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Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3	<html>
				4	<head>
				5	<title>LLVM Assembly Language Reference Manual</title>
Reid Spencer	3921c74	2004-08-26 20:44:00 +0000	[diff] [blame]	6	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
				7	<meta name="author" content="Chris Lattner">
				8	<meta name="description"
				9	content="LLVM Assembly Language Reference Manual.">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	10	<link rel="stylesheet" href="llvm.css" type="text/css">
				11	</head>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	12
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	13	<body>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	14
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	15	<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	16	<ol>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	17	<li><a href="#abstract">Abstract</a></li>
				18	<li><a href="#introduction">Introduction</a></li>
				19	<li><a href="#identifiers">Identifiers</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	20	<li><a href="#highlevel">High Level Structure</a>
				21	<ol>
				22	<li><a href="#modulestructure">Module Structure</a></li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	23	<li><a href="#linkage">Linkage Types</a></li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	24	<li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	25	<li><a href="#namedtypes">Named Types</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	26	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	27	<li><a href="#functionstructure">Functions</a></li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	28	<li><a href="#aliasstructure">Aliases</a></li>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	29	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	30	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	31	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	32	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	33	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	34	</ol>
				35	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	36	<li><a href="#typesystem">Type System</a>
				37	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	38	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	39	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	40	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	41	<li><a href="#t_floating">Floating Point Types</a></li>
				42	<li><a href="#t_void">Void Type</a></li>
				43	<li><a href="#t_label">Label Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	44	</ol>
				45	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	46	<li><a href="#t_derived">Derived Types</a>
				47	<ol>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	48	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	49	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	50	<li><a href="#t_function">Function Type</a></li>
				51	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	52	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	53	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	54	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	55	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	56	</ol>
				57	</li>
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	58	<li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	59	</ol>
				60	</li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	61	<li><a href="#constants">Constants</a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	62	<ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	63	<li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame^]	64	<li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	65	<li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
				66	<li><a href="#undefvalues">Undefined Values</a></li>
				67	<li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	68	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	69	</li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	70	<li><a href="#othervalues">Other Values</a>
				71	<ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	72	<li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	73	</ol>
				74	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	75	<li><a href="#instref">Instruction Reference</a>
				76	<ol>
				77	<li><a href="#terminators">Terminator Instructions</a>
				78	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	79	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				80	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	81	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				82	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	83	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	84	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	85	</ol>
				86	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	87	<li><a href="#binaryops">Binary Operations</a>
				88	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	89	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
				90	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
				91	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	92	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				93	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				94	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	95	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				96	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				97	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	98	</ol>
				99	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	100	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				101	<ol>
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	102	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				103	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				104	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	105	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	106	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	107	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	108	</ol>
				109	</li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	110	<li><a href="#vectorops">Vector Operations</a>
				111	<ol>
				112	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				113	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				114	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	115	</ol>
				116	</li>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	117	<li><a href="#aggregateops">Aggregate Operations</a>
				118	<ol>
				119	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				120	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				121	</ol>
				122	</li>
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	123	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	124	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	125	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				126	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				127	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	128	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				129	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				130	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	131	</ol>
				132	</li>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	133	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	134	<ol>
				135	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				136	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				137	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				138	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				139	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	140	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				141	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				142	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	144	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				145	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	146	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	147	</ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	148	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	149	<li><a href="#otherops">Other Operations</a>
				150	<ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	151	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				152	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	153	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				154	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	155	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	156	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	157	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	158	<li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	159	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	160	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	161	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	162	</li>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	163	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	164	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	165	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				166	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	167	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				168	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				169	<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]	170	</ol>
				171	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	172	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				173	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	174	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				175	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				176	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	177	</ol>
				178	</li>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	179	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				180	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	181	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				182	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				183	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				184	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				185	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				186	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				187	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	7123e27	2004-04-09 16:43:20 +0000	[diff] [blame]	188	</ol>
				189	</li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	190	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				191	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	192	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				193	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				194	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				195	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				196	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	197	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				198	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				199	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	200	</ol>
				201	</li>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	202	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	203	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	204	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	205	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				206	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				207	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	208	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				209	<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]	210	</ol>
				211	</li>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	212	<li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
				213	<ol>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	214	<li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
				215	<li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
				216	<li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
				217	<li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
				218	<li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	219	<li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	220	</ol>
				221	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	222	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	223	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	224	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	225	<ol>
				226	<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]	227	</ol>
				228	</li>
Bill Wendling	3c44f5b	2008-11-18 22:10:53 +0000	[diff] [blame]	229	<li><a href="#int_atomics">Atomic intrinsics</a>
				230	<ol>
				231	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
				232	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
				233	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
				234	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				235	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				236	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				237	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				238	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				239	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				240	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				241	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				242	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				243	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
				244	</ol>
				245	</li>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	246	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	247	<ol>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	248	<li><a href="#int_var_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	249	'<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	250	<li><a href="#int_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	251	'<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	252	<li><a href="#int_trap">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	253	'<tt>llvm.trap</tt>' Intrinsic</a></li>
				254	<li><a href="#int_stackprotector">
				255	'<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	256	</ol>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	257	</li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	258	</ol>
				259	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	260	</ol>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	261
				262	<div class="doc_author">
				263	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				264	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	265	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	266
