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

blob: 59d6581ce211e915c7ac6121c01f7e01acca662b [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
Chris Lattner	fa73021	2004-12-09 16:11:40 +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
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	488	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	489
				490	<dd>"<tt>weak</tt>" linkage is exactly the same as <tt>linkonce</tt> linkage,
				491	except that unreferenced <tt>weak</tt> globals may not be discarded. This is
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	492	used for globals that may be emitted in multiple translation units, but that
				493	are not guaranteed to be emitted into every translation unit that uses them.
				494	One example of this are common globals in C, such as "<tt>int X;</tt>" at
				495	global scope.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	496	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	497
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	498	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	499
				500	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				501	pointer to array type. When two global variables with appending linkage are
				502	linked together, the two global arrays are appended together. This is the
				503	LLVM, typesafe, equivalent of having the system linker append together
				504	"sections" with identical names when .o files are linked.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	505	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	506
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	507	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
				508	<dd>The semantics of this linkage follow the ELF model: the symbol is weak
				509	until linked, if not linked, the symbol becomes null instead of being an
				510	undefined reference.
				511	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	512
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	513	<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]	514
				515	<dd>If none of the above identifiers are used, the global is externally
				516	visible, meaning that it participates in linkage and can be used to resolve
				517	external symbol references.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	518	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	519	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	520
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	521	<p>
				522	The next two types of linkage are targeted for Microsoft Windows platform
				523	only. They are designed to support importing (exporting) symbols from (to)
				524	DLLs.
				525	</p>
				526
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	527	<dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	528	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				529
				530	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				531	or variable via a global pointer to a pointer that is set up by the DLL
				532	exporting the symbol. On Microsoft Windows targets, the pointer name is
				533	formed by combining <code>_imp__</code> and the function or variable name.
				534	</dd>
				535
				536	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				537
				538	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				539	pointer to a pointer in a DLL, so that it can be referenced with the
				540	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
				541	name is formed by combining <code>_imp__</code> and the function or variable
				542	name.
				543	</dd>
				544
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	545	</dl>
				546
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	547	<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]	548	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				549	variable and was linked with this one, one of the two would be renamed,
				550	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				551	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	ac8d276	2007-01-05 00:59:10 +0000	[diff] [blame]	552	outside of the current module.</p>
				553	<p>It is illegal for a function <i>declaration</i>
				554	to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	555	or <tt>extern_weak</tt>.</p>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	556	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
				557	linkages.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	558	</div>
				559
				560	<!-- ======================================================================= -->
				561	<div class="doc_subsection">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	562	<a name="callingconv">Calling Conventions</a>
				563	</div>
				564
				565	<div class="doc_text">
				566
				567	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				568	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				569	specified for the call. The calling convention of any pair of dynamic
				570	caller/callee must match, or the behavior of the program is undefined. The
				571	following calling conventions are supported by LLVM, and more may be added in
				572	the future:</p>
				573
				574	<dl>
				575	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				576
				577	<dd>This calling convention (the default if no other calling convention is
				578	specified) matches the target C calling conventions. This calling convention
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	579	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	580	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	581	</dd>
				582
				583	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				584
				585	<dd>This calling convention attempts to make calls as fast as possible
				586	(e.g. by passing things in registers). This calling convention allows the
				587	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]	588	without having to conform to an externally specified ABI. Implementations of
Arnold Schwaighofer	9097d14	2008-05-14 09:17:12 +0000	[diff] [blame]	589	this convention should allow arbitrary
				590	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				591	supported. This calling convention does not support varargs and requires the
				592	prototype of all callees to exactly match the prototype of the function
				593	definition.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	594	</dd>
				595
				596	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				597
				598	<dd>This calling convention attempts to make code in the caller as efficient
				599	as possible under the assumption that the call is not commonly executed. As
				600	such, these calls often preserve all registers so that the call does not break
				601	any live ranges in the caller side. This calling convention does not support
				602	varargs and requires the prototype of all callees to exactly match the
				603	prototype of the function definition.
				604	</dd>
				605
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	606	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	607
				608	<dd>Any calling convention may be specified by number, allowing
				609	target-specific calling conventions to be used. Target specific calling
				610	conventions start at 64.
				611	</dd>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	612	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	613
				614	<p>More calling conventions can be added/defined on an as-needed basis, to
				615	support pascal conventions or any other well-known target-independent
				616	convention.</p>
				617
				618	</div>
				619
				620	<!-- ======================================================================= -->
				621	<div class="doc_subsection">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	622	<a name="visibility">Visibility Styles</a>
				623	</div>
				624
				625	<div class="doc_text">
				626
				627	<p>
				628	All Global Variables and Functions have one of the following visibility styles:
				629	</p>
				630
				631	<dl>
				632	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				633
				634	<dd>On ELF, default visibility means that the declaration is visible to other
				635	modules and, in shared libraries, means that the declared entity may be
				636	overridden. On Darwin, default visibility means that the declaration is
				637	visible to other modules. Default visibility corresponds to "external
				638	linkage" in the language.
				639	</dd>
				640
				641	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				642
				643	<dd>Two declarations of an object with hidden visibility refer to the same
				644	object if they are in the same shared object. Usually, hidden visibility
				645	indicates that the symbol will not be placed into the dynamic symbol table,
				646	so no other module (executable or shared library) can reference it
				647	directly.
				648	</dd>
				649
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	650	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				651
				652	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				653	the dynamic symbol table, but that references within the defining module will
				654	bind to the local symbol. That is, the symbol cannot be overridden by another
				655	module.
				656	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	657	</dl>
				658
				659	</div>
				660
				661	<!-- ======================================================================= -->
				662	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	663	<a name="globalvars">Global Variables</a>
				664	</div>
				665
				666	<div class="doc_text">
				667
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	668	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	669	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	670	an explicit section to be placed in, and may have an optional explicit alignment
				671	specified. A variable may be defined as "thread_local", which means that it
				672	will not be shared by threads (each thread will have a separated copy of the
				673	variable). A variable may be defined as a global "constant," which indicates
				674	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]	675	optimization, allowing the global data to be placed in the read-only section of
				676	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	677	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]	678
				679	<p>
				680	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				681	constant, even if the final definition of the global is not. This capability
				682	can be used to enable slightly better optimization of the program, but requires
				683	the language definition to guarantee that optimizations based on the
				684	'constantness' are valid for the translation units that do not include the
				685	definition.
				686	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	687
				688	<p>As SSA values, global variables define pointer values that are in
				689	scope (i.e. they dominate) all basic blocks in the program. Global
				690	variables always define a pointer to their "content" type because they
				691	describe a region of memory, and all memory objects in LLVM are
				692	accessed through pointers.</p>
				693
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	694	<p>A global variable may be declared to reside in a target-specifc numbered
				695	address space. For targets that support them, address spaces may affect how
				696	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	697	the variable. The default address space is zero. The address space qualifier
				698	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	699
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	700	<p>LLVM allows an explicit section to be specified for globals. If the target
				701	supports it, it will emit globals to the section specified.</p>
				702
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	703	<p>An explicit alignment may be specified for a global. If not present, or if
				704	the alignment is set to zero, the alignment of the global is set by the target
				705	to whatever it feels convenient. If an explicit alignment is specified, the
				706	global is forced to have at least that much alignment. All alignments must be
				707	a power of 2.</p>
				708
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	709	<p>For example, the following defines a global in a numbered address space with
				710	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	711
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	712	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	713	<pre>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	714	@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	715	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	716	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	717
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	718	</div>
				719
				720
				721	<!-- ======================================================================= -->
				722	<div class="doc_subsection">
				723	<a name="functionstructure">Functions</a>
				724	</div>
				725
				726	<div class="doc_text">
				727
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	728	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				729	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	730	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	731	<a href="#callingconv">calling convention</a>, a return type, an optional
				732	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				733	name, a (possibly empty) argument list (each with optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	734	<a href="#paramattrs">parameter attributes</a>), an optional section, an
Gordon Henriksen	e754abe	2007-12-10 03:30:21 +0000	[diff] [blame]	735	optional alignment, an optional <a href="#gc">garbage collector name</a>, an
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	736	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]	737
				738	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				739	optional <a href="#linkage">linkage type</a>, an optional
				740	<a href="#visibility">visibility style</a>, an optional
				741	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	742	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	743	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]	744	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	745
				746	<p>A function definition contains a list of basic blocks, forming the CFG for
				747	the function. Each basic block may optionally start with a label (giving the
				748	basic block a symbol table entry), contains a list of instructions, and ends
				749	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				750	function return).</p>
				751
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	752	<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]	753	executed on entrance to the function, and it is not allowed to have predecessor
				754	basic blocks (i.e. there can not be any branches to the entry block of a
				755	function). Because the block can have no predecessors, it also cannot have any
				756	<a href="#i_phi">PHI nodes</a>.</p>
				757
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	758	<p>LLVM allows an explicit section to be specified for functions. If the target
				759	supports it, it will emit functions to the section specified.</p>
				760
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	761	<p>An explicit alignment may be specified for a function. If not present, or if
				762	the alignment is set to zero, the alignment of the function is set by the target
				763	to whatever it feels convenient. If an explicit alignment is specified, the
				764	function is forced to have at least that much alignment. All alignments must be
				765	a power of 2.</p>
				766
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	767	</div>
				768
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	769
				770	<!-- ======================================================================= -->
				771	<div class="doc_subsection">
				772	<a name="aliasstructure">Aliases</a>
				773	</div>
				774	<div class="doc_text">
				775	<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]	776	function, global variable, another alias or bitcast of global value). Aliases
				777	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	778	optional <a href="#visibility">visibility style</a>.</p>
				779
				780	<h5>Syntax:</h5>
				781
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	782	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	783	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	784	@<Name> = [Linkage] [Visibility] alias <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	785	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	786	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	787
				788	</div>
				789
				790
				791
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	792	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	793	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				794	<div class="doc_text">
				795	<p>The return type and each parameter of a function type may have a set of
				796	<i>parameter attributes</i> associated with them. Parameter attributes are
				797	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	798	a function. Parameter attributes are considered to be part of the function,
				799	not of the function type, so functions with different parameter attributes
				800	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	801
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	802	<p>Parameter attributes are simple keywords that follow the type specified. If
				803	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	804	example:</p>
				805
				806	<div class="doc_code">
				807	<pre>
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	808	declare i32 @printf(i8* noalias , ...) nounwind
				809	declare i32 @atoi(i8*) nounwind readonly
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	810	</pre>
				811	</div>
				812
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	813	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				814	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	815
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	816	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	817	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	818	<dt><tt>zeroext</tt></dt>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	819	<dd>This indicates that the parameter should be zero extended just before
				820	a call to this function.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	821
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	822	<dt><tt>signext</tt></dt>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	823	<dd>This indicates that the parameter should be sign extended just before
				824	a call to this function.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	825
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	826	<dt><tt>inreg</tt></dt>
				827	<dd>This indicates that the parameter should be placed in register (if
Anton Korobeynikov	66a8c8c	2007-01-28 15:27:21 +0000	[diff] [blame]	828	possible) during assembling function call. Support for this attribute is
				829	target-specific</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	830
				831	<dt><tt>byval</tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	832	<dd>This indicates that the pointer parameter should really be passed by
				833	value to the function. The attribute implies that a hidden copy of the
				834	pointee is made between the caller and the callee, so the callee is unable
				835	to modify the value in the callee. This attribute is only valid on llvm
				836	pointer arguments. It is generally used to pass structs and arrays by
				837	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]	838
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	839	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	840	<dd>This indicates that the pointer parameter specifies the address of a
				841	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]	842	Loads and stores to the structure are assumed not to trap.
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	843	May only be applied to the first parameter.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	844
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	845	<dt><tt>noalias</tt></dt>
Owen Anderson	117bbd3	2008-02-18 04:09:01 +0000	[diff] [blame]	846	<dd>This indicates that the parameter does not alias any global or any other
				847	parameter. The caller is responsible for ensuring that this is the case,
				848	usually by placing the value in a stack allocation.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	849
Reid Spencer	2dc5201	2007-03-22 02:18:56 +0000	[diff] [blame]	850	<dt><tt>noreturn</tt></dt>
				851	<dd>This function attribute indicates that the function never returns. This
				852	indicates to LLVM that every call to this function should be treated as if
				853	an <tt>unreachable</tt> instruction immediately followed the call.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	854
Reid Spencer	6760612	2007-03-22 02:02:11 +0000	[diff] [blame]	855	<dt><tt>nounwind</tt></dt>
Duncan Sands	b7f0c08	2008-03-17 12:17:41 +0000	[diff] [blame]	856	<dd>This function attribute indicates that no exceptions unwind out of the
				857	function. Usually this is because the function makes no use of exceptions,
				858	but it may also be that the function catches any exceptions thrown when
				859	executing it.</dd>
				860
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	861	<dt><tt>nest</tt></dt>
				862	<dd>This indicates that the parameter can be excised using the
				863	<a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Duncan Sands	ed4a2f1	2007-11-22 20:23:04 +0000	[diff] [blame]	864	<dt><tt>readonly</tt></dt>
Duncan Sands	f04d584	2007-11-14 21:14:02 +0000	[diff] [blame]	865	<dd>This function attribute indicates that the function has no side-effects
Duncan Sands	ed4a2f1	2007-11-22 20:23:04 +0000	[diff] [blame]	866	except for producing a return value or throwing an exception. The value
				867	returned must only depend on the function arguments and/or global variables.
				868	It may use values obtained by dereferencing pointers.</dd>
				869	<dt><tt>readnone</tt></dt>
				870	<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]	871	function, but in addition it is not allowed to dereference any pointer arguments
				872	or global variables.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	873	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	874
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	875	</div>
				876
				877	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	878	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	879	<a name="gc">Garbage Collector Names</a>
				880	</div>
				881
				882	<div class="doc_text">
				883	<p>Each function may specify a garbage collector name, which is simply a
				884	string.</p>
				885
				886	<div class="doc_code"><pre
				887	>define void @f() gc "name" { ...</pre></div>
				888
				889	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				890	collector which will cause the compiler to alter its output in order to support
				891	the named garbage collection algorithm.</p>
				892	</div>
				893
				894	<!-- ======================================================================= -->
				895	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	896	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	897	</div>
				898
				899	<div class="doc_text">
				900	<p>
				901	Modules may contain "module-level inline asm" blocks, which corresponds to the
				902	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				903	LLVM and treated as a single unit, but may be separated in the .ll file if
				904	desired. The syntax is very simple:
				905	</p>
				906
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	907	<div class="doc_code">
				908	<pre>
				909	module asm "inline asm code goes here"
				910	module asm "more can go here"
				911	</pre>
				912	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	913
				914	<p>The strings can contain any character by escaping non-printable characters.
				915	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				916	for the number.
				917	</p>
				918
				919	<p>
				920	The inline asm code is simply printed to the machine code .s file when
				921	assembly code is generated.
				922	</p>
				923	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	924
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	925	<!-- ======================================================================= -->
				926	<div class="doc_subsection">
				927	<a name="datalayout">Data Layout</a>
				928	</div>
				929
				930	<div class="doc_text">
				931	<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]	932	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				933	<pre> target datalayout = "<i>layout specification</i>"</pre>
				934	<p>The <i>layout specification</i> consists of a list of specifications
				935	separated by the minus sign character ('-'). Each specification starts with a
				936	letter and may include other information after the letter to define some
				937	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	938	<dl>
				939	<dt><tt>E</tt></dt>
				940	<dd>Specifies that the target lays out data in big-endian form. That is, the
				941	bits with the most significance have the lowest address location.</dd>
				942	<dt><tt>e</tt></dt>
				943	<dd>Specifies that hte target lays out data in little-endian form. That is,
				944	the bits with the least significance have the lowest address location.</dd>
				945	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				946	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				947	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				948	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				949	too.</dd>
				950	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				951	<dd>This specifies the alignment for an integer type of a given bit
				952	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				953	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				954	<dd>This specifies the alignment for a vector type of a given bit
				955	<i>size</i>.</dd>
				956	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				957	<dd>This specifies the alignment for a floating point type of a given bit
				958	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				959	(double).</dd>
				960	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				961	<dd>This specifies the alignment for an aggregate type of a given bit
				962	<i>size</i>.</dd>
				963	</dl>
				964	<p>When constructing the data layout for a given target, LLVM starts with a
				965	default set of specifications which are then (possibly) overriden by the
				966	specifications in the <tt>datalayout</tt> keyword. The default specifications
				967	are given in this list:</p>
				968	<ul>
				969	<li><tt>E</tt> - big endian</li>
				970	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				971	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				972	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				973	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				974	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
				975	<li><tt>i64:32:64</tt> - i64 has abi alignment of 32-bits but preferred
				976	alignment of 64-bits</li>
				977	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				978	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				979	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				980	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				981	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				982	</ul>
				983	<p>When llvm is determining the alignment for a given type, it uses the
				984	following rules:
				985	<ol>
				986	<li>If the type sought is an exact match for one of the specifications, that
				987	specification is used.</li>
				988	<li>If no match is found, and the type sought is an integer type, then the
				989	smallest integer type that is larger than the bitwidth of the sought type is
				990	used. If none of the specifications are larger than the bitwidth then the the
				991	largest integer type is used. For example, given the default specifications
				992	above, the i7 type will use the alignment of i8 (next largest) while both
				993	i65 and i256 will use the alignment of i64 (largest specified).</li>
				994	<li>If no match is found, and the type sought is a vector type, then the
				995	largest vector type that is smaller than the sought vector type will be used
				996	as a fall back. This happens because <128 x double> can be implemented in
				997	terms of 64 <2 x double>, for example.</li>
				998	</ol>
				999	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1000
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1001	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1002	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1003	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1004
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1005	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1006
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1007	<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]	1008	intermediate representation. Being typed enables a number of
				1009	optimizations to be performed on the IR directly, without having to do
				1010	extra analyses on the side before the transformation. A strong type
				1011	system makes it easier to read the generated code and enables novel
				1012	analyses and transformations that are not feasible to perform on normal
				1013	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1014
				1015	</div>
				1016
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1017	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1018	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1019	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1020	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1021	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1022	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1023
				1024	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1025	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1026	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1027	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1028	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1029	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1030	</tr>
				1031	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1032	<td><a href="#t_floating">floating point</a></td>
				1033	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1034	</tr>
				1035	<tr>
				1036	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1037	<td><a href="#t_integer">integer</a>,
				1038	<a href="#t_floating">floating point</a>,
				1039	<a href="#t_pointer">pointer</a>,
				1040	<a href="#t_vector">vector</a>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1041	<a href="#t_struct">structure</a>,
				1042	<a href="#t_array">array</a>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1043	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1044	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1045	<tr>
				1046	<td><a href="#t_primitive">primitive</a></td>
				1047	<td><a href="#t_label">label</a>,
				1048	<a href="#t_void">void</a>,
				1049	<a href="#t_integer">integer</a>,
				1050	<a href="#t_floating">floating point</a>.</td>
				1051	</tr>
				1052	<tr>
				1053	<td><a href="#t_derived">derived</a></td>
				1054	<td><a href="#t_integer">integer</a>,
				1055	<a href="#t_array">array</a>,
				1056	<a href="#t_function">function</a>,
				1057	<a href="#t_pointer">pointer</a>,
				1058	<a href="#t_struct">structure</a>,
				1059	<a href="#t_pstruct">packed structure</a>,
				1060	<a href="#t_vector">vector</a>,
				1061	<a href="#t_opaque">opaque</a>.
