Blame - docs/LangRef.html - fp2-dev/platform/external/llvm

blob: 5bc81cc98d63f051dc781be30e28023e863d093b [file] [log] [blame]

Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1	<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
				2	"http://www.w3.org/TR/html4/strict.dtd">
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>
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	29	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	30	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	31	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	32	</ol>
				33	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	34	<li><a href="#typesystem">Type System</a>
				35	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	36	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	37	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	38	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	39	<li><a href="#t_floating">Floating Point Types</a></li>
				40	<li><a href="#t_void">Void Type</a></li>
				41	<li><a href="#t_label">Label Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	42	</ol>
				43	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	44	<li><a href="#t_derived">Derived Types</a>
				45	<ol>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	46	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	47	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	48	<li><a href="#t_function">Function Type</a></li>
				49	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	50	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	51	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	52	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	53	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	54	</ol>
				55	</li>
				56	</ol>
				57	</li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	58	<li><a href="#constants">Constants</a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	59	<ol>
				60	<li><a href="#simpleconstants">Simple Constants</a>
				61	<li><a href="#aggregateconstants">Aggregate Constants</a>
				62	<li><a href="#globalconstants">Global Variable and Function Addresses</a>
				63	<li><a href="#undefvalues">Undefined Values</a>
				64	<li><a href="#constantexprs">Constant Expressions</a>
				65	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	66	</li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	67	<li><a href="#othervalues">Other Values</a>
				68	<ol>
				69	<li><a href="#inlineasm">Inline Assembler Expressions</a>
				70	</ol>
				71	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	72	<li><a href="#instref">Instruction Reference</a>
				73	<ol>
				74	<li><a href="#terminators">Terminator Instructions</a>
				75	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	76	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				77	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	78	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				79	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	80	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	81	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	82	</ol>
				83	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	84	<li><a href="#binaryops">Binary Operations</a>
				85	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	86	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
				87	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
				88	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	89	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				90	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				91	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	92	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				93	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				94	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	95	</ol>
				96	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	97	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				98	<ol>
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	99	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				100	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				101	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	102	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	103	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	104	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	105	</ol>
				106	</li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	107	<li><a href="#vectorops">Vector Operations</a>
				108	<ol>
				109	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				110	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				111	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	112	</ol>
				113	</li>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	114	<li><a href="#aggregateops">Aggregate Operations</a>
				115	<ol>
				116	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				117	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				118	</ol>
				119	</li>
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	120	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	121	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	122	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				123	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				124	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	125	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				126	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				127	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	128	</ol>
				129	</li>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	130	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	131	<ol>
				132	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				133	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				134	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				135	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				136	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	137	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				138	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				139	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				140	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	141	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				142	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	143	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	144	</ol>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	145	<li><a href="#otherops">Other Operations</a>
				146	<ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	147	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				148	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	149	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				150	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	151	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	152	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	153	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	154	<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]	155	<li><a href="#i_getresult">'<tt>getresult</tt>' Instruction</a></li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	156	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	157	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	158	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	159	</li>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	160	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	161	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	162	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				163	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	164	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				165	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				166	<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]	167	</ol>
				168	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	169	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				170	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	171	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				172	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				173	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	174	</ol>
				175	</li>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	176	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				177	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	178	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				179	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				180	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				181	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				182	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				183	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				184	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	7123e27	2004-04-09 16:43:20 +0000	[diff] [blame]	185	</ol>
				186	</li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	187	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				188	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	189	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				190	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				191	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				192	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				193	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	194	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				195	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				196	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	197	</ol>
				198	</li>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	199	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	200	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	201	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	202	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				203	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				204	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	205	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				206	<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]	207	</ol>
				208	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	209	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	210	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	211	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	212	<ol>
				213	<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]	214	</ol>
				215	</li>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	216	<li><a href="#int_atomics">Atomic intrinsics</a>
				217	<ol>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	218	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
				219	<li><a href="#int_atomic_lcs"><tt>llvm.atomic.lcs</tt></a></li>
				220	<li><a href="#int_atomic_las"><tt>llvm.atomic.las</tt></a></li>
				221	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	222	</ol>
				223	</li>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	224	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	225	<ol>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	226	<li><a href="#int_var_annotation">
Tanya Lattner	91d0b88	2007-09-22 00:01:26 +0000	[diff] [blame]	227	<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	228	<li><a href="#int_annotation">
Tanya Lattner	91d0b88	2007-09-22 00:01:26 +0000	[diff] [blame]	229	<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	230	<li><a href="#int_trap">
				231	<tt>llvm.trap</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	232	</ol>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	233	</li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	234	</ol>
				235	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	236	</ol>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	237
				238	<div class="doc_author">
				239	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				240	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	241	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	242
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	243	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	244	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				245	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	246
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	247	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	248	<p>This document is a reference manual for the LLVM assembly language.
				249	LLVM is an SSA based representation that provides type safety,
				250	low-level operations, flexibility, and the capability of representing
				251	'all' high-level languages cleanly. It is the common code
				252	representation used throughout all phases of the LLVM compilation
				253	strategy.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	254	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	255
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	256	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	257	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				258	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	259
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	260	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	261
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	262	<p>The LLVM code representation is designed to be used in three
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	263	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]	264	representation (suitable for fast loading by a Just-In-Time compiler),
				265	and as a human readable assembly language representation. This allows
				266	LLVM to provide a powerful intermediate representation for efficient
				267	compiler transformations and analysis, while providing a natural means
				268	to debug and visualize the transformations. The three different forms
				269	of LLVM are all equivalent. This document describes the human readable
				270	representation and notation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	271
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	272	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	273	while being expressive, typed, and extensible at the same time. It
				274	aims to be a "universal IR" of sorts, by being at a low enough level
				275	that high-level ideas may be cleanly mapped to it (similar to how
				276	microprocessors are "universal IR's", allowing many source languages to
				277	be mapped to them). By providing type information, LLVM can be used as
				278	the target of optimizations: for example, through pointer analysis, it
				279	can be proven that a C automatic variable is never accessed outside of
				280	the current function... allowing it to be promoted to a simple SSA
				281	value instead of a memory location.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	282
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	283	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	284
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	285	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	286	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	287
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	288	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	289
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	290	<p>It is important to note that this document describes 'well formed'
				291	LLVM assembly language. There is a difference between what the parser
				292	accepts and what is considered 'well formed'. For example, the
				293	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	294
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	295	<div class="doc_code">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	296	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	297	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	298	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	299	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	300
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	301	<p>...because the definition of <tt>%x</tt> does not dominate all of
				302	its uses. The LLVM infrastructure provides a verification pass that may
				303	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]	304	automatically run by the parser after parsing input assembly and by
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	305	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	306	by the verifier pass indicate bugs in transformation passes or input to
				307	the parser.</p>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	308	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	309
Chris Lattner	cc68939	2007-10-03 17:34:29 +0000	[diff] [blame]	310	<!-- Describe the typesetting conventions here. -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	311
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	312	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	313	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	314	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	315
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	316	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	317
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	318	<p>LLVM identifiers come in two basic types: global and local. Global
				319	identifiers (functions, global variables) begin with the @ character. Local
				320	identifiers (register names, types) begin with the % character. Additionally,
				321	there are three different formats for identifiers, for different purposes:
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	322
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	323	<ol>
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	324	<li>Named values are represented as a string of characters with their prefix.
				325	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				326	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]	327	Identifiers which require other characters in their names can be surrounded
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	328	with quotes. In this way, anything except a <tt>"</tt> character can
				329	be used in a named value.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	330
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	331	<li>Unnamed values are represented as an unsigned numeric value with their
				332	prefix. For example, %12, @2, %44.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	333
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	334	<li>Constants, which are described in a <a href="#constants">section about
				335	constants</a>, below.</li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	336	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	337
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	338	<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]	339	don't need to worry about name clashes with reserved words, and the set of
				340	reserved words may be expanded in the future without penalty. Additionally,
				341	unnamed identifiers allow a compiler to quickly come up with a temporary
				342	variable without having to avoid symbol table conflicts.</p>
				343
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	344	<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]	345	languages. There are keywords for different opcodes
				346	('<tt><a href="#i_add">add</a></tt>',
				347	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				348	'<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]	349	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]	350	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	351	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	352
				353	<p>Here is an example of LLVM code to multiply the integer variable
				354	'<tt>%X</tt>' by 8:</p>
				355
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	356	<p>The easy way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	357
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	358	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	359	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	360	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	361	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	362	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	363
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	364	<p>After strength reduction:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	365
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	366	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	367	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	368	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
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	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	371
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	372	<p>And the hard way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	373
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	374	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	375	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	376	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				377	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				378	%result = <a href="#i_add">add</a> i32 %1, %1
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
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	382	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				383	important lexical features of LLVM:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	384
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	385	<ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	386
				387	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				388	line.</li>
				389
				390	<li>Unnamed temporaries are created when the result of a computation is not
				391	assigned to a named value.</li>
				392
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	393	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	394
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	395	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	396
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	397	<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]	398	demonstrating instructions, we will follow an instruction with a comment that
				399	defines the type and name of value produced. Comments are shown in italic
				400	text.</p>
				401
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	402	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	403
				404	<!-- *********************************************************************** -->
				405	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				406	<!-- *********************************************************************** -->
				407
				408	<!-- ======================================================================= -->
				409	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				410	</div>
				411
				412	<div class="doc_text">
				413
				414	<p>LLVM programs are composed of "Module"s, each of which is a
				415	translation unit of the input programs. Each module consists of
				416	functions, global variables, and symbol table entries. Modules may be
				417	combined together with the LLVM linker, which merges function (and
				418	global variable) definitions, resolves forward declarations, and merges
				419	symbol table entries. Here is an example of the "hello world" module:</p>
				420
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	421	<div class="doc_code">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	422	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	423	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				424	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]	425
				426	<i>; External declaration of the puts function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	427	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	428
				429	<i>; Definition of main function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	430	define i32 @main() { <i>; i32()* </i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	431	<i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	432	%cast210 = <a
Chris Lattner	6c0955b	2007-06-12 17:01:15 +0000	[diff] [blame]	433	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]	434
				435	<i>; Call puts function to write out the string to stdout...</i>
				436	<a
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	437	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	438	<a
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	439	href="#i_ret">ret</a> i32 0<br>}<br>
				440	</pre>
				441	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	442
				443	<p>This example is made up of a <a href="#globalvars">global variable</a>
				444	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				445	function, and a <a href="#functionstructure">function definition</a>
				446	for "<tt>main</tt>".</p>
				447
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	448	<p>In general, a module is made up of a list of global values,
				449	where both functions and global variables are global values. Global values are
				450	represented by a pointer to a memory location (in this case, a pointer to an
				451	array of char, and a pointer to a function), and have one of the following <a
				452	href="#linkage">linkage types</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	453
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	454	</div>
				455
				456	<!-- ======================================================================= -->
				457	<div class="doc_subsection">
				458	<a name="linkage">Linkage Types</a>
				459	</div>
				460
				461	<div class="doc_text">
				462
				463	<p>
				464	All Global Variables and Functions have one of the following types of linkage:
				465	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	466
				467	<dl>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	468
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	469	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	470
				471	<dd>Global values with internal linkage are only directly accessible by
				472	objects in the current module. In particular, linking code into a module with
				473	an internal global value may cause the internal to be renamed as necessary to
				474	avoid collisions. Because the symbol is internal to the module, all
				475	references can be updated. This corresponds to the notion of the
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	476	'<tt>static</tt>' keyword in C.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	477	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	478
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	479	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	480
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	481	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				482	the same name when linkage occurs. This is typically used to implement
				483	inline functions, templates, or other code which must be generated in each
				484	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				485	allowed to be discarded.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	486	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	487
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	488	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				489
				490	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				491	linkage, except that unreferenced <tt>common</tt> globals may not be
				492	discarded. This is used for globals that may be emitted in multiple
				493	translation units, but that are not guaranteed to be emitted into every
				494	translation unit that uses them. One example of this is tentative
				495	definitions in C, such as "<tt>int X;</tt>" at global scope.
				496	</dd>
				497
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	498	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	499
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	500	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				501	that some targets may choose to emit different assembly sequences for them
				502	for target-dependent reasons. This is used for globals that are declared
				503	"weak" in C source code.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	504	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	505
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	506	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	507
				508	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				509	pointer to array type. When two global variables with appending linkage are
				510	linked together, the two global arrays are appended together. This is the
				511	LLVM, typesafe, equivalent of having the system linker append together
				512	"sections" with identical names when .o files are linked.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	513	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	514
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	515	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
				516	<dd>The semantics of this linkage follow the ELF model: the symbol is weak
				517	until linked, if not linked, the symbol becomes null instead of being an
				518	undefined reference.
				519	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	520
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	521	<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]	522
				523	<dd>If none of the above identifiers are used, the global is externally
				524	visible, meaning that it participates in linkage and can be used to resolve
				525	external symbol references.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	526	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	527	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	528
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	529	<p>
				530	The next two types of linkage are targeted for Microsoft Windows platform
				531	only. They are designed to support importing (exporting) symbols from (to)
				532	DLLs.
				533	</p>
				534
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	535	<dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	536	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				537
				538	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				539	or variable via a global pointer to a pointer that is set up by the DLL
				540	exporting the symbol. On Microsoft Windows targets, the pointer name is
				541	formed by combining <code>_imp__</code> and the function or variable name.
				542	</dd>
				543
				544	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				545
				546	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				547	pointer to a pointer in a DLL, so that it can be referenced with the
				548	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
				549	name is formed by combining <code>_imp__</code> and the function or variable
				550	name.
				551	</dd>
				552
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	553	</dl>
				554
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	555	<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]	556	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				557	variable and was linked with this one, one of the two would be renamed,
				558	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				559	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	ac8d276	2007-01-05 00:59:10 +0000	[diff] [blame]	560	outside of the current module.</p>
				561	<p>It is illegal for a function <i>declaration</i>
				562	to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	563	or <tt>extern_weak</tt>.</p>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	564	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
				565	linkages.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	566	</div>
				567
				568	<!-- ======================================================================= -->
				569	<div class="doc_subsection">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	570	<a name="callingconv">Calling Conventions</a>
				571	</div>
				572
				573	<div class="doc_text">
				574
				575	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				576	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				577	specified for the call. The calling convention of any pair of dynamic
				578	caller/callee must match, or the behavior of the program is undefined. The
				579	following calling conventions are supported by LLVM, and more may be added in
				580	the future:</p>
				581
				582	<dl>
				583	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				584
				585	<dd>This calling convention (the default if no other calling convention is
				586	specified) matches the target C calling conventions. This calling convention
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	587	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	588	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	589	</dd>
				590
				591	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				592
				593	<dd>This calling convention attempts to make calls as fast as possible
				594	(e.g. by passing things in registers). This calling convention allows the
				595	target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner	8cdc5bc	2005-05-06 23:08:23 +0000	[diff] [blame]	596	without having to conform to an externally specified ABI. Implementations of
Arnold Schwaighofer	9097d14	2008-05-14 09:17:12 +0000	[diff] [blame]	597	this convention should allow arbitrary
				598	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				599	supported. This calling convention does not support varargs and requires the
				600	prototype of all callees to exactly match the prototype of the function
				601	definition.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	602	</dd>
				603
				604	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				605
				606	<dd>This calling convention attempts to make code in the caller as efficient
				607	as possible under the assumption that the call is not commonly executed. As
				608	such, these calls often preserve all registers so that the call does not break
				609	any live ranges in the caller side. This calling convention does not support
				610	varargs and requires the prototype of all callees to exactly match the
				611	prototype of the function definition.
				612	</dd>
				613
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	614	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	615
				616	<dd>Any calling convention may be specified by number, allowing
				617	target-specific calling conventions to be used. Target specific calling
				618	conventions start at 64.
				619	</dd>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	620	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	621
				622	<p>More calling conventions can be added/defined on an as-needed basis, to
				623	support pascal conventions or any other well-known target-independent
				624	convention.</p>
				625
				626	</div>
				627
				628	<!-- ======================================================================= -->
				629	<div class="doc_subsection">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	630	<a name="visibility">Visibility Styles</a>
				631	</div>
				632
				633	<div class="doc_text">
				634
				635	<p>
				636	All Global Variables and Functions have one of the following visibility styles:
				637	</p>
				638
				639	<dl>
				640	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				641
				642	<dd>On ELF, default visibility means that the declaration is visible to other
				643	modules and, in shared libraries, means that the declared entity may be
				644	overridden. On Darwin, default visibility means that the declaration is
				645	visible to other modules. Default visibility corresponds to "external
				646	linkage" in the language.
				647	</dd>
				648
				649	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				650
				651	<dd>Two declarations of an object with hidden visibility refer to the same
				652	object if they are in the same shared object. Usually, hidden visibility
				653	indicates that the symbol will not be placed into the dynamic symbol table,
				654	so no other module (executable or shared library) can reference it
				655	directly.
				656	</dd>
				657
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	658	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				659
				660	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				661	the dynamic symbol table, but that references within the defining module will
				662	bind to the local symbol. That is, the symbol cannot be overridden by another
				663	module.
				664	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	665	</dl>
				666
				667	</div>
				668
				669	<!-- ======================================================================= -->
				670	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	671	<a name="globalvars">Global Variables</a>
				672	</div>
				673
				674	<div class="doc_text">
				675
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	676	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	677	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	678	an explicit section to be placed in, and may have an optional explicit alignment
				679	specified. A variable may be defined as "thread_local", which means that it
				680	will not be shared by threads (each thread will have a separated copy of the
				681	variable). A variable may be defined as a global "constant," which indicates
				682	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]	683	optimization, allowing the global data to be placed in the read-only section of
				684	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	685	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]	686
				687	<p>
				688	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				689	constant, even if the final definition of the global is not. This capability
				690	can be used to enable slightly better optimization of the program, but requires
				691	the language definition to guarantee that optimizations based on the
				692	'constantness' are valid for the translation units that do not include the
				693	definition.