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	267	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	268	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				269	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	270
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	271	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	272	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	837f39b	2008-08-05 22:29:16 +0000	[diff] [blame]	273	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	274	type safety, low-level operations, flexibility, and the capability of
				275	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	276	representation used throughout all phases of the LLVM compilation
				277	strategy.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	278	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	279
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	280	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	281	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				282	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	283
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	284	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	285
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	286	<p>The LLVM code representation is designed to be used in three
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	287	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]	288	representation (suitable for fast loading by a Just-In-Time compiler),
				289	and as a human readable assembly language representation. This allows
				290	LLVM to provide a powerful intermediate representation for efficient
				291	compiler transformations and analysis, while providing a natural means
				292	to debug and visualize the transformations. The three different forms
				293	of LLVM are all equivalent. This document describes the human readable
				294	representation and notation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	295
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	296	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	297	while being expressive, typed, and extensible at the same time. It
				298	aims to be a "universal IR" of sorts, by being at a low enough level
				299	that high-level ideas may be cleanly mapped to it (similar to how
				300	microprocessors are "universal IR's", allowing many source languages to
				301	be mapped to them). By providing type information, LLVM can be used as
				302	the target of optimizations: for example, through pointer analysis, it
				303	can be proven that a C automatic variable is never accessed outside of
				304	the current function... allowing it to be promoted to a simple SSA
				305	value instead of a memory location.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	306
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	307	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	308
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	309	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	310	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	311
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	312	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	313
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	314	<p>It is important to note that this document describes 'well formed'
				315	LLVM assembly language. There is a difference between what the parser
				316	accepts and what is considered 'well formed'. For example, the
				317	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	318
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	319	<div class="doc_code">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	320	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	321	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	322	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	323	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	324
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	325	<p>...because the definition of <tt>%x</tt> does not dominate all of
				326	its uses. The LLVM infrastructure provides a verification pass that may
				327	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]	328	automatically run by the parser after parsing input assembly and by
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	329	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	330	by the verifier pass indicate bugs in transformation passes or input to
				331	the parser.</p>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	332	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	333
Chris Lattner	cc68939	2007-10-03 17:34:29 +0000	[diff] [blame]	334	<!-- Describe the typesetting conventions here. -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	335
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	336	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	337	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	338	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	339
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	340	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	341
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	342	<p>LLVM identifiers come in two basic types: global and local. Global
				343	identifiers (functions, global variables) begin with the @ character. Local
				344	identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	345	there are three different formats for identifiers, for different purposes:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	346
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	347	<ol>
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	348	<li>Named values are represented as a string of characters with their prefix.
				349	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				350	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]	351	Identifiers which require other characters in their names can be surrounded
Daniel Dunbar	76dea95	2008-10-14 23:51:43 +0000	[diff] [blame]	352	with quotes. Special characters may be escaped using "\xx" where xx is the
				353	ASCII code for the character in hexadecimal. In this way, any character can
				354	be used in a name value, even quotes themselves.
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	355
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	356	<li>Unnamed values are represented as an unsigned numeric value with their
				357	prefix. For example, %12, @2, %44.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	358
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	359	<li>Constants, which are described in a <a href="#constants">section about
				360	constants</a>, below.</li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	361	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	362
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	363	<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]	364	don't need to worry about name clashes with reserved words, and the set of
				365	reserved words may be expanded in the future without penalty. Additionally,
				366	unnamed identifiers allow a compiler to quickly come up with a temporary
				367	variable without having to avoid symbol table conflicts.</p>
				368
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	369	<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]	370	languages. There are keywords for different opcodes
				371	('<tt><a href="#i_add">add</a></tt>',
				372	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				373	'<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]	374	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]	375	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	376	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	377
				378	<p>Here is an example of LLVM code to multiply the integer variable
				379	'<tt>%X</tt>' by 8:</p>
				380
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	381	<p>The easy way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	382
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	383	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	384	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	385	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	386	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	387	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	388
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	389	<p>After strength reduction:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	390
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	391	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	392	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	393	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	394	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	395	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	396
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	397	<p>And the hard way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	398
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	399	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	400	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	401	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				402	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				403	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	404	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	405	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	406
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	407	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				408	important lexical features of LLVM:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	409
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	410	<ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	411
				412	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				413	line.</li>
				414
				415	<li>Unnamed temporaries are created when the result of a computation is not
				416	assigned to a named value.</li>
				417
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	418	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	419
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	420	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	421
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	422	<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]	423	demonstrating instructions, we will follow an instruction with a comment that
				424	defines the type and name of value produced. Comments are shown in italic
				425	text.</p>
				426
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	427	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	428
				429	<!-- *********************************************************************** -->
				430	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				431	<!-- *********************************************************************** -->
				432
				433	<!-- ======================================================================= -->
				434	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				435	</div>
				436
				437	<div class="doc_text">
				438
				439	<p>LLVM programs are composed of "Module"s, each of which is a
				440	translation unit of the input programs. Each module consists of
				441	functions, global variables, and symbol table entries. Modules may be
				442	combined together with the LLVM linker, which merges function (and
				443	global variable) definitions, resolves forward declarations, and merges
				444	symbol table entries. Here is an example of the "hello world" module:</p>
				445
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	446	<div class="doc_code">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	447	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	448	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				449	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]	450
				451	<i>; External declaration of the puts function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	452	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	453
				454	<i>; Definition of main function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	455	define i32 @main() { <i>; i32()* </i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	456	<i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	457	%cast210 = <a
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	458	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]	459
				460	<i>; Call puts function to write out the string to stdout...</i>
				461	<a
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	462	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	463	<a
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	464	href="#i_ret">ret</a> i32 0<br>}<br>
				465	</pre>
				466	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	467
				468	<p>This example is made up of a <a href="#globalvars">global variable</a>
				469	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				470	function, and a <a href="#functionstructure">function definition</a>
				471	for "<tt>main</tt>".</p>
				472
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	473	<p>In general, a module is made up of a list of global values,
				474	where both functions and global variables are global values. Global values are
				475	represented by a pointer to a memory location (in this case, a pointer to an
				476	array of char, and a pointer to a function), and have one of the following <a
				477	href="#linkage">linkage types</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	478
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	479	</div>
				480
				481	<!-- ======================================================================= -->
				482	<div class="doc_subsection">
				483	<a name="linkage">Linkage Types</a>
				484	</div>
				485
				486	<div class="doc_text">
				487
				488	<p>
				489	All Global Variables and Functions have one of the following types of linkage:
				490	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	491
				492	<dl>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	493
Rafael Espindola	bb46f52	2009-01-15 20:18:42 +0000	[diff] [blame]	494	<dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
				495
				496	<dd>Global values with private linkage are only directly accessible by
				497	objects in the current module. In particular, linking code into a module with
				498	an private global value may cause the private to be renamed as necessary to
				499	avoid collisions. Because the symbol is private to the module, all
				500	references can be updated. This doesn't show up in any symbol table in the
				501	object file.