				1062	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1063	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1064	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1065
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1066	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1067	most important. Values of these types are the only ones which can be
				1068	produced by instructions, passed as arguments, or used as operands to
				1069	instructions. This means that all structures and arrays must be
				1070	manipulated either by pointer or by component.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1071	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1072
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1073	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1074	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1075
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1076	<div class="doc_text">
				1077	<p>The primitive types are the fundamental building blocks of the LLVM
				1078	system.</p>
				1079
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1080	</div>
				1081
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1082	<!-- _______________________________________________________________________ -->
				1083	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1084
				1085	<div class="doc_text">
				1086	<table>
				1087	<tbody>
				1088	<tr><th>Type</th><th>Description</th></tr>
				1089	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1090	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1091	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1092	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1093	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1094	</tbody>
				1095	</table>
				1096	</div>
				1097
				1098	<!-- _______________________________________________________________________ -->
				1099	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1100
				1101	<div class="doc_text">
				1102	<h5>Overview:</h5>
				1103	<p>The void type does not represent any value and has no size.</p>
				1104
				1105	<h5>Syntax:</h5>
				1106
				1107	<pre>
				1108	void
				1109	</pre>
				1110	</div>
				1111
				1112	<!-- _______________________________________________________________________ -->
				1113	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1114
				1115	<div class="doc_text">
				1116	<h5>Overview:</h5>
				1117	<p>The label type represents code labels.</p>
				1118
				1119	<h5>Syntax:</h5>
				1120
				1121	<pre>
				1122	label
				1123	</pre>
				1124	</div>
				1125
				1126
				1127	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1128	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1129
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1130	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1131
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1132	<p>The real power in LLVM comes from the derived types in the system.
				1133	This is what allows a programmer to represent arrays, functions,
				1134	pointers, and other useful types. Note that these derived types may be
				1135	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]	1136
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1137	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1138
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1139	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1140	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1141
				1142	<div class="doc_text">
				1143
				1144	<h5>Overview:</h5>
				1145	<p>The integer type is a very simple derived type that simply specifies an
				1146	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1147	2^23-1 (about 8 million) can be specified.</p>
				1148
				1149	<h5>Syntax:</h5>
				1150
				1151	<pre>
				1152	iN
				1153	</pre>
				1154
				1155	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1156	value.</p>
				1157
				1158	<h5>Examples:</h5>
				1159	<table class="layout">
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1160	<tbody>
				1161	<tr>
				1162	<td><tt>i1</tt></td>
				1163	<td>a single-bit integer.</td>
				1164	</tr><tr>
				1165	<td><tt>i32</tt></td>
				1166	<td>a 32-bit integer.</td>
				1167	</tr><tr>
				1168	<td><tt>i1942652</tt></td>
				1169	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1170	</tr>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1171	</tbody>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1172	</table>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1173	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1174
				1175	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1176	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1177
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1178	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1179
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1180	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1181
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1182	<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]	1183	sequentially in memory. The array type requires a size (number of
				1184	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1185
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1186	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1187
				1188	<pre>
				1189	[<# elements> x <elementtype>]
				1190	</pre>
				1191
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1192	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1193	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1194
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1195	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1196	<table class="layout">
				1197	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1198	<td class="left"><tt>[40 x i32]</tt></td>
				1199	<td class="left">Array of 40 32-bit integer values.</td>
				1200	</tr>
				1201	<tr class="layout">
				1202	<td class="left"><tt>[41 x i32]</tt></td>
				1203	<td class="left">Array of 41 32-bit integer values.</td>
				1204	</tr>
				1205	<tr class="layout">
				1206	<td class="left"><tt>[4 x i8]</tt></td>
				1207	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1208	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1209	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1210	<p>Here are some examples of multidimensional arrays:</p>
				1211	<table class="layout">
				1212	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1213	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1214	<td class="left">3x4 array of 32-bit integer values.</td>
				1215	</tr>
				1216	<tr class="layout">
				1217	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1218	<td class="left">12x10 array of single precision floating point values.</td>
				1219	</tr>
				1220	<tr class="layout">
				1221	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1222	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1223	</tr>
				1224	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1225
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1226	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1227	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]	1228	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1229	As a special case, however, zero length arrays are recognized to be variable
				1230	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1231	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1232
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1233	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1234
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1235	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1236	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1237	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1238
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1239	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1240
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1241	<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]	1242	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]	1243	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]	1244	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]	1245	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1246
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1247	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1248
				1249	<pre>
				1250	<returntype list> (<parameter list>)
				1251	</pre>
				1252
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1253	<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]	1254	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1255	which indicates that the function takes a variable number of arguments.
				1256	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1257	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1258	'<tt><returntype list></tt>' is a comma-separated list of
				1259	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1260
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1261	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1262	<table class="layout">
				1263	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1264	<td class="left"><tt>i32 (i32)</tt></td>
				1265	<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]	1266	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1267	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1268	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1269	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1270	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1271	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1272	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1273	<tt>float</tt>.
				1274	</td>
				1275	</tr><tr class="layout">
				1276	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1277	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1278	<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]	1279	which returns an integer. This is the signature for <tt>printf</tt> in
				1280	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1281	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1282	</tr><tr class="layout">
				1283	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel	3a5bff8	2008-03-24 18:10:52 +0000	[diff] [blame]	1284	<td class="left">A function taking an <tt>i32></tt>, returning two
				1285	<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]	1286	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1287	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1288	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1289
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1290	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1291	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1292	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1293	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1294	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1295	<p>The structure type is used to represent a collection of data members
				1296	together in memory. The packing of the field types is defined to match
				1297	the ABI of the underlying processor. The elements of a structure may
				1298	be any type that has a size.</p>
				1299	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1300	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1301	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1302	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1303	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1304	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1305	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1306	<table class="layout">
				1307	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1308	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1309	<td class="left">A triple of three <tt>i32</tt> values</td>
				1310	</tr><tr class="layout">
				1311	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1312	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1313	second element is a <a href="#t_pointer">pointer</a> to a
				1314	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1315	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1316	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1317	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1318	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1319
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1320	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1321	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1322	</div>
				1323	<div class="doc_text">
				1324	<h5>Overview:</h5>
				1325	<p>The packed structure type is used to represent a collection of data members
				1326	together in memory. There is no padding between fields. Further, the alignment
				1327	of a packed structure is 1 byte. The elements of a packed structure may
				1328	be any type that has a size.</p>
				1329	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1330	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1331	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1332	instruction.</p>
				1333	<h5>Syntax:</h5>
				1334	<pre> < { <type list> } > <br></pre>
				1335	<h5>Examples:</h5>
				1336	<table class="layout">
				1337	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1338	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1339	<td class="left">A triple of three <tt>i32</tt> values</td>
				1340	</tr><tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1341	<td class="left"><tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1342	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1343	second element is a <a href="#t_pointer">pointer</a> to a
				1344	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1345	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1346	</tr>
				1347	</table>
				1348	</div>
				1349
				1350	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1351	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1352	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1353	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1354	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1355	reference to another object, which must live in memory. Pointer types may have
				1356	an optional address space attribute defining the target-specific numbered
				1357	address space where the pointed-to object resides. The default address space is
				1358	zero.</p>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1359	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1360	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1361	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1362	<table class="layout">
				1363	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1364	<td class="left"><tt>[4x i32]*</tt></td>
				1365	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1366	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1367	</tr>
				1368	<tr class="layout">
				1369	<td class="left"><tt>i32 (i32 ) </tt></td>
				1370	<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]	1371	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]	1372	<tt>i32</tt>.</td>
				1373	</tr>
				1374	<tr class="layout">
				1375	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1376	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1377	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1378	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1379	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1380	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1381
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1382	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1383	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1384	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1385
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1386	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1387
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1388	<p>A vector type is a simple derived type that represents a vector
				1389	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1390	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1391	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1392	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1393	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1394	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1395
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1396	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1397
				1398	<pre>
				1399	< <# elements> x <elementtype> >
				1400	</pre>
				1401
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1402	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1403	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1404
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1405	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1406
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1407	<table class="layout">
				1408	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1409	<td class="left"><tt><4 x i32></tt></td>
				1410	<td class="left">Vector of 4 32-bit integer values.</td>
				1411	</tr>
				1412	<tr class="layout">
				1413	<td class="left"><tt><8 x float></tt></td>
				1414	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1415	</tr>
				1416	<tr class="layout">
				1417	<td class="left"><tt><2 x i64></tt></td>
				1418	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1419	</tr>
				1420	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1421	</div>
				1422
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1423	<!-- _______________________________________________________________________ -->
				1424	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1425	<div class="doc_text">
				1426
				1427	<h5>Overview:</h5>
				1428
				1429	<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]	1430	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]	1431	In LLVM, opaque types can eventually be resolved to any type (not just a
				1432	structure type).</p>
				1433
				1434	<h5>Syntax:</h5>
				1435
				1436	<pre>
				1437	opaque
				1438	</pre>
				1439
				1440	<h5>Examples:</h5>
				1441
				1442	<table class="layout">
				1443	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1444	<td class="left"><tt>opaque</tt></td>
				1445	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1446	</tr>
				1447	</table>
				1448	</div>
				1449
				1450
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1451	<!-- *********************************************************************** -->
				1452	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1453	<!-- *********************************************************************** -->
				1454
				1455	<div class="doc_text">
				1456
				1457	<p>LLVM has several different basic types of constants. This section describes
				1458	them all and their syntax.</p>
				1459
				1460	</div>
				1461
				1462	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1463	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1464
				1465	<div class="doc_text">
				1466
				1467	<dl>
				1468	<dt><b>Boolean constants</b></dt>
				1469
				1470	<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]	1471	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1472	</dd>
				1473
				1474	<dt><b>Integer constants</b></dt>
				1475
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1476	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1477	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1478	integer types.
				1479	</dd>
				1480
				1481	<dt><b>Floating point constants</b></dt>
				1482
				1483	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1484	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1485	notation (see below). The assembler requires the exact decimal value of
				1486	a floating-point constant. For example, the assembler accepts 1.25 but
				1487	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1488	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]	1489
				1490	<dt><b>Null pointer constants</b></dt>
				1491
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1492	<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]	1493	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1494
				1495	</dl>
				1496
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1497	<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]	1498	of floating point constants. For example, the form '<tt>double
				1499	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1500	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]	1501	(and the only time that they are generated by the disassembler) is when a
				1502	floating point constant must be emitted but it cannot be represented as a
				1503	decimal floating point number. For example, NaN's, infinities, and other
				1504	special values are represented in their IEEE hexadecimal format so that
				1505	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]	1506
				1507	</div>
				1508
				1509	<!-- ======================================================================= -->
				1510	<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
				1511	</div>
				1512
				1513	<div class="doc_text">
Chris Lattner	d4f6b17	2005-03-07 22:13:59 +0000	[diff] [blame]	1514	<p>Aggregate constants arise from aggregation of simple constants
				1515	and smaller aggregate constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1516
				1517	<dl>
				1518	<dt><b>Structure constants</b></dt>
				1519
				1520	<dd>Structure constants are represented with notation similar to structure
				1521	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1522	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1523	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]	1524	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]	1525	types of elements must match those specified by the type.
				1526	</dd>
				1527
				1528	<dt><b>Array constants</b></dt>
				1529
				1530	<dd>Array constants are represented with notation similar to array type
				1531	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1532	(<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]	1533	constants must have <a href="#t_array">array type</a>, and the number and
				1534	types of elements must match those specified by the type.
				1535	</dd>
				1536
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1537	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1538
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1539	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1540	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1541	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1542	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1543	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]	1544	match those specified by the type.
				1545	</dd>
				1546
				1547	<dt><b>Zero initialization</b></dt>
				1548
				1549	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1550	value to zero of <em>any</em> type, including scalar and aggregate types.
				1551	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]	1552	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1553	initializers.
				1554	</dd>
				1555	</dl>
				1556
				1557	</div>
				1558
				1559	<!-- ======================================================================= -->
				1560	<div class="doc_subsection">
				1561	<a name="globalconstants">Global Variable and Function Addresses</a>
				1562	</div>
				1563
				1564	<div class="doc_text">
				1565
				1566	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1567	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1568	constants. These constants are explicitly referenced when the <a
				1569	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]	1570	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1571	file:</p>
				1572
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1573	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1574	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1575	@X = global i32 17
				1576	@Y = global i32 42
				1577	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1578	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1579	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1580
				1581	</div>
				1582
				1583	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1584	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1585	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1586	<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]	1587	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]	1588	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1589
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1590	<p>Undefined values indicate to the compiler that the program is well defined
				1591	no matter what value is used, giving the compiler more freedom to optimize.
				1592	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1593	</div>
				1594
				1595	<!-- ======================================================================= -->
				1596	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1597	</div>
				1598
				1599	<div class="doc_text">
				1600
				1601	<p>Constant expressions are used to allow expressions involving other constants
				1602	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1603	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]	1604	that does not have side effects (e.g. load and call are not supported). The
				1605	following is the syntax for constant expressions:</p>
				1606
				1607	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1608	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1609	<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]	1610	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1611
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1612	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1613	<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]	1614	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]	1615
				1616	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1617	<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]	1618	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]	1619
				1620	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1621	<dd>Truncate a floating point constant to another floating point type. The
				1622	size of CST must be larger than the size of TYPE. Both types must be
				1623	floating point.</dd>
				1624
				1625	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1626	<dd>Floating point extend a constant to another type. The size of CST must be
				1627	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1628
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1629	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1630	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1631	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1632	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1633	of the same number of elements. If the value won't fit in the integer type,
				1634	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1635
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1636	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1637	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1638	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1639	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1640	of the same number of elements. If the value won't fit in the integer type,
				1641	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1642
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1643	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1644	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1645	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1646	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1647	of the same number of elements. If the value won't fit in the floating point
				1648	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1649
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1650	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1651	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1652	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1653	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1654	of the same number of elements. If the value won't fit in the floating point
				1655	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1656
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1657	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1658	<dd>Convert a pointer typed constant to the corresponding integer constant
				1659	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1660	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1661
				1662	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1663	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1664	pointer type. CST must be of integer type. The CST value is zero extended,
				1665	truncated, or unchanged to make it fit in a pointer size. This one is
				1666	<i>really</i> dangerous!</dd>
				1667
				1668	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1669	<dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
				1670	identical (same number of bits). The conversion is done as if the CST value
				1671	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]	1672	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]	1673	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]	1674	pointers it is only valid to cast to another pointer type.
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1675	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1676
				1677	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1678
				1679	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1680	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1681	instruction, the index list may have zero or more indexes, which are required
				1682	to make sense for the type of "CSTPTR".</dd>
				1683
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1684	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1685
				1686	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1687	constants.</dd>
				1688
				1689	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1690	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1691
				1692	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1693	<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]	1694
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	1695	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1696	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1697
				1698	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1699	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1700
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1701	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1702
				1703	<dd>Perform the <a href="#i_extractelement">extractelement
				1704	operation</a> on constants.