				694	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	695
				696	<p>As SSA values, global variables define pointer values that are in
				697	scope (i.e. they dominate) all basic blocks in the program. Global
				698	variables always define a pointer to their "content" type because they
				699	describe a region of memory, and all memory objects in LLVM are
				700	accessed through pointers.</p>
				701
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	702	<p>A global variable may be declared to reside in a target-specifc numbered
				703	address space. For targets that support them, address spaces may affect how
				704	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	705	the variable. The default address space is zero. The address space qualifier
				706	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	707
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	708	<p>LLVM allows an explicit section to be specified for globals. If the target
				709	supports it, it will emit globals to the section specified.</p>
				710
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	711	<p>An explicit alignment may be specified for a global. If not present, or if
				712	the alignment is set to zero, the alignment of the global is set by the target
				713	to whatever it feels convenient. If an explicit alignment is specified, the
				714	global is forced to have at least that much alignment. All alignments must be
				715	a power of 2.</p>
				716
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	717	<p>For example, the following defines a global in a numbered address space with
				718	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	719
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	720	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	721	<pre>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	722	@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	723	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	724	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	725
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	726	</div>
				727
				728
				729	<!-- ======================================================================= -->
				730	<div class="doc_subsection">
				731	<a name="functionstructure">Functions</a>
				732	</div>
				733
				734	<div class="doc_text">
				735
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	736	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				737	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	738	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	739	<a href="#callingconv">calling convention</a>, a return type, an optional
				740	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				741	name, a (possibly empty) argument list (each with optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	742	<a href="#paramattrs">parameter attributes</a>), an optional section, an
Gordon Henriksen	e754abe	2007-12-10 03:30:21 +0000	[diff] [blame]	743	optional alignment, an optional <a href="#gc">garbage collector name</a>, an
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	744	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]	745
				746	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				747	optional <a href="#linkage">linkage type</a>, an optional
				748	<a href="#visibility">visibility style</a>, an optional
				749	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	750	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	751	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]	752	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	753
				754	<p>A function definition contains a list of basic blocks, forming the CFG for
				755	the function. Each basic block may optionally start with a label (giving the
				756	basic block a symbol table entry), contains a list of instructions, and ends
				757	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				758	function return).</p>
				759
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	760	<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]	761	executed on entrance to the function, and it is not allowed to have predecessor
				762	basic blocks (i.e. there can not be any branches to the entry block of a
				763	function). Because the block can have no predecessors, it also cannot have any
				764	<a href="#i_phi">PHI nodes</a>.</p>
				765
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	766	<p>LLVM allows an explicit section to be specified for functions. If the target
				767	supports it, it will emit functions to the section specified.</p>
				768
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	769	<p>An explicit alignment may be specified for a function. If not present, or if
				770	the alignment is set to zero, the alignment of the function is set by the target
				771	to whatever it feels convenient. If an explicit alignment is specified, the
				772	function is forced to have at least that much alignment. All alignments must be
				773	a power of 2.</p>
				774
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	775	</div>
				776
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	777
				778	<!-- ======================================================================= -->
				779	<div class="doc_subsection">
				780	<a name="aliasstructure">Aliases</a>
				781	</div>
				782	<div class="doc_text">
				783	<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]	784	function, global variable, another alias or bitcast of global value). Aliases
				785	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	786	optional <a href="#visibility">visibility style</a>.</p>
				787
				788	<h5>Syntax:</h5>
				789
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	790	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	791	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	792	@<Name> = [Linkage] [Visibility] alias <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	793	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	794	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	795
				796	</div>
				797
				798
				799
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	800	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	801	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				802	<div class="doc_text">
				803	<p>The return type and each parameter of a function type may have a set of
				804	<i>parameter attributes</i> associated with them. Parameter attributes are
				805	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	806	a function. Parameter attributes are considered to be part of the function,
				807	not of the function type, so functions with different parameter attributes
				808	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	809
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	810	<p>Parameter attributes are simple keywords that follow the type specified. If
				811	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	812	example:</p>
				813
				814	<div class="doc_code">
				815	<pre>
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	816	declare i32 @printf(i8* noalias , ...) nounwind
				817	declare i32 @atoi(i8*) nounwind readonly
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	818	</pre>
				819	</div>
				820
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	821	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				822	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	823
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	824	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	825	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	826	<dt><tt>zeroext</tt></dt>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	827	<dd>This indicates that the parameter should be zero extended just before
				828	a call to this function.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	829
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	830	<dt><tt>signext</tt></dt>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	831	<dd>This indicates that the parameter should be sign extended just before
				832	a call to this function.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	833
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	834	<dt><tt>inreg</tt></dt>
				835	<dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikov	66a8c8c	2007-01-28 15:27:21 +0000	[diff] [blame]	836	possible) during assembling function call. Support for this attribute is
				837	target-specific</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	838
				839	<dt><tt>byval</tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	840	<dd>This indicates that the pointer parameter should really be passed by
				841	value to the function. The attribute implies that a hidden copy of the
				842	pointee is made between the caller and the callee, so the callee is unable
				843	to modify the value in the callee. This attribute is only valid on llvm
				844	pointer arguments. It is generally used to pass structs and arrays by
				845	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]	846
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	847	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	848	<dd>This indicates that the pointer parameter specifies the address of a
				849	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]	850	Loads and stores to the structure are assumed not to trap.
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	851	May only be applied to the first parameter.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	852
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	853	<dt><tt>noalias</tt></dt>
Owen Anderson	117bbd3	2008-02-18 04:09:01 +0000	[diff] [blame]	854	<dd>This indicates that the parameter does not alias any global or any other
				855	parameter. The caller is responsible for ensuring that this is the case,
				856	usually by placing the value in a stack allocation.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	857
Reid Spencer	2dc5201	2007-03-22 02:18:56 +0000	[diff] [blame]	858	<dt><tt>noreturn</tt></dt>
				859	<dd>This function attribute indicates that the function never returns. This
				860	indicates to LLVM that every call to this function should be treated as if
				861	an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	862
Reid Spencer	6760612	2007-03-22 02:02:11 +0000	[diff] [blame]	863	<dt><tt>nounwind</tt></dt>
Duncan Sands	b7f0c08	2008-03-17 12:17:41 +0000	[diff] [blame]	864	<dd>This function attribute indicates that no exceptions unwind out of the
				865	function. Usually this is because the function makes no use of exceptions,
				866	but it may also be that the function catches any exceptions thrown when
				867	executing it.</dd>
				868
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	869	<dt><tt>nest</tt></dt>
				870	<dd>This indicates that the parameter can be excised using the
				871	<a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sands	ed4a2f1	2007-11-22 20:23:04 +0000	[diff] [blame]	872	<dt><tt>readonly</tt></dt>
Duncan Sands	f04d584	2007-11-14 21:14:02 +0000	[diff] [blame]	873	<dd>This function attribute indicates that the function has no side-effects
Duncan Sands	ed4a2f1	2007-11-22 20:23:04 +0000	[diff] [blame]	874	except for producing a return value or throwing an exception. The value
				875	returned must only depend on the function arguments and/or global variables.
				876	It may use values obtained by dereferencing pointers.</dd>
				877	<dt><tt>readnone</tt></dt>
				878	<dd>A <tt>readnone</tt> function has the same restrictions as a <tt>readonly</tt>
Duncan Sands	f04d584	2007-11-14 21:14:02 +0000	[diff] [blame]	879	function, but in addition it is not allowed to dereference any pointer arguments
				880	or global variables.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	881	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	882
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	883	</div>
				884
				885	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	886	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	887	<a name="gc">Garbage Collector Names</a>
				888	</div>
				889
				890	<div class="doc_text">
				891	<p>Each function may specify a garbage collector name, which is simply a
				892	string.</p>
				893
				894	<div class="doc_code"><pre
				895	>define void @f() gc "name" { ...</pre></div>
				896
				897	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				898	collector which will cause the compiler to alter its output in order to support
				899	the named garbage collection algorithm.</p>
				900	</div>
				901
				902	<!-- ======================================================================= -->
				903	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	904	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	905	</div>
				906
				907	<div class="doc_text">
				908	<p>
				909	Modules may contain "module-level inline asm" blocks, which corresponds to the
				910	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				911	LLVM and treated as a single unit, but may be separated in the .ll file if
				912	desired. The syntax is very simple:
				913	</p>
				914
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	915	<div class="doc_code">
				916	<pre>
				917	module asm "inline asm code goes here"
				918	module asm "more can go here"
				919	</pre>
				920	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	921
				922	<p>The strings can contain any character by escaping non-printable characters.
				923	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				924	for the number.
				925	</p>
				926
				927	<p>
				928	The inline asm code is simply printed to the machine code .s file when
				929	assembly code is generated.
				930	</p>
				931	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	932
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	933	<!-- ======================================================================= -->
				934	<div class="doc_subsection">
				935	<a name="datalayout">Data Layout</a>
				936	</div>
				937
				938	<div class="doc_text">
				939	<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]	940	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				941	<pre> target datalayout = "<i>layout specification</i>"</pre>
				942	<p>The <i>layout specification</i> consists of a list of specifications
				943	separated by the minus sign character ('-'). Each specification starts with a
				944	letter and may include other information after the letter to define some
				945	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	946	<dl>
				947	<dt><tt>E</tt></dt>
				948	<dd>Specifies that the target lays out data in big-endian form. That is, the
				949	bits with the most significance have the lowest address location.</dd>
				950	<dt><tt>e</tt></dt>
				951	<dd>Specifies that hte target lays out data in little-endian form. That is,
				952	the bits with the least significance have the lowest address location.</dd>
				953	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				954	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				955	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				956	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				957	too.</dd>
				958	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				959	<dd>This specifies the alignment for an integer type of a given bit
				960	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				961	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				962	<dd>This specifies the alignment for a vector type of a given bit
				963	<i>size</i>.</dd>
				964	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				965	<dd>This specifies the alignment for a floating point type of a given bit
				966	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				967	(double).</dd>
				968	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				969	<dd>This specifies the alignment for an aggregate type of a given bit
				970	<i>size</i>.</dd>
				971	</dl>
				972	<p>When constructing the data layout for a given target, LLVM starts with a
				973	default set of specifications which are then (possibly) overriden by the
				974	specifications in the <tt>datalayout</tt> keyword. The default specifications
				975	are given in this list:</p>
				976	<ul>
				977	<li><tt>E</tt> - big endian</li>
				978	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				979	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				980	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				981	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				982	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
				983	<li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
				984	alignment of 64-bits</li>
				985	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				986	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				987	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				988	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				989	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				990	</ul>
				991	<p>When llvm is determining the alignment for a given type, it uses the
				992	following rules:
				993	<ol>
				994	<li>If the type sought is an exact match for one of the specifications, that
				995	specification is used.</li>
				996	<li>If no match is found, and the type sought is an integer type, then the
				997	smallest integer type that is larger than the bitwidth of the sought type is
				998	used. If none of the specifications are larger than the bitwidth then the the
				999	largest integer type is used. For example, given the default specifications
				1000	above, the i7 type will use the alignment of i8 (next largest) while both
				1001	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1002	<li>If no match is found, and the type sought is a vector type, then the
				1003	largest vector type that is smaller than the sought vector type will be used
				1004	as a fall back. This happens because <128 x double> can be implemented in
				1005	terms of 64 <2 x double>, for example.</li>
				1006	</ol>
				1007	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1008
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1009	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1010	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1011	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1012
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1013	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1014
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1015	<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]	1016	intermediate representation. Being typed enables a number of
				1017	optimizations to be performed on the IR directly, without having to do
				1018	extra analyses on the side before the transformation. A strong type
				1019	system makes it easier to read the generated code and enables novel
				1020	analyses and transformations that are not feasible to perform on normal
				1021	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1022
				1023	</div>
				1024
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1025	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1026	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1027	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1028	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1029	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1030	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1031
				1032	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1033	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1034	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1035	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1036	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1037	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1038	</tr>
				1039	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1040	<td><a href="#t_floating">floating point</a></td>
				1041	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1042	</tr>
				1043	<tr>
				1044	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1045	<td><a href="#t_integer">integer</a>,
				1046	<a href="#t_floating">floating point</a>,
				1047	<a href="#t_pointer">pointer</a>,
Dan Gohman	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame^]	1048	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1049	<a href="#t_struct">structure</a>,
				1050	<a href="#t_array">array</a>,
Dan Gohman	ade5faa	2008-05-23 22:50:26 +0000	[diff] [blame]	1051	<a href="#t_label">label</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1052	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1053	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1054	<tr>
				1055	<td><a href="#t_primitive">primitive</a></td>
				1056	<td><a href="#t_label">label</a>,
				1057	<a href="#t_void">void</a>,
				1058	<a href="#t_integer">integer</a>,
				1059	<a href="#t_floating">floating point</a>.</td>
				1060	</tr>
				1061	<tr>
				1062	<td><a href="#t_derived">derived</a></td>
				1063	<td><a href="#t_integer">integer</a>,
				1064	<a href="#t_array">array</a>,
				1065	<a href="#t_function">function</a>,
				1066	<a href="#t_pointer">pointer</a>,
				1067	<a href="#t_struct">structure</a>,
				1068	<a href="#t_pstruct">packed structure</a>,
				1069	<a href="#t_vector">vector</a>,
				1070	<a href="#t_opaque">opaque</a>.
				1071	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1072	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1073	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1074
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1075	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1076	most important. Values of these types are the only ones which can be
				1077	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1078	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1079	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1080
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1081	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1082	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1083
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1084	<div class="doc_text">
				1085	<p>The primitive types are the fundamental building blocks of the LLVM
				1086	system.</p>
				1087
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1088	</div>
				1089
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1090	<!-- _______________________________________________________________________ -->
				1091	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1092
				1093	<div class="doc_text">
				1094	<table>
				1095	<tbody>
				1096	<tr><th>Type</th><th>Description</th></tr>
				1097	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1098	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1099	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1100	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1101	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1102	</tbody>
				1103	</table>
				1104	</div>
				1105
				1106	<!-- _______________________________________________________________________ -->
				1107	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1108
				1109	<div class="doc_text">
				1110	<h5>Overview:</h5>
				1111	<p>The void type does not represent any value and has no size.</p>
				1112
				1113	<h5>Syntax:</h5>
				1114
				1115	<pre>
				1116	void
				1117	</pre>
				1118	</div>
				1119
				1120	<!-- _______________________________________________________________________ -->
				1121	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1122
				1123	<div class="doc_text">
				1124	<h5>Overview:</h5>
				1125	<p>The label type represents code labels.</p>
				1126
				1127	<h5>Syntax:</h5>
				1128
				1129	<pre>
				1130	label
				1131	</pre>
				1132	</div>
				1133
				1134
				1135	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1136	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1137
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1138	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1139
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1140	<p>The real power in LLVM comes from the derived types in the system.
				1141	This is what allows a programmer to represent arrays, functions,
				1142	pointers, and other useful types. Note that these derived types may be
				1143	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]	1144
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1145	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1146
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1147	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1148	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1149
				1150	<div class="doc_text">
				1151
				1152	<h5>Overview:</h5>
				1153	<p>The integer type is a very simple derived type that simply specifies an
				1154	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1155	2^23-1 (about 8 million) can be specified.</p>
				1156
				1157	<h5>Syntax:</h5>
				1158
				1159	<pre>
				1160	iN
				1161	</pre>
				1162
				1163	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1164	value.</p>
				1165
				1166	<h5>Examples:</h5>
				1167	<table class="layout">
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1168	<tbody>
				1169	<tr>
				1170	<td><tt>i1</tt></td>
				1171	<td>a single-bit integer.</td>
				1172	</tr><tr>
				1173	<td><tt>i32</tt></td>
				1174	<td>a 32-bit integer.</td>
				1175	</tr><tr>
				1176	<td><tt>i1942652</tt></td>
				1177	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1178	</tr>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1179	</tbody>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1180	</table>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1181	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1182
				1183	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1184	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1185
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1186	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1187
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1188	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1189
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1190	<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]	1191	sequentially in memory. The array type requires a size (number of
				1192	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1193
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1194	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1195
				1196	<pre>
				1197	[<# elements> x <elementtype>]
				1198	</pre>
				1199
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1200	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1201	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1202
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1203	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1204	<table class="layout">
				1205	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1206	<td class="left"><tt>[40 x i32]</tt></td>
				1207	<td class="left">Array of 40 32-bit integer values.</td>
				1208	</tr>
				1209	<tr class="layout">
				1210	<td class="left"><tt>[41 x i32]</tt></td>
				1211	<td class="left">Array of 41 32-bit integer values.</td>
				1212	</tr>
				1213	<tr class="layout">
				1214	<td class="left"><tt>[4 x i8]</tt></td>
				1215	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1216	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1217	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1218	<p>Here are some examples of multidimensional arrays:</p>
				1219	<table class="layout">
				1220	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1221	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1222	<td class="left">3x4 array of 32-bit integer values.</td>
				1223	</tr>
				1224	<tr class="layout">
				1225	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1226	<td class="left">12x10 array of single precision floating point values.</td>
				1227	</tr>
				1228	<tr class="layout">
				1229	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1230	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1231	</tr>
				1232	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1233
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1234	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1235	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]	1236	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1237	As a special case, however, zero length arrays are recognized to be variable
				1238	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1239	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1240
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1241	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1242
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1243	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1244	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1245	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1246
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1247	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1248
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1249	<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]	1250	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]	1251	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]	1252	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]	1253	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1254
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1255	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1256
				1257	<pre>
				1258	<returntype list> (<parameter list>)
				1259	</pre>
				1260
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1261	<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]	1262	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1263	which indicates that the function takes a variable number of arguments.
				1264	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1265	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1266	'<tt><returntype list></tt>' is a comma-separated list of
				1267	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1268
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1269	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1270	<table class="layout">
				1271	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1272	<td class="left"><tt>i32 (i32)</tt></td>
				1273	<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]	1274	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1275	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1276	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1277	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1278	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1279	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1280	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1281	<tt>float</tt>.