				502	</dd>
				503
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	504	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	505
Duncan Sands	81d05c2	2009-01-16 09:29:46 +0000	[diff] [blame]	506	<dd> Similar to private, but the value shows as a local symbol (STB_LOCAL in
Rafael Espindola	bb46f52	2009-01-15 20:18:42 +0000	[diff] [blame]	507	the case of ELF) in the object file. This corresponds to the notion of the
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	508	'<tt>static</tt>' keyword in C.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	509	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	510
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	511	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	512
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	513	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				514	the same name when linkage occurs. This is typically used to implement
				515	inline functions, templates, or other code which must be generated in each
				516	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				517	allowed to be discarded.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	518	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	519
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	520	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				521
				522	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				523	linkage, except that unreferenced <tt>common</tt> globals may not be
				524	discarded. This is used for globals that may be emitted in multiple
				525	translation units, but that are not guaranteed to be emitted into every
				526	translation unit that uses them. One example of this is tentative
				527	definitions in C, such as "<tt>int X;</tt>" at global scope.
				528	</dd>
				529
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	530	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	531
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	532	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				533	that some targets may choose to emit different assembly sequences for them
				534	for target-dependent reasons. This is used for globals that are declared
				535	"weak" in C source code.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	536	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	537
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	538	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	539
				540	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				541	pointer to array type. When two global variables with appending linkage are
				542	linked together, the two global arrays are appended together. This is the
				543	LLVM, typesafe, equivalent of having the system linker append together
				544	"sections" with identical names when .o files are linked.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	545	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	546
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	547	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	548	<dd>The semantics of this linkage follow the ELF object file model: the
				549	symbol is weak until linked, if not linked, the symbol becomes null instead
				550	of being an undefined reference.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	551	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	552
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	553	<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]	554
				555	<dd>If none of the above identifiers are used, the global is externally
				556	visible, meaning that it participates in linkage and can be used to resolve
				557	external symbol references.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	558	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	559	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	560
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	561	<p>
				562	The next two types of linkage are targeted for Microsoft Windows platform
				563	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	564	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	565	</p>
				566
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	567	<dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	568	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				569
				570	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				571	or variable via a global pointer to a pointer that is set up by the DLL
				572	exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman	7956412	2009-01-12 21:35:55 +0000	[diff] [blame]	573	formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	574	</dd>
				575
				576	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				577
				578	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				579	pointer to a pointer in a DLL, so that it can be referenced with the
				580	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman	7956412	2009-01-12 21:35:55 +0000	[diff] [blame]	581	name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	582	name.
				583	</dd>
				584
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	585	</dl>
				586
Dan Gohman	f003276	2008-11-24 17:18:39 +0000	[diff] [blame]	587	<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	588	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				589	variable and was linked with this one, one of the two would be renamed,
				590	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				591	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	ac8d276	2007-01-05 00:59:10 +0000	[diff] [blame]	592	outside of the current module.</p>
				593	<p>It is illegal for a function <i>declaration</i>
				594	to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	595	or <tt>extern_weak</tt>.</p>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	596	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	597	linkages.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	598	</div>
				599
				600	<!-- ======================================================================= -->
				601	<div class="doc_subsection">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	602	<a name="callingconv">Calling Conventions</a>
				603	</div>
				604
				605	<div class="doc_text">
				606
				607	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				608	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				609	specified for the call. The calling convention of any pair of dynamic
				610	caller/callee must match, or the behavior of the program is undefined. The
				611	following calling conventions are supported by LLVM, and more may be added in
				612	the future:</p>
				613
				614	<dl>
				615	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				616
				617	<dd>This calling convention (the default if no other calling convention is
				618	specified) matches the target C calling conventions. This calling convention
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	619	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	620	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	621	</dd>
				622
				623	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				624
				625	<dd>This calling convention attempts to make calls as fast as possible
				626	(e.g. by passing things in registers). This calling convention allows the
				627	target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	628	without having to conform to an externally specified ABI (Application Binary
				629	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	9097d14	2008-05-14 09:17:12 +0000	[diff] [blame]	630	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				631	supported. This calling convention does not support varargs and requires the
				632	prototype of all callees to exactly match the prototype of the function
				633	definition.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	634	</dd>
				635
				636	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				637
				638	<dd>This calling convention attempts to make code in the caller as efficient
				639	as possible under the assumption that the call is not commonly executed. As
				640	such, these calls often preserve all registers so that the call does not break
				641	any live ranges in the caller side. This calling convention does not support
				642	varargs and requires the prototype of all callees to exactly match the
				643	prototype of the function definition.
				644	</dd>
				645
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	646	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	647
				648	<dd>Any calling convention may be specified by number, allowing
				649	target-specific calling conventions to be used. Target specific calling
				650	conventions start at 64.