				1705
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1706	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				1707
				1708	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1709	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1710
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1711
				1712	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				1713
				1714	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1715	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1716
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1717	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				1718
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1719	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				1720	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]	1721	binary</a> operations. The constraints on operands are the same as those for
				1722	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1723	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1724	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1725	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	1726
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1727	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1728	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				1729	<!-- *********************************************************************** -->
				1730
				1731	<!-- ======================================================================= -->
				1732	<div class="doc_subsection">
				1733	<a name="inlineasm">Inline Assembler Expressions</a>
				1734	</div>
				1735
				1736	<div class="doc_text">
				1737
				1738	<p>
				1739	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				1740	Module-Level Inline Assembly</a>) through the use of a special value. This
				1741	value represents the inline assembler as a string (containing the instructions
				1742	to emit), a list of operand constraints (stored as a string), and a flag that
				1743	indicates whether or not the inline asm expression has side effects. An example
				1744	inline assembler expression is:
				1745	</p>
				1746
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1747	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1748	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1749	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1750	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1751	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1752
				1753	<p>
				1754	Inline assembler expressions may <b>only</b> be used as the callee operand of
				1755	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				1756	</p>
				1757
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1758	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1759	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1760	%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]	1761	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1762	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1763
				1764	<p>
				1765	Inline asms with side effects not visible in the constraint list must be marked
				1766	as having side effects. This is done through the use of the
				1767	'<tt>sideeffect</tt>' keyword, like so:
				1768	</p>
				1769
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1770	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1771	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1772	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1773	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1774	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1775
				1776	<p>TODO: The format of the asm and constraints string still need to be
				1777	documented here. Constraints on what can be done (e.g. duplication, moving, etc
				1778	need to be documented).
				1779	</p>
				1780
				1781	</div>
				1782
				1783	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1784	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				1785	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1786
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1787	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1788
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1789	<p>The LLVM instruction set consists of several different
				1790	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1791	instructions</a>, <a href="#binaryops">binary instructions</a>,
				1792	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1793	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				1794	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1795
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1796	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1797
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1798	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1799	<div class="doc_subsection"> <a name="terminators">Terminator
				1800	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1801
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1802	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1803
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1804	<p>As mentioned <a href="#functionstructure">previously</a>, every
				1805	basic block in a program ends with a "Terminator" instruction, which
				1806	indicates which block should be executed after the current block is
				1807	finished. These terminator instructions typically yield a '<tt>void</tt>'
				1808	value: they produce control flow, not values (the one exception being
				1809	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1810	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1811	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				1812	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	1813	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				1814	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				1815	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1816
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1817	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1818
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1819	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1820	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				1821	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1822	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1823	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1824	<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]	1825	ret void <i>; Return from void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1826	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]	1827	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1828
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1829	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1830
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1831	<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]	1832	value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	1833	<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]	1834	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]	1835	control flow to occur.</p>
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>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1838
				1839	<p>The '<tt>ret</tt>' instruction may return zero, one or multiple values.
				1840	The type of each return value must be a '<a href="#t_firstclass">first
				1841	class</a>' type. Note that a function is not <a href="#wellformed">well
				1842	formed</a> if there exists a '<tt>ret</tt>' instruction inside of the
				1843	function that returns values that do not match the return type of the
				1844	function.</p>
				1845
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1846	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1847
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1848	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				1849	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]	1850	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1851	the instruction after the call. If the caller was an "<a
				1852	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1853	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1854	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]	1855	return value. If the instruction returns multiple values then these
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	1856	values can only be accessed through a '<a href="#i_getresult"><tt>getresult</tt>
				1857	</a>' instruction.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1858
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1859	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1860
				1861	<pre>
				1862	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1863	ret void <i>; Return from a void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1864	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]	1865	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1866	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1867	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1868	<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]	1869	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1870	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1871	<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]	1872	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1873	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1874	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				1875	transfer to a different basic block in the current function. There are
				1876	two forms of this instruction, corresponding to a conditional branch
				1877	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1878	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1879	<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]	1880	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1881	unconditional form of the '<tt>br</tt>' instruction takes a single
				1882	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1883	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1884	<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]	1885	argument is evaluated. If the value is <tt>true</tt>, control flows
				1886	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				1887	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1888	<h5>Example:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1889	<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]	1890	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]	1891	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1892	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1893	<div class="doc_subsubsection">
				1894	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				1895	</div>
				1896
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1897	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1898	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1899
				1900	<pre>
				1901	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				1902	</pre>
				1903
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1904	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1905
				1906	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				1907	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1908	instruction, allowing a branch to occur to one of many possible
				1909	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1910
				1911
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1912	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1913
				1914	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				1915	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				1916	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				1917	table is not allowed to contain duplicate constant entries.</p>
				1918
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1919	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1920
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1921	<p>The <tt>switch</tt> instruction specifies a table of values and
				1922	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	1923	table is searched for the given value. If the value is found, control flow is
				1924	transfered to the corresponding destination; otherwise, control flow is
				1925	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1926
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1927	<h5>Implementation:</h5>
				1928
				1929	<p>Depending on properties of the target machine and the particular
				1930	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	1931	ways. For example, it could be generated as a series of chained conditional
				1932	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1933
				1934	<h5>Example:</h5>
				1935
				1936	<pre>
				1937	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1938	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1939	switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1940
				1941	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1942	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1943
				1944	<i>; Implement a jump table:</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1945	switch i32 %val, label %otherwise [ i32 0, label %onzero
				1946	i32 1, label %onone
				1947	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1948	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1949	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1950
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1951	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1952	<div class="doc_subsubsection">
				1953	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				1954	</div>
				1955
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1956	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1957
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1958	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1959
				1960	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	1961	<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]	1962	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1963	</pre>
				1964
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	1965	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1966
				1967	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				1968	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1969	'<tt>normal</tt>' label or the
				1970	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1971	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				1972	"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]	1973	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1974	continued at the dynamically nearest "exception" label. If the callee function
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	1975	returns multiple values then individual return values are only accessible through
				1976	a '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1977
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1978	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1979
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1980	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1981
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1982	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1983	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	1984	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	1985	convention</a> the call should use. If none is specified, the call defaults
				1986	to using C calling conventions.
				1987	</li>
				1988	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				1989	function value being invoked. In most cases, this is a direct function
				1990	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				1991	an arbitrary pointer to function value.
				1992	</li>
				1993
				1994	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				1995	function to be invoked. </li>
				1996
				1997	<li>'<tt>function args</tt>': argument list whose types match the function
				1998	signature argument types. If the function signature indicates the function
				1999	accepts a variable number of arguments, the extra arguments can be
				2000	specified. </li>
				2001
				2002	<li>'<tt>normal label</tt>': the label reached when the called function
				2003	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2004
				2005	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2006	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2007
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2008	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2009
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2010	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2011
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2012	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2013	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2014	difference is that it establishes an association with a label, which is used by
				2015	the runtime library to unwind the stack.</p>
				2016
				2017	<p>This instruction is used in languages with destructors to ensure that proper
				2018	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2019	exception. Additionally, this is important for implementation of
				2020	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2021
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2022	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2023	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2024	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2025	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2026	%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]	2027	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2028	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2029	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2030
				2031
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2032	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2033
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2034	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2035	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2036
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2037	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2038
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2039	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2040	<pre>
				2041	unwind
				2042	</pre>
				2043
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2044	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2045
				2046	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2047	at the first callee in the dynamic call stack which used an <a
				2048	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2049	primarily used to implement exception handling.</p>
				2050
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2051	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2052
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2053	<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]	2054	immediately halt. The dynamic call stack is then searched for the first <a
				2055	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2056	execution continues at the "exceptional" destination block specified by the
				2057	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2058	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2059	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2060
				2061	<!-- _______________________________________________________________________ -->
				2062
				2063	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2064	Instruction</a> </div>
				2065
				2066	<div class="doc_text">
				2067
				2068	<h5>Syntax:</h5>
				2069	<pre>
				2070	unreachable
				2071	</pre>
				2072
				2073	<h5>Overview:</h5>
				2074
				2075	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2076	instruction is used to inform the optimizer that a particular portion of the
				2077	code is not reachable. This can be used to indicate that the code after a
				2078	no-return function cannot be reached, and other facts.</p>
				2079
				2080	<h5>Semantics:</h5>
				2081
				2082	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2083	</div>
				2084
				2085
				2086
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2087	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2088	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2089	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2090	<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]	2091	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]	2092	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2093	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]	2094	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2095	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2096	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2097	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2098	<div class="doc_subsubsection">
				2099	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2100	</div>
				2101
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2102	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2103
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2104	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2105
				2106	<pre>
				2107	<result> = add <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2108	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2109
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2110	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2111
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2112	<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^]	2113
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2114	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2115
				2116	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2117	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2118	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2119	types.</p>
				2120
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2121	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2122
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2123	<p>The value produced is the integer or floating point sum of the two
				2124	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2125
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2126	<p>If an integer sum has unsigned overflow, the result returned is the
				2127	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2128	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2129
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2130	<p>Because LLVM integers use a two's complement representation, this
				2131	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2132
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2133	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2134
				2135	<pre>
				2136	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2137	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2138	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2139	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2140	<div class="doc_subsubsection">
				2141	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2142	</div>
				2143
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2144	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2145
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2146	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2147
				2148	<pre>
				2149	<result> = sub <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2150	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2151
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2152	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2153
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2154	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2155	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2156
				2157	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2158	'<tt>neg</tt>' instruction present in most other intermediate
				2159	representations.</p>
				2160
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2161	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2162
				2163	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2164	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2165	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2166	types.</p>
				2167
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2168	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2169
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2170	<p>The value produced is the integer or floating point difference of
				2171	the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2172
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2173	<p>If an integer difference has unsigned overflow, the result returned is the
				2174	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2175	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2176
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2177	<p>Because LLVM integers use a two's complement representation, this
				2178	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2179
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2180	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2181	<pre>
				2182	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2183	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2184	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2185	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2186
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2187	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2188	<div class="doc_subsubsection">
				2189	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2190	</div>
				2191
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2192	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2193
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2194	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2195	<pre> <result> = mul <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2196	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2197	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2198	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2199	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2200
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2201	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2202
				2203	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2204	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2205	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2206	types.</p>
				2207
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2208	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2209
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2210	<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]	2211	two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2212
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2213	<p>If the result of an integer multiplication has unsigned overflow,
				2214	the result returned is the mathematical result modulo
				2215	2<sup>n</sup>, where n is the bit width of the result.</p>
				2216	<p>Because LLVM integers use a two's complement representation, and the
				2217	result is the same width as the operands, this instruction returns the
				2218	correct result for both signed and unsigned integers. If a full product
				2219	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2220	should be sign-extended or zero-extended as appropriate to the
				2221	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2222	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2223	<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]	2224	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2225	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2226
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2227	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2228	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2229	</a></div>
				2230	<div class="doc_text">
				2231	<h5>Syntax:</h5>
				2232	<pre> <result> = udiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2233	</pre>
				2234	<h5>Overview:</h5>
				2235	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2236	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2237
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2238	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2239
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2240	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2241	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2242	values. Both arguments must have identical types.</p>
				2243
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2244	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2245
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2246	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2247	<p>Note that unsigned integer division and signed integer division are distinct
				2248	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2249	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2250	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2251	<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]	2252	</pre>
				2253	</div>
				2254	<!-- _______________________________________________________________________ -->
				2255	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2256	</a> </div>
				2257	<div class="doc_text">
				2258	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2259	<pre>
				2260	<result> = sdiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2261	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2262
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2263	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2264
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2265	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2266	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2267
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2268	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2269
				2270	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2271	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2272	values. Both arguments must have identical types.</p>
				2273
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2274	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2275	<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]	2276	<p>Note that signed integer division and unsigned integer division are distinct
				2277	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2278	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2279	undefined behavior; this is a rare case, but can occur, for example,
				2280	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2281	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2282	<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]	2283	</pre>
				2284	</div>
				2285	<!-- _______________________________________________________________________ -->
				2286	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2287	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2288	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2289	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2290	<pre>
				2291	<result> = fdiv <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2292	</pre>
				2293	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2294
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2295	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2296	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2297
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2298	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2299
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2300	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2301	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2302	of floating point values. Both arguments must have identical types.</p>
				2303
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2304	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2305
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2306	<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^]	2307
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2308	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2309
				2310	<pre>
				2311	<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]	2312	</pre>
				2313	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2314
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2315	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2316	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2317	</div>
				2318	<div class="doc_text">
				2319	<h5>Syntax:</h5>
				2320	<pre> <result> = urem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2321	</pre>
				2322	<h5>Overview:</h5>
				2323	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2324	unsigned division of its two arguments.</p>
				2325	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2326	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2327	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2328	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2329	<h5>Semantics:</h5>
				2330	<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]	2331	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2332	<p>Note that unsigned integer remainder and signed integer remainder are
				2333	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2334	<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]	2335	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2336	<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]	2337	</pre>
				2338
				2339	</div>
				2340	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2341	<div class="doc_subsubsection">
				2342	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2343	</div>
				2344
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2345	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2346
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2347	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2348
				2349	<pre>
				2350	<result> = srem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2351	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2352
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2353	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2354
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2355	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2356	signed division of its two operands. This instruction can also take
				2357	<a href="#t_vector">vector</a> versions of the values in which case
				2358	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2359
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2360	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2361
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2362	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2363	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2364	values. Both arguments must have identical types.</p>
				2365
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2366	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2367
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2368	<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]	2369	has the same sign as the dividend, <tt>var1</tt>), not the <i>modulo</i>
				2370	operator (where the result has the same sign as the divisor, <tt>var2</tt>) of
				2371	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2372	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]	2373	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]	2374	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2375	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2376	<p>Note that signed integer remainder and unsigned integer remainder are
				2377	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2378	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2379	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2380	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2381	(The remainder doesn't actually overflow, but this rule lets srem be
				2382	implemented using instructions that return both the result of the division
				2383	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2384	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2385	<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]	2386	</pre>
				2387
				2388	</div>
				2389	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2390	<div class="doc_subsubsection">
				2391	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2392
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2393	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2394
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2395	<h5>Syntax:</h5>
				2396	<pre> <result> = frem <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2397	</pre>
				2398	<h5>Overview:</h5>
				2399	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2400	division of its two operands.</p>
				2401	<h5>Arguments:</h5>
				2402	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2403	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2404	of floating point values. Both arguments must have identical types.</p>
				2405
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2406	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2407
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2408	<p>This instruction returns the <i>remainder</i> of a division.
				2409	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2410
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2411	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2412
				2413	<pre>
				2414	<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]	2415	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2416	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2417
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2418	<!-- ======================================================================= -->
				2419	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2420	Operations</a> </div>
				2421	<div class="doc_text">
				2422	<p>Bitwise binary operators are used to do various forms of
				2423	bit-twiddling in a program. They are generally very efficient
				2424	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2425	instructions. They require two operands of the same type, execute an operation on them,
				2426	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]	2427	</div>
				2428
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2429	<!-- _______________________________________________________________________ -->
				2430	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2431	Instruction</a> </div>
				2432	<div class="doc_text">
				2433	<h5>Syntax:</h5>
				2434	<pre> <result> = shl <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2435	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2436
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2437	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2438
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2439	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2440	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2441
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2442	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2443
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2444	<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]	2445	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^]	2446	unsigned value. This instruction does not support
				2447	<a href="#t_vector">vector</a> operands.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2448
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2449	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2450
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2451	<p>The value produced is <tt>var1</tt> * 2<sup><tt>var2</tt></sup> mod 2<sup>n</sup>,
				2452	where n is the width of the result. If <tt>var2</tt> is (statically or dynamically) negative or
				2453	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]	2454
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2455	<h5>Example:</h5><pre>
				2456	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2457	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2458	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2459	<result> = shl i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2460	</pre>
				2461	</div>
				2462	<!-- _______________________________________________________________________ -->
				2463	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2464	Instruction</a> </div>
				2465	<div class="doc_text">
				2466	<h5>Syntax:</h5>
				2467	<pre> <result> = lshr <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2468	</pre>
				2469
				2470	<h5>Overview:</h5>
				2471	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2472	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]	2473
				2474	<h5>Arguments:</h5>
				2475	<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]	2476	<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^]	2477	unsigned value. This instruction does not support
				2478	<a href="#t_vector">vector</a> operands.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2479
				2480	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2481
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2482	<p>This instruction always performs a logical shift right operation. The most
				2483	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]	2484	shift. If <tt>var2</tt> is (statically or dynamically) equal to or larger than
				2485	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]	2486
				2487	<h5>Example:</h5>
				2488	<pre>
				2489	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2490	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2491	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2492	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2493	<result> = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2494	</pre>
				2495	</div>
				2496
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2497	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2498	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2499	Instruction</a> </div>
				2500	<div class="doc_text">
				2501
				2502	<h5>Syntax:</h5>
				2503	<pre> <result> = ashr <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				2504	</pre>
				2505
				2506	<h5>Overview:</h5>
				2507	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2508	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]	2509
				2510	<h5>Arguments:</h5>
				2511	<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]	2512	<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^]	2513	unsigned value. This instruction does not support
				2514	<a href="#t_vector">vector</a> operands.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2515
				2516	<h5>Semantics:</h5>
				2517	<p>This instruction always performs an arithmetic shift right operation,
				2518	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]	2519	of <tt>var1</tt>. If <tt>var2</tt> is (statically or dynamically) equal to or
				2520	larger than the number of bits in <tt>var1</tt>, the result is undefined.