				1282	</td>
				1283	</tr><tr class="layout">
				1284	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1285	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1286	<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]	1287	which returns an integer. This is the signature for <tt>printf</tt> in
				1288	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1289	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1290	</tr><tr class="layout">
				1291	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel	3a5bff8	2008-03-24 18:10:52 +0000	[diff] [blame]	1292	<td class="left">A function taking an <tt>i32></tt>, returning two
				1293	<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]	1294	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1295	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1296	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1297
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1298	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1299	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1300	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1301	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1302	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1303	<p>The structure type is used to represent a collection of data members
				1304	together in memory. The packing of the field types is defined to match
				1305	the ABI of the underlying processor. The elements of a structure may
				1306	be any type that has a size.</p>
				1307	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1308	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1309	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1310	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1311	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1312	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1313	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1314	<table class="layout">
				1315	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1316	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1317	<td class="left">A triple of three <tt>i32</tt> values</td>
				1318	</tr><tr class="layout">
				1319	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1320	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1321	second element is a <a href="#t_pointer">pointer</a> to a
				1322	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1323	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1324	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1325	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1326	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1327
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1328	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1329	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1330	</div>
				1331	<div class="doc_text">
				1332	<h5>Overview:</h5>
				1333	<p>The packed structure type is used to represent a collection of data members
				1334	together in memory. There is no padding between fields. Further, the alignment
				1335	of a packed structure is 1 byte. The elements of a packed structure may
				1336	be any type that has a size.</p>
				1337	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1338	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1339	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1340	instruction.</p>
				1341	<h5>Syntax:</h5>
				1342	<pre> < { <type list> } > <br></pre>
				1343	<h5>Examples:</h5>
				1344	<table class="layout">
				1345	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1346	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1347	<td class="left">A triple of three <tt>i32</tt> values</td>
				1348	</tr><tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1349	<td class="left"><tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1350	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1351	second element is a <a href="#t_pointer">pointer</a> to a
				1352	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1353	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1354	</tr>
				1355	</table>
				1356	</div>
				1357
				1358	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1359	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1360	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1361	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1362	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1363	reference to another object, which must live in memory. Pointer types may have
				1364	an optional address space attribute defining the target-specific numbered
				1365	address space where the pointed-to object resides. The default address space is
				1366	zero.</p>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1367	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1368	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1369	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1370	<table class="layout">
				1371	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1372	<td class="left"><tt>[4x i32]*</tt></td>
				1373	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1374	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1375	</tr>
				1376	<tr class="layout">
				1377	<td class="left"><tt>i32 (i32 ) </tt></td>
				1378	<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]	1379	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]	1380	<tt>i32</tt>.</td>
				1381	</tr>
				1382	<tr class="layout">
				1383	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1384	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1385	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1386	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1387	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1388	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1389
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1390	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1391	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1392	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1393
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1394	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1395
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1396	<p>A vector type is a simple derived type that represents a vector
				1397	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1398	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1399	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1400	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1401	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1402	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1403
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1404	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1405
				1406	<pre>
				1407	< <# elements> x <elementtype> >
				1408	</pre>
				1409
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1410	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1411	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1412
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1413	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1414
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1415	<table class="layout">
				1416	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1417	<td class="left"><tt><4 x i32></tt></td>
				1418	<td class="left">Vector of 4 32-bit integer values.</td>
				1419	</tr>
				1420	<tr class="layout">
				1421	<td class="left"><tt><8 x float></tt></td>
				1422	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1423	</tr>
				1424	<tr class="layout">
				1425	<td class="left"><tt><2 x i64></tt></td>
				1426	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1427	</tr>
				1428	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1429	</div>
				1430
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1431	<!-- _______________________________________________________________________ -->
				1432	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1433	<div class="doc_text">
				1434
				1435	<h5>Overview:</h5>
				1436
				1437	<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]	1438	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]	1439	In LLVM, opaque types can eventually be resolved to any type (not just a
				1440	structure type).</p>
				1441
				1442	<h5>Syntax:</h5>
				1443
				1444	<pre>
				1445	opaque
				1446	</pre>
				1447
				1448	<h5>Examples:</h5>
				1449
				1450	<table class="layout">
				1451	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1452	<td class="left"><tt>opaque</tt></td>
				1453	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1454	</tr>
				1455	</table>
				1456	</div>
				1457
				1458
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1459	<!-- *********************************************************************** -->
				1460	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1461	<!-- *********************************************************************** -->
				1462
				1463	<div class="doc_text">
				1464
				1465	<p>LLVM has several different basic types of constants. This section describes
				1466	them all and their syntax.</p>
				1467
				1468	</div>
				1469
				1470	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1471	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1472
				1473	<div class="doc_text">
				1474
				1475	<dl>
				1476	<dt><b>Boolean constants</b></dt>
				1477
				1478	<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]	1479	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1480	</dd>
				1481
				1482	<dt><b>Integer constants</b></dt>
				1483
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1484	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1485	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1486	integer types.
				1487	</dd>
				1488
				1489	<dt><b>Floating point constants</b></dt>
				1490
				1491	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1492	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1493	notation (see below). The assembler requires the exact decimal value of
				1494	a floating-point constant. For example, the assembler accepts 1.25 but
				1495	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1496	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]	1497
				1498	<dt><b>Null pointer constants</b></dt>
				1499
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1500	<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]	1501	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1502
				1503	</dl>
				1504
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1505	<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]	1506	of floating point constants. For example, the form '<tt>double
				1507	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1508	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]	1509	(and the only time that they are generated by the disassembler) is when a
				1510	floating point constant must be emitted but it cannot be represented as a
				1511	decimal floating point number. For example, NaN's, infinities, and other
				1512	special values are represented in their IEEE hexadecimal format so that
				1513	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]	1514
				1515	</div>
				1516
				1517	<!-- ======================================================================= -->
				1518	<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
				1519	</div>
				1520
				1521	<div class="doc_text">
Chris Lattner	d4f6b17	2005-03-07 22:13:59 +0000	[diff] [blame]	1522	<p>Aggregate constants arise from aggregation of simple constants
				1523	and smaller aggregate constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1524
				1525	<dl>
				1526	<dt><b>Structure constants</b></dt>
				1527
				1528	<dd>Structure constants are represented with notation similar to structure
				1529	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1530	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1531	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]	1532	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]	1533	types of elements must match those specified by the type.
				1534	</dd>
				1535
				1536	<dt><b>Array constants</b></dt>
				1537
				1538	<dd>Array constants are represented with notation similar to array type
				1539	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1540	(<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]	1541	constants must have <a href="#t_array">array type</a>, and the number and
				1542	types of elements must match those specified by the type.
				1543	</dd>
				1544
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1545	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1546
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1547	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1548	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1549	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1550	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1551	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]	1552	match those specified by the type.
				1553	</dd>
				1554
				1555	<dt><b>Zero initialization</b></dt>
				1556
				1557	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1558	value to zero of <em>any</em> type, including scalar and aggregate types.
				1559	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]	1560	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1561	initializers.
				1562	</dd>
				1563	</dl>
				1564
				1565	</div>
				1566
				1567	<!-- ======================================================================= -->
				1568	<div class="doc_subsection">
				1569	<a name="globalconstants">Global Variable and Function Addresses</a>
				1570	</div>
				1571
				1572	<div class="doc_text">
				1573
				1574	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1575	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1576	constants. These constants are explicitly referenced when the <a
				1577	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]	1578	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1579	file:</p>
				1580
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1581	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1582	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1583	@X = global i32 17
				1584	@Y = global i32 42
				1585	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1586	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1587	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1588
				1589	</div>
				1590
				1591	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1592	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1593	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1594	<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]	1595	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]	1596	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1597
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1598	<p>Undefined values indicate to the compiler that the program is well defined
				1599	no matter what value is used, giving the compiler more freedom to optimize.
				1600	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1601	</div>
				1602
				1603	<!-- ======================================================================= -->
				1604	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1605	</div>
				1606
				1607	<div class="doc_text">
				1608
				1609	<p>Constant expressions are used to allow expressions involving other constants
				1610	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1611	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]	1612	that does not have side effects (e.g. load and call are not supported). The
				1613	following is the syntax for constant expressions:</p>
				1614
				1615	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1616	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1617	<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]	1618	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1619
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1620	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1621	<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]	1622	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]	1623
				1624	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1625	<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]	1626	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]	1627
				1628	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1629	<dd>Truncate a floating point constant to another floating point type. The
				1630	size of CST must be larger than the size of TYPE. Both types must be
				1631	floating point.</dd>
				1632
				1633	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1634	<dd>Floating point extend a constant to another type. The size of CST must be
				1635	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1636
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1637	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1638	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1639	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1640	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1641	of the same number of elements. If the value won't fit in the integer type,
				1642	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1643
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1644	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1645	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1646	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1647	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1648	of the same number of elements. If the value won't fit in the integer type,
				1649	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1650
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1651	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1652	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1653	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1654	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1655	of the same number of elements. If the value won't fit in the floating point
				1656	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1657
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1658	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1659	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1660	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1661	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1662	of the same number of elements. If the value won't fit in the floating point
				1663	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1664
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1665	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1666	<dd>Convert a pointer typed constant to the corresponding integer constant
				1667	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1668	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1669
				1670	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1671	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1672	pointer type. CST must be of integer type. The CST value is zero extended,
				1673	truncated, or unchanged to make it fit in a pointer size. This one is
				1674	<i>really</i> dangerous!</dd>
				1675
				1676	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1677	<dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
				1678	identical (same number of bits). The conversion is done as if the CST value
				1679	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]	1680	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]	1681	vector types to any other type, as long as they have the same bit width. For
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1682	pointers it is only valid to cast to another pointer type.
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1683	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1684
				1685	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1686
				1687	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1688	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1689	instruction, the index list may have zero or more indexes, which are required
				1690	to make sense for the type of "CSTPTR".</dd>
				1691
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1692	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1693
				1694	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1695	constants.</dd>
				1696
				1697	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1698	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1699
				1700	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1701	<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]	1702
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	1703	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1704	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1705
				1706	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1707	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1708
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1709	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1710
				1711	<dd>Perform the <a href="#i_extractelement">extractelement
				1712	operation</a> on constants.
				1713
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1714	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				1715
				1716	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1717	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1718
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1719
				1720	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				1721
				1722	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1723	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1724
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1725	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				1726
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1727	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				1728	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]	1729	binary</a> operations. The constraints on operands are the same as those for
				1730	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1731	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1732	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1733	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	1734
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1735	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1736	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				1737	<!-- *********************************************************************** -->
				1738
				1739	<!-- ======================================================================= -->
				1740	<div class="doc_subsection">
				1741	<a name="inlineasm">Inline Assembler Expressions</a>
				1742	</div>
				1743
				1744	<div class="doc_text">
				1745
				1746	<p>
				1747	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				1748	Module-Level Inline Assembly</a>) through the use of a special value. This
				1749	value represents the inline assembler as a string (containing the instructions
				1750	to emit), a list of operand constraints (stored as a string), and a flag that
				1751	indicates whether or not the inline asm expression has side effects. An example
				1752	inline assembler expression is:
				1753	</p>
				1754
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1755	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1756	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1757	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1758	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1759	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1760
				1761	<p>
				1762	Inline assembler expressions may <b>only</b> be used as the callee operand of
				1763	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				1764	</p>
				1765
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1766	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1767	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1768	%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]	1769	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1770	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1771
				1772	<p>
				1773	Inline asms with side effects not visible in the constraint list must be marked
				1774	as having side effects. This is done through the use of the
				1775	'<tt>sideeffect</tt>' keyword, like so:
				1776	</p>
				1777
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1778	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1779	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1780	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1781	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1782	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1783
				1784	<p>TODO: The format of the asm and constraints string still need to be
				1785	documented here. Constraints on what can be done (e.g. duplication, moving, etc
				1786	need to be documented).
				1787	</p>
				1788
				1789	</div>
				1790
				1791	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1792	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				1793	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1794
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1795	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1796
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1797	<p>The LLVM instruction set consists of several different
				1798	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1799	instructions</a>, <a href="#binaryops">binary instructions</a>,
				1800	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1801	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				1802	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1803
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1804	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1805
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1806	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1807	<div class="doc_subsection"> <a name="terminators">Terminator
				1808	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1809
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1810	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1811
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1812	<p>As mentioned <a href="#functionstructure">previously</a>, every
				1813	basic block in a program ends with a "Terminator" instruction, which
				1814	indicates which block should be executed after the current block is
				1815	finished. These terminator instructions typically yield a '<tt>void</tt>'
				1816	value: they produce control flow, not values (the one exception being
				1817	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1818	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1819	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				1820	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	1821	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				1822	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				1823	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1824
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1825	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1826
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1827	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1828	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				1829	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1830	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1831	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1832	<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]	1833	ret void <i>; Return from void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1834	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]	1835	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1836
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1837	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1838
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1839	<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]	1840	value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	1841	<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]	1842	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]	1843	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1844
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1845	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1846
				1847	<p>The '<tt>ret</tt>' instruction may return zero, one or multiple values.
				1848	The type of each return value must be a '<a href="#t_firstclass">first
				1849	class</a>' type. Note that a function is not <a href="#wellformed">well
				1850	formed</a> if there exists a '<tt>ret</tt>' instruction inside of the
				1851	function that returns values that do not match the return type of the
				1852	function.</p>
				1853
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1854	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1855
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1856	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				1857	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]	1858	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1859	the instruction after the call. If the caller was an "<a
				1860	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1861	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1862	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]	1863	return value. If the instruction returns multiple values then these
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	1864	values can only be accessed through a '<a href="#i_getresult"><tt>getresult</tt>
				1865	</a>' instruction.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1866
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1867	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1868
				1869	<pre>
				1870	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1871	ret void <i>; Return from a void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1872	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]	1873	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1874	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1875	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1876	<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]	1877	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1878	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1879	<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]	1880	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1881	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1882	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				1883	transfer to a different basic block in the current function. There are
				1884	two forms of this instruction, corresponding to a conditional branch
				1885	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1886	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1887	<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]	1888	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1889	unconditional form of the '<tt>br</tt>' instruction takes a single
				1890	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1891	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1892	<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]	1893	argument is evaluated. If the value is <tt>true</tt>, control flows
				1894	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				1895	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1896	<h5>Example:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1897	<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]	1898	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]	1899	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1900	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1901	<div class="doc_subsubsection">
				1902	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				1903	</div>
				1904
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1905	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1906	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1907
				1908	<pre>
				1909	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				1910	</pre>
				1911
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1912	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1913
				1914	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				1915	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1916	instruction, allowing a branch to occur to one of many possible
				1917	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1918
				1919
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1920	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1921
				1922	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				1923	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				1924	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				1925	table is not allowed to contain duplicate constant entries.</p>
				1926
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1927	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1928
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1929	<p>The <tt>switch</tt> instruction specifies a table of values and
				1930	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	1931	table is searched for the given value. If the value is found, control flow is
				1932	transfered to the corresponding destination; otherwise, control flow is
				1933	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1934
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1935	<h5>Implementation:</h5>
				1936
				1937	<p>Depending on properties of the target machine and the particular
				1938	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	1939	ways. For example, it could be generated as a series of chained conditional
				1940	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1941
				1942	<h5>Example:</h5>
				1943
				1944	<pre>
				1945	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1946	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1947	switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1948
				1949	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1950	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1951
				1952	<i>; Implement a jump table:</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1953	switch i32 %val, label %otherwise [ i32 0, label %onzero
				1954	i32 1, label %onone
				1955	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1956	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1957	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1958
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1959	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1960	<div class="doc_subsubsection">
				1961	<a name="i_invoke">'<tt>invoke</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	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1965
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1966	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1967
				1968	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	1969	<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]	1970	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1971	</pre>
				1972
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	1973	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1974
				1975	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				1976	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1977	'<tt>normal</tt>' label or the
				1978	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1979	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				1980	"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]	1981	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1982	continued at the dynamically nearest "exception" label. If the callee function
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	1983	returns multiple values then individual return values are only accessible through
				1984	a '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1985
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1986	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1987
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1988	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1989
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1990	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1991	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	1992	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1993	convention</a> the call should use. If none is specified, the call defaults
				1994	to using C calling conventions.
				1995	</li>
				1996	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				1997	function value being invoked. In most cases, this is a direct function
				1998	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				1999	an arbitrary pointer to function value.
				2000	</li>
				2001
				2002	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2003	function to be invoked. </li>
				2004
				2005	<li>'<tt>function args</tt>': argument list whose types match the function
				2006	signature argument types. If the function signature indicates the function
				2007	accepts a variable number of arguments, the extra arguments can be
				2008	specified. </li>
				2009
				2010	<li>'<tt>normal label</tt>': the label reached when the called function
				2011	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2012
				2013	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2014	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2015
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2016	</ol>
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	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2019
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2020	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2021	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2022	difference is that it establishes an association with a label, which is used by
				2023	the runtime library to unwind the stack.</p>
				2024
				2025	<p>This instruction is used in languages with destructors to ensure that proper
				2026	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2027	exception. Additionally, this is important for implementation of
				2028	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2029
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2030	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2031	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2032	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2033	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2034	%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]	2035	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2036	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2037	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2038
				2039
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2040	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2041
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2042	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2043	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2044
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2045	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2046
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2047	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2048	<pre>
				2049	unwind
				2050	</pre>
				2051
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2052	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2053
				2054	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2055	at the first callee in the dynamic call stack which used an <a
				2056	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2057	primarily used to implement exception handling.</p>
				2058
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2059	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2060
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2061	<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]	2062	immediately halt. The dynamic call stack is then searched for the first <a
				2063	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2064	execution continues at the "exceptional" destination block specified by the
				2065	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2066	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2067	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2068
				2069	<!-- _______________________________________________________________________ -->
				2070
				2071	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2072	Instruction</a> </div>
				2073
				2074	<div class="doc_text">
				2075
				2076	<h5>Syntax:</h5>
				2077	<pre>
				2078	unreachable
				2079	</pre>
				2080
				2081	<h5>Overview:</h5>
				2082
				2083	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2084	instruction is used to inform the optimizer that a particular portion of the
				2085	code is not reachable. This can be used to indicate that the code after a
				2086	no-return function cannot be reached, and other facts.</p>
				2087
				2088	<h5>Semantics:</h5>
				2089
				2090	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2091	</div>
				2092
				2093
				2094
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2095	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2096	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2097	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2098	<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]	2099	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]	2100	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2101	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]	2102	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2103	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2104	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2105	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2106	<div class="doc_subsubsection">
				2107	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2108	</div>
				2109
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2110	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2111
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2112	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2113
				2114	<pre>
				2115	<result> = add <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2116	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2117
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2118	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2119
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2120	<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]	2121
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2122	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2123
				2124	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2125	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2126	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2127	types.</p>
				2128
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2129	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2130
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2131	<p>The value produced is the integer or floating point sum of the two
				2132	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2133
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2134	<p>If an integer sum has unsigned overflow, the result returned is the
				2135	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2136	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2137
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2138	<p>Because LLVM integers use a two's complement representation, this
				2139	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2140
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2141	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2142
				2143	<pre>
				2144	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2145	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2146	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2147	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2148	<div class="doc_subsubsection">
				2149	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2150	</div>
				2151
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2152	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2153
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2154	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2155
				2156	<pre>
				2157	<result> = sub <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2158	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2159
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2160	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2161
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2162	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2163	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2164
				2165	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2166	'<tt>neg</tt>' instruction present in most other intermediate
				2167	representations.</p>
				2168
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2169	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2170
				2171	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2172	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2173	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2174	types.</p>
				2175
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2176	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2177
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2178	<p>The value produced is the integer or floating point difference of
				2179	the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2180
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2181	<p>If an integer difference has unsigned overflow, the result returned is the
				2182	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2183	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2184
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2185	<p>Because LLVM integers use a two's complement representation, this
				2186	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2187
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2188	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2189	<pre>
				2190	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2191	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2192	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2193	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2194
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2195	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2196	<div class="doc_subsubsection">
				2197	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2198	</div>
				2199
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2200	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2201
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2202	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2203	<pre> <result> = mul <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2204	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2205	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2206	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2207	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2208
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2209	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2210
				2211	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2212	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2213	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2214	types.</p>
				2215
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2216	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2217
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2218	<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]	2219	two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2220
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2221	<p>If the result of an integer multiplication has unsigned overflow,
				2222	the result returned is the mathematical result modulo
				2223	2<sup>n</sup>, where n is the bit width of the result.</p>
				2224	<p>Because LLVM integers use a two's complement representation, and the
				2225	result is the same width as the operands, this instruction returns the
				2226	correct result for both signed and unsigned integers. If a full product
				2227	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2228	should be sign-extended or zero-extended as appropriate to the
				2229	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2230	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2231	<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]	2232	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2233	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2234
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2235	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2236	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2237	</a></div>
				2238	<div class="doc_text">
				2239	<h5>Syntax:</h5>
				2240	<pre> <result> = udiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2241	</pre>
				2242	<h5>Overview:</h5>
				2243	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2244	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2245
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2246	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2247
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2248	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2249	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2250	values. Both arguments must have identical types.</p>
				2251
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2252	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2253
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2254	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2255	<p>Note that unsigned integer division and signed integer division are distinct
				2256	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2257	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2258	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2259	<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]	2260	</pre>
				2261	</div>
				2262	<!-- _______________________________________________________________________ -->
				2263	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2264	</a> </div>
				2265	<div class="doc_text">
				2266	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2267	<pre>
				2268	<result> = sdiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2269	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2270
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2271	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2272
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2273	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2274	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2275
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2276	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2277
				2278	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2279	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2280	values. Both arguments must have identical types.</p>
				2281
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2282	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2283	<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]	2284	<p>Note that signed integer division and unsigned integer division are distinct
				2285	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2286	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2287	undefined behavior; this is a rare case, but can occur, for example,
				2288	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2289	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2290	<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]	2291	</pre>
				2292	</div>
				2293	<!-- _______________________________________________________________________ -->
				2294	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2295	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2296	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2297	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2298	<pre>
				2299	<result> = fdiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2300	</pre>
				2301	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2302
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2303	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2304	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2305
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2306	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2307
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2308	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2309	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2310	of floating point values. Both arguments must have identical types.</p>
				2311
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2312	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2313
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2314	<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]	2315
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2316	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2317
				2318	<pre>
				2319	<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]	2320	</pre>
				2321	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2322
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2323	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2324	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2325	</div>
				2326	<div class="doc_text">
				2327	<h5>Syntax:</h5>
				2328	<pre> <result> = urem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2329	</pre>
				2330	<h5>Overview:</h5>
				2331	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2332	unsigned division of its two arguments.</p>
				2333	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2334	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2335	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2336	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2337	<h5>Semantics:</h5>
				2338	<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]	2339	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2340	<p>Note that unsigned integer remainder and signed integer remainder are
				2341	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2342	<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]	2343	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2344	<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]	2345	</pre>
				2346
				2347	</div>
				2348	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2349	<div class="doc_subsubsection">
				2350	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2351	</div>
				2352
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2353	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2354
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2355	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2356
				2357	<pre>
				2358	<result> = srem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2359	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2360
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2361	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2362
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2363	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2364	signed division of its two operands. This instruction can also take
				2365	<a href="#t_vector">vector</a> versions of the values in which case
				2366	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2367
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2368	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2369
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2370	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2371	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2372	values. Both arguments must have identical types.</p>
				2373
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2374	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2375
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2376	<p>This instruction returns the <i>remainder</i> of a division (where the result
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2377	has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
				2378	operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
				2379	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2380	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]	2381	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]	2382	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2383	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2384	<p>Note that signed integer remainder and unsigned integer remainder are
				2385	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2386	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2387	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2388	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2389	(The remainder doesn't actually overflow, but this rule lets srem be
				2390	implemented using instructions that return both the result of the division
				2391	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2392	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2393	<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]	2394	</pre>
				2395
				2396	</div>
				2397	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2398	<div class="doc_subsubsection">
				2399	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2400
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2401	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2402
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2403	<h5>Syntax:</h5>
				2404	<pre> <result> = frem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2405	</pre>
				2406	<h5>Overview:</h5>
				2407	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2408	division of its two operands.</p>
				2409	<h5>Arguments:</h5>
				2410	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2411	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2412	of floating point values. Both arguments must have identical types.</p>
				2413
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2414	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2415
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2416	<p>This instruction returns the <i>remainder</i> of a division.