				651	</dd>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	652	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	653
				654	<p>More calling conventions can be added/defined on an as-needed basis, to
				655	support pascal conventions or any other well-known target-independent
				656	convention.</p>
				657
				658	</div>
				659
				660	<!-- ======================================================================= -->
				661	<div class="doc_subsection">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	662	<a name="visibility">Visibility Styles</a>
				663	</div>
				664
				665	<div class="doc_text">
				666
				667	<p>
				668	All Global Variables and Functions have one of the following visibility styles:
				669	</p>
				670
				671	<dl>
				672	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				673
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	674	<dd>On targets that use the ELF object file format, default visibility means
				675	that the declaration is visible to other
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	676	modules and, in shared libraries, means that the declared entity may be
				677	overridden. On Darwin, default visibility means that the declaration is
				678	visible to other modules. Default visibility corresponds to "external
				679	linkage" in the language.
				680	</dd>
				681
				682	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				683
				684	<dd>Two declarations of an object with hidden visibility refer to the same
				685	object if they are in the same shared object. Usually, hidden visibility
				686	indicates that the symbol will not be placed into the dynamic symbol table,
				687	so no other module (executable or shared library) can reference it
				688	directly.
				689	</dd>
				690
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	691	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				692
				693	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				694	the dynamic symbol table, but that references within the defining module will
				695	bind to the local symbol. That is, the symbol cannot be overridden by another
				696	module.
				697	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	698	</dl>
				699
				700	</div>
				701
				702	<!-- ======================================================================= -->
				703	<div class="doc_subsection">
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	704	<a name="namedtypes">Named Types</a>
				705	</div>
				706
				707	<div class="doc_text">
				708
				709	<p>LLVM IR allows you to specify name aliases for certain types. This can make
				710	it easier to read the IR and make the IR more condensed (particularly when
				711	recursive types are involved). An example of a name specification is:
				712	</p>
				713
				714	<div class="doc_code">
				715	<pre>
				716	%mytype = type { %mytype*, i32 }
				717	</pre>
				718	</div>
				719
				720	<p>You may give a name to any <a href="#typesystem">type</a> except "<a
				721	href="t_void">void</a>". Type name aliases may be used anywhere a type is
				722	expected with the syntax "%mytype".</p>
				723
				724	<p>Note that type names are aliases for the structural type that they indicate,
				725	and that you can therefore specify multiple names for the same type. This often
				726	leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
				727	structural typing, the name is not part of the type. When printing out LLVM IR,
				728	the printer will pick <em>one name</em> to render all types of a particular
				729	shape. This means that if you have code where two different source types end up
				730	having the same LLVM type, that the dumper will sometimes print the "wrong" or
				731	unexpected type. This is an important design point and isn't going to
				732	change.</p>
				733
				734	</div>
				735
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	736	<!-- ======================================================================= -->
				737	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	738	<a name="globalvars">Global Variables</a>
				739	</div>
				740
				741	<div class="doc_text">
				742
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	743	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	744	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	745	an explicit section to be placed in, and may have an optional explicit alignment
				746	specified. A variable may be defined as "thread_local", which means that it
				747	will not be shared by threads (each thread will have a separated copy of the
				748	variable). A variable may be defined as a global "constant," which indicates
				749	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]	750	optimization, allowing the global data to be placed in the read-only section of
				751	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	752	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]	753
				754	<p>
				755	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				756	constant, even if the final definition of the global is not. This capability
				757	can be used to enable slightly better optimization of the program, but requires
				758	the language definition to guarantee that optimizations based on the
				759	'constantness' are valid for the translation units that do not include the
				760	definition.
				761	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	762
				763	<p>As SSA values, global variables define pointer values that are in
				764	scope (i.e. they dominate) all basic blocks in the program. Global
				765	variables always define a pointer to their "content" type because they
				766	describe a region of memory, and all memory objects in LLVM are
				767	accessed through pointers.</p>
				768
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	769	<p>A global variable may be declared to reside in a target-specifc numbered
				770	address space. For targets that support them, address spaces may affect how
				771	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	772	the variable. The default address space is zero. The address space qualifier
				773	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	774
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	775	<p>LLVM allows an explicit section to be specified for globals. If the target
				776	supports it, it will emit globals to the section specified.</p>
				777
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	778	<p>An explicit alignment may be specified for a global. If not present, or if
				779	the alignment is set to zero, the alignment of the global is set by the target
				780	to whatever it feels convenient. If an explicit alignment is specified, the
				781	global is forced to have at least that much alignment. All alignments must be
				782	a power of 2.</p>
				783
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	784	<p>For example, the following defines a global in a numbered address space with
				785	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	786
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	787	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	788	<pre>
Dan Gohman	398873c	2009-01-11 00:40:00 +0000	[diff] [blame]	789	@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	790	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	791	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	792
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	793	</div>
				794
				795
				796	<!-- ======================================================================= -->
				797	<div class="doc_subsection">
				798	<a name="functionstructure">Functions</a>
				799	</div>
				800
				801	<div class="doc_text">
				802
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	803	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				804	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	805	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	806	<a href="#callingconv">calling convention</a>, a return type, an optional
				807	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				808	name, a (possibly empty) argument list (each with optional
