i>
				5923	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				5924
				5925	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				5926	</pre>
				5927	</div>
				5928
				5929	<!-- _______________________________________________________________________ -->
				5930	<div class="doc_subsubsection">
				5931	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				5932	</div>
				5933	<div class="doc_text">
				5934	<h5>Syntax:</h5>
				5935
				5936	<p>
				5937	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				5938	integer bit width. Not all targets support all bit widths however.</p>
				5939	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5940	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				5941	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				5942	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				5943	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5944
				5945	</pre>
				5946	<h5>Overview:</h5>
				5947	<p>
				5948	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				5949	the value from memory. It then stores the value in <tt>val</tt> in the memory
				5950	at <tt>ptr</tt>.
				5951	</p>
				5952	<h5>Arguments:</h5>
				5953
				5954	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5955	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5956	<tt>val</tt> argument and the result must be integers of the same bit width.
				5957	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				5958	integer type. The targets may only lower integer representations they
				5959	support.
				5960	</p>
				5961	<h5>Semantics:</h5>
				5962	<p>
				5963	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				5964	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				5965	equivalent of an atomic swap operation within the SSA framework.
				5966
				5967	</p>
				5968	<h5>Examples:</h5>
				5969	<pre>
				5970	%ptr = malloc i32
				5971	store i32 4, %ptr
				5972
				5973	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5974	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5975	<i>; yields {i32}:result1 = 4</i>
				5976	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5977	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5978
				5979	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5980	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5981	<i>; yields {i32}:result2 = 8</i>
				5982
				5983	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				5984	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				5985	</pre>
				5986	</div>
				5987
				5988	<!-- _______________________________________________________________________ -->
				5989	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5990	<a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5991
				5992	</div>
				5993	<div class="doc_text">
				5994	<h5>Syntax:</h5>
				5995	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5996	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on any
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5997	integer bit width. Not all targets support all bit widths however.</p>
				5998	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5999	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6000	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6001	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6002	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6003
				6004	</pre>
				6005	<h5>Overview:</h5>
				6006	<p>
				6007	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6008	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6009	</p>
				6010	<h5>Arguments:</h5>
				6011	<p>
				6012
				6013	The intrinsic takes two arguments, the first a pointer to an integer value
				6014	and the second an integer value. The result is also an integer value. These
				6015	integer types can have any bit width, but they must all have the same bit
				6016	width. The targets may only lower integer representations they support.
				6017	</p>
				6018	<h5>Semantics:</h5>
				6019	<p>
				6020	This intrinsic does a series of operations atomically. It first loads the
				6021	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6022	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6023	</p>
				6024
				6025	<h5>Examples:</h5>
				6026	<pre>
				6027	%ptr = malloc i32
				6028	store i32 4, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6029	%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6030	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6031	%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6032	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6033	%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6034	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6035	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6036	</pre>
				6037	</div>
				6038
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6039	<!-- _______________________________________________________________________ -->
				6040	<div class="doc_subsubsection">
				6041	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6042
				6043	</div>
				6044	<div class="doc_text">
				6045	<h5>Syntax:</h5>
				6046	<p>
				6047	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6048	any integer bit width and for different address spaces. Not all targets
				6049	support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6050	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6051	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6052	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6053	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6054	declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6055
				6056	</pre>
				6057	<h5>Overview:</h5>
				6058	<p>
				6059	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6060	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6061	</p>
				6062	<h5>Arguments:</h5>
				6063	<p>
				6064
				6065	The intrinsic takes two arguments, the first a pointer to an integer value
				6066	and the second an integer value. The result is also an integer value. These
				6067	integer types can have any bit width, but they must all have the same bit
				6068	width. The targets may only lower integer representations they support.