				2417	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2418
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2419	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2420
				2421	<pre>
				2422	<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]	2423	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2424	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2425
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2426	<!-- ======================================================================= -->
				2427	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2428	Operations</a> </div>
				2429	<div class="doc_text">
				2430	<p>Bitwise binary operators are used to do various forms of
				2431	bit-twiddling in a program. They are generally very efficient
				2432	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2433	instructions. They require two operands of the same type, execute an operation on them,
				2434	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]	2435	</div>
				2436
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2437	<!-- _______________________________________________________________________ -->
				2438	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2439	Instruction</a> </div>
				2440	<div class="doc_text">
				2441	<h5>Syntax:</h5>
				2442	<pre> <result> = shl <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2443	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2444
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2445	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2446
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2447	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2448	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2449
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2450	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2451
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2452	<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2453	href="#t_integer">integer</a> type. '<tt>var2</tt>' is treated as an
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2454	unsigned value. This instruction does not support
				2455	<a href="#t_vector">vector</a> operands.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2456
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2457	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2458
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2459	<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup> mod 2<sup>n</sup>,
				2460	where n is the width of the result. If <tt>var2</tt> is (statically or dynamically) negative or
				2461	equal to or larger than the number of bits in <tt>var1</tt>, the result is undefined.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2462
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2463	<h5>Example:</h5><pre>
				2464	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2465	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2466	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2467	<result> = shl i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2468	</pre>
				2469	</div>
				2470	<!-- _______________________________________________________________________ -->
				2471	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2472	Instruction</a> </div>
				2473	<div class="doc_text">
				2474	<h5>Syntax:</h5>
				2475	<pre> <result> = lshr <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2476	</pre>
				2477
				2478	<h5>Overview:</h5>
				2479	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2480	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]	2481
				2482	<h5>Arguments:</h5>
				2483	<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2484	<a href="#t_integer">integer</a> type. '<tt>var2</tt>' is treated as an
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2485	unsigned value. This instruction does not support
				2486	<a href="#t_vector">vector</a> operands.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2487
				2488	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2489
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2490	<p>This instruction always performs a logical shift right operation. The most
				2491	significant bits of the result will be filled with zero bits after the
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2492	shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
				2493	the number of bits in <tt>var1</tt>, the result is undefined.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2494
				2495	<h5>Example:</h5>
				2496	<pre>
				2497	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2498	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2499	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2500	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2501	<result> = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2502	</pre>
				2503	</div>
				2504
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2505	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2506	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2507	Instruction</a> </div>
				2508	<div class="doc_text">
				2509
				2510	<h5>Syntax:</h5>
				2511	<pre> <result> = ashr <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2512	</pre>
				2513
				2514	<h5>Overview:</h5>
				2515	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2516	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]	2517
				2518	<h5>Arguments:</h5>
				2519	<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2520	<a href="#t_integer">integer</a> type. '<tt>var2</tt>' is treated as an
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2521	unsigned value. This instruction does not support
				2522	<a href="#t_vector">vector</a> operands.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2523
				2524	<h5>Semantics:</h5>
				2525	<p>This instruction always performs an arithmetic shift right operation,
				2526	The most significant bits of the result will be filled with the sign bit
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2527	of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
				2528	larger than the number of bits in <tt>var1</tt>, the result is undefined.
				2529	</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2530
				2531	<h5>Example:</h5>
				2532	<pre>
				2533	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2534	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2535	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2536	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2537	<result> = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2538	</pre>
				2539	</div>
				2540
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2541	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2542	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2543	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2544
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2545	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2546
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2547	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2548
				2549	<pre>
				2550	<result> = and <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2551	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2552
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2553	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2554
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2555	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2556	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2557
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2558	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2559
				2560	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2561	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2562	values. Both arguments must have identical types.</p>
				2563
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2564	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2565	<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]	2566	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2567	<div style="align: center">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2568	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2569	<tbody>
				2570	<tr>
				2571	<td>In0</td>
				2572	<td>In1</td>
				2573	<td>Out</td>
				2574	</tr>
				2575	<tr>
				2576	<td>0</td>
				2577	<td>0</td>
				2578	<td>0</td>
				2579	</tr>
				2580	<tr>
				2581	<td>0</td>
				2582	<td>1</td>
				2583	<td>0</td>
				2584	</tr>
				2585	<tr>
				2586	<td>1</td>
				2587	<td>0</td>
				2588	<td>0</td>
				2589	</tr>
				2590	<tr>
				2591	<td>1</td>
				2592	<td>1</td>
				2593	<td>1</td>
				2594	</tr>
				2595	</tbody>
				2596	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2597	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2598	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2599	<pre>
				2600	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2601	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2602	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2603	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2604	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2605	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2606	<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]	2607	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2608	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2609	<pre> <result> = or <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2610	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2611	<h5>Overview:</h5>
				2612	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2613	or of its two operands.</p>
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>or</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>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2619	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2620	<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]	2621	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2622	<div style="align: center">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2623	<table border="1" cellspacing="0" cellpadding="4">
				2624	<tbody>
				2625	<tr>
				2626	<td>In0</td>
				2627	<td>In1</td>
				2628	<td>Out</td>
				2629	</tr>
				2630	<tr>
				2631	<td>0</td>
				2632	<td>0</td>
				2633	<td>0</td>
				2634	</tr>
				2635	<tr>
				2636	<td>0</td>
				2637	<td>1</td>
				2638	<td>1</td>
				2639	</tr>
				2640	<tr>
				2641	<td>1</td>
				2642	<td>0</td>
				2643	<td>1</td>
				2644	</tr>
				2645	<tr>
				2646	<td>1</td>
				2647	<td>1</td>
				2648	<td>1</td>
				2649	</tr>
				2650	</tbody>
				2651	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2652	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2653	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2654	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2655	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2656	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2657	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2658	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2659	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2660	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2661	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2662	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2663	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2664	<pre> <result> = xor <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2665	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2666	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2667	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2668	or of its two operands. The <tt>xor</tt> is used to implement the
				2669	"one's complement" operation, which is the "~" operator in C.</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	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				2672	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2673	values. Both arguments must have identical types.</p>
				2674
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2675	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2676
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2677	<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]	2678	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2679	<div style="align: center">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2680	<table border="1" cellspacing="0" cellpadding="4">
				2681	<tbody>
				2682	<tr>
				2683	<td>In0</td>
				2684	<td>In1</td>
				2685	<td>Out</td>
				2686	</tr>
				2687	<tr>
				2688	<td>0</td>
				2689	<td>0</td>
				2690	<td>0</td>
				2691	</tr>
				2692	<tr>
				2693	<td>0</td>
				2694	<td>1</td>
				2695	<td>1</td>
				2696	</tr>
				2697	<tr>
				2698	<td>1</td>
				2699	<td>0</td>
				2700	<td>1</td>
				2701	</tr>
				2702	<tr>
				2703	<td>1</td>
				2704	<td>1</td>
				2705	<td>0</td>
				2706	</tr>
				2707	</tbody>
				2708	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2709	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2710	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2711	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2712	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				2713	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				2714	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				2715	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2716	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2717	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2718
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2719	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2720	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2721	<a name="vectorops">Vector Operations</a>
				2722	</div>
				2723
				2724	<div class="doc_text">
				2725
				2726	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2727	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2728	vector-specific operations needed to process vectors effectively. While LLVM
				2729	does directly support these vector operations, many sophisticated algorithms
				2730	will want to use target-specific intrinsics to take full advantage of a specific
				2731	target.</p>
				2732
				2733	</div>
				2734
				2735	<!-- _______________________________________________________________________ -->
				2736	<div class="doc_subsubsection">
				2737	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				2738	</div>
				2739
				2740	<div class="doc_text">
				2741
				2742	<h5>Syntax:</h5>
				2743
				2744	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2745	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2746	</pre>
				2747
				2748	<h5>Overview:</h5>
				2749
				2750	<p>
				2751	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2752	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2753	</p>
				2754
				2755
				2756	<h5>Arguments:</h5>
				2757
				2758	<p>
				2759	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2760	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]	2761	an index indicating the position from which to extract the element.
				2762	The index may be a variable.</p>
				2763
				2764	<h5>Semantics:</h5>
				2765
				2766	<p>
				2767	The result is a scalar of the same type as the element type of
				2768	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				2769	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				2770	results are undefined.
				2771	</p>
				2772
				2773	<h5>Example:</h5>
				2774
				2775	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2776	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2777	</pre>
				2778	</div>
				2779
				2780
				2781	<!-- _______________________________________________________________________ -->
				2782	<div class="doc_subsubsection">
				2783	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				2784	</div>
				2785
				2786	<div class="doc_text">
				2787
				2788	<h5>Syntax:</h5>
				2789
				2790	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	2791	<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]	2792	</pre>
				2793
				2794	<h5>Overview:</h5>
				2795
				2796	<p>
				2797	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2798	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2799	</p>
				2800
				2801
				2802	<h5>Arguments:</h5>
				2803
				2804	<p>
				2805	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2806	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]	2807	scalar value whose type must equal the element type of the first
				2808	operand. The third operand is an index indicating the position at
				2809	which to insert the value. The index may be a variable.</p>
				2810
				2811	<h5>Semantics:</h5>
				2812
				2813	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2814	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]	2815	element values are those of <tt>val</tt> except at position
				2816	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				2817	exceeds the length of <tt>val</tt>, the results are undefined.
				2818	</p>
				2819
				2820	<h5>Example:</h5>
				2821
				2822	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2823	%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]	2824	</pre>
				2825	</div>
				2826
				2827	<!-- _______________________________________________________________________ -->
				2828	<div class="doc_subsubsection">
				2829	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				2830	</div>
				2831
				2832	<div class="doc_text">
				2833
				2834	<h5>Syntax:</h5>
				2835
				2836	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2837	<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]	2838	</pre>
				2839
				2840	<h5>Overview:</h5>
				2841
				2842	<p>
				2843	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
				2844	from two input vectors, returning a vector of the same type.
				2845	</p>
				2846
				2847	<h5>Arguments:</h5>
				2848
				2849	<p>
				2850	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				2851	with types that match each other and types that match the result of the
				2852	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]	2853	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]	2854	</p>
				2855
				2856	<p>
				2857	The shuffle mask operand is required to be a constant vector with either
				2858	constant integer or undef values.
				2859	</p>
				2860
				2861	<h5>Semantics:</h5>
				2862
				2863	<p>
				2864	The elements of the two input vectors are numbered from left to right across
				2865	both of the vectors. The shuffle mask operand specifies, for each element of
				2866	the result vector, which element of the two input registers the result element
				2867	gets. The element selector may be undef (meaning "don't care") and the second
				2868	operand may be undef if performing a shuffle from only one vector.
				2869	</p>
				2870
				2871	<h5>Example:</h5>
				2872
				2873	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2874	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2875	<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]	2876	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				2877	<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]	2878	</pre>
				2879	</div>
				2880
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	2881
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2882	<!-- ======================================================================= -->
				2883	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2884	<a name="aggregateops">Aggregate Operations</a>
				2885	</div>
				2886
				2887	<div class="doc_text">
				2888
				2889	<p>LLVM supports several instructions for working with aggregate values.
				2890	</p>
				2891
				2892	</div>
				2893
				2894	<!-- _______________________________________________________________________ -->
				2895	<div class="doc_subsubsection">
				2896	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				2897	</div>
				2898
				2899	<div class="doc_text">
				2900
				2901	<h5>Syntax:</h5>
				2902
				2903	<pre>
				2904	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				2905	</pre>
				2906
				2907	<h5>Overview:</h5>
				2908
				2909	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2910	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				2911	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2912	</p>
				2913
				2914
				2915	<h5>Arguments:</h5>
				2916
				2917	<p>
				2918	The first operand of an '<tt>extractvalue</tt>' instruction is a
				2919	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]	2920	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2921	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2922	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2923	</p>
				2924
				2925	<h5>Semantics:</h5>
				2926
				2927	<p>
				2928	The result is the value at the position in the aggregate specified by
				2929	the index operands.
				2930	</p>
				2931
				2932	<h5>Example:</h5>
				2933
				2934	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2935	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2936	</pre>
				2937	</div>
				2938
				2939
				2940	<!-- _______________________________________________________________________ -->
				2941	<div class="doc_subsubsection">
				2942	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				2943	</div>
				2944
				2945	<div class="doc_text">
				2946
				2947	<h5>Syntax:</h5>
				2948
				2949	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2950	<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]	2951	</pre>
				2952
				2953	<h5>Overview:</h5>
				2954
				2955	<p>
				2956	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2957	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2958	</p>
				2959
				2960
				2961	<h5>Arguments:</h5>
				2962
				2963	<p>
				2964	The first operand of an '<tt>insertvalue</tt>' instruction is a
				2965	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				2966	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	2967	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2968	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]	2969	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2970	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2971	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]	2972	by the indices.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2973
				2974	<h5>Semantics:</h5>
				2975
				2976	<p>
				2977	The result is an aggregate of the same type as <tt>val</tt>. Its
				2978	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]	2979	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2980	</p>
				2981
				2982	<h5>Example:</h5>
				2983
				2984	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2985	%result = insertvalue {i32, float} %agg, 1, 0 <i>; yields {i32, float}</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2986	</pre>
				2987	</div>
				2988
				2989
				2990	<!-- ======================================================================= -->
				2991	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	2992	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2993	</div>
				2994
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2995	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2996
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2997	<p>A key design point of an SSA-based representation is how it
				2998	represents memory. In LLVM, no memory locations are in SSA form, which
				2999	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3000	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3001
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3002	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3003
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3004	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3005	<div class="doc_subsubsection">
				3006	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3007	</div>
				3008
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3009	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3010
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3011	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3012
				3013	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3014	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3015	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3016
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3017	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3018
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3019	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3020	heap and returns a pointer to it. The object is always allocated in the generic
				3021	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3022
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3023	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3024
				3025	<p>The '<tt>malloc</tt>' instruction allocates
				3026	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3027	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]	3028	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3029	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3030	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]	3031	be aligned to at least that boundary. If not specified, or if zero, the target can
				3032	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3033
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3034	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3035
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3036	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3037
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3038	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3039	a pointer is returned. The result of a zero byte allocattion is undefined. The
				3040	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3041
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3042	<h5>Example:</h5>
				3043
				3044	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3045	%array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3046
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3047	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3048	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3049	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3050	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3051	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3052	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3053	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3054
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3055	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3056	<div class="doc_subsubsection">
				3057	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3058	</div>
				3059
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3060	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3061
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3062	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3063
				3064	<pre>
				3065	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3066	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3067
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3068	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3069
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3070	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3071	memory heap to be reallocated in the future.</p>
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>Arguments:</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>'<tt>value</tt>' shall be a pointer value that points to a value
				3076	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3077	instruction.</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>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3080
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3081	<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]	3082	after this instruction executes. If the pointer is null, the operation
				3083	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3084
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3085	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3086
				3087	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3088	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
				3089	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3090	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3091	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3092
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3093	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3094	<div class="doc_subsubsection">
				3095	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3096	</div>
				3097
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3098	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3099
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3100	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3101
				3102	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3103	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3104	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3105
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3106	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3107
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3108	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3109	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3110	returns to its caller. The object is always allocated in the generic address
				3111	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3112
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3113	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3114
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3115	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3116	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3117	appropriate type to the program. If "NumElements" is specified, it is the
				3118	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3119	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]	3120	to be aligned to at least that boundary. If not specified, or if zero, the target
				3121	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3122
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3123	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3124
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3125	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3126
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3127	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3128	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3129	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3130	instruction is commonly used to represent automatic variables that must
				3131	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]	3132	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]	3133	instructions), the memory is reclaimed. Allocating zero bytes
				3134	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3135
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3136	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3137
				3138	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3139	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3140	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3141	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3142	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3143	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3144	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3145
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3146	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3147	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3148	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3149	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3150	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3151	<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]	3152	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3153	<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]	3154	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3155	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3156	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3157	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]	3158	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]	3159	the number or order of execution of this <tt>load</tt> with other
				3160	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3161	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3162	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3163	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3164	(that is, the alignment of the memory address). A value of 0 or an
				3165	omitted "align" argument means that the operation has the preferential
				3166	alignment for the target. It is the responsibility of the code emitter
				3167	to ensure that the alignment information is correct. Overestimating
				3168	the alignment results in an undefined behavior. Underestimating the
				3169	alignment may produce less efficient code. An alignment of 1 is always
				3170	safe.