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	809	<a href="#paramattrs">parameter attributes</a>), optional
				810	<a href="#fnattrs">function attributes</a>, an optional section,
				811	an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	0c46a7d	2008-10-04 18:10:21 +0000	[diff] [blame]	812	an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	813
				814	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				815	optional <a href="#linkage">linkage type</a>, an optional
				816	<a href="#visibility">visibility style</a>, an optional
				817	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	818	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	819	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]	820	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	821
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	822	<p>A function definition contains a list of basic blocks, forming the CFG
				823	(Control Flow Graph) for
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	824	the function. Each basic block may optionally start with a label (giving the
				825	basic block a symbol table entry), contains a list of instructions, and ends
				826	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				827	function return).</p>
				828
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	829	<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]	830	executed on entrance to the function, and it is not allowed to have predecessor
				831	basic blocks (i.e. there can not be any branches to the entry block of a
				832	function). Because the block can have no predecessors, it also cannot have any
				833	<a href="#i_phi">PHI nodes</a>.</p>
				834
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	835	<p>LLVM allows an explicit section to be specified for functions. If the target
				836	supports it, it will emit functions to the section specified.</p>
				837
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	838	<p>An explicit alignment may be specified for a function. If not present, or if
				839	the alignment is set to zero, the alignment of the function is set by the target
				840	to whatever it feels convenient. If an explicit alignment is specified, the
				841	function is forced to have at least that much alignment. All alignments must be
				842	a power of 2.</p>
				843
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	844	<h5>Syntax:</h5>
				845
				846	<div class="doc_code">
Chris Lattner	50ad45c	2008-10-13 16:55:18 +0000	[diff] [blame]	847	<tt>
				848	define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
				849	[<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
				850	<ResultType> @<FunctionName> ([argument list])
				851	[<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
				852	[<a href="#gc">gc</a>] { ... }
				853	</tt>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	854	</div>
				855
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	856	</div>
				857
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	858
				859	<!-- ======================================================================= -->
				860	<div class="doc_subsection">
				861	<a name="aliasstructure">Aliases</a>
				862	</div>
				863	<div class="doc_text">
				864	<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]	865	function, global variable, another alias or bitcast of global value). Aliases
				866	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	867	optional <a href="#visibility">visibility style</a>.</p>
				868
				869	<h5>Syntax:</h5>
				870
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	871	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	872	<pre>
Duncan Sands	0b23ac1	2008-09-12 20:48:21 +0000	[diff] [blame]	873	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	874	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	875	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	876
				877	</div>
				878
				879
				880
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	881	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	882	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				883	<div class="doc_text">
				884	<p>The return type and each parameter of a function type may have a set of
				885	<i>parameter attributes</i> associated with them. Parameter attributes are
				886	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	887	a function. Parameter attributes are considered to be part of the function,
				888	not of the function type, so functions with different parameter attributes
				889	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	890
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	891	<p>Parameter attributes are simple keywords that follow the type specified. If
				892	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	893	example:</p>
				894
				895	<div class="doc_code">
				896	<pre>
Nick Lewycky	b6a7d25	2009-02-15 23:06:14 +0000	[diff] [blame]	897	declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	898	declare i32 @atoi(i8 zeroext)
				899	declare signext i8 @returns_signed_char()
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	900	</pre>
				901	</div>
				902
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	903	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				904	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	905
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	906	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	907	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	908	<dt><tt>zeroext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	909	<dd>This indicates to the code generator that the parameter or return value
				910	should be zero-extended to a 32-bit value by the caller (for a parameter)
				911	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	912
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	913	<dt><tt>signext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	914	<dd>This indicates to the code generator that the parameter or return value
				915	should be sign-extended to a 32-bit value by the caller (for a parameter)
				916	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	917
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	918	<dt><tt>inreg</tt></dt>
Dale Johannesen	c9c6da6	2008-09-25 20:47:45 +0000	[diff] [blame]	919	<dd>This indicates that this parameter or return value should be treated
				920	in a special target-dependent fashion during while emitting code for a
				921	function call or return (usually, by putting it in a register as opposed
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	922	to memory, though some targets use it to distinguish between two different
				923	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	924
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	925	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	926	<dd>This indicates that the pointer parameter should really be passed by
				927	value to the function. The attribute implies that a hidden copy of the
				928	pointee is made between the caller and the callee, so the callee is unable
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	929	to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	930	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	931	value, but is also valid on pointers to scalars. The copy is considered to
				932	belong to the caller not the callee (for example,
				933	<tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	934	<tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattner	ce459b1	2009-02-05 05:42:28 +0000	[diff] [blame]	935	values. The byval attribute also supports specifying an alignment with the
				936	align attribute. This has a target-specific effect on the code generator
				937	that usually indicates a desired alignment for the synthesized stack
				938	slot.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	939
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	940	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	941	<dd>This indicates that the pointer parameter specifies the address of a
				942	structure that is the return value of the function in the source program.