				6069	</p>
				6070	<h5>Semantics:</h5>
				6071	<p>
				6072	This intrinsic does a series of operations atomically. It first loads the
				6073	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6074	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6075	</p>
				6076
				6077	<h5>Examples:</h5>
				6078	<pre>
				6079	%ptr = malloc i32
				6080	store i32 8, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6081	%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6082	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6083	%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6084	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6085	%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6086	<i>; yields {i32}:result3 = 2</i>
				6087	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6088	</pre>
				6089	</div>
				6090
				6091	<!-- _______________________________________________________________________ -->
				6092	<div class="doc_subsubsection">
				6093	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6094	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6095	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6096	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6097
				6098	</div>
				6099	<div class="doc_text">
				6100	<h5>Syntax:</h5>
				6101	<p>
				6102	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6103	<tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6104	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6105	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6106	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6107	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6108	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6109	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6110	declare i64 @llvm.atomic.load.and.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6111
				6112	</pre>
				6113
				6114	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6115	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6116	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6117	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6118	declare i64 @llvm.atomic.load.or.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6119
				6120	</pre>
				6121
				6122	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6123	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6124	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6125	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6126	declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6127
				6128	</pre>
				6129
				6130	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6131	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6132	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6133	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6134	declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6135
				6136	</pre>
				6137	<h5>Overview:</h5>
				6138	<p>
				6139	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6140	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6141	at <tt>ptr</tt>.
				6142	</p>
				6143	<h5>Arguments:</h5>
				6144	<p>
				6145
				6146	These intrinsics take two arguments, the first a pointer to an integer value
				6147	and the second an integer value. The result is also an integer value. These
				6148	integer types can have any bit width, but they must all have the same bit
				6149	width. The targets may only lower integer representations they support.
				6150	</p>
				6151	<h5>Semantics:</h5>
				6152	<p>
				6153	These intrinsics does a series of operations atomically. They first load the
				6154	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6155	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6156	value stored at <tt>ptr</tt>.
				6157	</p>
				6158
				6159	<h5>Examples:</h5>
				6160	<pre>
				6161	%ptr = malloc i32
				6162	store i32 0x0F0F, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6163	%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6164	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6165	%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6166	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6167	%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6168	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6169	%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6170	<i>; yields {i32}:result3 = FF</i>
				6171	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6172	</pre>
				6173	</div>
				6174
				6175
				6176	<!-- _______________________________________________________________________ -->
				6177	<div class="doc_subsubsection">
				6178	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6179	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6180	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6181	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6182
				6183	</div>
				6184	<div class="doc_text">
				6185	<h5>Syntax:</h5>
				6186	<p>
				6187	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6188	<tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6189	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6190	address spaces. Not all targets
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6191	support all bit widths however.</p>
				6192	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6193	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6194	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6195	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6196	declare i64 @llvm.atomic.load.max.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6197
				6198	</pre>
				6199
				6200	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6201	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6202	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6203	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6204	declare i64 @llvm.atomic.load.min.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6205
				6206	</pre>
				6207
				6208	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6209	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6210	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6211	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6212	declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6213
				6214	</pre>
				6215
				6216	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6217	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6218	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6219	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6220	declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6221
				6222	</pre>
				6223	<h5>Overview:</h5>
				6224	<p>
				6225	These intrinsics takes the signed or unsigned minimum or maximum of
				6226	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6227	original value at <tt>ptr</tt>.
				6228	</p>
				6229	<h5>Arguments:</h5>
				6230	<p>
				6231
				6232	These intrinsics take two arguments, the first a pointer to an integer value
				6233	and the second an integer value. The result is also an integer value. These
				6234	integer types can have any bit width, but they must all have the same bit
				6235	width. The targets may only lower integer representations they support.
				6236	</p>
				6237	<h5>Semantics:</h5>
				6238	<p>
				6239	These intrinsics does a series of operations atomically. They first load the
				6240	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6241	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6242	the original value stored at <tt>ptr</tt>.