				2521	</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2522
				2523	<h5>Example:</h5>
				2524	<pre>
				2525	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2526	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2527	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2528	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2529	<result> = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2530	</pre>
				2531	</div>
				2532
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2533	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2534	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2535	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2536
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2537	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2538
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2539	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2540
				2541	<pre>
				2542	<result> = and <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2543	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2544
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2545	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2546
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2547	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2548	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2549
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2550	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2551
				2552	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2553	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2554	values. Both arguments must have identical types.</p>
				2555
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2556	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2557	<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]	2558	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2559	<div style="align: center">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2560	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2561	<tbody>
				2562	<tr>
				2563	<td>In0</td>
				2564	<td>In1</td>
				2565	<td>Out</td>
				2566	</tr>
				2567	<tr>
				2568	<td>0</td>
				2569	<td>0</td>
				2570	<td>0</td>
				2571	</tr>
				2572	<tr>
				2573	<td>0</td>
				2574	<td>1</td>
				2575	<td>0</td>
				2576	</tr>
				2577	<tr>
				2578	<td>1</td>
				2579	<td>0</td>
				2580	<td>0</td>
				2581	</tr>
				2582	<tr>
				2583	<td>1</td>
				2584	<td>1</td>
				2585	<td>1</td>
				2586	</tr>
				2587	</tbody>
				2588	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2589	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2590	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2591	<pre>
				2592	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2593	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2594	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2595	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2596	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2597	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2598	<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2599	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2600	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2601	<pre> <result> = or <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2602	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2603	<h5>Overview:</h5>
				2604	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2605	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2606	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2607
				2608	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2609	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2610	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2611	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2612	<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]	2613	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2614	<div style="align: center">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2615	<table border="1" cellspacing="0" cellpadding="4">
				2616	<tbody>
				2617	<tr>
				2618	<td>In0</td>
				2619	<td>In1</td>
				2620	<td>Out</td>
				2621	</tr>
				2622	<tr>
				2623	<td>0</td>
				2624	<td>0</td>
				2625	<td>0</td>
				2626	</tr>
				2627	<tr>
				2628	<td>0</td>
				2629	<td>1</td>
				2630	<td>1</td>
				2631	</tr>
				2632	<tr>
				2633	<td>1</td>
				2634	<td>0</td>
				2635	<td>1</td>
				2636	</tr>
				2637	<tr>
				2638	<td>1</td>
				2639	<td>1</td>
				2640	<td>1</td>
				2641	</tr>
				2642	</tbody>
				2643	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2644	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2645	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2646	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2647	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2648	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2649	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2650	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2651	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2652	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2653	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2654	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2655	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2656	<pre> <result> = xor <ty> <var1>, <var2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2657	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2658	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2659	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2660	or of its two operands. The <tt>xor</tt> is used to implement the
				2661	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2662	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2663	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				2664	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2665	values. Both arguments must have identical types.</p>
				2666
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2667	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	2668
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2669	<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]	2670	<p> </p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2671	<div style="align: center">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2672	<table border="1" cellspacing="0" cellpadding="4">
				2673	<tbody>
				2674	<tr>
				2675	<td>In0</td>
				2676	<td>In1</td>
				2677	<td>Out</td>
				2678	</tr>
				2679	<tr>
				2680	<td>0</td>
				2681	<td>0</td>
				2682	<td>0</td>
				2683	</tr>
				2684	<tr>
				2685	<td>0</td>
				2686	<td>1</td>
				2687	<td>1</td>
				2688	</tr>
				2689	<tr>
				2690	<td>1</td>
				2691	<td>0</td>
				2692	<td>1</td>
				2693	</tr>
				2694	<tr>
				2695	<td>1</td>
				2696	<td>1</td>
				2697	<td>0</td>
				2698	</tr>
				2699	</tbody>
				2700	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2701	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2702	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2703	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2704	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				2705	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				2706	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				2707	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2708	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2709	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2710
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2711	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2712	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2713	<a name="vectorops">Vector Operations</a>
				2714	</div>
				2715
				2716	<div class="doc_text">
				2717
				2718	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2719	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2720	vector-specific operations needed to process vectors effectively. While LLVM
				2721	does directly support these vector operations, many sophisticated algorithms
				2722	will want to use target-specific intrinsics to take full advantage of a specific
				2723	target.</p>
				2724
				2725	</div>
				2726
				2727	<!-- _______________________________________________________________________ -->
				2728	<div class="doc_subsubsection">
				2729	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				2730	</div>
				2731
				2732	<div class="doc_text">
				2733
				2734	<h5>Syntax:</h5>
				2735
				2736	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2737	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2738	</pre>
				2739
				2740	<h5>Overview:</h5>
				2741
				2742	<p>
				2743	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2744	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2745	</p>
				2746
				2747
				2748	<h5>Arguments:</h5>
				2749
				2750	<p>
				2751	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2752	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]	2753	an index indicating the position from which to extract the element.
				2754	The index may be a variable.</p>
				2755
				2756	<h5>Semantics:</h5>
				2757
				2758	<p>
				2759	The result is a scalar of the same type as the element type of
				2760	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				2761	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				2762	results are undefined.
				2763	</p>
				2764
				2765	<h5>Example:</h5>
				2766
				2767	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2768	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2769	</pre>
				2770	</div>
				2771
				2772
				2773	<!-- _______________________________________________________________________ -->
				2774	<div class="doc_subsubsection">
				2775	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				2776	</div>
				2777
				2778	<div class="doc_text">
				2779
				2780	<h5>Syntax:</h5>
				2781
				2782	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	2783	<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]	2784	</pre>
				2785
				2786	<h5>Overview:</h5>
				2787
				2788	<p>
				2789	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2790	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2791	</p>
				2792
				2793
				2794	<h5>Arguments:</h5>
				2795
				2796	<p>
				2797	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2798	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]	2799	scalar value whose type must equal the element type of the first
				2800	operand. The third operand is an index indicating the position at
				2801	which to insert the value. The index may be a variable.</p>
				2802
				2803	<h5>Semantics:</h5>
				2804
				2805	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2806	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]	2807	element values are those of <tt>val</tt> except at position
				2808	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				2809	exceeds the length of <tt>val</tt>, the results are undefined.
				2810	</p>
				2811
				2812	<h5>Example:</h5>
				2813
				2814	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2815	%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]	2816	</pre>
				2817	</div>
				2818
				2819	<!-- _______________________________________________________________________ -->
				2820	<div class="doc_subsubsection">
				2821	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				2822	</div>
				2823
				2824	<div class="doc_text">
				2825
				2826	<h5>Syntax:</h5>
				2827
				2828	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2829	<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]	2830	</pre>
				2831
				2832	<h5>Overview:</h5>
				2833
				2834	<p>
				2835	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
				2836	from two input vectors, returning a vector of the same type.
				2837	</p>
				2838
				2839	<h5>Arguments:</h5>
				2840
				2841	<p>
				2842	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				2843	with types that match each other and types that match the result of the
				2844	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]	2845	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]	2846	</p>
				2847
				2848	<p>
				2849	The shuffle mask operand is required to be a constant vector with either
				2850	constant integer or undef values.
				2851	</p>
				2852
				2853	<h5>Semantics:</h5>
				2854
				2855	<p>
				2856	The elements of the two input vectors are numbered from left to right across
				2857	both of the vectors. The shuffle mask operand specifies, for each element of
				2858	the result vector, which element of the two input registers the result element
				2859	gets. The element selector may be undef (meaning "don't care") and the second
				2860	operand may be undef if performing a shuffle from only one vector.
				2861	</p>
				2862
				2863	<h5>Example:</h5>
				2864
				2865	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2866	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2867	<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]	2868	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				2869	<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]	2870	</pre>
				2871	</div>
				2872
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	2873
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2874	<!-- ======================================================================= -->
				2875	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2876	<a name="aggregateops">Aggregate Operations</a>
				2877	</div>
				2878
				2879	<div class="doc_text">
				2880
				2881	<p>LLVM supports several instructions for working with aggregate values.
				2882	</p>
				2883
				2884	</div>
				2885
				2886	<!-- _______________________________________________________________________ -->
				2887	<div class="doc_subsubsection">
				2888	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				2889	</div>
				2890
				2891	<div class="doc_text">
				2892
				2893	<h5>Syntax:</h5>
				2894
				2895	<pre>
				2896	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				2897	</pre>
				2898
				2899	<h5>Overview:</h5>
				2900
				2901	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2902	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				2903	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2904	</p>
				2905
				2906
				2907	<h5>Arguments:</h5>
				2908
				2909	<p>
				2910	The first operand of an '<tt>extractvalue</tt>' instruction is a
				2911	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]	2912	type. The operands are constant indices to specify which value to extract
				2913	in the same manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2914	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2915	</p>
				2916
				2917	<h5>Semantics:</h5>
				2918
				2919	<p>
				2920	The result is the value at the position in the aggregate specified by
				2921	the index operands.
				2922	</p>
				2923
				2924	<h5>Example:</h5>
				2925
				2926	<pre>
				2927	%result = extractvalue {i32, float} %agg, i32 0 <i>; yields i32</i>
				2928	</pre>
				2929	</div>
				2930
				2931
				2932	<!-- _______________________________________________________________________ -->
				2933	<div class="doc_subsubsection">
				2934	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				2935	</div>
				2936
				2937	<div class="doc_text">
				2938
				2939	<h5>Syntax:</h5>
				2940
				2941	<pre>
				2942	<result> = insertvalue <aggregate type> <val>, <ty> <val>, i32 <idx> <i>; yields <n x <ty>></i>
				2943	</pre>
				2944
				2945	<h5>Overview:</h5>
				2946
				2947	<p>
				2948	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2949	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2950	</p>
				2951
				2952
				2953	<h5>Arguments:</h5>
				2954
				2955	<p>
				2956	The first operand of an '<tt>insertvalue</tt>' instruction is a
				2957	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				2958	The second operand is a first-class value to insert.
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2959	type of the first operand. The following operands are constant indices
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2960	indicating the position at which to insert the value in the same manner as
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2961	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2962	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2963	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]	2964	by the indices.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2965
				2966	<h5>Semantics:</h5>
				2967
				2968	<p>
				2969	The result is an aggregate of the same type as <tt>val</tt>. Its
				2970	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]	2971	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2972	</p>
				2973
				2974	<h5>Example:</h5>
				2975
				2976	<pre>
				2977	%result = insertvalue {i32, float} %agg, i32 1, i32 0 <i>; yields {i32, float}</i>
				2978	</pre>
				2979	</div>
				2980
				2981
				2982	<!-- ======================================================================= -->
				2983	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	2984	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2985	</div>
				2986
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2987	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2988
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2989	<p>A key design point of an SSA-based representation is how it
				2990	represents memory. In LLVM, no memory locations are in SSA form, which
				2991	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2992	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2993
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2994	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2995
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2996	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2997	<div class="doc_subsubsection">
				2998	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				2999	</div>
				3000
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3001	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3002
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3003	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3004
				3005	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3006	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3007	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3008
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3009	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3010
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3011	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3012	heap and returns a pointer to it. The object is always allocated in the generic
				3013	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3014
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3015	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3016
				3017	<p>The '<tt>malloc</tt>' instruction allocates
				3018	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3019	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]	3020	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3021	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3022	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]	3023	be aligned to at least that boundary. If not specified, or if zero, the target can
				3024	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3025
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3026	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3027
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3028	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3029
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3030	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3031	a pointer is returned. The result of a zero byte allocattion is undefined. The
				3032	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3033
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3034	<h5>Example:</h5>
				3035
				3036	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3037	%array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3038
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3039	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3040	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3041	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3042	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3043	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3044	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3045	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3046
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3047	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3048	<div class="doc_subsubsection">
				3049	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3050	</div>
				3051
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3052	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3053
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3054	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3055
				3056	<pre>
				3057	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3058	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3059
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3060	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3061
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3062	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3063	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3064
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3065	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3066
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3067	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3068	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3069	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3070
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3071	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3072
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3073	<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]	3074	after this instruction executes. If the pointer is null, the operation
				3075	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3076
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3077	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3078
				3079	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3080	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
				3081	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3082	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3083	</div>
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	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3086	<div class="doc_subsubsection">
				3087	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3088	</div>
				3089
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3090	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3091
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3092	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3093
				3094	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3095	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3096	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3097
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3098	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3099
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3100	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3101	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3102	returns to its caller. The object is always allocated in the generic address
				3103	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3104
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3105	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3106
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3107	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3108	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3109	appropriate type to the program. If "NumElements" is specified, it is the
				3110	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3111	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]	3112	to be aligned to at least that boundary. If not specified, or if zero, the target
				3113	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3114
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3115	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3116
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3117	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3118
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3119	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3120	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3121	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3122	instruction is commonly used to represent automatic variables that must
				3123	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]	3124	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]	3125	instructions), the memory is reclaimed. Allocating zero bytes
				3126	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3127
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3128	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3129
				3130	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3131	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3132	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3133	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3134	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3135	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3136	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3137
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3138	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3139	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3140	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3141	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3142	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3143	<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]	3144	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3145	<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]	3146	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3147	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3148	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3149	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]	3150	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]	3151	the number or order of execution of this <tt>load</tt> with other
				3152	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3153	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3154	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3155	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3156	(that is, the alignment of the memory address). A value of 0 or an
				3157	omitted "align" argument means that the operation has the preferential
				3158	alignment for the target. It is the responsibility of the code emitter
				3159	to ensure that the alignment information is correct. Overestimating
				3160	the alignment results in an undefined behavior. Underestimating the
				3161	alignment may produce less efficient code. An alignment of 1 is always
				3162	safe.
				3163	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3164	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3165	<p>The location of memory pointed to is loaded.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3166	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3167	<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]	3168	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3169	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3170	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3171	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3172	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3173	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3174	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3175	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3176	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3177	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3178	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3179	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3180	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3181	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3182	<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]	3183	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3184	<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]	3185	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]	3186	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3187	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3188	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]	3189	optimizer is not allowed to modify the number or order of execution of
				3190	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3191	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3192	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3193	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3194	(that is, the alignment of the memory address). A value of 0 or an
				3195	omitted "align" argument means that the operation has the preferential
				3196	alignment for the target. It is the responsibility of the code emitter
				3197	to ensure that the alignment information is correct. Overestimating
				3198	the alignment results in an undefined behavior. Underestimating the
				3199	alignment may produce less efficient code. An alignment of 1 is always
				3200	safe.
				3201	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3202	<h5>Semantics:</h5>
				3203	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3204	at the location specified by the '<tt><pointer></tt>' operand.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3205	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3206	<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]	3207	store i32 3, i32* %ptr <i>; yields {void}</i>
				3208	%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]	3209	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3210	</div>
				3211
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3212	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3213	<div class="doc_subsubsection">
				3214	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3215	</div>
				3216
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3217	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3218	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3219	<pre>
				3220	<result> = getelementptr <ty>* <ptrval>{, <ty> <idx>}*
				3221	</pre>
				3222
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3223	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3224
				3225	<p>
				3226	The '<tt>getelementptr</tt>' instruction is used to get the address of a
				3227	subelement of an aggregate data structure.</p>
				3228
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3229	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3230
Reid Spencer	85f5b5b	2006-12-04 21:29:24 +0000	[diff] [blame]	3231	<p>This instruction takes a list of integer operands that indicate what
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3232	elements of the aggregate object to index to. The actual types of the arguments
				3233	provided depend on the type of the first pointer argument. The
				3234	'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	3235	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]	3236	structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	3237	into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
				3238	values will be sign extended to 64-bits if required.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3239
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3240	<p>For example, let's consider a C code fragment and how it gets
				3241	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3242
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3243	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3244	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3245	struct RT {
				3246	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3247	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3248	char C;
				3249	};
				3250	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3251	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3252	double Y;
				3253	struct RT Z;
				3254	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3255
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3256	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3257	return &s[1].Z.B[5][13];
				3258	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3259	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3260	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3261
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3262	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3263
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3264	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3265	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3266	%RT = type { i8 , [10 x [20 x i32]], i8 }
				3267	%ST = type { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3268
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3269	define i32* %foo(%ST* %s) {
				3270	entry:
				3271	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3272	ret i32* %reg
				3273	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3274	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3275	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3276
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3277	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3278
				3279	<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3280	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]	3281	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]	3282	<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]	3283	to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
				3284	structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3285
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3286	<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]	3287	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]	3288	}</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]	3289	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3290	i8 }</tt>' type, another structure. The third index indexes into the second
				3291	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]	3292	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3293	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3294	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]	3295
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3296	<p>Note that it is perfectly legal to index partially through a
				3297	structure, returning a pointer to an inner element. Because of this,
				3298	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3299
				3300	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3301	define i32* %foo(%ST* %s) {
				3302	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3303	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3304	%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]	3305	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3306	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3307	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3308	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3309	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3310
				3311	<p>Note that it is undefined to access an array out of bounds: array and
				3312	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]	3313	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]	3314	defined to be accessible as variable length arrays, which requires access
				3315	beyond the zero'th element.</p>
				3316
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3317	<p>The getelementptr instruction is often confusing. For some more insight
				3318	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3319	FAQ</a>.</p>
				3320
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3321	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3322
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3323	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3324	<i>; yields [12 x i8]*:aptr</i>
				3325	%aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3326	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3327	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3328
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3329	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3330	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3331	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3332	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3333	<p>The instructions in this category are the conversion instructions (casting)
				3334	which all take a single operand and a type. They perform various bit conversions
				3335	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3336	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3337
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3338	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3339	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3340	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3341	</div>
				3342	<div class="doc_text">
				3343
				3344	<h5>Syntax:</h5>
				3345	<pre>
				3346	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3347	</pre>
				3348
				3349	<h5>Overview:</h5>
				3350	<p>
				3351	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3352	</p>
				3353
				3354	<h5>Arguments:</h5>
				3355	<p>
				3356	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3357	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]	3358	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]	3359	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3360	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3361
				3362	<h5>Semantics:</h5>
				3363	<p>
				3364	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]	3365	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3366	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3367	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3368
				3369	<h5>Example:</h5>
				3370	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3371	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3372	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3373	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3374	</pre>
				3375	</div>
				3376
				3377	<!-- _______________________________________________________________________ -->
				3378	<div class="doc_subsubsection">
				3379	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3380	</div>
				3381	<div class="doc_text">
				3382
				3383	<h5>Syntax:</h5>
				3384	<pre>
				3385	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3386	</pre>
				3387
				3388	<h5>Overview:</h5>
				3389	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3390	<tt>ty2</tt>.</p>
				3391
				3392
				3393	<h5>Arguments:</h5>
				3394	<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]	3395	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3396	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]	3397	<tt>value</tt> must be smaller than the bit size of the destination type,
				3398	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3399
				3400	<h5>Semantics:</h5>
				3401	<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]	3402	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]	3403
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3404	<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]	3405
				3406	<h5>Example:</h5>
				3407	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3408	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3409	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3410	</pre>
				3411	</div>
				3412
				3413	<!-- _______________________________________________________________________ -->
				3414	<div class="doc_subsubsection">
				3415	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3416	</div>
				3417	<div class="doc_text">
				3418
				3419	<h5>Syntax:</h5>
				3420	<pre>
				3421	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3422	</pre>
				3423
				3424	<h5>Overview:</h5>
				3425	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3426
				3427	<h5>Arguments:</h5>
				3428	<p>
				3429	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]	3430	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3431	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]	3432	<tt>value</tt> must be smaller than the bit size of the destination type,
				3433	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3434
				3435	<h5>Semantics:</h5>
				3436	<p>
				3437	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3438	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]	3439	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3440
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3441	<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]	3442
				3443	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3444	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3445	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3446	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3447	</pre>
				3448	</div>
				3449
				3450	<!-- _______________________________________________________________________ -->
				3451	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3452	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3453	</div>
				3454
				3455	<div class="doc_text">
				3456
				3457	<h5>Syntax:</h5>
				3458
				3459	<pre>
				3460	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3461	</pre>
				3462
				3463	<h5>Overview:</h5>
				3464	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3465	<tt>ty2</tt>.</p>
				3466
				3467
				3468	<h5>Arguments:</h5>
				3469	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3470	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3471	cast it to. The size of <tt>value</tt> must be larger than the size of
				3472	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3473	<i>no-op cast</i>.</p>
				3474
				3475	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3476	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3477	<a href="#t_floating">floating point</a> type to a smaller
				3478	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3479	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3480
				3481	<h5>Example:</h5>
				3482	<pre>
				3483	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3484	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3485	</pre>
				3486	</div>
				3487
				3488	<!-- _______________________________________________________________________ -->
				3489	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3490	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3491	</div>
				3492	<div class="doc_text">
				3493
				3494	<h5>Syntax:</h5>
				3495	<pre>
				3496	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3497	</pre>
				3498
				3499	<h5>Overview:</h5>
				3500	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3501	floating point value.</p>
				3502
				3503	<h5>Arguments:</h5>
				3504	<p>The '<tt>fpext</tt>' instruction takes a
				3505	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3506	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3507	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3508
				3509	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3510	<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]	3511	<a href="#t_floating">floating point</a> type to a larger
				3512	<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]	3513	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]	3514	<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]	3515
				3516	<h5>Example:</h5>
				3517	<pre>
				3518	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3519	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3520	</pre>
				3521	</div>
				3522
				3523	<!-- _______________________________________________________________________ -->
				3524	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	3525	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3526	</div>
				3527	<div class="doc_text">
				3528
				3529	<h5>Syntax:</h5>
				3530	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3531	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3532	</pre>
				3533
				3534	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3535	<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]	3536	unsigned integer equivalent of type <tt>ty2</tt>.