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	943	This pointer must be guaranteed by the caller to be valid: loads and stores
				944	to the structure may be assumed by the callee to not to trap. This may only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	945	be applied to the first parameter. This is not a valid attribute for
				946	return values. </dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	947
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	948	<dt><tt>noalias</tt></dt>
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	949	<dd>This indicates that the pointer does not alias any global or any other
				950	parameter. The caller is responsible for ensuring that this is the
Nick Lewycky	b2b32fd	2008-11-24 05:00:44 +0000	[diff] [blame]	951	case. On a function return value, <tt>noalias</tt> additionally indicates
				952	that the pointer does not alias any other pointers visible to the
Nick Lewycky	f23d0d3	2008-12-19 06:39:12 +0000	[diff] [blame]	953	caller. For further details, please see the discussion of the NoAlias
				954	response in
				955	<a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
				956	analysis</a>.</dd>
				957
				958	<dt><tt>nocapture</tt></dt>
				959	<dd>This indicates that the callee does not make any copies of the pointer
				960	that outlive the callee itself. This is not a valid attribute for return
				961	values.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	962
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	963	<dt><tt>nest</tt></dt>
Duncan Sands	0789b8b	2008-07-08 09:27:25 +0000	[diff] [blame]	964	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	965	<a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
				966	attribute for return values.</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	967	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	968
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	969	</div>
				970
				971	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	972	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	973	<a name="gc">Garbage Collector Names</a>
				974	</div>
				975
				976	<div class="doc_text">
				977	<p>Each function may specify a garbage collector name, which is simply a
				978	string.</p>
				979
				980	<div class="doc_code"><pre
				981	>define void @f() gc "name" { ...</pre></div>
				982
				983	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				984	collector which will cause the compiler to alter its output in order to support
				985	the named garbage collection algorithm.</p>
				986	</div>
				987
				988	<!-- ======================================================================= -->
				989	<div class="doc_subsection">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	990	<a name="fnattrs">Function Attributes</a>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	991	</div>
				992
				993	<div class="doc_text">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	994
				995	<p>Function attributes are set to communicate additional information about
				996	a function. Function attributes are considered to be part of the function,
				997	not of the function type, so functions with different parameter attributes
				998	can have the same function type.</p>
				999
				1000	<p>Function attributes are simple keywords that follow the type specified. If
				1001	multiple attributes are needed, they are space separated. For
				1002	example:</p>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1003
				1004	<div class="doc_code">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1005	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1006	define void @f() noinline { ... }
				1007	define void @f() alwaysinline { ... }
				1008	define void @f() alwaysinline optsize { ... }
				1009	define void @f() optsize
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1010	</pre>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1011	</div>
				1012
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1013	<dl>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1014	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1015	<dd>This attribute indicates that the inliner should attempt to inline this
				1016	function into callers whenever possible, ignoring any active inlining size
				1017	threshold for this caller.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1018
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1019	<dt><tt>noinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1020	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	94b5f7d	2008-10-05 17:14:59 +0000	[diff] [blame]	1021	in any situation. This attribute may not be used together with the
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1022	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1023
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1024	<dt><tt>optsize</tt></dt>
Devang Patel	66c6c65	2008-09-29 18:34:44 +0000	[diff] [blame]	1025	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1026	make choices that keep the code size of this function low, and otherwise do
				1027	optimizations specifically to reduce code size.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1028
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1029	<dt><tt>noreturn</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1030	<dd>This function attribute indicates that the function never returns normally.
				1031	This produces undefined behavior at runtime if the function ever does
				1032	dynamically return.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1033
				1034	<dt><tt>nounwind</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1035	<dd>This function attribute indicates that the function never returns with an
				1036	unwind or exceptional control flow. If the function does unwind, its runtime
				1037	behavior is undefined.</dd>
				1038
				1039	<dt><tt>readnone</tt></dt>
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	1040	<dd>This attribute indicates that the function computes its result (or the
				1041	exception it throws) based strictly on its arguments, without dereferencing any
				1042	pointer arguments or otherwise accessing any mutable state (e.g. memory, control
				1043	registers, etc) visible to caller functions. It does not write through any
				1044	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
				1045	never changes any state visible to callers.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1046
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	1047	<dt><tt><a name="readonly">readonly</a></tt></dt>
				1048	<dd>This attribute indicates that the function does not write through any
				1049	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
				1050	or otherwise modify any state (e.g. memory, control registers, etc) visible to
				1051	caller functions. It may dereference pointer arguments and read state that may
				1052	be set in the caller. A readonly function always returns the same value (or
				1053	throws the same exception) when called with the same set of arguments and global
				1054	state.</dd>
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1055
				1056	<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1057	<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1058	protector. It is in the form of a "canary"—a random value placed on the
				1059	stack before the local variables that's checked upon return from the function to
				1060	see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1061	needs stack protectors or not.
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1062
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1063	<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
				1064	that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
				1065	have an <tt>ssp</tt> attribute.</p></dd>
				1066
				1067	<dt><tt>sspreq</tt></dt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1068	<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1069	stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1070	function attribute.
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1071
				1072	<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
				1073	function that doesn't have an <tt>sspreq</tt> attribute or which has
				1074	an <tt>ssp</tt> attribute, then the resulting function will have
				1075	an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1076	</dl>
				1077
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1078	</div>
				1079
				1080	<!-- ======================================================================= -->
				1081	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	1082	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1083	</div>
				1084
				1085	<div class="doc_text">
				1086	<p>
				1087	Modules may contain "module-level inline asm" blocks, which corresponds to the
				1088	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				1089	LLVM and treated as a single unit, but may be separated in the .ll file if
				1090	desired. The syntax is very simple:
				1091	</p>
				1092
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1093	<div class="doc_code">
				1094	<pre>
				1095	module asm "inline asm code goes here"
				1096	module asm "more can go here"
				1097	</pre>
				1098	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1099
				1100	<p>The strings can contain any character by escaping non-printable characters.
				1101	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1102	for the number.
				1103	</p>
				1104
				1105	<p>
				1106	The inline asm code is simply printed to the machine code .s file when
				1107	assembly code is generated.