				6243	</p>
				6244
				6245	<h5>Examples:</h5>
				6246	<pre>
				6247	%ptr = malloc i32
				6248	store i32 7, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6249	%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6250	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6251	%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6252	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6253	%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6254	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6255	%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6256	<i>; yields {i32}:result3 = 8</i>
				6257	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6258	</pre>
				6259	</div>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6260
				6261	<!-- ======================================================================= -->
				6262	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6263	<a name="int_general">General Intrinsics</a>
				6264	</div>
				6265
				6266	<div class="doc_text">
				6267	<p> This class of intrinsics is designed to be generic and has
				6268	no specific purpose. </p>
				6269	</div>
				6270
				6271	<!-- _______________________________________________________________________ -->
				6272	<div class="doc_subsubsection">
				6273	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6274	</div>
				6275
				6276	<div class="doc_text">
				6277
				6278	<h5>Syntax:</h5>
				6279	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6280	declare void @llvm.var.annotation(i8* <val>, i8* <str>, i8* <str>, i32 <int> )
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6281	</pre>
				6282
				6283	<h5>Overview:</h5>
				6284
				6285	<p>
				6286	The '<tt>llvm.var.annotation</tt>' intrinsic
				6287	</p>
				6288
				6289	<h5>Arguments:</h5>
				6290
				6291	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6292	The first argument is a pointer to a value, the second is a pointer to a
				6293	global string, the third is a pointer to a global string which is the source
				6294	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6295	</p>
				6296
				6297	<h5>Semantics:</h5>
				6298
				6299	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6300	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6301	This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6302	annotations. These have no other defined use, they are ignored by code
				6303	generation and optimization.
				6304	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6305	</div>
				6306
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6307	<!-- _______________________________________________________________________ -->
				6308	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	6309	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6310	</div>
				6311
				6312	<div class="doc_text">
				6313
				6314	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6315	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6316	any integer bit width.
				6317	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6318	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	6319	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6320	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6321	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6322	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6323	declare i256 @llvm.annotation.i256(i256 <val>, i8* <str>, i8* <str>, i32 <int> )
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6324	</pre>
				6325
				6326	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6327
				6328	<p>
				6329	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6330	</p>
				6331
				6332	<h5>Arguments:</h5>
				6333
				6334	<p>
				6335	The first argument is an integer value (result of some expression),
				6336	the second is a pointer to a global string, the third is a pointer to a global
				6337	string which is the source file name, and the last argument is the line number.
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6338	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6339	</p>
				6340
				6341	<h5>Semantics:</h5>
				6342
				6343	<p>
				6344	This intrinsic allows annotations to be put on arbitrary expressions
				6345	with arbitrary strings. This can be useful for special purpose optimizations
				6346	that want to look for these annotations. These have no other defined use, they
				6347	are ignored by code generation and optimization.
				6348	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6349
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6350	<!-- _______________________________________________________________________ -->
				6351	<div class="doc_subsubsection">
				6352	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6353	</div>
				6354
				6355	<div class="doc_text">
				6356
				6357	<h5>Syntax:</h5>
				6358	<pre>
				6359	declare void @llvm.trap()
				6360	</pre>
				6361
				6362	<h5>Overview:</h5>
				6363
				6364	<p>
				6365	The '<tt>llvm.trap</tt>' intrinsic
				6366	</p>
				6367
				6368	<h5>Arguments:</h5>
				6369
				6370	<p>
				6371	None
				6372	</p>
				6373
				6374	<h5>Semantics:</h5>
				6375
				6376	<p>
				6377	This intrinsics is lowered to the target dependent trap instruction. If the
				6378	target does not have a trap instruction, this intrinsic will be lowered to the
				6379	call of the abort() function.
				6380	</p>
				6381	</div>
				6382
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6383	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6384	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6385	<address>
				6386	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
				6387	src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
				6388	<a href="http://validator.w3.org/check/referer"><img
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6389	src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6390
				6391	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	6392	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6393	Last modified: $Date$
				6394	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6395
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	6396	</body>
				6397	</html>