				3537	</p>
				3538
				3539	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3540	<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]	3541	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3542	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3543	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3544	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]	3545
				3546	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3547	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3548	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3549	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3550	the results are undefined.</p>
				3551
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3552	<h5>Example:</h5>
				3553	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3554	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3555	%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]	3556	%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]	3557	</pre>
				3558	</div>
				3559
				3560	<!-- _______________________________________________________________________ -->
				3561	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3562	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3563	</div>
				3564	<div class="doc_text">
				3565
				3566	<h5>Syntax:</h5>
				3567	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3568	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3569	</pre>
				3570
				3571	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3572	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3573	<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]	3574	</p>
				3575
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3576	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3577	<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]	3578	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3579	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3580	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3581	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]	3582
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3583	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3584	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3585	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3586	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3587	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3588
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3589	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3590	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3591	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3592	%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]	3593	%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]	3594	</pre>
				3595	</div>
				3596
				3597	<!-- _______________________________________________________________________ -->
				3598	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3599	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3600	</div>
				3601	<div class="doc_text">
				3602
				3603	<h5>Syntax:</h5>
				3604	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3605	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3606	</pre>
				3607
				3608	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3609	<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]	3610	integer and converts that value to the <tt>ty2</tt> type.</p>
				3611
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3612	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3613	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3614	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3615	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3616	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3617	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]	3618
				3619	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3620	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3621	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3622	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]	3623
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3624	<h5>Example:</h5>
				3625	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3626	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3627	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3628	</pre>
				3629	</div>
				3630
				3631	<!-- _______________________________________________________________________ -->
				3632	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3633	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3634	</div>
				3635	<div class="doc_text">
				3636
				3637	<h5>Syntax:</h5>
				3638	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3639	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3640	</pre>
				3641
				3642	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3643	<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]	3644	integer and converts that value to the <tt>ty2</tt> type.</p>
				3645
				3646	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3647	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3648	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3649	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3650	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3651	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]	3652
				3653	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3654	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3655	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3656	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]	3657
				3658	<h5>Example:</h5>
				3659	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3660	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3661	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3662	</pre>
				3663	</div>
				3664
				3665	<!-- _______________________________________________________________________ -->
				3666	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3667	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				3668	</div>
				3669	<div class="doc_text">
				3670
				3671	<h5>Syntax:</h5>
				3672	<pre>
				3673	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				3674	</pre>
				3675
				3676	<h5>Overview:</h5>
				3677	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				3678	the integer type <tt>ty2</tt>.</p>
				3679
				3680	<h5>Arguments:</h5>
				3681	<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]	3682	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]	3683	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
				3684
				3685	<h5>Semantics:</h5>
				3686	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				3687	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				3688	truncating or zero extending that value to the size of the integer type. If
				3689	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				3690	<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]	3691	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				3692	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3693
				3694	<h5>Example:</h5>
				3695	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3696	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				3697	%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]	3698	</pre>
				3699	</div>
				3700
				3701	<!-- _______________________________________________________________________ -->
				3702	<div class="doc_subsubsection">
				3703	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				3704	</div>
				3705	<div class="doc_text">
				3706
				3707	<h5>Syntax:</h5>
				3708	<pre>
				3709	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				3710	</pre>
				3711
				3712	<h5>Overview:</h5>
				3713	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				3714	a pointer type, <tt>ty2</tt>.</p>
				3715
				3716	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	3717	<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]	3718	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]	3719	<a href="#t_pointer">pointer</a> type.
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3720
				3721	<h5>Semantics:</h5>
				3722	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				3723	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				3724	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				3725	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				3726	the size of a pointer then a zero extension is done. If they are the same size,
				3727	nothing is done (<i>no-op cast</i>).</p>
				3728
				3729	<h5>Example:</h5>
				3730	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3731	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				3732	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				3733	%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]	3734	</pre>
				3735	</div>
				3736
				3737	<!-- _______________________________________________________________________ -->
				3738	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3739	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3740	</div>
				3741	<div class="doc_text">
				3742
				3743	<h5>Syntax:</h5>
				3744	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3745	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3746	</pre>
				3747
				3748	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	3749
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3750	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3751	<tt>ty2</tt> without changing any bits.</p>
				3752
				3753	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	3754
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3755	<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]	3756	a first class value, and a type to cast it to, which must also be a <a
				3757	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]	3758	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^]	3759	type is a pointer, the destination type must also be a pointer. This
				3760	instruction supports bitwise conversion of vectors to integers and to vectors
				3761	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3762
				3763	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3764	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3765	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				3766	this conversion. The conversion is done as if the <tt>value</tt> had been
				3767	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				3768	converted to other pointer types with this instruction. To convert pointers to
				3769	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				3770	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3771
				3772	<h5>Example:</h5>
				3773	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3774	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3775	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
				3776	%Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3777	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3778	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3779
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3780	<!-- ======================================================================= -->
				3781	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				3782	<div class="doc_text">
				3783	<p>The instructions in this category are the "miscellaneous"
				3784	instructions, which defy better classification.</p>
				3785	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3786
				3787	<!-- _______________________________________________________________________ -->
				3788	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				3789	</div>
				3790	<div class="doc_text">
				3791	<h5>Syntax:</h5>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3792	<pre> <result> = icmp <cond> <ty> <var1>, <var2> <i>; yields {i1}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3793	</pre>
				3794	<h5>Overview:</h5>
				3795	<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]	3796	of its two integer or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3797	<h5>Arguments:</h5>
				3798	<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]	3799	the condition code indicating the kind of comparison to perform. It is not
				3800	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3801	<ol>
				3802	<li><tt>eq</tt>: equal</li>
				3803	<li><tt>ne</tt>: not equal </li>
				3804	<li><tt>ugt</tt>: unsigned greater than</li>
				3805	<li><tt>uge</tt>: unsigned greater or equal</li>
				3806	<li><tt>ult</tt>: unsigned less than</li>
				3807	<li><tt>ule</tt>: unsigned less or equal</li>
				3808	<li><tt>sgt</tt>: signed greater than</li>
				3809	<li><tt>sge</tt>: signed greater or equal</li>
				3810	<li><tt>slt</tt>: signed less than</li>
				3811	<li><tt>sle</tt>: signed less or equal</li>
				3812	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3813	<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]	3814	<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]	3815	<h5>Semantics:</h5>
				3816	<p>The '<tt>icmp</tt>' compares <tt>var1</tt> and <tt>var2</tt> according to
				3817	the condition code given as <tt>cond</tt>. The comparison performed always
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3818	yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3819	<ol>
				3820	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				3821	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3822	</li>
				3823	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
				3824	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3825	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
				3826	<tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
				3827	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
				3828	<tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
				3829	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
				3830	<tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
				3831	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
				3832	<tt>true</tt> if <tt>var1</tt> is less than or equal to <tt>var2</tt>.</li>
				3833	<li><tt>sgt</tt>: interprets the operands as signed values and yields
				3834	<tt>true</tt> if <tt>var1</tt> is greater than <tt>var2</tt>.</li>
				3835	<li><tt>sge</tt>: interprets the operands as signed values and yields
				3836	<tt>true</tt> if <tt>var1</tt> is greater than or equal to <tt>var2</tt>.</li>
				3837	<li><tt>slt</tt>: interprets the operands as signed values and yields
				3838	<tt>true</tt> if <tt>var1</tt> is less than <tt>var2</tt>.</li>
				3839	<li><tt>sle</tt>: interprets the operands as signed values and yields
				3840	<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]	3841	</ol>
				3842	<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]	3843	values are compared as if they were integers.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3844
				3845	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3846	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				3847	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				3848	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				3849	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				3850	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				3851	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3852	</pre>
				3853	</div>
				3854
				3855	<!-- _______________________________________________________________________ -->
				3856	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				3857	</div>
				3858	<div class="doc_text">
				3859	<h5>Syntax:</h5>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3860	<pre> <result> = fcmp <cond> <ty> <var1>, <var2> <i>; yields {i1}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3861	</pre>
				3862	<h5>Overview:</h5>
				3863	<p>The '<tt>fcmp</tt>' instruction returns a boolean value based on comparison
				3864	of its floating point operands.</p>
				3865	<h5>Arguments:</h5>
				3866	<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]	3867	the condition code indicating the kind of comparison to perform. It is not
				3868	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3869	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3870	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3871	<li><tt>oeq</tt>: ordered and equal</li>
				3872	<li><tt>ogt</tt>: ordered and greater than </li>
				3873	<li><tt>oge</tt>: ordered and greater than or equal</li>
				3874	<li><tt>olt</tt>: ordered and less than </li>
				3875	<li><tt>ole</tt>: ordered and less than or equal</li>
				3876	<li><tt>one</tt>: ordered and not equal</li>
				3877	<li><tt>ord</tt>: ordered (no nans)</li>
				3878	<li><tt>ueq</tt>: unordered or equal</li>
				3879	<li><tt>ugt</tt>: unordered or greater than </li>
				3880	<li><tt>uge</tt>: unordered or greater than or equal</li>
				3881	<li><tt>ult</tt>: unordered or less than </li>
				3882	<li><tt>ule</tt>: unordered or less than or equal</li>
				3883	<li><tt>une</tt>: unordered or not equal</li>
				3884	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3885	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3886	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3887	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	3888	<i>unordered</i> means that either operand may be a QNAN.</p>
Reid Spencer	350f8aa	2007-01-04 05:19:58 +0000	[diff] [blame]	3889	<p>The <tt>val1</tt> and <tt>val2</tt> arguments must be
				3890	<a href="#t_floating">floating point</a> typed. They must have identical
				3891	types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3892	<h5>Semantics:</h5>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	3893	<p>The '<tt>fcmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				3894	according to the condition code given as <tt>cond</tt>. The comparison performed
				3895	always yields a <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3896	<ol>
				3897	<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]	3898	<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]	3899	<tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3900	<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]	3901	<tt>var1</tt> is greather than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3902	<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]	3903	<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]	3904	<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]	3905	<tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3906	<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]	3907	<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]	3908	<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]	3909	<tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3910	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				3911	<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]	3912	<tt>var1</tt> is equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3913	<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]	3914	<tt>var1</tt> is greater than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3915	<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]	3916	<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]	3917	<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]	3918	<tt>var1</tt> is less than <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3919	<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]	3920	<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]	3921	<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]	3922	<tt>var1</tt> is not equal to <tt>var2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3923	<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]	3924	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				3925	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3926
				3927	<h5>Example:</h5>
				3928	<pre> <result> = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
				3929	<result> = icmp one float 4.0, 5.0 <i>; yields: result=true</i>
				3930	<result> = icmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				3931	<result> = icmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
				3932	</pre>
				3933	</div>
				3934
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3935	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	3936	<div class="doc_subsubsection">
				3937	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				3938	</div>
				3939	<div class="doc_text">
				3940	<h5>Syntax:</h5>
				3941	<pre> <result> = vicmp <cond> <ty> <var1>, <var2> <i>; yields {ty}:result</i>
				3942	</pre>
				3943	<h5>Overview:</h5>
				3944	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				3945	element-wise comparison of its two integer vector operands.</p>
				3946	<h5>Arguments:</h5>
				3947	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				3948	the condition code indicating the kind of comparison to perform. It is not
				3949	a value, just a keyword. The possible condition code are:
				3950	<ol>
				3951	<li><tt>eq</tt>: equal</li>
				3952	<li><tt>ne</tt>: not equal </li>
				3953	<li><tt>ugt</tt>: unsigned greater than</li>
				3954	<li><tt>uge</tt>: unsigned greater or equal</li>
				3955	<li><tt>ult</tt>: unsigned less than</li>
				3956	<li><tt>ule</tt>: unsigned less or equal</li>
				3957	<li><tt>sgt</tt>: signed greater than</li>
				3958	<li><tt>sge</tt>: signed greater or equal</li>
				3959	<li><tt>slt</tt>: signed less than</li>
				3960	<li><tt>sle</tt>: signed less or equal</li>
				3961	</ol>
				3962	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				3963	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				3964	<h5>Semantics:</h5>
				3965	<p>The '<tt>vicmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				3966	according to the condition code given as <tt>cond</tt>. The comparison yields a
				3967	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				3968	identical type as the values being compared. The most significant bit in each
				3969	element is 1 if the element-wise comparison evaluates to true, and is 0
				3970	otherwise. All other bits of the result are undefined. The condition codes
				3971	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
				3972	instruction</a>.