				3171	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3172	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3173	<p>The location of memory pointed to is loaded.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3174	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3175	<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]	3176	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3177	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3178	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3179	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3180	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3181	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3182	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3183	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3184	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3185	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3186	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3187	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3188	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3189	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3190	<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]	3191	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3192	<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]	3193	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]	3194	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3195	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3196	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]	3197	optimizer is not allowed to modify the number or order of execution of
				3198	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3199	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3200	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3201	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3202	(that is, the alignment of the memory address). A value of 0 or an
				3203	omitted "align" argument means that the operation has the preferential
				3204	alignment for the target. It is the responsibility of the code emitter
				3205	to ensure that the alignment information is correct. Overestimating
				3206	the alignment results in an undefined behavior. Underestimating the
				3207	alignment may produce less efficient code. An alignment of 1 is always
				3208	safe.
				3209	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3210	<h5>Semantics:</h5>
				3211	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3212	at the location specified by the '<tt><pointer></tt>' operand.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3213	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3214	<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]	3215	store i32 3, i32* %ptr <i>; yields {void}</i>
				3216	%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]	3217	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3218	</div>
				3219
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3220	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3221	<div class="doc_subsubsection">
				3222	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3223	</div>
				3224
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3225	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3226	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3227	<pre>
				3228	<result> = getelementptr <ty>* <ptrval>{, <ty> <idx>}*
				3229	</pre>
				3230
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3231	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3232
				3233	<p>
				3234	The '<tt>getelementptr</tt>' instruction is used to get the address of a
				3235	subelement of an aggregate data structure.</p>
				3236
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3237	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3238
Reid Spencer	85f5b5b	2006-12-04 21:29:24 +0000	[diff] [blame]	3239	<p>This instruction takes a list of integer operands that indicate what
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3240	elements of the aggregate object to index to. The actual types of the arguments
				3241	provided depend on the type of the first pointer argument. The
				3242	'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	3243	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]	3244	structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	3245	into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
				3246	values will be sign extended to 64-bits if required.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3247
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3248	<p>For example, let's consider a C code fragment and how it gets
				3249	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3250
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3251	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3252	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3253	struct RT {
				3254	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3255	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3256	char C;
				3257	};
				3258	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3259	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3260	double Y;
				3261	struct RT Z;
				3262	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3263
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3264	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3265	return &s[1].Z.B[5][13];
				3266	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3267	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3268	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3269
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3270	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3271
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3272	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3273	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3274	%RT = type { i8 , [10 x [20 x i32]], i8 }
				3275	%ST = type { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3276
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3277	define i32* %foo(%ST* %s) {
				3278	entry:
				3279	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3280	ret i32* %reg
				3281	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3282	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3283	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3284
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3285	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3286
				3287	<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3288	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]	3289	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]	3290	<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]	3291	to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
				3292	structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3293
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3294	<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]	3295	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]	3296	}</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]	3297	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3298	i8 }</tt>' type, another structure. The third index indexes into the second
				3299	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]	3300	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3301	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3302	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]	3303
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3304	<p>Note that it is perfectly legal to index partially through a
				3305	structure, returning a pointer to an inner element. Because of this,
				3306	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3307
				3308	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3309	define i32* %foo(%ST* %s) {
				3310	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3311	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3312	%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]	3313	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3314	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3315	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3316	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3317	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3318
				3319	<p>Note that it is undefined to access an array out of bounds: array and
				3320	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]	3321	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]	3322	defined to be accessible as variable length arrays, which requires access
				3323	beyond the zero'th element.</p>
				3324
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3325	<p>The getelementptr instruction is often confusing. For some more insight
				3326	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3327	FAQ</a>.</p>
				3328
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3329	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3330
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3331	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3332	<i>; yields [12 x i8]*:aptr</i>
				3333	%aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3334	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3335	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3336
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3337	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3338	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3339	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3340	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3341	<p>The instructions in this category are the conversion instructions (casting)
				3342	which all take a single operand and a type. They perform various bit conversions
				3343	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3344	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3345
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3346	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3347	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3348	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3349	</div>
				3350	<div class="doc_text">
				3351
				3352	<h5>Syntax:</h5>
				3353	<pre>
				3354	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3355	</pre>
				3356
				3357	<h5>Overview:</h5>
				3358	<p>
				3359	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3360	</p>
				3361
				3362	<h5>Arguments:</h5>
				3363	<p>
				3364	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3365	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]	3366	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]	3367	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3368	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3369
				3370	<h5>Semantics:</h5>
				3371	<p>
				3372	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]	3373	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3374	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3375	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3376
				3377	<h5>Example:</h5>
				3378	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3379	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3380	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3381	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3382	</pre>
				3383	</div>
				3384
				3385	<!-- _______________________________________________________________________ -->
				3386	<div class="doc_subsubsection">
				3387	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3388	</div>
				3389	<div class="doc_text">
				3390
				3391	<h5>Syntax:</h5>
				3392	<pre>
				3393	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3394	</pre>
				3395
				3396	<h5>Overview:</h5>
				3397	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3398	<tt>ty2</tt>.</p>
				3399
				3400
				3401	<h5>Arguments:</h5>
				3402	<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]	3403	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3404	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]	3405	<tt>value</tt> must be smaller than the bit size of the destination type,
				3406	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3407
				3408	<h5>Semantics:</h5>
				3409	<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]	3410	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]	3411
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3412	<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]	3413
				3414	<h5>Example:</h5>
				3415	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3416	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3417	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3418	</pre>
				3419	</div>
				3420
				3421	<!-- _______________________________________________________________________ -->
				3422	<div class="doc_subsubsection">
				3423	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3424	</div>
				3425	<div class="doc_text">
				3426
				3427	<h5>Syntax:</h5>
				3428	<pre>
				3429	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3430	</pre>
				3431
				3432	<h5>Overview:</h5>
				3433	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3434
				3435	<h5>Arguments:</h5>
				3436	<p>
				3437	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]	3438	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3439	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]	3440	<tt>value</tt> must be smaller than the bit size of the destination type,
				3441	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3442
				3443	<h5>Semantics:</h5>
				3444	<p>
				3445	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3446	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]	3447	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3448
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3449	<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]	3450
				3451	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3452	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3453	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3454	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3455	</pre>
				3456	</div>
				3457
				3458	<!-- _______________________________________________________________________ -->
				3459	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3460	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3461	</div>
				3462
				3463	<div class="doc_text">
				3464
				3465	<h5>Syntax:</h5>
				3466
				3467	<pre>
				3468	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3469	</pre>
				3470
				3471	<h5>Overview:</h5>
				3472	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3473	<tt>ty2</tt>.</p>
				3474
				3475
				3476	<h5>Arguments:</h5>
				3477	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3478	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3479	cast it to. The size of <tt>value</tt> must be larger than the size of
				3480	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3481	<i>no-op cast</i>.</p>
				3482
				3483	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3484	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3485	<a href="#t_floating">floating point</a> type to a smaller
				3486	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3487	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3488
				3489	<h5>Example:</h5>
				3490	<pre>
				3491	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3492	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3493	</pre>
				3494	</div>
				3495
				3496	<!-- _______________________________________________________________________ -->
				3497	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3498	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3499	</div>
				3500	<div class="doc_text">
				3501
				3502	<h5>Syntax:</h5>
				3503	<pre>
				3504	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3505	</pre>
				3506
				3507	<h5>Overview:</h5>
				3508	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3509	floating point value.</p>
				3510
				3511	<h5>Arguments:</h5>
				3512	<p>The '<tt>fpext</tt>' instruction takes a
				3513	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3514	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3515	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3516
				3517	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3518	<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]	3519	<a href="#t_floating">floating point</a> type to a larger
				3520	<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]	3521	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]	3522	<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]	3523
				3524	<h5>Example:</h5>
				3525	<pre>
				3526	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3527	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3528	</pre>
				3529	</div>
				3530
				3531	<!-- _______________________________________________________________________ -->
				3532	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	3533	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3534	</div>
				3535	<div class="doc_text">
				3536
				3537	<h5>Syntax:</h5>
				3538	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3539	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3540	</pre>
				3541
				3542	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3543	<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]	3544	unsigned integer equivalent of type <tt>ty2</tt>.
				3545	</p>
				3546
				3547	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3548	<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]	3549	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3550	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3551	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3552	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]	3553
				3554	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3555	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3556	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3557	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3558	the results are undefined.</p>
				3559
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3560	<h5>Example:</h5>
				3561	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3562	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3563	%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]	3564	%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]	3565	</pre>
				3566	</div>
				3567
				3568	<!-- _______________________________________________________________________ -->
				3569	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3570	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3571	</div>
				3572	<div class="doc_text">
				3573
				3574	<h5>Syntax:</h5>
				3575	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3576	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3577	</pre>
				3578
				3579	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3580	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3581	<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]	3582	</p>
				3583
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3584	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3585	<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]	3586	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3587	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3588	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3589	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]	3590
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3591	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3592	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3593	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3594	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3595	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3596
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3597	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3598	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3599	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3600	%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]	3601	%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]	3602	</pre>
				3603	</div>
				3604
				3605	<!-- _______________________________________________________________________ -->
				3606	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3607	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3608	</div>
				3609	<div class="doc_text">
				3610
				3611	<h5>Syntax:</h5>
				3612	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3613	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3614	</pre>
				3615
				3616	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3617	<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]	3618	integer and converts that value to the <tt>ty2</tt> type.</p>
				3619
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3620	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3621	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3622	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3623	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3624	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3625	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]	3626
				3627	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3628	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3629	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3630	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]	3631
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3632	<h5>Example:</h5>
				3633	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3634	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3635	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3636	</pre>
				3637	</div>
				3638
				3639	<!-- _______________________________________________________________________ -->
				3640	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3641	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3642	</div>
				3643	<div class="doc_text">
				3644
				3645	<h5>Syntax:</h5>
				3646	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3647	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3648	</pre>
				3649
				3650	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3651	<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]	3652	integer and converts that value to the <tt>ty2</tt> type.</p>
				3653
				3654	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3655	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3656	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3657	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3658	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3659	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]	3660
				3661	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3662	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3663	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3664	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]	3665
				3666	<h5>Example:</h5>
				3667	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3668	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3669	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3670	</pre>
				3671	</div>
				3672
				3673	<!-- _______________________________________________________________________ -->
				3674	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3675	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				3676	</div>
				3677	<div class="doc_text">
				3678
				3679	<h5>Syntax:</h5>
				3680	<pre>
				3681	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				3682	</pre>
				3683
				3684	<h5>Overview:</h5>
				3685	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				3686	the integer type <tt>ty2</tt>.</p>
				3687
				3688	<h5>Arguments:</h5>
				3689	<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]	3690	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]	3691	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
				3692
				3693	<h5>Semantics:</h5>
				3694	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				3695	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				3696	truncating or zero extending that value to the size of the integer type. If
				3697	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				3698	<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]	3699	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				3700	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3701
				3702	<h5>Example:</h5>
				3703	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3704	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				3705	%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]	3706	</pre>
				3707	</div>
				3708
				3709	<!-- _______________________________________________________________________ -->
				3710	<div class="doc_subsubsection">
				3711	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				3712	</div>
				3713	<div class="doc_text">
				3714
				3715	<h5>Syntax:</h5>
				3716	<pre>
				3717	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				3718	</pre>
				3719
				3720	<h5>Overview:</h5>
				3721	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				3722	a pointer type, <tt>ty2</tt>.</p>
				3723
				3724	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	3725	<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]	3726	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]	3727	<a href="#t_pointer">pointer</a> type.
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3728
				3729	<h5>Semantics:</h5>
				3730	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				3731	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				3732	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				3733	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				3734	the size of a pointer then a zero extension is done. If they are the same size,
				3735	nothing is done (<i>no-op cast</i>).</p>
				3736
				3737	<h5>Example:</h5>
				3738	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3739	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				3740	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				3741	%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]	3742	</pre>
				3743	</div>
				3744
				3745	<!-- _______________________________________________________________________ -->
				3746	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3747	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3748	</div>
				3749	<div class="doc_text">
				3750
				3751	<h5>Syntax:</h5>
				3752	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3753	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3754	</pre>
				3755
				3756	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3757
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3758	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3759	<tt>ty2</tt> without changing any bits.</p>
				3760
				3761	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3762
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3763	<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3764	a first class value, and a type to cast it to, which must also be a <a
				3765	href="#t_firstclass">first class</a> type. The bit sizes of <tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	3766	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]	3767	type is a pointer, the destination type must also be a pointer. This
				3768	instruction supports bitwise conversion of vectors to integers and to vectors
				3769	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3770
				3771	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3772	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3773	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				3774	this conversion. The conversion is done as if the <tt>value</tt> had been
				3775	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				3776	converted to other pointer types with this instruction. To convert pointers to
				3777	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				3778	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3779
				3780	<h5>Example:</h5>
				3781	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3782	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3783	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
				3784	%Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3785	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3786	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3787
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3788	<!-- ======================================================================= -->
				3789	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				3790	<div class="doc_text">
				3791	<p>The instructions in this category are the "miscellaneous"
				3792	instructions, which defy better classification.</p>
				3793	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3794
				3795	<!-- _______________________________________________________________________ -->
				3796	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				3797	</div>
				3798	<div class="doc_text">
				3799	<h5>Syntax:</h5>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3800	<pre> <result> = icmp <cond> <ty> <var1>, <var2> <i>; yields {i1}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3801	</pre>
				3802	<h5>Overview:</h5>
				3803	<p>The '<tt>icmp</tt>' instruction returns a boolean value based on comparison
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3804	of its two integer or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3805	<h5>Arguments:</h5>
				3806	<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]	3807	the condition code indicating the kind of comparison to perform. It is not
				3808	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3809	<ol>
				3810	<li><tt>eq</tt>: equal</li>
				3811	<li><tt>ne</tt>: not equal </li>
				3812	<li><tt>ugt</tt>: unsigned greater than</li>
				3813	<li><tt>uge</tt>: unsigned greater or equal</li>
				3814	<li><tt>ult</tt>: unsigned less than</li>
				3815	<li><tt>ule</tt>: unsigned less or equal</li>
				3816	<li><tt>sgt</tt>: signed greater than</li>
				3817	<li><tt>sge</tt>: signed greater or equal</li>
				3818	<li><tt>slt</tt>: signed less than</li>
				3819	<li><tt>sle</tt>: signed less or equal</li>
				3820	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3821	<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Reid Spencer	350f8aa	2007-01-04 05:19:58 +0000	[diff] [blame]	3822	<a href="#t_pointer">pointer</a> typed. They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3823	<h5>Semantics:</h5>
				3824	<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
				3825	the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3826	yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3827	<ol>
				3828	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				3829	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3830	</li>
				3831	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
				3832	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3833	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
				3834	<tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
				3835	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
				3836	<tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
				3837	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
				3838	<tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
				3839	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
				3840	<tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
				3841	<li><tt>sgt</tt>: interprets the operands as signed values and yields
				3842	<tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
				3843	<li><tt>sge</tt>: interprets the operands as signed values and yields
				3844	<tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
				3845	<li><tt>slt</tt>: interprets the operands as signed values and yields
				3846	<tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
				3847	<li><tt>sle</tt>: interprets the operands as signed values and yields
				3848	<tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3849	</ol>
				3850	<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]	3851	values are compared as if they were integers.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3852
				3853	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3854	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				3855	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				3856	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				3857	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				3858	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				3859	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3860	</pre>
				3861	</div>
				3862
				3863	<!-- _______________________________________________________________________ -->
				3864	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				3865	</div>
				3866	<div class="doc_text">
				3867	<h5>Syntax:</h5>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3868	<pre> <result> = fcmp <cond> <ty> <var1>, <var2> <i>; yields {i1}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3869	</pre>
				3870	<h5>Overview:</h5>
				3871	<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
				3872	of its floating point operands.</p>
				3873	<h5>Arguments:</h5>
				3874	<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]	3875	the condition code indicating the kind of comparison to perform. It is not
				3876	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3877	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3878	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3879	<li><tt>oeq</tt>: ordered and equal</li>
				3880	<li><tt>ogt</tt>: ordered and greater than </li>
				3881	<li><tt>oge</tt>: ordered and greater than or equal</li>
				3882	<li><tt>olt</tt>: ordered and less than </li>
				3883	<li><tt>ole</tt>: ordered and less than or equal</li>
				3884	<li><tt>one</tt>: ordered and not equal</li>
				3885	<li><tt>ord</tt>: ordered (no nans)</li>
				3886	<li><tt>ueq</tt>: unordered or equal</li>
				3887	<li><tt>ugt</tt>: unordered or greater than </li>
				3888	<li><tt>uge</tt>: unordered or greater than or equal</li>
				3889	<li><tt>ult</tt>: unordered or less than </li>
				3890	<li><tt>ule</tt>: unordered or less than or equal</li>
				3891	<li><tt>une</tt>: unordered or not equal</li>
				3892	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3893	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3894	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3895	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	3896	<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer	350f8aa	2007-01-04 05:19:58 +0000	[diff] [blame]	3897	<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
				3898	<a href="#t_floating">floating point</a> typed. They must have identical
				3899	types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3900	<h5>Semantics:</h5>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	3901	<p>The '<tt>fcmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				3902	according to the condition code given as <tt>cond</tt>. The comparison performed
				3903	always yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3904	<ol>
				3905	<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]	3906	<li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3907	<tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3908	<li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3909	<tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3910	<li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3911	<tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3912	<li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3913	<tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3914	<li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3915	<tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3916	<li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3917	<tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3918	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				3919	<li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3920	<tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3921	<li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3922	<tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3923	<li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3924	<tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3925	<li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3926	<tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3927	<li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3928	<tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3929	<li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3930	<tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3931	<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]	3932	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				3933	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3934
				3935	<h5>Example:</h5>
				3936	<pre> <result> = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
				3937	<result> = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
				3938	<result> = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				3939	<result> = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
				3940	</pre>
				3941	</div>
				3942
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3943	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	3944	<div class="doc_subsubsection">
				3945	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				3946	</div>
				3947	<div class="doc_text">
				3948	<h5>Syntax:</h5>
				3949	<pre> <result> = vicmp <cond> <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				3950	</pre>
				3951	<h5>Overview:</h5>
				3952	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				3953	element-wise comparison of its two integer vector operands.</p>
				3954	<h5>Arguments:</h5>
				3955	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				3956	the condition code indicating the kind of comparison to perform. It is not
				3957	a value, just a keyword. The possible condition code are:
				3958	<ol>
				3959	<li><tt>eq</tt>: equal</li>
				3960	<li><tt>ne</tt>: not equal </li>
				3961	<li><tt>ugt</tt>: unsigned greater than</li>
				3962	<li><tt>uge</tt>: unsigned greater or equal</li>
				3963	<li><tt>ult</tt>: unsigned less than</li>
				3964	<li><tt>ule</tt>: unsigned less or equal</li>
				3965	<li><tt>sgt</tt>: signed greater than</li>
				3966	<li><tt>sge</tt>: signed greater or equal</li>
				3967	<li><tt>slt</tt>: signed less than</li>
				3968	<li><tt>sle</tt>: signed less or equal</li>
				3969	</ol>
				3970	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				3971	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				3972	<h5>Semantics:</h5>
				3973	<p>The '<tt>vicmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				3974	according to the condition code given as <tt>cond</tt>. The comparison yields a
				3975	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				3976	identical type as the values being compared. The most significant bit in each
				3977	element is 1 if the element-wise comparison evaluates to true, and is 0
				3978	otherwise. All other bits of the result are undefined. The condition codes
				3979	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
				3980	instruction</a>.