				1108	</p>
				1109	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1110
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1111	<!-- ======================================================================= -->
				1112	<div class="doc_subsection">
				1113	<a name="datalayout">Data Layout</a>
				1114	</div>
				1115
				1116	<div class="doc_text">
				1117	<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]	1118	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1119	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1120	<p>The <i>layout specification</i> consists of a list of specifications
				1121	separated by the minus sign character ('-'). Each specification starts with a
				1122	letter and may include other information after the letter to define some
				1123	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1124	<dl>
				1125	<dt><tt>E</tt></dt>
				1126	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1127	bits with the most significance have the lowest address location.</dd>
				1128	<dt><tt>e</tt></dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1129	<dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1130	the bits with the least significance have the lowest address location.</dd>
				1131	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1132	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1133	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1134	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1135	too.</dd>
				1136	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1137	<dd>This specifies the alignment for an integer type of a given bit
				1138	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1139	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1140	<dd>This specifies the alignment for a vector type of a given bit
				1141	<i>size</i>.</dd>
				1142	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1143	<dd>This specifies the alignment for a floating point type of a given bit
				1144	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1145	(double).</dd>
				1146	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1147	<dd>This specifies the alignment for an aggregate type of a given bit
				1148	<i>size</i>.</dd>
				1149	</dl>
				1150	<p>When constructing the data layout for a given target, LLVM starts with a
				1151	default set of specifications which are then (possibly) overriden by the
				1152	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1153	are given in this list:</p>
				1154	<ul>
				1155	<li><tt>E</tt> - big endian</li>
				1156	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1157	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1158	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1159	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1160	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1161	<li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1162	alignment of 64-bits</li>
				1163	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1164	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1165	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1166	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1167	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				1168	</ul>
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	1169	<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	1170	following rules:</p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1171	<ol>
				1172	<li>If the type sought is an exact match for one of the specifications, that
				1173	specification is used.</li>
				1174	<li>If no match is found, and the type sought is an integer type, then the
				1175	smallest integer type that is larger than the bitwidth of the sought type is
				1176	used. If none of the specifications are larger than the bitwidth then the the
				1177	largest integer type is used. For example, given the default specifications
				1178	above, the i7 type will use the alignment of i8 (next largest) while both
				1179	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1180	<li>If no match is found, and the type sought is a vector type, then the
				1181	largest vector type that is smaller than the sought vector type will be used
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	1182	as a fall back. This happens because <128 x double> can be implemented
				1183	in terms of 64 <2 x double>, for example.</li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1184	</ol>
				1185	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1186
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1187	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1188	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1189	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1190
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1191	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1192
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1193	<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]	1194	intermediate representation. Being typed enables a number of
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1195	optimizations to be performed on the intermediate representation directly,
				1196	without having to do
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1197	extra analyses on the side before the transformation. A strong type
				1198	system makes it easier to read the generated code and enables novel
				1199	analyses and transformations that are not feasible to perform on normal
				1200	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1201
				1202	</div>
				1203
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1204	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1205	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1206	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1207	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1208	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1209	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1210
				1211	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1212	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1213	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1214	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1215	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1216	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1217	</tr>
				1218	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1219	<td><a href="#t_floating">floating point</a></td>
				1220	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1221	</tr>
				1222	<tr>
				1223	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1224	<td><a href="#t_integer">integer</a>,
				1225	<a href="#t_floating">floating point</a>,
				1226	<a href="#t_pointer">pointer</a>,
Dan Gohman	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame]	1227	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1228	<a href="#t_struct">structure</a>,
				1229	<a href="#t_array">array</a>,
Dan Gohman	ade5faa	2008-05-23 22:50:26 +0000	[diff] [blame]	1230	<a href="#t_label">label</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1231	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1232	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1233	<tr>
				1234	<td><a href="#t_primitive">primitive</a></td>
				1235	<td><a href="#t_label">label</a>,
				1236	<a href="#t_void">void</a>,
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1237	<a href="#t_floating">floating point</a>.</td>
				1238	</tr>
				1239	<tr>
				1240	<td><a href="#t_derived">derived</a></td>
				1241	<td><a href="#t_integer">integer</a>,
				1242	<a href="#t_array">array</a>,
				1243	<a href="#t_function">function</a>,
				1244	<a href="#t_pointer">pointer</a>,
				1245	<a href="#t_struct">structure</a>,
				1246	<a href="#t_pstruct">packed structure</a>,
				1247	<a href="#t_vector">vector</a>,
				1248	<a href="#t_opaque">opaque</a>.
Dan Gohman	01ac101	2008-10-14 16:32:04 +0000	[diff] [blame]	1249	</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1250	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1251	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1252	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1253
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1254	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1255	most important. Values of these types are the only ones which can be
				1256	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1257	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1258	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1259
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1260	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1261	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1262
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1263	<div class="doc_text">
				1264	<p>The primitive types are the fundamental building blocks of the LLVM
				1265	system.</p>
				1266
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1267	</div>
				1268
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1269	<!-- _______________________________________________________________________ -->
				1270	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1271
				1272	<div class="doc_text">
				1273	<table>
				1274	<tbody>
				1275	<tr><th>Type</th><th>Description</th></tr>
				1276	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1277	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1278	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1279	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1280	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1281	</tbody>
				1282	</table>
				1283	</div>
				1284
				1285	<!-- _______________________________________________________________________ -->
				1286	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1287
				1288	<div class="doc_text">
				1289	<h5>Overview:</h5>
				1290	<p>The void type does not represent any value and has no size.</p>
				1291
				1292	<h5>Syntax:</h5>
				1293
				1294	<pre>
				1295	void
				1296	</pre>
				1297	</div>
				1298
				1299	<!-- _______________________________________________________________________ -->
				1300	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1301
				1302	<div class="doc_text">
				1303	<h5>Overview:</h5>
				1304	<p>The label type represents code labels.</p>
				1305
				1306	<h5>Syntax:</h5>
				1307
				1308	<pre>
				1309	label
				1310	</pre>
				1311	</div>
				1312
				1313
				1314	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1315	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1316
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1317	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1318
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1319	<p>The real power in LLVM comes from the derived types in the system.