				3973
				3974	<h5>Example:</h5>
				3975	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	3976	<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>
				3977	<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]	3978	</pre>
				3979	</div>
				3980
				3981	<!-- _______________________________________________________________________ -->
				3982	<div class="doc_subsubsection">
				3983	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				3984	</div>
				3985	<div class="doc_text">
				3986	<h5>Syntax:</h5>
				3987	<pre> <result> = vfcmp <cond> <ty> <var1>, <var2></pre>
				3988	<h5>Overview:</h5>
				3989	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				3990	element-wise comparison of its two floating point vector operands. The output
				3991	elements have the same width as the input elements.</p>
				3992	<h5>Arguments:</h5>
				3993	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				3994	the condition code indicating the kind of comparison to perform. It is not
				3995	a value, just a keyword. The possible condition code are:
				3996	<ol>
				3997	<li><tt>false</tt>: no comparison, always returns false</li>
				3998	<li><tt>oeq</tt>: ordered and equal</li>
				3999	<li><tt>ogt</tt>: ordered and greater than </li>
				4000	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4001	<li><tt>olt</tt>: ordered and less than </li>
				4002	<li><tt>ole</tt>: ordered and less than or equal</li>
				4003	<li><tt>one</tt>: ordered and not equal</li>
				4004	<li><tt>ord</tt>: ordered (no nans)</li>
				4005	<li><tt>ueq</tt>: unordered or equal</li>
				4006	<li><tt>ugt</tt>: unordered or greater than </li>
				4007	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4008	<li><tt>ult</tt>: unordered or less than </li>
				4009	<li><tt>ule</tt>: unordered or less than or equal</li>
				4010	<li><tt>une</tt>: unordered or not equal</li>
				4011	<li><tt>uno</tt>: unordered (either nans)</li>
				4012	<li><tt>true</tt>: no comparison, always returns true</li>
				4013	</ol>
				4014	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4015	<a href="#t_floating">floating point</a> typed. They must also be identical
				4016	types.</p>
				4017	<h5>Semantics:</h5>
				4018	<p>The '<tt>vfcmp</tt>' instruction compares <tt>var1</tt> and <tt>var2</tt>
				4019	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4020	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4021	an identical number of elements as the values being compared, and each element
				4022	having identical with to the width of the floating point elements. The most
				4023	significant bit in each element is 1 if the element-wise comparison evaluates to
				4024	true, and is 0 otherwise. All other bits of the result are undefined. The
				4025	condition codes are evaluated identically to the
				4026	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
				4027
				4028	<h5>Example:</h5>
				4029	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	4030	<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>
				4031	<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]	4032	</pre>
				4033	</div>
				4034
				4035	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	4036	<div class="doc_subsubsection">
				4037	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4038	</div>
				4039
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4040	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	4041
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4042	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	4043
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4044	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4045	<h5>Overview:</h5>
				4046	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4047	the SSA graph representing the function.</p>
				4048	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	4049
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4050	<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]	4051	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4052	as arguments, with one pair for each predecessor basic block of the
				4053	current block. Only values of <a href="#t_firstclass">first class</a>
				4054	type may be used as the value arguments to the PHI node. Only labels
				4055	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	4056
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4057	<p>There must be no non-phi instructions between the start of a basic
				4058	block and the PHI instructions: i.e. PHI instructions must be first in
				4059	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	4060
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4061	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	4062
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4063	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4064	specified by the pair corresponding to the predecessor basic block that executed
				4065	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	4066
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4067	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	4068	<pre>
				4069	Loop: ; Infinite loop that counts from 0 on up...
				4070	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4071	%nextindvar = add i32 %indvar, 1
				4072	br label %Loop
				4073	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4074	</div>
				4075
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4076	<!-- _______________________________________________________________________ -->
				4077	<div class="doc_subsubsection">
				4078	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4079	</div>
				4080
				4081	<div class="doc_text">
				4082
				4083	<h5>Syntax:</h5>
				4084
				4085	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4086	<result> = select i1 <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4087	</pre>
				4088
				4089	<h5>Overview:</h5>
				4090
				4091	<p>
				4092	The '<tt>select</tt>' instruction is used to choose one value based on a
				4093	condition, without branching.
				4094	</p>
				4095
				4096
				4097	<h5>Arguments:</h5>
				4098
				4099	<p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	4100	The '<tt>select</tt>' instruction requires an 'i1' value indicating the
				4101	condition, and two values of the same <a href="#t_firstclass">first class</a>
				4102	type. If the val1/val2 are vectors, the entire vectors are selected, not
				4103	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4104	</p>
				4105
				4106	<h5>Semantics:</h5>
				4107
				4108	<p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame^]	4109	If the i1 condition evaluates is 1, the instruction returns the first
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4110	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4111	</p>
				4112
				4113	<h5>Example:</h5>
				4114
				4115	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4116	%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]	4117	</pre>
				4118	</div>
				4119
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4120
				4121	<!-- _______________________________________________________________________ -->
				4122	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4123	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4124	</div>
				4125
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4126	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4127
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4128	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4129	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4130	<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]	4131	</pre>
				4132
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4133	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4134
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4135	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4136
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4137	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4138
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4139	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4140
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4141	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4142	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4143	<p>The optional "tail" marker indicates whether the callee function accesses
				4144	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]	4145	function call is eligible for tail call optimization. Note that calls may
				4146	be marked "tail" even if they do not occur before a <a
				4147	href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4148	</li>
				4149	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4150	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4151	convention</a> the call should use. If none is specified, the call defaults
				4152	to using C calling conventions.
				4153	</li>
				4154	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4155	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4156	the type of the return value. Functions that return no value are marked
				4157	<tt><a href="#t_void">void</a></tt>.</p>
				4158	</li>
				4159	<li>
				4160	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4161	value being invoked. The argument types must match the types implied by
				4162	this signature. This type can be omitted if the function is not varargs
				4163	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]	4164	</li>
				4165	<li>
				4166	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4167	be invoked. In most cases, this is a direct function invocation, but
				4168	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]	4169	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4170	</li>
				4171	<li>
				4172	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4173	function signature argument types. All arguments must be of
				4174	<a href="#t_firstclass">first class</a> type. If the function signature
				4175	indicates the function accepts a variable number of arguments, the extra
				4176	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4177	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4178	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4179
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4180	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4181
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4182	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4183	transfer to a specified function, with its incoming arguments bound to
				4184	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4185	instruction in the called function, control flow continues with the
				4186	instruction after the function call, and the return value of the
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4187	function is bound to the result argument. If the callee returns multiple
				4188	values then the return values of the function are only accessible through
				4189	the '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4190
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4191	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4192
				4193	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4194	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4195	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4196	%X = tail call i32 @foo() <i>; yields i32</i>
				4197	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4198	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4199
				4200	%struct.A = type { i32, i8 }
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4201	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
				4202	%gr = getresult %struct.A %r, 0 <i>; yields i32</i>
				4203	%gr1 = getresult %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4204	</pre>
				4205
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4206	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4207
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4208	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4209	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4210	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4211	</div>
				4212
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4213	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4214
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4215	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4216
				4217	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4218	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4219	</pre>
				4220
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4221	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4222
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4223	<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]	4224	the "variable argument" area of a function call. It is used to implement the
				4225	<tt>va_arg</tt> macro in C.</p>
				4226
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4227	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4228
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4229	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4230	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4231	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]	4232	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4233
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4234	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4235
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4236	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4237	type from the specified <tt>va_list</tt> and causes the
				4238	<tt>va_list</tt> to point to the next argument. For more information,
				4239	see the variable argument handling <a href="#int_varargs">Intrinsic
				4240	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4241
				4242	<p>It is legal for this instruction to be called in a function which does not
				4243	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4244	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4245
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4246	<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]	4247	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4248	argument.</p>
				4249
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4250	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4251
				4252	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4253
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4254	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4255
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4256	<!-- _______________________________________________________________________ -->
				4257	<div class="doc_subsubsection">
				4258	<a name="i_getresult">'<tt>getresult</tt>' Instruction</a>
				4259	</div>
				4260
				4261	<div class="doc_text">
				4262
				4263	<h5>Syntax:</h5>
				4264	<pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4265	<resultval> = getresult <type> <retval>, <index>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4266	</pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4267
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4268	<h5>Overview:</h5>
				4269
				4270	<p> The '<tt>getresult</tt>' instruction is used to extract individual values
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4271	from a '<tt><a href="#i_call">call</a></tt>'
				4272	or '<tt><a href="#i_invoke">invoke</a></tt>' instruction that returns multiple
				4273	results.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4274
				4275	<h5>Arguments:</h5>
				4276
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4277	<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]	4278	first argument, or an undef value. The value must have <a
				4279	href="#t_struct">structure type</a>. The second argument is a constant
				4280	unsigned index value which must be in range for the number of values returned
				4281	by the call.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4282
				4283	<h5>Semantics:</h5>
				4284
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4285	<p>The '<tt>getresult</tt>' instruction extracts the element identified by
				4286	'<tt>index</tt>' from the aggregate value.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4287
				4288	<h5>Example:</h5>
				4289
				4290	<pre>
				4291	%struct.A = type { i32, i8 }
				4292
				4293	%r = call %struct.A @foo()
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4294	%gr = getresult %struct.A %r, 0 <i>; yields i32:%gr</i>
				4295	%gr1 = getresult %struct.A %r, 1 <i>; yields i8:%gr1</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4296	add i32 %gr, 42
				4297	add i8 %gr1, 41
				4298	</pre>
				4299
				4300	</div>
				4301
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4302	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4303	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4304	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4305
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4306	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4307
				4308	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4309	well known names and semantics and are required to follow certain restrictions.
				4310	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4311	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]	4312	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]	4313
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4314	<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]	4315	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4316	begin with this prefix. Intrinsic functions must always be external functions:
				4317	you cannot define the body of intrinsic functions. Intrinsic functions may
				4318	only be used in call or invoke instructions: it is illegal to take the address
				4319	of an intrinsic function. Additionally, because intrinsic functions are part
				4320	of the LLVM language, it is required if any are added that they be documented
				4321	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4322
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4323	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4324	a family of functions that perform the same operation but on different data
				4325	types. Because LLVM can represent over 8 million different integer types,
				4326	overloading is used commonly to allow an intrinsic function to operate on any
				4327	integer type. One or more of the argument types or the result type can be
				4328	overloaded to accept any integer type. Argument types may also be defined as
				4329	exactly matching a previous argument's type or the result type. This allows an
				4330	intrinsic function which accepts multiple arguments, but needs all of them to
				4331	be of the same type, to only be overloaded with respect to a single argument or
				4332	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4333
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4334	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4335	encoded into its function name, each preceded by a period. Only those types
				4336	which are overloaded result in a name suffix. Arguments whose type is matched
				4337	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4338	take an integer of any width and returns an integer of exactly the same integer
				4339	width. This leads to a family of functions such as
				4340	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4341	Only one type, the return type, is overloaded, and only one type suffix is
				4342	required. Because the argument's type is matched against the return type, it
				4343	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4344
				4345	<p>To learn how to add an intrinsic function, please see the
				4346	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4347	</p>
				4348
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4349	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4350
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4351	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4352	<div class="doc_subsection">
				4353	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4354	</div>
				4355
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4356	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4357
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4358	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4359	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]	4360	intrinsic functions. These functions are related to the similarly
				4361	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4362
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4363	<p>All of these functions operate on arguments that use a
				4364	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4365	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4366	transformations should be prepared to handle these functions regardless of
				4367	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4368
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4369	<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]	4370	instruction and the variable argument handling intrinsic functions are
				4371	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4372
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4373	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4374	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4375	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4376	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4377	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4378	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4379	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4380
				4381	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4382	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4383
				4384	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4385	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4386	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4387	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4388	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4389
				4390	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4391	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4392	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4393	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4394
				4395	declare void @llvm.va_start(i8*)
				4396	declare void @llvm.va_copy(i8, i8)
				4397	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4398	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4399	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4400
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4401	</div>
				4402
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4403	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4404	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4405	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4406	</div>
				4407
				4408
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4409	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4410	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4411	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4412	<h5>Overview:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4413	<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
				4414	<tt>*<arglist></tt> for subsequent use by <tt><a
				4415	href="#i_va_arg">va_arg</a></tt>.</p>
				4416
				4417	<h5>Arguments:</h5>
				4418
				4419	<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
				4420
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4421	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4422
				4423	<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
				4424	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4425	<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]	4426	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4427	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]	4428	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]	4429
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4430	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4431
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4432	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4433	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4434	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4435	</div>
				4436
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4437	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4438	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4439	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4440	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4441
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4442	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4443	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]	4444	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]	4445
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4446	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4447
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4448	<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]	4449
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4450	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4451
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4452	<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]	4453	macro available in C. In a target-dependent way, it destroys the
				4454	<tt>va_list</tt> element to which the argument points. Calls to <a
				4455	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4456	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4457	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4458
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4459	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4460
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4461	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4462	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4463	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4464	</div>
				4465
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4466	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4467
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4468	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4469
				4470	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4471	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4472	</pre>
				4473
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4474	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4475
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4476	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4477	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4478
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4479	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4480
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4481	<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]	4482	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]	4483
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4484
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4485	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4486
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4487	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4488	macro available in C. In a target-dependent way, it copies the source
				4489	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4490	intrinsic is necessary because the <tt><a href="#int_va_start">
				4491	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4492	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4493
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4494	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4495
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4496	<!-- ======================================================================= -->
				4497	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4498	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4499	</div>
				4500
				4501	<div class="doc_text">
				4502
				4503	<p>
				4504	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
				4505	Collection</a> requires the implementation and generation of these intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4506	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]	4507	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4508	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]	4509	Front-ends for type-safe garbage collected languages should generate these
				4510	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4511	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4512	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4513
				4514	<p>The garbage collection intrinsics only operate on objects in the generic
				4515	address space (address space zero).</p>
				4516
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4517	</div>
				4518
				4519	<!-- _______________________________________________________________________ -->
				4520	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4521	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4522	</div>
				4523
				4524	<div class="doc_text">
				4525
				4526	<h5>Syntax:</h5>
				4527
				4528	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4529	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4530	</pre>
				4531
				4532	<h5>Overview:</h5>
				4533
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4534	<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]	4535	the code generator, and allows some metadata to be associated with it.</p>
				4536
				4537	<h5>Arguments:</h5>
				4538
				4539	<p>The first argument specifies the address of a stack object that contains the
				4540	root pointer. The second pointer (which must be either a constant or a global
				4541	value address) contains the meta-data to be associated with the root.</p>
				4542
				4543	<h5>Semantics:</h5>
				4544
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	4545	<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]	4546	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4547	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4548	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4549	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4550
				4551	</div>
				4552
				4553
				4554	<!-- _______________________________________________________________________ -->
				4555	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4556	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4557	</div>
				4558
				4559	<div class="doc_text">
				4560
				4561	<h5>Syntax:</h5>
				4562
				4563	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4564	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4565	</pre>
				4566
				4567	<h5>Overview:</h5>
				4568
				4569	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4570	locations, allowing garbage collector implementations that require read
				4571	barriers.</p>
				4572
				4573	<h5>Arguments:</h5>
				4574
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4575	<p>The second argument is the address to read from, which should be an address
				4576	allocated from the garbage collector. The first object is a pointer to the
				4577	start of the referenced object, if needed by the language runtime (otherwise
				4578	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4579
				4580	<h5>Semantics:</h5>
				4581
				4582	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4583	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4584	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4585	may only be used in a function which <a href="#gc">specifies a GC
				4586	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4587
				4588	</div>
				4589
				4590
				4591	<!-- _______________________________________________________________________ -->
				4592	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4593	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4594	</div>
				4595
				4596	<div class="doc_text">
				4597
				4598	<h5>Syntax:</h5>
				4599
				4600	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4601	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4602	</pre>
				4603
				4604	<h5>Overview:</h5>
				4605
				4606	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4607	locations, allowing garbage collector implementations that require write
				4608	barriers (such as generational or reference counting collectors).</p>
				4609
				4610	<h5>Arguments:</h5>
				4611
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4612	<p>The first argument is the reference to store, the second is the start of the
				4613	object to store it to, and the third is the address of the field of Obj to
				4614	store to. If the runtime does not require a pointer to the object, Obj may be
				4615	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4616
				4617	<h5>Semantics:</h5>
				4618
				4619	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4620	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4621	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4622	may only be used in a function which <a href="#gc">specifies a GC
				4623	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4624
				4625	</div>
				4626
				4627
				4628
				4629	<!-- ======================================================================= -->
				4630	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4631	<a name="int_codegen">Code Generator Intrinsics</a>
				4632	</div>
				4633
				4634	<div class="doc_text">
				4635	<p>
				4636	These intrinsics are provided by LLVM to expose special features that may only
				4637	be implemented with code generator support.
				4638	</p>
				4639
				4640	</div>
				4641
				4642	<!-- _______________________________________________________________________ -->
				4643	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4644	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4645	</div>
				4646
				4647	<div class="doc_text">
				4648
				4649	<h5>Syntax:</h5>
				4650	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4651	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4652	</pre>
				4653
				4654	<h5>Overview:</h5>
				4655
				4656	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4657	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				4658	target-specific value indicating the return address of the current function
				4659	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4660	</p>
				4661
				4662	<h5>Arguments:</h5>
				4663
				4664	<p>
				4665	The argument to this intrinsic indicates which function to return the address
				4666	for. Zero indicates the calling function, one indicates its caller, etc. The
				4667	argument is <b>required</b> to be a constant integer value.
				4668	</p>
				4669
				4670	<h5>Semantics:</h5>
				4671
				4672	<p>
				4673	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				4674	the return address of the specified call frame, or zero if it cannot be
				4675	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4676	for arguments other than zero, so it should only be used for debugging purposes.
				4677	</p>
				4678
				4679	<p>
				4680	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4681	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]	4682	source-language caller.
				4683	</p>
				4684	</div>
				4685
				4686
				4687	<!-- _______________________________________________________________________ -->
				4688	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4689	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4690	</div>
				4691
				4692	<div class="doc_text">
				4693
				4694	<h5>Syntax:</h5>
				4695	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4696	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4697	</pre>
				4698
				4699	<h5>Overview:</h5>
				4700
				4701	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4702	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				4703	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4704	</p>
				4705
				4706	<h5>Arguments:</h5>
				4707
				4708	<p>
				4709	The argument to this intrinsic indicates which function to return the frame
				4710	pointer for. Zero indicates the calling function, one indicates its caller,
				4711	etc. The argument is <b>required</b> to be a constant integer value.
				4712	</p>
				4713
				4714	<h5>Semantics:</h5>
				4715
				4716	<p>
				4717	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				4718	the frame address of the specified call frame, or zero if it cannot be
				4719	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4720	for arguments other than zero, so it should only be used for debugging purposes.
				4721	</p>
				4722
				4723	<p>
				4724	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4725	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]	4726	source-language caller.
				4727	</p>
				4728	</div>
				4729
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4730	<!-- _______________________________________________________________________ -->
				4731	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4732	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4733	</div>
				4734
				4735	<div class="doc_text">
				4736
				4737	<h5>Syntax:</h5>
				4738	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4739	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4740	</pre>
				4741
				4742	<h5>Overview:</h5>
				4743
				4744	<p>
				4745	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]	4746	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4747	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				4748	features like scoped automatic variable sized arrays in C99.