				3981
				3982	<h5>Example:</h5>
				3983	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3984	<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>
				3985	<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]	3986	</pre>
				3987	</div>
				3988
				3989	<!-- _______________________________________________________________________ -->
				3990	<div class="doc_subsubsection">
				3991	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				3992	</div>
				3993	<div class="doc_text">
				3994	<h5>Syntax:</h5>
				3995	<pre> <result> = vfcmp <cond> <ty> <var1>, <var2></pre>
				3996	<h5>Overview:</h5>
				3997	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				3998	element-wise comparison of its two floating point vector operands. The output
				3999	elements have the same width as the input elements.</p>
				4000	<h5>Arguments:</h5>
				4001	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4002	the condition code indicating the kind of comparison to perform. It is not
				4003	a value, just a keyword. The possible condition code are:
				4004	<ol>
				4005	<li><tt>false</tt>: no comparison, always returns false</li>
				4006	<li><tt>oeq</tt>: ordered and equal</li>
				4007	<li><tt>ogt</tt>: ordered and greater than </li>
				4008	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4009	<li><tt>olt</tt>: ordered and less than </li>
				4010	<li><tt>ole</tt>: ordered and less than or equal</li>
				4011	<li><tt>one</tt>: ordered and not equal</li>
				4012	<li><tt>ord</tt>: ordered (no nans)</li>
				4013	<li><tt>ueq</tt>: unordered or equal</li>
				4014	<li><tt>ugt</tt>: unordered or greater than </li>
				4015	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4016	<li><tt>ult</tt>: unordered or less than </li>
				4017	<li><tt>ule</tt>: unordered or less than or equal</li>
				4018	<li><tt>une</tt>: unordered or not equal</li>
				4019	<li><tt>uno</tt>: unordered (either nans)</li>
				4020	<li><tt>true</tt>: no comparison, always returns true</li>
				4021	</ol>
				4022	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4023	<a href="#t_floating">floating point</a> typed. They must also be identical
				4024	types.</p>
				4025	<h5>Semantics:</h5>
				4026	<p>The '<tt>vfcmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				4027	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4028	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4029	an identical number of elements as the values being compared, and each element
				4030	having identical with to the width of the floating point elements. The most
				4031	significant bit in each element is 1 if the element-wise comparison evaluates to
				4032	true, and is 0 otherwise. All other bits of the result are undefined. The
				4033	condition codes are evaluated identically to the
				4034	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
				4035
				4036	<h5>Example:</h5>
				4037	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4038	<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>
				4039	<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]	4040	</pre>
				4041	</div>
				4042
				4043	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4044	<div class="doc_subsubsection">
				4045	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4046	</div>
				4047
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4048	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4049
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4050	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4051
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4052	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4053	<h5>Overview:</h5>
				4054	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4055	the SSA graph representing the function.</p>
				4056	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4057
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4058	<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]	4059	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4060	as arguments, with one pair for each predecessor basic block of the
				4061	current block. Only values of <a href="#t_firstclass">first class</a>
				4062	type may be used as the value arguments to the PHI node. Only labels
				4063	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4064
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4065	<p>There must be no non-phi instructions between the start of a basic
				4066	block and the PHI instructions: i.e. PHI instructions must be first in
				4067	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4068
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4069	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4070
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4071	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4072	specified by the pair corresponding to the predecessor basic block that executed
				4073	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4074
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4075	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4076	<pre>
				4077	Loop: ; Infinite loop that counts from 0 on up...
				4078	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4079	%nextindvar = add i32 %indvar, 1
				4080	br label %Loop
				4081	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4082	</div>
				4083
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4084	<!-- _______________________________________________________________________ -->
				4085	<div class="doc_subsubsection">
				4086	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4087	</div>
				4088
				4089	<div class="doc_text">
				4090
				4091	<h5>Syntax:</h5>
				4092
				4093	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4094	<result> = select i1 <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4095	</pre>
				4096
				4097	<h5>Overview:</h5>
				4098
				4099	<p>
				4100	The '<tt>select</tt>' instruction is used to choose one value based on a
				4101	condition, without branching.
				4102	</p>
				4103
				4104
				4105	<h5>Arguments:</h5>
				4106
				4107	<p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4108	The '<tt>select</tt>' instruction requires an 'i1' value indicating the
				4109	condition, and two values of the same <a href="#t_firstclass">first class</a>
				4110	type. If the val1/val2 are vectors, the entire vectors are selected, not
				4111	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4112	</p>
				4113
				4114	<h5>Semantics:</h5>
				4115
				4116	<p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4117	If the i1 condition evaluates is 1, the instruction returns the first
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4118	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4119	</p>
				4120
				4121	<h5>Example:</h5>
				4122
				4123	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4124	%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]	4125	</pre>
				4126	</div>
				4127
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4128
				4129	<!-- _______________________________________________________________________ -->
				4130	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4131	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4132	</div>
				4133
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4134	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4135
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4136	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4137	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4138	<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]	4139	</pre>
				4140
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4141	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4142
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4143	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4144
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4145	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4146
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4147	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4148
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4149	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4150	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4151	<p>The optional "tail" marker indicates whether the callee function accesses
				4152	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]	4153	function call is eligible for tail call optimization. Note that calls may
				4154	be marked "tail" even if they do not occur before a <a
				4155	href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4156	</li>
				4157	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4158	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4159	convention</a> the call should use. If none is specified, the call defaults
				4160	to using C calling conventions.
				4161	</li>
				4162	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4163	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4164	the type of the return value. Functions that return no value are marked
				4165	<tt><a href="#t_void">void</a></tt>.</p>
				4166	</li>
				4167	<li>
				4168	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4169	value being invoked. The argument types must match the types implied by
				4170	this signature. This type can be omitted if the function is not varargs
				4171	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]	4172	</li>
				4173	<li>
				4174	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4175	be invoked. In most cases, this is a direct function invocation, but
				4176	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]	4177	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4178	</li>
				4179	<li>
				4180	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4181	function signature argument types. All arguments must be of
				4182	<a href="#t_firstclass">first class</a> type. If the function signature
				4183	indicates the function accepts a variable number of arguments, the extra
				4184	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4185	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4186	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4187
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4188	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4189
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4190	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4191	transfer to a specified function, with its incoming arguments bound to
				4192	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4193	instruction in the called function, control flow continues with the
				4194	instruction after the function call, and the return value of the
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4195	function is bound to the result argument. If the callee returns multiple
				4196	values then the return values of the function are only accessible through
				4197	the '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4198
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4199	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4200
				4201	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4202	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4203	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4204	%X = tail call i32 @foo() <i>; yields i32</i>
				4205	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4206	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4207
				4208	%struct.A = type { i32, i8 }
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4209	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
				4210	%gr = getresult %struct.A %r, 0 <i>; yields i32</i>
				4211	%gr1 = getresult %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4212	</pre>
				4213
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4214	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4215
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4216	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4217	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4218	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4219	</div>
				4220
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4221	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4222
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4223	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4224
				4225	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4226	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4227	</pre>
				4228
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4229	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4230
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4231	<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]	4232	the "variable argument" area of a function call. It is used to implement the
				4233	<tt>va_arg</tt> macro in C.</p>
				4234
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4235	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4236
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4237	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4238	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4239	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]	4240	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4241
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4242	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4243
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4244	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4245	type from the specified <tt>va_list</tt> and causes the
				4246	<tt>va_list</tt> to point to the next argument. For more information,
				4247	see the variable argument handling <a href="#int_varargs">Intrinsic
				4248	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4249
				4250	<p>It is legal for this instruction to be called in a function which does not
				4251	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4252	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4253
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4254	<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]	4255	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4256	argument.</p>
				4257
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4258	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4259
				4260	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4261
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4262	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4263
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4264	<!-- _______________________________________________________________________ -->
				4265	<div class="doc_subsubsection">
				4266	<a name="i_getresult">'<tt>getresult</tt>' Instruction</a>
				4267	</div>
				4268
				4269	<div class="doc_text">
				4270
				4271	<h5>Syntax:</h5>
				4272	<pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4273	<resultval> = getresult <type> <retval>, <index>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4274	</pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4275
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4276	<h5>Overview:</h5>
				4277
				4278	<p> The '<tt>getresult</tt>' instruction is used to extract individual values
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4279	from a '<tt><a href="#i_call">call</a></tt>'
				4280	or '<tt><a href="#i_invoke">invoke</a></tt>' instruction that returns multiple
				4281	results.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4282
				4283	<h5>Arguments:</h5>
				4284
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4285	<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]	4286	first argument, or an undef value. The value must have <a
				4287	href="#t_struct">structure type</a>. The second argument is a constant
				4288	unsigned index value which must be in range for the number of values returned
				4289	by the call.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4290
				4291	<h5>Semantics:</h5>
				4292
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4293	<p>The '<tt>getresult</tt>' instruction extracts the element identified by
				4294	'<tt>index</tt>' from the aggregate value.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4295
				4296	<h5>Example:</h5>
				4297
				4298	<pre>
				4299	%struct.A = type { i32, i8 }
				4300
				4301	%r = call %struct.A @foo()
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4302	%gr = getresult %struct.A %r, 0 <i>; yields i32:%gr</i>
				4303	%gr1 = getresult %struct.A %r, 1 <i>; yields i8:%gr1</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4304	add i32 %gr, 42
				4305	add i8 %gr1, 41
				4306	</pre>
				4307
				4308	</div>
				4309
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4310	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4311	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4312	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4313
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4314	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4315
				4316	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4317	well known names and semantics and are required to follow certain restrictions.
				4318	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4319	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]	4320	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]	4321
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4322	<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]	4323	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4324	begin with this prefix. Intrinsic functions must always be external functions:
				4325	you cannot define the body of intrinsic functions. Intrinsic functions may
				4326	only be used in call or invoke instructions: it is illegal to take the address
				4327	of an intrinsic function. Additionally, because intrinsic functions are part
				4328	of the LLVM language, it is required if any are added that they be documented
				4329	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4330
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4331	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4332	a family of functions that perform the same operation but on different data
				4333	types. Because LLVM can represent over 8 million different integer types,
				4334	overloading is used commonly to allow an intrinsic function to operate on any
				4335	integer type. One or more of the argument types or the result type can be
				4336	overloaded to accept any integer type. Argument types may also be defined as
				4337	exactly matching a previous argument's type or the result type. This allows an
				4338	intrinsic function which accepts multiple arguments, but needs all of them to
				4339	be of the same type, to only be overloaded with respect to a single argument or
				4340	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4341
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4342	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4343	encoded into its function name, each preceded by a period. Only those types
				4344	which are overloaded result in a name suffix. Arguments whose type is matched
				4345	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4346	take an integer of any width and returns an integer of exactly the same integer
				4347	width. This leads to a family of functions such as
				4348	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4349	Only one type, the return type, is overloaded, and only one type suffix is
				4350	required. Because the argument's type is matched against the return type, it
				4351	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4352
				4353	<p>To learn how to add an intrinsic function, please see the
				4354	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4355	</p>
				4356
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4357	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4358
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4359	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4360	<div class="doc_subsection">
				4361	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4362	</div>
				4363
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4364	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4365
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4366	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4367	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]	4368	intrinsic functions. These functions are related to the similarly
				4369	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4370
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4371	<p>All of these functions operate on arguments that use a
				4372	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4373	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4374	transformations should be prepared to handle these functions regardless of
				4375	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4376
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4377	<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]	4378	instruction and the variable argument handling intrinsic functions are
				4379	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4380
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4381	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4382	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4383	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4384	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4385	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4386	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4387	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4388
				4389	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4390	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4391
				4392	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4393	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4394	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4395	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4396	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4397
				4398	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4399	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4400	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4401	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4402
				4403	declare void @llvm.va_start(i8*)
				4404	declare void @llvm.va_copy(i8, i8)
				4405	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4406	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4407	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4408
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4409	</div>
				4410
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4411	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4412	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4413	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4414	</div>
				4415
				4416
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4417	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4418	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4419	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4420	<h5>Overview:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4421	<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
				4422	<tt>*<arglist></tt> for subsequent use by <tt><a
				4423	href="#i_va_arg">va_arg</a></tt>.</p>
				4424
				4425	<h5>Arguments:</h5>
				4426
				4427	<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
				4428
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4429	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4430
				4431	<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
				4432	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4433	<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]	4434	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4435	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]	4436	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]	4437
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4438	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4439
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4440	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4441	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4442	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4443	</div>
				4444
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4445	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4446	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4447	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4448	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4449
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4450	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4451	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]	4452	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]	4453
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4454	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4455
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4456	<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]	4457
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4458	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4459
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4460	<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]	4461	macro available in C. In a target-dependent way, it destroys the
				4462	<tt>va_list</tt> element to which the argument points. Calls to <a
				4463	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4464	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4465	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4466
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4467	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4468
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4469	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4470	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4471	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4472	</div>
				4473
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4474	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4475
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4476	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4477
				4478	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4479	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4480	</pre>
				4481
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4482	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4483
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4484	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4485	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4486
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4487	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4488
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4489	<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]	4490	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]	4491
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4492
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4493	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4494
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4495	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4496	macro available in C. In a target-dependent way, it copies the source
				4497	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4498	intrinsic is necessary because the <tt><a href="#int_va_start">
				4499	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4500	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4501
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4502	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4503
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4504	<!-- ======================================================================= -->
				4505	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4506	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4507	</div>
				4508
				4509	<div class="doc_text">
				4510
				4511	<p>
				4512	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
				4513	Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4514	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]	4515	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4516	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]	4517	Front-ends for type-safe garbage collected languages should generate these
				4518	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4519	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4520	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4521
				4522	<p>The garbage collection intrinsics only operate on objects in the generic
				4523	address space (address space zero).</p>
				4524
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4525	</div>
				4526
				4527	<!-- _______________________________________________________________________ -->
				4528	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4529	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4530	</div>
				4531
				4532	<div class="doc_text">
				4533
				4534	<h5>Syntax:</h5>
				4535
				4536	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4537	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4538	</pre>
				4539
				4540	<h5>Overview:</h5>
				4541
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4542	<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]	4543	the code generator, and allows some metadata to be associated with it.</p>
				4544
				4545	<h5>Arguments:</h5>
				4546
				4547	<p>The first argument specifies the address of a stack object that contains the
				4548	root pointer. The second pointer (which must be either a constant or a global
				4549	value address) contains the meta-data to be associated with the root.</p>
				4550
				4551	<h5>Semantics:</h5>
				4552
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	4553	<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]	4554	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4555	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4556	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4557	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4558
				4559	</div>
				4560
				4561
				4562	<!-- _______________________________________________________________________ -->
				4563	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4564	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4565	</div>
				4566
				4567	<div class="doc_text">
				4568
				4569	<h5>Syntax:</h5>
				4570
				4571	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4572	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4573	</pre>
				4574
				4575	<h5>Overview:</h5>
				4576
				4577	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4578	locations, allowing garbage collector implementations that require read
				4579	barriers.</p>
				4580
				4581	<h5>Arguments:</h5>
				4582
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4583	<p>The second argument is the address to read from, which should be an address
				4584	allocated from the garbage collector. The first object is a pointer to the
				4585	start of the referenced object, if needed by the language runtime (otherwise
				4586	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4587
				4588	<h5>Semantics:</h5>
				4589
				4590	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4591	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4592	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4593	may only be used in a function which <a href="#gc">specifies a GC
				4594	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4595
				4596	</div>
				4597
				4598
				4599	<!-- _______________________________________________________________________ -->
				4600	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4601	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4602	</div>
				4603
				4604	<div class="doc_text">
				4605
				4606	<h5>Syntax:</h5>
				4607
				4608	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4609	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4610	</pre>
				4611
				4612	<h5>Overview:</h5>
				4613
				4614	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4615	locations, allowing garbage collector implementations that require write
				4616	barriers (such as generational or reference counting collectors).</p>
				4617
				4618	<h5>Arguments:</h5>
				4619
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4620	<p>The first argument is the reference to store, the second is the start of the
				4621	object to store it to, and the third is the address of the field of Obj to
				4622	store to. If the runtime does not require a pointer to the object, Obj may be
				4623	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4624
				4625	<h5>Semantics:</h5>
				4626
				4627	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4628	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4629	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4630	may only be used in a function which <a href="#gc">specifies a GC
				4631	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4632
				4633	</div>
				4634
				4635
				4636
				4637	<!-- ======================================================================= -->
				4638	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4639	<a name="int_codegen">Code Generator Intrinsics</a>
				4640	</div>
				4641
				4642	<div class="doc_text">
				4643	<p>
				4644	These intrinsics are provided by LLVM to expose special features that may only
				4645	be implemented with code generator support.