				4749	</p>
				4750
				4751	<h5>Semantics:</h5>
				4752
				4753	<p>
				4754	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]	4755	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4756	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				4757	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				4758	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				4759	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				4760	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				4761	</p>
				4762
				4763	</div>
				4764
				4765	<!-- _______________________________________________________________________ -->
				4766	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4767	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4768	</div>
				4769
				4770	<div class="doc_text">
				4771
				4772	<h5>Syntax:</h5>
				4773	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4774	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4775	</pre>
				4776
				4777	<h5>Overview:</h5>
				4778
				4779	<p>
				4780	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				4781	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]	4782	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4783	useful for implementing language features like scoped automatic variable sized
				4784	arrays in C99.
				4785	</p>
				4786
				4787	<h5>Semantics:</h5>
				4788
				4789	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4790	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]	4791	</p>
				4792
				4793	</div>
				4794
				4795
				4796	<!-- _______________________________________________________________________ -->
				4797	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4798	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4799	</div>
				4800
				4801	<div class="doc_text">
				4802
				4803	<h5>Syntax:</h5>
				4804	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4805	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4806	</pre>
				4807
				4808	<h5>Overview:</h5>
				4809
				4810
				4811	<p>
				4812	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]	4813	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				4814	no
				4815	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	4816	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4817	</p>
				4818
				4819	<h5>Arguments:</h5>
				4820
				4821	<p>
				4822	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				4823	determining if the fetch should be for a read (0) or write (1), and
				4824	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	4825	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]	4826	<tt>locality</tt> arguments must be constant integers.
				4827	</p>
				4828
				4829	<h5>Semantics:</h5>
				4830
				4831	<p>
				4832	This intrinsic does not modify the behavior of the program. In particular,
				4833	prefetches cannot trap and do not produce a value. On targets that support this
				4834	intrinsic, the prefetch can provide hints to the processor cache for better
				4835	performance.
				4836	</p>
				4837
				4838	</div>
				4839
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4840	<!-- _______________________________________________________________________ -->
				4841	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4842	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4843	</div>
				4844
				4845	<div class="doc_text">
				4846
				4847	<h5>Syntax:</h5>
				4848	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4849	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4850	</pre>
				4851
				4852	<h5>Overview:</h5>
				4853
				4854
				4855	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4856	The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
				4857	(PC) in a region of
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4858	code to simulators and other tools. The method is target specific, but it is
				4859	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]	4860	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]	4861	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]	4862	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4863	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4864	</p>
				4865
				4866	<h5>Arguments:</h5>
				4867
				4868	<p>
				4869	<tt>id</tt> is a numerical id identifying the marker.
				4870	</p>
				4871
				4872	<h5>Semantics:</h5>
				4873
				4874	<p>
				4875	This intrinsic does not modify the behavior of the program. Backends that do not
				4876	support this intrinisic may ignore it.
				4877	</p>
				4878
				4879	</div>
				4880
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4881	<!-- _______________________________________________________________________ -->
				4882	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4883	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4884	</div>
				4885
				4886	<div class="doc_text">
				4887
				4888	<h5>Syntax:</h5>
				4889	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4890	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4891	</pre>
				4892
				4893	<h5>Overview:</h5>
				4894
				4895
				4896	<p>
				4897	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				4898	counter register (or similar low latency, high accuracy clocks) on those targets
				4899	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				4900	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				4901	should only be used for small timings.
				4902	</p>
				4903
				4904	<h5>Semantics:</h5>
				4905
				4906	<p>
				4907	When directly supported, reading the cycle counter should not modify any memory.
				4908	Implementations are allowed to either return a application specific value or a
				4909	system wide value. On backends without support, this is lowered to a constant 0.
				4910	</p>
				4911
				4912	</div>
				4913
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4914	<!-- ======================================================================= -->
				4915	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4916	<a name="int_libc">Standard C Library Intrinsics</a>
				4917	</div>
				4918
				4919	<div class="doc_text">
				4920	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4921	LLVM provides intrinsics for a few important standard C library functions.
				4922	These intrinsics allow source-language front-ends to pass information about the
				4923	alignment of the pointer arguments to the code generator, providing opportunity
				4924	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4925	</p>
				4926
				4927	</div>
				4928
				4929	<!-- _______________________________________________________________________ -->
				4930	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4931	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4932	</div>
				4933
				4934	<div class="doc_text">
				4935
				4936	<h5>Syntax:</h5>
				4937	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4938	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4939	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4940	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4941	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4942	</pre>
				4943
				4944	<h5>Overview:</h5>
				4945
				4946	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4947	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]	4948	location to the destination location.
				4949	</p>
				4950
				4951	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4952	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				4953	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4954	</p>
				4955
				4956	<h5>Arguments:</h5>
				4957
				4958	<p>
				4959	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]	4960	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4961	specifying the number of bytes to copy, and the fourth argument is the alignment
				4962	of the source and destination locations.
				4963	</p>
				4964
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	4965	<p>
				4966	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]	4967	the caller guarantees that both the source and destination pointers are aligned
				4968	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	4969	</p>
				4970
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4971	<h5>Semantics:</h5>
				4972
				4973	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	4974	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]	4975	location to the destination location, which are not allowed to overlap. It
				4976	copies "len" bytes of memory over. If the argument is known to be aligned to
				4977	some boundary, this can be specified as the fourth argument, otherwise it should
				4978	be set to 0 or 1.
				4979	</p>
				4980	</div>
				4981
				4982
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	4983	<!-- _______________________________________________________________________ -->
				4984	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4985	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	4986	</div>
				4987
				4988	<div class="doc_text">
				4989
				4990	<h5>Syntax:</h5>
				4991	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4992	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4993	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4994	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4995	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	4996	</pre>
				4997
				4998	<h5>Overview:</h5>
				4999
				5000	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5001	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5002	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5003	'<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]	5004	</p>
				5005
				5006	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5007	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5008	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5009	</p>
				5010
				5011	<h5>Arguments:</h5>
				5012
				5013	<p>
				5014	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]	5015	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5016	specifying the number of bytes to copy, and the fourth argument is the alignment
				5017	of the source and destination locations.
				5018	</p>
				5019
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5020	<p>
				5021	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]	5022	the caller guarantees that the source and destination pointers are aligned to
				5023	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5024	</p>
				5025
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5026	<h5>Semantics:</h5>
				5027
				5028	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5029	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]	5030	location to the destination location, which may overlap. It
				5031	copies "len" bytes of memory over. If the argument is known to be aligned to
				5032	some boundary, this can be specified as the fourth argument, otherwise it should
				5033	be set to 0 or 1.
				5034	</p>
				5035	</div>
				5036
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5037
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5038	<!-- _______________________________________________________________________ -->
				5039	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5040	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5041	</div>
				5042
				5043	<div class="doc_text">
				5044
				5045	<h5>Syntax:</h5>
				5046	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5047	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5048	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5049	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5050	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5051	</pre>
				5052
				5053	<h5>Overview:</h5>
				5054
				5055	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5056	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]	5057	byte value.
				5058	</p>
				5059
				5060	<p>
				5061	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5062	does not return a value, and takes an extra alignment argument.
				5063	</p>
				5064
				5065	<h5>Arguments:</h5>
				5066
				5067	<p>
				5068	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]	5069	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5070	argument specifying the number of bytes to fill, and the fourth argument is the
				5071	known alignment of destination location.
				5072	</p>
				5073
				5074	<p>
				5075	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]	5076	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5077	</p>
				5078
				5079	<h5>Semantics:</h5>
				5080
				5081	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5082	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5083	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5084	destination location. If the argument is known to be aligned to some boundary,
				5085	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5086	1.
				5087	</p>
				5088	</div>
				5089
				5090
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5091	<!-- _______________________________________________________________________ -->
				5092	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5093	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5094	</div>
				5095
				5096	<div class="doc_text">
				5097
				5098	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5099	<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]	5100	floating point or vector of floating point type. Not all targets support all
				5101	types however.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5102	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5103	declare float @llvm.sqrt.f32(float %Val)
				5104	declare double @llvm.sqrt.f64(double %Val)
				5105	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5106	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5107	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5108	</pre>
				5109
				5110	<h5>Overview:</h5>
				5111
				5112	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5113	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]	5114	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]	5115	<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]	5116	negative numbers other than -0.0 (which allows for better optimization, because
				5117	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5118	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5119	</p>
				5120
				5121	<h5>Arguments:</h5>
				5122
				5123	<p>
				5124	The argument and return value are floating point numbers of the same type.
				5125	</p>
				5126
				5127	<h5>Semantics:</h5>
				5128
				5129	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5130	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]	5131	floating point number.
				5132	</p>
				5133	</div>
				5134
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5135	<!-- _______________________________________________________________________ -->
				5136	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5137	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5138	</div>
				5139
				5140	<div class="doc_text">
				5141
				5142	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5143	<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]	5144	floating point or vector of floating point type. Not all targets support all
				5145	types however.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5146	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5147	declare float @llvm.powi.f32(float %Val, i32 %power)
				5148	declare double @llvm.powi.f64(double %Val, i32 %power)
				5149	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5150	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5151	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5152	</pre>
				5153
				5154	<h5>Overview:</h5>
				5155
				5156	<p>
				5157	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5158	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5159	multiplications is not defined. When a vector of floating point type is
				5160	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5161	</p>
				5162
				5163	<h5>Arguments:</h5>
				5164
				5165	<p>
				5166	The second argument is an integer power, and the first is a value to raise to
				5167	that power.
				5168	</p>
				5169
				5170	<h5>Semantics:</h5>
				5171
				5172	<p>
				5173	This function returns the first value raised to the second power with an
				5174	unspecified sequence of rounding operations.</p>
				5175	</div>
				5176
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5177	<!-- _______________________________________________________________________ -->
				5178	<div class="doc_subsubsection">
				5179	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5180	</div>
				5181
				5182	<div class="doc_text">
				5183
				5184	<h5>Syntax:</h5>
				5185	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5186	floating point or vector of floating point type. Not all targets support all
				5187	types however.
				5188	<pre>
				5189	declare float @llvm.sin.f32(float %Val)
				5190	declare double @llvm.sin.f64(double %Val)
				5191	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5192	declare fp128 @llvm.sin.f128(fp128 %Val)
				5193	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5194	</pre>
				5195
				5196	<h5>Overview:</h5>
				5197
				5198	<p>
				5199	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5200	</p>
				5201
				5202	<h5>Arguments:</h5>
				5203
				5204	<p>
				5205	The argument and return value are floating point numbers of the same type.
				5206	</p>
				5207
				5208	<h5>Semantics:</h5>
				5209
				5210	<p>
				5211	This function returns the sine of the specified operand, returning the
				5212	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]	5213	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5214	</div>
				5215
				5216	<!-- _______________________________________________________________________ -->
				5217	<div class="doc_subsubsection">
				5218	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5219	</div>
				5220
				5221	<div class="doc_text">
				5222
				5223	<h5>Syntax:</h5>
				5224	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5225	floating point or vector of floating point type. Not all targets support all
				5226	types however.
				5227	<pre>
				5228	declare float @llvm.cos.f32(float %Val)
				5229	declare double @llvm.cos.f64(double %Val)
				5230	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5231	declare fp128 @llvm.cos.f128(fp128 %Val)
				5232	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5233	</pre>
				5234
				5235	<h5>Overview:</h5>
				5236
				5237	<p>
				5238	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5239	</p>
				5240
				5241	<h5>Arguments:</h5>
				5242
				5243	<p>
				5244	The argument and return value are floating point numbers of the same type.
				5245	</p>
				5246
				5247	<h5>Semantics:</h5>
				5248
				5249	<p>
				5250	This function returns the cosine of the specified operand, returning the
				5251	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]	5252	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5253	</div>
				5254
				5255	<!-- _______________________________________________________________________ -->
				5256	<div class="doc_subsubsection">
				5257	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5258	</div>
				5259
				5260	<div class="doc_text">
				5261
				5262	<h5>Syntax:</h5>
				5263	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5264	floating point or vector of floating point type. Not all targets support all
				5265	types however.
				5266	<pre>
				5267	declare float @llvm.pow.f32(float %Val, float %Power)
				5268	declare double @llvm.pow.f64(double %Val, double %Power)
				5269	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5270	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5271	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5272	</pre>
				5273
				5274	<h5>Overview:</h5>
				5275
				5276	<p>
				5277	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5278	specified (positive or negative) power.
				5279	</p>
				5280
				5281	<h5>Arguments:</h5>
				5282
				5283	<p>
				5284	The second argument is a floating point power, and the first is a value to
				5285	raise to that power.
				5286	</p>
				5287
				5288	<h5>Semantics:</h5>
				5289
				5290	<p>
				5291	This function returns the first value raised to the second power,
				5292	returning the
				5293	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]	5294	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5295	</div>
				5296
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5297
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5298	<!-- ======================================================================= -->
				5299	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5300	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5301	</div>
				5302
				5303	<div class="doc_text">
				5304	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5305	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5306	These allow efficient code generation for some algorithms.
				5307	</p>
				5308
				5309	</div>
				5310
				5311	<!-- _______________________________________________________________________ -->
				5312	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5313	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5314	</div>
				5315
				5316	<div class="doc_text">
				5317
				5318	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5319	<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]	5320	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]	5321	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5322	declare i16 @llvm.bswap.i16(i16 <id>)
				5323	declare i32 @llvm.bswap.i32(i32 <id>)
				5324	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5325	</pre>
				5326
				5327	<h5>Overview:</h5>
				5328
				5329	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5330	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]	5331	values with an even number of bytes (positive multiple of 16 bits). These are
				5332	useful for performing operations on data that is not in the target's native
				5333	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5334	</p>
				5335
				5336	<h5>Semantics:</h5>
				5337
				5338	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5339	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]	5340	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5341	intrinsic returns an i32 value that has the four bytes of the input i32
				5342	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]	5343	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5344	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5345	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5346	</p>
				5347
				5348	</div>
				5349
				5350	<!-- _______________________________________________________________________ -->
				5351	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5352	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5353	</div>
				5354
				5355	<div class="doc_text">
				5356
				5357	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5358	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
				5359	width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5360	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5361	declare i8 @llvm.ctpop.i8 (i8 <src>)
				5362	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5363	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5364	declare i64 @llvm.ctpop.i64(i64 <src>)
				5365	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5366	</pre>
				5367
				5368	<h5>Overview:</h5>
				5369
				5370	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5371	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5372	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5373	</p>
				5374
				5375	<h5>Arguments:</h5>
				5376
				5377	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5378	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]	5379	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5380	</p>
				5381
				5382	<h5>Semantics:</h5>
				5383
				5384	<p>
				5385	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5386	</p>
				5387	</div>
				5388
				5389	<!-- _______________________________________________________________________ -->
				5390	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5391	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5392	</div>
				5393
				5394	<div class="doc_text">
				5395
				5396	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5397	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
				5398	integer bit width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5399	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5400	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5401	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5402	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5403	declare i64 @llvm.ctlz.i64(i64 <src>)
				5404	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5405	</pre>
				5406
				5407	<h5>Overview:</h5>
				5408
				5409	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5410	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5411	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5412	</p>
				5413
				5414	<h5>Arguments:</h5>
				5415
				5416	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5417	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]	5418	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5419	</p>
				5420
				5421	<h5>Semantics:</h5>
				5422
				5423	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5424	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5425	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]	5426	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5427	</p>
				5428	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5429
				5430
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5431
				5432	<!-- _______________________________________________________________________ -->
				5433	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5434	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5435	</div>
				5436
				5437	<div class="doc_text">
				5438
				5439	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5440	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
				5441	integer bit width. Not all targets support all bit widths however.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5442	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5443	declare i8 @llvm.cttz.i8 (i8 <src>)
				5444	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5445	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5446	declare i64 @llvm.cttz.i64(i64 <src>)
				5447	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5448	</pre>
				5449
				5450	<h5>Overview:</h5>
				5451
				5452	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5453	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5454	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5455	</p>
				5456
				5457	<h5>Arguments:</h5>
				5458
				5459	<p>
				5460	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]	5461	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5462	</p>
				5463
				5464	<h5>Semantics:</h5>
				5465
				5466	<p>
				5467	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5468	in a variable. If the src == 0 then the result is the size in bits of the type
				5469	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5470	</p>
				5471	</div>
				5472
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	5473	<!-- _______________________________________________________________________ -->
				5474	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5475	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5476	</div>
				5477
				5478	<div class="doc_text">
				5479
				5480	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5481	<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]	5482	on any integer bit width.
				5483	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5484	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5485	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5486	</pre>
				5487
				5488	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5489	<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]	5490	range of bits from an integer value and returns them in the same bit width as
				5491	the original value.</p>
				5492
				5493	<h5>Arguments:</h5>
				5494	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5495	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]	5496	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]	5497
				5498	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5499	<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]	5500	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5501	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5502	operates in forward mode.</p>
				5503	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5504	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]	5505	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5506	<ol>
				5507	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5508	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5509	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5510	to determine the number of bits to retain.</li>
				5511	<li>A mask of the retained bits is created by shifting a -1 value.</li>
				5512	<li>The mask is ANDed with <tt>%val</tt> to produce the result.
				5513	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	5514	<p>In reverse mode, a similar computation is made except that the bits are
				5515	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5516	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5517	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5518	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5519	</div>
				5520
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5521	<div class="doc_subsubsection">
				5522	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5523	</div>
				5524
				5525	<div class="doc_text">
				5526
				5527	<h5>Syntax:</h5>
				5528	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
				5529	on any integer bit width.