				4646	</p>
				4647
				4648	</div>
				4649
				4650	<!-- _______________________________________________________________________ -->
				4651	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4652	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4653	</div>
				4654
				4655	<div class="doc_text">
				4656
				4657	<h5>Syntax:</h5>
				4658	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4659	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4660	</pre>
				4661
				4662	<h5>Overview:</h5>
				4663
				4664	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4665	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				4666	target-specific value indicating the return address of the current function
				4667	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4668	</p>
				4669
				4670	<h5>Arguments:</h5>
				4671
				4672	<p>
				4673	The argument to this intrinsic indicates which function to return the address
				4674	for. Zero indicates the calling function, one indicates its caller, etc. The
				4675	argument is <b>required</b> to be a constant integer value.
				4676	</p>
				4677
				4678	<h5>Semantics:</h5>
				4679
				4680	<p>
				4681	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				4682	the return address of the specified call frame, or zero if it cannot be
				4683	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4684	for arguments other than zero, so it should only be used for debugging purposes.
				4685	</p>
				4686
				4687	<p>
				4688	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4689	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]	4690	source-language caller.
				4691	</p>
				4692	</div>
				4693
				4694
				4695	<!-- _______________________________________________________________________ -->
				4696	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4697	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4698	</div>
				4699
				4700	<div class="doc_text">
				4701
				4702	<h5>Syntax:</h5>
				4703	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4704	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4705	</pre>
				4706
				4707	<h5>Overview:</h5>
				4708
				4709	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4710	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				4711	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4712	</p>
				4713
				4714	<h5>Arguments:</h5>
				4715
				4716	<p>
				4717	The argument to this intrinsic indicates which function to return the frame
				4718	pointer for. Zero indicates the calling function, one indicates its caller,
				4719	etc. The argument is <b>required</b> to be a constant integer value.
				4720	</p>
				4721
				4722	<h5>Semantics:</h5>
				4723
				4724	<p>
				4725	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				4726	the frame address of the specified call frame, or zero if it cannot be
				4727	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4728	for arguments other than zero, so it should only be used for debugging purposes.
				4729	</p>
				4730
				4731	<p>
				4732	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4733	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]	4734	source-language caller.
				4735	</p>
				4736	</div>
				4737
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4738	<!-- _______________________________________________________________________ -->
				4739	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4740	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4741	</div>
				4742
				4743	<div class="doc_text">
				4744
				4745	<h5>Syntax:</h5>
				4746	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4747	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4748	</pre>
				4749
				4750	<h5>Overview:</h5>
				4751
				4752	<p>
				4753	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]	4754	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4755	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				4756	features like scoped automatic variable sized arrays in C99.
				4757	</p>
				4758
				4759	<h5>Semantics:</h5>
				4760
				4761	<p>
				4762	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]	4763	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4764	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				4765	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				4766	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				4767	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				4768	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				4769	</p>
				4770
				4771	</div>
				4772
				4773	<!-- _______________________________________________________________________ -->
				4774	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4775	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4776	</div>
				4777
				4778	<div class="doc_text">
				4779
				4780	<h5>Syntax:</h5>
				4781	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4782	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4783	</pre>
				4784
				4785	<h5>Overview:</h5>
				4786
				4787	<p>
				4788	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				4789	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]	4790	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4791	useful for implementing language features like scoped automatic variable sized
				4792	arrays in C99.
				4793	</p>
				4794
				4795	<h5>Semantics:</h5>
				4796
				4797	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4798	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]	4799	</p>
				4800
				4801	</div>
				4802
				4803
				4804	<!-- _______________________________________________________________________ -->
				4805	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4806	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4807	</div>
				4808
				4809	<div class="doc_text">
				4810
				4811	<h5>Syntax:</h5>
				4812	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4813	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4814	</pre>
				4815
				4816	<h5>Overview:</h5>
				4817
				4818
				4819	<p>
				4820	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]	4821	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				4822	no
				4823	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	4824	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4825	</p>
				4826
				4827	<h5>Arguments:</h5>
				4828
				4829	<p>
				4830	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				4831	determining if the fetch should be for a read (0) or write (1), and
				4832	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	4833	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]	4834	<tt>locality</tt> arguments must be constant integers.
				4835	</p>
				4836
				4837	<h5>Semantics:</h5>
				4838
				4839	<p>
				4840	This intrinsic does not modify the behavior of the program. In particular,
				4841	prefetches cannot trap and do not produce a value. On targets that support this
				4842	intrinsic, the prefetch can provide hints to the processor cache for better
				4843	performance.
				4844	</p>
				4845
				4846	</div>
				4847
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4848	<!-- _______________________________________________________________________ -->
				4849	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4850	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4851	</div>
				4852
				4853	<div class="doc_text">
				4854
				4855	<h5>Syntax:</h5>
				4856	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4857	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4858	</pre>
				4859
				4860	<h5>Overview:</h5>
				4861
				4862
				4863	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4864	The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
				4865	(PC) in a region of
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4866	code to simulators and other tools. The method is target specific, but it is
				4867	expected that the marker will use exported symbols to transmit the PC of the marker.
Jeff Cohen	25d4f7e	2005-11-11 02:15:27 +0000	[diff] [blame]	4868	The marker makes no guarantees that it will remain with any specific instruction
Chris Lattner	d07c3f4	2005-11-15 06:07:55 +0000	[diff] [blame]	4869	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]	4870	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4871	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4872	</p>
				4873
				4874	<h5>Arguments:</h5>
				4875
				4876	<p>
				4877	<tt>id</tt> is a numerical id identifying the marker.
				4878	</p>
				4879
				4880	<h5>Semantics:</h5>
				4881
				4882	<p>
				4883	This intrinsic does not modify the behavior of the program. Backends that do not
				4884	support this intrinisic may ignore it.
				4885	</p>
				4886
				4887	</div>
				4888
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4889	<!-- _______________________________________________________________________ -->
				4890	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4891	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4892	</div>
				4893
				4894	<div class="doc_text">
				4895
				4896	<h5>Syntax:</h5>
				4897	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4898	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4899	</pre>
				4900
				4901	<h5>Overview:</h5>
				4902
				4903
				4904	<p>
				4905	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				4906	counter register (or similar low latency, high accuracy clocks) on those targets
				4907	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				4908	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				4909	should only be used for small timings.
				4910	</p>
				4911
				4912	<h5>Semantics:</h5>
				4913
				4914	<p>
				4915	When directly supported, reading the cycle counter should not modify any memory.
				4916	Implementations are allowed to either return a application specific value or a
				4917	system wide value. On backends without support, this is lowered to a constant 0.
				4918	</p>
				4919
				4920	</div>
				4921
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4922	<!-- ======================================================================= -->
				4923	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4924	<a name="int_libc">Standard C Library Intrinsics</a>
				4925	</div>
				4926
				4927	<div class="doc_text">
				4928	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4929	LLVM provides intrinsics for a few important standard C library functions.
				4930	These intrinsics allow source-language front-ends to pass information about the
				4931	alignment of the pointer arguments to the code generator, providing opportunity
				4932	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4933	</p>
				4934
				4935	</div>
				4936
				4937	<!-- _______________________________________________________________________ -->
				4938	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4939	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4940	</div>
				4941
				4942	<div class="doc_text">
				4943
				4944	<h5>Syntax:</h5>
				4945	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4946	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4947	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4948	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4949	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4950	</pre>
				4951
				4952	<h5>Overview:</h5>
				4953
				4954	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4955	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]	4956	location to the destination location.
				4957	</p>
				4958
				4959	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4960	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				4961	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4962	</p>
				4963
				4964	<h5>Arguments:</h5>
				4965
				4966	<p>
				4967	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]	4968	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4969	specifying the number of bytes to copy, and the fourth argument is the alignment
				4970	of the source and destination locations.
				4971	</p>
				4972
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	4973	<p>
				4974	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]	4975	the caller guarantees that both the source and destination pointers are aligned
				4976	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	4977	</p>
				4978
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4979	<h5>Semantics:</h5>
				4980
				4981	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4982	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]	4983	location to the destination location, which are not allowed to overlap. It
				4984	copies "len" bytes of memory over. If the argument is known to be aligned to
				4985	some boundary, this can be specified as the fourth argument, otherwise it should
				4986	be set to 0 or 1.
				4987	</p>
				4988	</div>
				4989
				4990
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	4991	<!-- _______________________________________________________________________ -->
				4992	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4993	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	4994	</div>
				4995
				4996	<div class="doc_text">
				4997
				4998	<h5>Syntax:</h5>
				4999	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5000	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5001	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5002	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5003	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5004	</pre>
				5005
				5006	<h5>Overview:</h5>
				5007
				5008	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5009	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5010	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5011	'<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]	5012	</p>
				5013
				5014	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5015	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5016	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5017	</p>
				5018
				5019	<h5>Arguments:</h5>
				5020
				5021	<p>
				5022	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]	5023	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5024	specifying the number of bytes to copy, and the fourth argument is the alignment
				5025	of the source and destination locations.
				5026	</p>
				5027
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5028	<p>
				5029	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]	5030	the caller guarantees that the source and destination pointers are aligned to
				5031	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5032	</p>
				5033
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5034	<h5>Semantics:</h5>
				5035
				5036	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5037	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]	5038	location to the destination location, which may overlap. It
				5039	copies "len" bytes of memory over. If the argument is known to be aligned to
				5040	some boundary, this can be specified as the fourth argument, otherwise it should
				5041	be set to 0 or 1.
				5042	</p>
				5043	</div>
				5044
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5045
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5046	<!-- _______________________________________________________________________ -->
				5047	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5048	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5049	</div>
				5050
				5051	<div class="doc_text">
				5052
				5053	<h5>Syntax:</h5>
				5054	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5055	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5056	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5057	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5058	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5059	</pre>
				5060
				5061	<h5>Overview:</h5>
				5062
				5063	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5064	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]	5065	byte value.
				5066	</p>
				5067
				5068	<p>
				5069	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5070	does not return a value, and takes an extra alignment argument.
				5071	</p>
				5072
				5073	<h5>Arguments:</h5>
				5074
				5075	<p>
				5076	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]	5077	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5078	argument specifying the number of bytes to fill, and the fourth argument is the
				5079	known alignment of destination location.
				5080	</p>
				5081
				5082	<p>
				5083	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]	5084	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5085	</p>
				5086
				5087	<h5>Semantics:</h5>
				5088
				5089	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5090	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5091	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5092	destination location. If the argument is known to be aligned to some boundary,
				5093	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5094	1.
				5095	</p>
				5096	</div>
				5097
				5098
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5099	<!-- _______________________________________________________________________ -->
				5100	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5101	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5102	</div>
				5103
				5104	<div class="doc_text">
				5105
				5106	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5107	<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]	5108	floating point or vector of floating point type. Not all targets support all
				5109	types however.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5110	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5111	declare float @llvm.sqrt.f32(float %Val)
				5112	declare double @llvm.sqrt.f64(double %Val)
				5113	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5114	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5115	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5116	</pre>
				5117
				5118	<h5>Overview:</h5>
				5119
				5120	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5121	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]	5122	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]	5123	<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]	5124	negative numbers other than -0.0 (which allows for better optimization, because
				5125	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5126	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5127	</p>
				5128
				5129	<h5>Arguments:</h5>
				5130
				5131	<p>
				5132	The argument and return value are floating point numbers of the same type.
				5133	</p>
				5134
				5135	<h5>Semantics:</h5>
				5136
				5137	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5138	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]	5139	floating point number.
				5140	</p>
				5141	</div>
				5142
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5143	<!-- _______________________________________________________________________ -->
				5144	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5145	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5146	</div>
				5147
				5148	<div class="doc_text">
				5149
				5150	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5151	<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]	5152	floating point or vector of floating point type. Not all targets support all
				5153	types however.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5154	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5155	declare float @llvm.powi.f32(float %Val, i32 %power)
				5156	declare double @llvm.powi.f64(double %Val, i32 %power)
				5157	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5158	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5159	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5160	</pre>
				5161
				5162	<h5>Overview:</h5>
				5163
				5164	<p>
				5165	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5166	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5167	multiplications is not defined. When a vector of floating point type is
				5168	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5169	</p>
				5170
				5171	<h5>Arguments:</h5>
				5172
				5173	<p>
				5174	The second argument is an integer power, and the first is a value to raise to
				5175	that power.
				5176	</p>
				5177
				5178	<h5>Semantics:</h5>
				5179
				5180	<p>
				5181	This function returns the first value raised to the second power with an
				5182	unspecified sequence of rounding operations.</p>
				5183	</div>
				5184
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5185	<!-- _______________________________________________________________________ -->
				5186	<div class="doc_subsubsection">
				5187	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5188	</div>
				5189
				5190	<div class="doc_text">
				5191
				5192	<h5>Syntax:</h5>
				5193	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5194	floating point or vector of floating point type. Not all targets support all
				5195	types however.
				5196	<pre>
				5197	declare float @llvm.sin.f32(float %Val)
				5198	declare double @llvm.sin.f64(double %Val)
				5199	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5200	declare fp128 @llvm.sin.f128(fp128 %Val)
				5201	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5202	</pre>
				5203
				5204	<h5>Overview:</h5>
				5205
				5206	<p>
				5207	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5208	</p>
				5209
				5210	<h5>Arguments:</h5>
				5211
				5212	<p>
				5213	The argument and return value are floating point numbers of the same type.
				5214	</p>
				5215
				5216	<h5>Semantics:</h5>
				5217
				5218	<p>
				5219	This function returns the sine of the specified operand, returning the
				5220	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]	5221	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5222	</div>
				5223
				5224	<!-- _______________________________________________________________________ -->
				5225	<div class="doc_subsubsection">
				5226	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5227	</div>
				5228
				5229	<div class="doc_text">
				5230
				5231	<h5>Syntax:</h5>
				5232	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5233	floating point or vector of floating point type. Not all targets support all
				5234	types however.
				5235	<pre>
				5236	declare float @llvm.cos.f32(float %Val)
				5237	declare double @llvm.cos.f64(double %Val)
				5238	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5239	declare fp128 @llvm.cos.f128(fp128 %Val)
				5240	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5241	</pre>
				5242
				5243	<h5>Overview:</h5>
				5244
				5245	<p>
				5246	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5247	</p>
				5248
				5249	<h5>Arguments:</h5>
				5250
				5251	<p>
				5252	The argument and return value are floating point numbers of the same type.
				5253	</p>
				5254
				5255	<h5>Semantics:</h5>
				5256
				5257	<p>
				5258	This function returns the cosine of the specified operand, returning the
				5259	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]	5260	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5261	</div>
				5262
				5263	<!-- _______________________________________________________________________ -->
				5264	<div class="doc_subsubsection">
				5265	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5266	</div>
				5267
				5268	<div class="doc_text">
				5269
				5270	<h5>Syntax:</h5>
				5271	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5272	floating point or vector of floating point type. Not all targets support all
				5273	types however.
				5274	<pre>
				5275	declare float @llvm.pow.f32(float %Val, float %Power)
				5276	declare double @llvm.pow.f64(double %Val, double %Power)
				5277	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5278	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5279	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5280	</pre>
				5281
				5282	<h5>Overview:</h5>
				5283
				5284	<p>
				5285	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5286	specified (positive or negative) power.
				5287	</p>
				5288
				5289	<h5>Arguments:</h5>
				5290
				5291	<p>
				5292	The second argument is a floating point power, and the first is a value to
				5293	raise to that power.
				5294	</p>
				5295
				5296	<h5>Semantics:</h5>
				5297
				5298	<p>
				5299	This function returns the first value raised to the second power,
				5300	returning the
				5301	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]	5302	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5303	</div>
				5304
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5305
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5306	<!-- ======================================================================= -->
				5307	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5308	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5309	</div>
				5310
				5311	<div class="doc_text">
				5312	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5313	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5314	These allow efficient code generation for some algorithms.
				5315	</p>
				5316
				5317	</div>
				5318
				5319	<!-- _______________________________________________________________________ -->
				5320	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5321	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5322	</div>
				5323
				5324	<div class="doc_text">
				5325
				5326	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5327	<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]	5328	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]	5329	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5330	declare i16 @llvm.bswap.i16(i16 <id>)
				5331	declare i32 @llvm.bswap.i32(i32 <id>)
				5332	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5333	</pre>
				5334
				5335	<h5>Overview:</h5>
				5336
				5337	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5338	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]	5339	values with an even number of bytes (positive multiple of 16 bits). These are
				5340	useful for performing operations on data that is not in the target's native
				5341	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5342	</p>
				5343
				5344	<h5>Semantics:</h5>
				5345
				5346	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5347	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]	5348	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5349	intrinsic returns an i32 value that has the four bytes of the input i32
				5350	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]	5351	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5352	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5353	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5354	</p>
				5355
				5356	</div>
				5357
				5358	<!-- _______________________________________________________________________ -->
				5359	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5360	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5361	</div>
				5362
				5363	<div class="doc_text">
				5364
				5365	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5366	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
				5367	width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5368	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5369	declare i8 @llvm.ctpop.i8 (i8 <src>)
				5370	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5371	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5372	declare i64 @llvm.ctpop.i64(i64 <src>)
				5373	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5374	</pre>
				5375
				5376	<h5>Overview:</h5>
				5377
				5378	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5379	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5380	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5381	</p>
				5382
				5383	<h5>Arguments:</h5>
				5384
				5385	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5386	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]	5387	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5388	</p>
				5389
				5390	<h5>Semantics:</h5>
				5391
				5392	<p>
				5393	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5394	</p>
				5395	</div>
				5396
				5397	<!-- _______________________________________________________________________ -->
				5398	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5399	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5400	</div>
				5401
				5402	<div class="doc_text">
				5403
				5404	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5405	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
				5406	integer bit width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5407	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5408	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5409	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5410	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5411	declare i64 @llvm.ctlz.i64(i64 <src>)
				5412	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5413	</pre>
				5414
				5415	<h5>Overview:</h5>
				5416
				5417	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5418	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5419	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5420	</p>
				5421
				5422	<h5>Arguments:</h5>
				5423
				5424	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5425	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]	5426	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5427	</p>
				5428
				5429	<h5>Semantics:</h5>
				5430
				5431	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5432	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5433	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]	5434	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5435	</p>
				5436	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5437
				5438
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5439
				5440	<!-- _______________________________________________________________________ -->
				5441	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5442	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5443	</div>
				5444
				5445	<div class="doc_text">
				5446
				5447	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5448	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
				5449	integer bit width. Not all targets support all bit widths however.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5450	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5451	declare i8 @llvm.cttz.i8 (i8 <src>)
				5452	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5453	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5454	declare i64 @llvm.cttz.i64(i64 <src>)
				5455	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5456	</pre>
				5457
				5458	<h5>Overview:</h5>
				5459
				5460	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5461	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5462	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5463	</p>
				5464
				5465	<h5>Arguments:</h5>
				5466
				5467	<p>
				5468	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]	5469	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5470	</p>
				5471
				5472	<h5>Semantics:</h5>
				5473
				5474	<p>
				5475	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5476	in a variable. If the src == 0 then the result is the size in bits of the type
				5477	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5478	</p>
				5479	</div>
				5480
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	5481	<!-- _______________________________________________________________________ -->
				5482	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5483	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5484	</div>
				5485
				5486	<div class="doc_text">
				5487
				5488	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5489	<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]	5490	on any integer bit width.
				5491	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5492	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5493	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5494	</pre>
				5495
				5496	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5497	<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]	5498	range of bits from an integer value and returns them in the same bit width as
				5499	the original value.</p>
				5500
				5501	<h5>Arguments:</h5>
				5502	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5503	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]	5504	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]	5505
				5506	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5507	<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]	5508	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5509	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5510	operates in forward mode.</p>
				5511	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5512	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]	5513	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5514	<ol>
				5515	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5516	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5517	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5518	to determine the number of bits to retain.</li>
				5519	<li>A mask of the retained bits is created by shifting a -1 value.</li>
				5520	<li>The mask is ANDed with <tt>%val</tt> to produce the result.
				5521	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	5522	<p>In reverse mode, a similar computation is made except that the bits are
				5523	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5524	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5525	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5526	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5527	</div>
				5528
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5529	<div class="doc_subsubsection">
				5530	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5531	</div>
				5532
				5533	<div class="doc_text">
				5534
				5535	<h5>Syntax:</h5>
				5536	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
				5537	on any integer bit width.
				5538	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5539	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5540	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]	5541	</pre>
				5542
				5543	<h5>Overview:</h5>
				5544	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5545	of bits in an integer value with another integer value. It returns the integer
				5546	with the replaced bits.</p>
				5547
				5548	<h5>Arguments:</h5>
				5549	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5550	any bit width but they must have the same bit width. <tt>%val</tt> is the value
				5551	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5552	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5553	type since they specify only a bit index.</p>
				5554
				5555	<h5>Semantics:</h5>
				5556	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5557	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5558	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5559	operates in forward mode.</p>
				5560	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5561	truncating it down to the size of the replacement area or zero extending it
				5562	up to that size.</p>
				5563	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5564	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5565	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
				5566	to the <tt>%hi</tt>th bit.
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5567	<p>In reverse mode, a similar computation is made except that the bits are
				5568	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
				5569	<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]	5570	<h5>Examples:</h5>
				5571	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5572	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5573	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5574	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5575	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5576	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	5577	</pre>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5578	</div>
				5579
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5580	<!-- ======================================================================= -->
				5581	<div class="doc_subsection">
				5582	<a name="int_debugger">Debugger Intrinsics</a>
				5583	</div>
				5584
				5585	<div class="doc_text">
				5586	<p>
				5587	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				5588	are described in the <a
				5589	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				5590	Debugging</a> document.
				5591	</p>
				5592	</div>
				5593
				5594
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	5595	<!-- ======================================================================= -->
				5596	<div class="doc_subsection">
				5597	<a name="int_eh">Exception Handling Intrinsics</a>
				5598	</div>
				5599
				5600	<div class="doc_text">
				5601	<p> The LLVM exception handling intrinsics (which all start with
				5602	<tt>llvm.eh.</tt> prefix), are described in the <a
				5603	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				5604	Handling</a> document. </p>
				5605	</div>
				5606
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5607	<!-- ======================================================================= -->
				5608	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5609	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5610	</div>
				5611
				5612	<div class="doc_text">
				5613	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5614	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5615	the <tt>nest</tt> attribute, from a function. The result is a callable
				5616	function pointer lacking the nest parameter - the caller does not need
				5617	to provide a value for it. Instead, the value to use is stored in
				5618	advance in a "trampoline", a block of memory usually allocated
				5619	on the stack, which also contains code to splice the nest value into the
				5620	argument list. This is used to implement the GCC nested function address
				5621	extension.
				5622	</p>
				5623	<p>
				5624	For example, if the function is
				5625	<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]	5626	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]	5627	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5628	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				5629	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				5630	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				5631	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5632	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	5633	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				5634	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]	5635	</div>
				5636
				5637	<!-- _______________________________________________________________________ -->
				5638	<div class="doc_subsubsection">
				5639	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				5640	</div>
				5641	<div class="doc_text">
				5642	<h5>Syntax:</h5>
				5643	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5644	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5645	</pre>
				5646	<h5>Overview:</h5>
				5647	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5648	This fills the memory pointed to by <tt>tramp</tt> with code
				5649	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5650	</p>
				5651	<h5>Arguments:</h5>
				5652	<p>
				5653	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				5654	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				5655	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]	5656	intrinsic. Note that the size and the alignment are target-specific - LLVM
				5657	currently provides no portable way of determining them, so a front-end that
				5658	generates this intrinsic needs to have some target-specific knowledge.
				5659	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]	5660	</p>
				5661	<h5>Semantics:</h5>
				5662	<p>
				5663	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]	5664	dependent code, turning it into a function. A pointer to this function is
				5665	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5666	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5667	before being called. The new function's signature is the same as that of
				5668	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				5669	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				5670	of pointer type. Calling the new function is equivalent to calling
				5671	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				5672	missing <tt>nest</tt> argument. If, after calling
				5673	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				5674	modified, then the effect of any later call to the returned function pointer is
				5675	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5676	</p>
				5677	</div>
				5678
				5679	<!-- ======================================================================= -->
				5680	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5681	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				5682	</div>
				5683
				5684	<div class="doc_text">
				5685	<p>
				5686	These intrinsic functions expand the "universal IR" of LLVM to represent
				5687	hardware constructs for atomic operations and memory synchronization. This
				5688	provides an interface to the hardware, not an interface to the programmer. It
				5689	is aimed at a low enough level to allow any programming models or APIs which
				5690	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				5691	hardware behavior. Just as hardware provides a "universal IR" for source
				5692	languages, it also provides a starting point for developing a "universal"
				5693	atomic operation and synchronization IR.
				5694	</p>
				5695	<p>
				5696	These do <em>not</em> form an API such as high-level threading libraries,
				5697	software transaction memory systems, atomic primitives, and intrinsic
				5698	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				5699	application libraries. The hardware interface provided by LLVM should allow
				5700	a clean implementation of all of these APIs and parallel programming models.
				5701	No one model or paradigm should be selected above others unless the hardware
				5702	itself ubiquitously does so.
				5703
				5704	</p>
				5705	</div>
				5706
				5707	<!-- _______________________________________________________________________ -->
				5708	<div class="doc_subsubsection">
				5709	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				5710	</div>
				5711	<div class="doc_text">
				5712	<h5>Syntax:</h5>
				5713	<pre>
				5714	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				5715	i1 <device> )
				5716
				5717	</pre>
				5718	<h5>Overview:</h5>
				5719	<p>
				5720	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				5721	specific pairs of memory access types.
				5722	</p>
				5723	<h5>Arguments:</h5>
				5724	<p>
				5725	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				5726	The first four arguments enables a specific barrier as listed below. The fith
				5727	argument specifies that the barrier applies to io or device or uncached memory.
				5728
				5729	</p>
				5730	<ul>
				5731	<li><tt>ll</tt>: load-load barrier</li>
				5732	<li><tt>ls</tt>: load-store barrier</li>
				5733	<li><tt>sl</tt>: store-load barrier</li>
				5734	<li><tt>ss</tt>: store-store barrier</li>
				5735	<li><tt>device</tt>: barrier applies to device and uncached memory also.
				5736	</ul>
				5737	<h5>Semantics:</h5>
				5738	<p>
				5739	This intrinsic causes the system to enforce some ordering constraints upon
				5740	the loads and stores of the program. This barrier does not indicate
				5741	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				5742	which they occur. For any of the specified pairs of load and store operations
				5743	(f.ex. load-load, or store-load), all of the first operations preceding the
				5744	barrier will complete before any of the second operations succeeding the
				5745	barrier begin. Specifically the semantics for each pairing is as follows:
				5746	</p>
				5747	<ul>
				5748	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				5749	after the barrier begins.</li>
				5750
				5751	<li><tt>ls</tt>: All loads before the barrier must complete before any
				5752	store after the barrier begins.</li>
				5753	<li><tt>ss</tt>: All stores before the barrier must complete before any
				5754	store after the barrier begins.</li>
				5755	<li><tt>sl</tt>: All stores before the barrier must complete before any
				5756	load after the barrier begins.</li>
				5757	</ul>
				5758	<p>
				5759	These semantics are applied with a logical "and" behavior when more than one
				5760	is enabled in a single memory barrier intrinsic.
				5761	</p>
				5762	<p>
				5763	Backends may implement stronger barriers than those requested when they do not
				5764	support as fine grained a barrier as requested. Some architectures do not
				5765	need all types of barriers and on such architectures, these become noops.
				5766	</p>
				5767	<h5>Example:</h5>
				5768	<pre>
				5769	%ptr = malloc i32
				5770	store i32 4, %ptr
				5771
				5772	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				5773	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				5774	<i>; guarantee the above finishes</i>
				5775	store i32 8, %ptr <i>; before this begins</i>
				5776	</pre>
				5777	</div>
				5778
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5779	<!-- _______________________________________________________________________ -->
				5780	<div class="doc_subsubsection">
				5781	<a name="int_atomic_lcs">'<tt>llvm.atomic.lcs.*</tt>' Intrinsic</a>
				5782	</div>
				5783	<div class="doc_text">
				5784	<h5>Syntax:</h5>
				5785	<p>
				5786	This is an overloaded intrinsic. You can use <tt>llvm.atomic.lcs</tt> on any
				5787	integer bit width. Not all targets support all bit widths however.</p>
				5788
				5789	<pre>
				5790	declare i8 @llvm.atomic.lcs.i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				5791	declare i16 @llvm.atomic.lcs.i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				5792	declare i32 @llvm.atomic.lcs.i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				5793	declare i64 @llvm.atomic.lcs.i64( i64* <ptr>, i64 <cmp>, i64 <val> )
				5794
				5795	</pre>
				5796	<h5>Overview:</h5>
				5797	<p>
				5798	This loads a value in memory and compares it to a given value. If they are
				5799	equal, it stores a new value into the memory.
				5800	</p>
				5801	<h5>Arguments:</h5>
				5802	<p>
				5803	The <tt>llvm.atomic.lcs</tt> intrinsic takes three arguments. The result as
				5804	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				5805	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				5806	this integer type. While any bit width integer may be used, targets may only
				5807	lower representations they support in hardware.
				5808
				5809	</p>
				5810	<h5>Semantics:</h5>
				5811	<p>
				5812	This entire intrinsic must be executed atomically. It first loads the value
				5813	in memory pointed to by <tt>ptr</tt> and compares it with the value
				5814	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				5815	loaded value is yielded in all cases. This provides the equivalent of an
				5816	atomic compare-and-swap operation within the SSA framework.
				5817	</p>
				5818	<h5>Examples:</h5>
				5819
				5820	<pre>
				5821	%ptr = malloc i32
				5822	store i32 4, %ptr
				5823
				5824	%val1 = add i32 4, 4
				5825	%result1 = call i32 @llvm.atomic.lcs.i32( i32* %ptr, i32 4, %val1 )
				5826	<i>; yields {i32}:result1 = 4</i>
				5827	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5828	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5829
				5830	%val2 = add i32 1, 1
				5831	%result2 = call i32 @llvm.atomic.lcs.i32( i32* %ptr, i32 5, %val2 )
				5832	<i>; yields {i32}:result2 = 8</i>
				5833	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				5834
				5835	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				5836	</pre>
				5837	</div>
				5838
				5839	<!-- _______________________________________________________________________ -->
				5840	<div class="doc_subsubsection">
				5841	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				5842	</div>
				5843	<div class="doc_text">
				5844	<h5>Syntax:</h5>
				5845
				5846	<p>
				5847	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				5848	integer bit width. Not all targets support all bit widths however.</p>
				5849	<pre>
				5850	declare i8 @llvm.atomic.swap.i8( i8* <ptr>, i8 <val> )
				5851	declare i16 @llvm.atomic.swap.i16( i16* <ptr>, i16 <val> )
				5852	declare i32 @llvm.atomic.swap.i32( i32* <ptr>, i32 <val> )
				5853	declare i64 @llvm.atomic.swap.i64( i64* <ptr>, i64 <val> )
				5854
				5855	</pre>
				5856	<h5>Overview:</h5>
				5857	<p>
				5858	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				5859	the value from memory. It then stores the value in <tt>val</tt> in the memory
				5860	at <tt>ptr</tt>.
				5861	</p>
				5862	<h5>Arguments:</h5>
				5863
				5864	<p>
				5865	The <tt>llvm.atomic.ls</tt> intrinsic takes two arguments. Both the
				5866	<tt>val</tt> argument and the result must be integers of the same bit width.
				5867	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				5868	integer type. The targets may only lower integer representations they
				5869	support.
				5870	</p>
				5871	<h5>Semantics:</h5>
				5872	<p>
				5873	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				5874	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				5875	equivalent of an atomic swap operation within the SSA framework.
				5876
				5877	</p>
				5878	<h5>Examples:</h5>
				5879	<pre>
				5880	%ptr = malloc i32
				5881	store i32 4, %ptr
				5882
				5883	%val1 = add i32 4, 4
				5884	%result1 = call i32 @llvm.atomic.swap.i32( i32* %ptr, i32 %val1 )
				5885	<i>; yields {i32}:result1 = 4</i>
				5886	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5887	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5888
				5889	%val2 = add i32 1, 1
				5890	%result2 = call i32 @llvm.atomic.swap.i32( i32* %ptr, i32 %val2 )
				5891	<i>; yields {i32}:result2 = 8</i>
				5892
				5893	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				5894	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				5895	</pre>
				5896	</div>
				5897
				5898	<!-- _______________________________________________________________________ -->
				5899	<div class="doc_subsubsection">
				5900	<a name="int_atomic_las">'<tt>llvm.atomic.las.*</tt>' Intrinsic</a>
				5901
				5902	</div>
				5903	<div class="doc_text">
				5904	<h5>Syntax:</h5>
				5905	<p>
				5906	This is an overloaded intrinsic. You can use <tt>llvm.atomic.las</tt> on any
				5907	integer bit width. Not all targets support all bit widths however.</p>
				5908	<pre>
				5909	declare i8 @llvm.atomic.las.i8.( i8* <ptr>, i8 <delta> )
				5910	declare i16 @llvm.atomic.las.i16.( i16* <ptr>, i16 <delta> )
				5911	declare i32 @llvm.atomic.las.i32.( i32* <ptr>, i32 <delta> )
				5912	declare i64 @llvm.atomic.las.i64.( i64* <ptr>, i64 <delta> )
				5913
				5914	</pre>
				5915	<h5>Overview:</h5>
				5916	<p>
				5917	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				5918	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				5919	</p>
				5920	<h5>Arguments:</h5>
				5921	<p>
				5922
				5923	The intrinsic takes two arguments, the first a pointer to an integer value
				5924	and the second an integer value. The result is also an integer value. These
				5925	integer types can have any bit width, but they must all have the same bit
				5926	width. The targets may only lower integer representations they support.
				5927	</p>
				5928	<h5>Semantics:</h5>
				5929	<p>
				5930	This intrinsic does a series of operations atomically. It first loads the
				5931	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				5932	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				5933	</p>
				5934
				5935	<h5>Examples:</h5>
				5936	<pre>
				5937	%ptr = malloc i32
				5938	store i32 4, %ptr
				5939	%result1 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 4 )
				5940	<i>; yields {i32}:result1 = 4</i>
				5941	%result2 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 2 )
				5942	<i>; yields {i32}:result2 = 8</i>
				5943	%result3 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 5 )
				5944	<i>; yields {i32}:result3 = 10</i>
				5945	%memval = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
				5946	</pre>
				5947	</div>
				5948
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5949
				5950	<!-- ======================================================================= -->
				5951	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5952	<a name="int_general">General Intrinsics</a>
				5953	</div>
				5954
				5955	<div class="doc_text">
				5956	<p> This class of intrinsics is designed to be generic and has
				5957	no specific purpose. </p>
				5958	</div>
				5959
				5960	<!-- _______________________________________________________________________ -->
				5961	<div class="doc_subsubsection">
				5962	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				5963	</div>
				5964
				5965	<div class="doc_text">
				5966
				5967	<h5>Syntax:</h5>
				5968	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	5969	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]	5970	</pre>
				5971
				5972	<h5>Overview:</h5>
				5973
				5974	<p>
				5975	The '<tt>llvm.var.annotation</tt>' intrinsic
				5976	</p>
				5977
				5978	<h5>Arguments:</h5>
				5979
				5980	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	5981	The first argument is a pointer to a value, the second is a pointer to a
				5982	global string, the third is a pointer to a global string which is the source
				5983	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5984	</p>
				5985
				5986	<h5>Semantics:</h5>
				5987
				5988	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	5989	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5990	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]	5991	annotations. These have no other defined use, they are ignored by code
				5992	generation and optimization.
				5993	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5994	</div>
				5995
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	5996	<!-- _______________________________________________________________________ -->
				5997	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	5998	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	5999	</div>
				6000
				6001	<div class="doc_text">
				6002
				6003	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6004	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6005	any integer bit width.
				6006	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6007	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	6008	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6009	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6010	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6011	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6012	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]	6013	</pre>
				6014
				6015	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6016
				6017	<p>
				6018	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6019	</p>
				6020
				6021	<h5>Arguments:</h5>
				6022
				6023	<p>
				6024	The first argument is an integer value (result of some expression),
				6025	the second is a pointer to a global string, the third is a pointer to a global
				6026	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]	6027	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6028	</p>
				6029
				6030	<h5>Semantics:</h5>
				6031
				6032	<p>
				6033	This intrinsic allows annotations to be put on arbitrary expressions
				6034	with arbitrary strings. This can be useful for special purpose optimizations
				6035	that want to look for these annotations. These have no other defined use, they
				6036	are ignored by code generation and optimization.
				6037	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6038
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6039	<!-- _______________________________________________________________________ -->
				6040	<div class="doc_subsubsection">
				6041	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6042	</div>
				6043
				6044	<div class="doc_text">
				6045
				6046	<h5>Syntax:</h5>
				6047	<pre>
				6048	declare void @llvm.trap()
				6049	</pre>
				6050
				6051	<h5>Overview:</h5>
				6052
				6053	<p>
				6054	The '<tt>llvm.trap</tt>' intrinsic
				6055	</p>
				6056
				6057	<h5>Arguments:</h5>
				6058
				6059	<p>
				6060	None
				6061	</p>
				6062
				6063	<h5>Semantics:</h5>
				6064
				6065	<p>
				6066	This intrinsics is lowered to the target dependent trap instruction. If the
				6067	target does not have a trap instruction, this intrinsic will be lowered to the
				6068	call of the abort() function.
				6069	</p>
				6070	</div>
				6071
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6072	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6073	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6074	<address>
				6075	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
				6076	src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
				6077	<a href="http://validator.w3.org/check/referer"><img
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6078	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]	6079
				6080	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	6081	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6082	Last modified: $Date$
				6083	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6084
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	6085	</body>
				6086	</html>