				5530	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5531	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5532	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]	5533	</pre>
				5534
				5535	<h5>Overview:</h5>
				5536	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5537	of bits in an integer value with another integer value. It returns the integer
				5538	with the replaced bits.</p>
				5539
				5540	<h5>Arguments:</h5>
				5541	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5542	any bit width but they must have the same bit width. <tt>%val</tt> is the value
				5543	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5544	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5545	type since they specify only a bit index.</p>
				5546
				5547	<h5>Semantics:</h5>
				5548	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5549	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5550	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5551	operates in forward mode.</p>
				5552	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5553	truncating it down to the size of the replacement area or zero extending it
				5554	up to that size.</p>
				5555	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5556	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5557	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
				5558	to the <tt>%hi</tt>th bit.
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5559	<p>In reverse mode, a similar computation is made except that the bits are
				5560	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
				5561	<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]	5562	<h5>Examples:</h5>
				5563	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5564	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5565	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5566	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5567	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5568	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	5569	</pre>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5570	</div>
				5571
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5572	<!-- ======================================================================= -->
				5573	<div class="doc_subsection">
				5574	<a name="int_debugger">Debugger Intrinsics</a>
				5575	</div>
				5576
				5577	<div class="doc_text">
				5578	<p>
				5579	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				5580	are described in the <a
				5581	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				5582	Debugging</a> document.
				5583	</p>
				5584	</div>
				5585
				5586
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	5587	<!-- ======================================================================= -->
				5588	<div class="doc_subsection">
				5589	<a name="int_eh">Exception Handling Intrinsics</a>
				5590	</div>
				5591
				5592	<div class="doc_text">
				5593	<p> The LLVM exception handling intrinsics (which all start with
				5594	<tt>llvm.eh.</tt> prefix), are described in the <a
				5595	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				5596	Handling</a> document. </p>
				5597	</div>
				5598
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5599	<!-- ======================================================================= -->
				5600	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5601	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5602	</div>
				5603
				5604	<div class="doc_text">
				5605	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5606	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5607	the <tt>nest</tt> attribute, from a function. The result is a callable
				5608	function pointer lacking the nest parameter - the caller does not need
				5609	to provide a value for it. Instead, the value to use is stored in
				5610	advance in a "trampoline", a block of memory usually allocated
				5611	on the stack, which also contains code to splice the nest value into the
				5612	argument list. This is used to implement the GCC nested function address
				5613	extension.
				5614	</p>
				5615	<p>
				5616	For example, if the function is
				5617	<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]	5618	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]	5619	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5620	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				5621	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				5622	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				5623	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5624	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	5625	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				5626	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]	5627	</div>
				5628
				5629	<!-- _______________________________________________________________________ -->
				5630	<div class="doc_subsubsection">
				5631	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				5632	</div>
				5633	<div class="doc_text">
				5634	<h5>Syntax:</h5>
				5635	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5636	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5637	</pre>
				5638	<h5>Overview:</h5>
				5639	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5640	This fills the memory pointed to by <tt>tramp</tt> with code
				5641	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5642	</p>
				5643	<h5>Arguments:</h5>
				5644	<p>
				5645	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				5646	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				5647	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]	5648	intrinsic. Note that the size and the alignment are target-specific - LLVM
				5649	currently provides no portable way of determining them, so a front-end that
				5650	generates this intrinsic needs to have some target-specific knowledge.
				5651	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]	5652	</p>
				5653	<h5>Semantics:</h5>
				5654	<p>
				5655	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]	5656	dependent code, turning it into a function. A pointer to this function is
				5657	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5658	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5659	before being called. The new function's signature is the same as that of
				5660	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				5661	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				5662	of pointer type. Calling the new function is equivalent to calling
				5663	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				5664	missing <tt>nest</tt> argument. If, after calling
				5665	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				5666	modified, then the effect of any later call to the returned function pointer is
				5667	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5668	</p>
				5669	</div>
				5670
				5671	<!-- ======================================================================= -->
				5672	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5673	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				5674	</div>
				5675
				5676	<div class="doc_text">
				5677	<p>
				5678	These intrinsic functions expand the "universal IR" of LLVM to represent
				5679	hardware constructs for atomic operations and memory synchronization. This
				5680	provides an interface to the hardware, not an interface to the programmer. It
				5681	is aimed at a low enough level to allow any programming models or APIs which
				5682	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				5683	hardware behavior. Just as hardware provides a "universal IR" for source
				5684	languages, it also provides a starting point for developing a "universal"
				5685	atomic operation and synchronization IR.
				5686	</p>
				5687	<p>
				5688	These do <em>not</em> form an API such as high-level threading libraries,
				5689	software transaction memory systems, atomic primitives, and intrinsic
				5690	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				5691	application libraries. The hardware interface provided by LLVM should allow
				5692	a clean implementation of all of these APIs and parallel programming models.
				5693	No one model or paradigm should be selected above others unless the hardware
				5694	itself ubiquitously does so.
				5695
				5696	</p>
				5697	</div>
				5698
				5699	<!-- _______________________________________________________________________ -->
				5700	<div class="doc_subsubsection">
				5701	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				5702	</div>
				5703	<div class="doc_text">
				5704	<h5>Syntax:</h5>
				5705	<pre>
				5706	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				5707	i1 <device> )
				5708
				5709	</pre>
				5710	<h5>Overview:</h5>
				5711	<p>
				5712	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				5713	specific pairs of memory access types.
				5714	</p>
				5715	<h5>Arguments:</h5>
				5716	<p>
				5717	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				5718	The first four arguments enables a specific barrier as listed below. The fith
				5719	argument specifies that the barrier applies to io or device or uncached memory.
				5720
				5721	</p>
				5722	<ul>
				5723	<li><tt>ll</tt>: load-load barrier</li>
				5724	<li><tt>ls</tt>: load-store barrier</li>
				5725	<li><tt>sl</tt>: store-load barrier</li>
				5726	<li><tt>ss</tt>: store-store barrier</li>
				5727	<li><tt>device</tt>: barrier applies to device and uncached memory also.
				5728	</ul>
				5729	<h5>Semantics:</h5>
				5730	<p>
				5731	This intrinsic causes the system to enforce some ordering constraints upon
				5732	the loads and stores of the program. This barrier does not indicate
				5733	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				5734	which they occur. For any of the specified pairs of load and store operations
				5735	(f.ex. load-load, or store-load), all of the first operations preceding the
				5736	barrier will complete before any of the second operations succeeding the
				5737	barrier begin. Specifically the semantics for each pairing is as follows:
				5738	</p>
				5739	<ul>
				5740	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				5741	after the barrier begins.</li>
				5742
				5743	<li><tt>ls</tt>: All loads before the barrier must complete before any
				5744	store after the barrier begins.</li>
				5745	<li><tt>ss</tt>: All stores before the barrier must complete before any
				5746	store after the barrier begins.</li>
				5747	<li><tt>sl</tt>: All stores before the barrier must complete before any
				5748	load after the barrier begins.</li>
				5749	</ul>
				5750	<p>
				5751	These semantics are applied with a logical "and" behavior when more than one
				5752	is enabled in a single memory barrier intrinsic.
				5753	</p>
				5754	<p>
				5755	Backends may implement stronger barriers than those requested when they do not
				5756	support as fine grained a barrier as requested. Some architectures do not
				5757	need all types of barriers and on such architectures, these become noops.
				5758	</p>
				5759	<h5>Example:</h5>
				5760	<pre>
				5761	%ptr = malloc i32
				5762	store i32 4, %ptr
				5763
				5764	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				5765	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				5766	<i>; guarantee the above finishes</i>
				5767	store i32 8, %ptr <i>; before this begins</i>
				5768	</pre>
				5769	</div>
				5770
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5771	<!-- _______________________________________________________________________ -->
				5772	<div class="doc_subsubsection">
				5773	<a name="int_atomic_lcs">'<tt>llvm.atomic.lcs.*</tt>' Intrinsic</a>
				5774	</div>
				5775	<div class="doc_text">
				5776	<h5>Syntax:</h5>
				5777	<p>
				5778	This is an overloaded intrinsic. You can use <tt>llvm.atomic.lcs</tt> on any
				5779	integer bit width. Not all targets support all bit widths however.</p>
				5780
				5781	<pre>
				5782	declare i8 @llvm.atomic.lcs.i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				5783	declare i16 @llvm.atomic.lcs.i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				5784	declare i32 @llvm.atomic.lcs.i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				5785	declare i64 @llvm.atomic.lcs.i64( i64* <ptr>, i64 <cmp>, i64 <val> )
				5786
				5787	</pre>
				5788	<h5>Overview:</h5>
				5789	<p>
				5790	This loads a value in memory and compares it to a given value. If they are
				5791	equal, it stores a new value into the memory.
				5792	</p>
				5793	<h5>Arguments:</h5>
				5794	<p>
				5795	The <tt>llvm.atomic.lcs</tt> intrinsic takes three arguments. The result as
				5796	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				5797	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				5798	this integer type. While any bit width integer may be used, targets may only
				5799	lower representations they support in hardware.
				5800
				5801	</p>
				5802	<h5>Semantics:</h5>
				5803	<p>
				5804	This entire intrinsic must be executed atomically. It first loads the value
				5805	in memory pointed to by <tt>ptr</tt> and compares it with the value
				5806	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				5807	loaded value is yielded in all cases. This provides the equivalent of an
				5808	atomic compare-and-swap operation within the SSA framework.
				5809	</p>
				5810	<h5>Examples:</h5>
				5811
				5812	<pre>
				5813	%ptr = malloc i32
				5814	store i32 4, %ptr
				5815
				5816	%val1 = add i32 4, 4
				5817	%result1 = call i32 @llvm.atomic.lcs.i32( i32* %ptr, i32 4, %val1 )
				5818	<i>; yields {i32}:result1 = 4</i>
				5819	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5820	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5821
				5822	%val2 = add i32 1, 1
				5823	%result2 = call i32 @llvm.atomic.lcs.i32( i32* %ptr, i32 5, %val2 )
				5824	<i>; yields {i32}:result2 = 8</i>
				5825	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				5826
				5827	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				5828	</pre>
				5829	</div>
				5830
				5831	<!-- _______________________________________________________________________ -->
				5832	<div class="doc_subsubsection">
				5833	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				5834	</div>
				5835	<div class="doc_text">
				5836	<h5>Syntax:</h5>
				5837
				5838	<p>
				5839	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				5840	integer bit width. Not all targets support all bit widths however.</p>
				5841	<pre>
				5842	declare i8 @llvm.atomic.swap.i8( i8* <ptr>, i8 <val> )
				5843	declare i16 @llvm.atomic.swap.i16( i16* <ptr>, i16 <val> )
				5844	declare i32 @llvm.atomic.swap.i32( i32* <ptr>, i32 <val> )
				5845	declare i64 @llvm.atomic.swap.i64( i64* <ptr>, i64 <val> )
				5846
				5847	</pre>
				5848	<h5>Overview:</h5>
				5849	<p>
				5850	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				5851	the value from memory. It then stores the value in <tt>val</tt> in the memory
				5852	at <tt>ptr</tt>.
				5853	</p>
				5854	<h5>Arguments:</h5>
				5855
				5856	<p>
				5857	The <tt>llvm.atomic.ls</tt> intrinsic takes two arguments. Both the
				5858	<tt>val</tt> argument and the result must be integers of the same bit width.
				5859	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				5860	integer type. The targets may only lower integer representations they
				5861	support.
				5862	</p>
				5863	<h5>Semantics:</h5>
				5864	<p>
				5865	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				5866	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				5867	equivalent of an atomic swap operation within the SSA framework.
				5868
				5869	</p>
				5870	<h5>Examples:</h5>
				5871	<pre>
				5872	%ptr = malloc i32
				5873	store i32 4, %ptr
				5874
				5875	%val1 = add i32 4, 4
				5876	%result1 = call i32 @llvm.atomic.swap.i32( i32* %ptr, i32 %val1 )
				5877	<i>; yields {i32}:result1 = 4</i>
				5878	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5879	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5880
				5881	%val2 = add i32 1, 1
				5882	%result2 = call i32 @llvm.atomic.swap.i32( i32* %ptr, i32 %val2 )
				5883	<i>; yields {i32}:result2 = 8</i>
				5884
				5885	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				5886	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				5887	</pre>
				5888	</div>
				5889
				5890	<!-- _______________________________________________________________________ -->
				5891	<div class="doc_subsubsection">
				5892	<a name="int_atomic_las">'<tt>llvm.atomic.las.*</tt>' Intrinsic</a>
				5893
				5894	</div>
				5895	<div class="doc_text">
				5896	<h5>Syntax:</h5>
				5897	<p>
				5898	This is an overloaded intrinsic. You can use <tt>llvm.atomic.las</tt> on any
				5899	integer bit width. Not all targets support all bit widths however.</p>
				5900	<pre>
				5901	declare i8 @llvm.atomic.las.i8.( i8* <ptr>, i8 <delta> )
				5902	declare i16 @llvm.atomic.las.i16.( i16* <ptr>, i16 <delta> )
				5903	declare i32 @llvm.atomic.las.i32.( i32* <ptr>, i32 <delta> )
				5904	declare i64 @llvm.atomic.las.i64.( i64* <ptr>, i64 <delta> )
				5905
				5906	</pre>
				5907	<h5>Overview:</h5>
				5908	<p>
				5909	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				5910	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				5911	</p>
				5912	<h5>Arguments:</h5>
				5913	<p>
				5914
				5915	The intrinsic takes two arguments, the first a pointer to an integer value
				5916	and the second an integer value. The result is also an integer value. These
				5917	integer types can have any bit width, but they must all have the same bit
				5918	width. The targets may only lower integer representations they support.
				5919	</p>
				5920	<h5>Semantics:</h5>
				5921	<p>
				5922	This intrinsic does a series of operations atomically. It first loads the
				5923	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				5924	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				5925	</p>
				5926
				5927	<h5>Examples:</h5>
				5928	<pre>
				5929	%ptr = malloc i32
				5930	store i32 4, %ptr
				5931	%result1 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 4 )
				5932	<i>; yields {i32}:result1 = 4</i>
				5933	%result2 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 2 )
				5934	<i>; yields {i32}:result2 = 8</i>
				5935	%result3 = call i32 @llvm.atomic.las.i32( i32* %ptr, i32 5 )
				5936	<i>; yields {i32}:result3 = 10</i>
				5937	%memval = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
				5938	</pre>
				5939	</div>
				5940
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5941
				5942	<!-- ======================================================================= -->
				5943	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5944	<a name="int_general">General Intrinsics</a>
				5945	</div>
				5946
				5947	<div class="doc_text">
				5948	<p> This class of intrinsics is designed to be generic and has
				5949	no specific purpose. </p>
				5950	</div>
				5951
				5952	<!-- _______________________________________________________________________ -->
				5953	<div class="doc_subsubsection">
				5954	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				5955	</div>
				5956
				5957	<div class="doc_text">
				5958
				5959	<h5>Syntax:</h5>
				5960	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	5961	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]	5962	</pre>
				5963
				5964	<h5>Overview:</h5>
				5965
				5966	<p>
				5967	The '<tt>llvm.var.annotation</tt>' intrinsic
				5968	</p>
				5969
				5970	<h5>Arguments:</h5>
				5971
				5972	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	5973	The first argument is a pointer to a value, the second is a pointer to a
				5974	global string, the third is a pointer to a global string which is the source
				5975	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5976	</p>
				5977
				5978	<h5>Semantics:</h5>
				5979
				5980	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	5981	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5982	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]	5983	annotations. These have no other defined use, they are ignored by code
				5984	generation and optimization.
				5985	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5986	</div>
				5987
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	5988	<!-- _______________________________________________________________________ -->
				5989	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	5990	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	5991	</div>
				5992
				5993	<div class="doc_text">
				5994
				5995	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	5996	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				5997	any integer bit width.
				5998	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	5999	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	6000	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6001	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6002	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6003	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6004	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]	6005	</pre>
				6006
				6007	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6008
				6009	<p>
				6010	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6011	</p>
				6012
				6013	<h5>Arguments:</h5>
				6014
				6015	<p>
				6016	The first argument is an integer value (result of some expression),
				6017	the second is a pointer to a global string, the third is a pointer to a global
				6018	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]	6019	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6020	</p>
				6021
				6022	<h5>Semantics:</h5>
				6023
				6024	<p>
				6025	This intrinsic allows annotations to be put on arbitrary expressions
				6026	with arbitrary strings. This can be useful for special purpose optimizations
				6027	that want to look for these annotations. These have no other defined use, they
				6028	are ignored by code generation and optimization.
				6029	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6030
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6031	<!-- _______________________________________________________________________ -->
				6032	<div class="doc_subsubsection">
				6033	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6034	</div>
				6035
				6036	<div class="doc_text">
				6037
				6038	<h5>Syntax:</h5>
				6039	<pre>
				6040	declare void @llvm.trap()
				6041	</pre>
				6042
				6043	<h5>Overview:</h5>
				6044
				6045	<p>
				6046	The '<tt>llvm.trap</tt>' intrinsic
				6047	</p>
				6048
				6049	<h5>Arguments:</h5>
				6050
				6051	<p>
				6052	None
				6053	</p>
				6054
				6055	<h5>Semantics:</h5>
				6056
				6057	<p>
				6058	This intrinsics is lowered to the target dependent trap instruction. If the
				6059	target does not have a trap instruction, this intrinsic will be lowered to the
				6060	call of the abort() function.
				6061	</p>
				6062	</div>
				6063
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6064	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6065	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6066	<address>
				6067	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
				6068	src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
				6069	<a href="http://validator.w3.org/check/referer"><img
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6070	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]	6071
				6072	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	6073	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6074	Last modified: $Date$
				6075	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6076
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	6077	</body>
				6078	</html>