				1320	This is what allows a programmer to represent arrays, functions,
				1321	pointers, and other useful types. Note that these derived types may be
				1322	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]	1323
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1324	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1325
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1326	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1327	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1328
				1329	<div class="doc_text">
				1330
				1331	<h5>Overview:</h5>
				1332	<p>The integer type is a very simple derived type that simply specifies an
				1333	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1334	2^23-1 (about 8 million) can be specified.</p>
				1335
				1336	<h5>Syntax:</h5>
				1337
				1338	<pre>
				1339	iN
				1340	</pre>
				1341
				1342	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1343	value.</p>
				1344
				1345	<h5>Examples:</h5>
				1346	<table class="layout">
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1347	<tbody>
				1348	<tr>
				1349	<td><tt>i1</tt></td>
				1350	<td>a single-bit integer.</td>
				1351	</tr><tr>
				1352	<td><tt>i32</tt></td>
				1353	<td>a 32-bit integer.</td>
				1354	</tr><tr>
				1355	<td><tt>i1942652</tt></td>
				1356	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1357	</tr>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1358	</tbody>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1359	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1360
				1361	<p>Note that the code generator does not yet support large integer types
				1362	to be used as function return types. The specific limit on how large a
				1363	return type the code generator can currently handle is target-dependent;
				1364	currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
				1365	targets.</p>
				1366
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1367	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1368
				1369	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1370	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1371
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1372	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1373
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1374	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1375
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1376	<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]	1377	sequentially in memory. The array type requires a size (number of
				1378	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1379
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1380	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1381
				1382	<pre>
				1383	[<# elements> x <elementtype>]
				1384	</pre>
				1385
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1386	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1387	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1388
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1389	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1390	<table class="layout">
				1391	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1392	<td class="left"><tt>[40 x i32]</tt></td>
				1393	<td class="left">Array of 40 32-bit integer values.</td>
				1394	</tr>
				1395	<tr class="layout">
				1396	<td class="left"><tt>[41 x i32]</tt></td>
				1397	<td class="left">Array of 41 32-bit integer values.</td>
				1398	</tr>
				1399	<tr class="layout">
				1400	<td class="left"><tt>[4 x i8]</tt></td>
				1401	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1402	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1403	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1404	<p>Here are some examples of multidimensional arrays:</p>
				1405	<table class="layout">
				1406	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1407	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1408	<td class="left">3x4 array of 32-bit integer values.</td>
				1409	</tr>
				1410	<tr class="layout">
				1411	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1412	<td class="left">12x10 array of single precision floating point values.</td>
				1413	</tr>
				1414	<tr class="layout">
				1415	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1416	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1417	</tr>
				1418	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1419
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1420	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1421	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]	1422	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1423	As a special case, however, zero length arrays are recognized to be variable
				1424	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1425	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1426
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1427	<p>Note that the code generator does not yet support large aggregate types
				1428	to be used as function return types. The specific limit on how large an
				1429	aggregate return type the code generator can currently handle is
				1430	target-dependent, and also dependent on the aggregate element types.</p>
				1431
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1432	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1433
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1434	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1435	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1436	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1437
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1438	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1439
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1440	<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]	1441	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]	1442	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]	1443	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]	1444	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1445
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1446	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1447
				1448	<pre>
				1449	<returntype list> (<parameter list>)
				1450	</pre>
				1451
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1452	<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]	1453	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1454	which indicates that the function takes a variable number of arguments.
				1455	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1456	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1457	'<tt><returntype list></tt>' is a comma-separated list of
				1458	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1459
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1460	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1461	<table class="layout">
				1462	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1463	<td class="left"><tt>i32 (i32)</tt></td>
				1464	<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]	1465	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1466	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1467	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1468	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1469	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1470	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1471	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1472	<tt>float</tt>.
				1473	</td>
				1474	</tr><tr class="layout">
				1475	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1476	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1477	<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]	1478	which returns an integer. This is the signature for <tt>printf</tt> in
				1479	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1480	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1481	</tr><tr class="layout">
				1482	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukman	b0a57aa	2008-11-27 06:41:20 +0000	[diff] [blame]	1483	<td class="left">A function taking an <tt>i32</tt>, returning two
				1484	<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]	1485	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1486	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1487	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1488
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1489	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1490	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1491	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1492	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1493	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1494	<p>The structure type is used to represent a collection of data members
				1495	together in memory. The packing of the field types is defined to match
				1496	the ABI of the underlying processor. The elements of a structure may
				1497	be any type that has a size.</p>
				1498	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1499	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1500	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1501	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1502	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1503	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1504	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1505	<table class="layout">
				1506	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1507	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1508	<td class="left">A triple of three <tt>i32</tt> values</td>
				1509	</tr><tr class="layout">
				1510	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1511	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1512	second element is a <a href="#t_pointer">pointer</a> to a
				1513	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1514	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1515	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1516	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1517
				1518	<p>Note that the code generator does not yet support large aggregate types
				1519	to be used as function return types. The specific limit on how large an
				1520	aggregate return type the code generator can currently handle is
				1521	target-dependent, and also dependent on the aggregate element types.</p>
				1522
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1523	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1524
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1525	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1526	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1527	</div>
				1528	<div class="doc_text">
				1529	<h5>Overview:</h5>
				1530	<p>The packed structure type is used to represent a collection of data members
				1531	together in memory. There is no padding between fields. Further, the alignment
				1532	of a packed structure is 1 byte. The elements of a packed structure may
				1533	be any type that has a size.</p>
				1534	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1535	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1536	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1537	instruction.</p>
				1538	<h5>Syntax:</h5>
				1539	<pre> < { <type list> } > <br></pre>
				1540	<h5>Examples:</h5>
				1541	<table class="layout">
				1542	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1543	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1544	<td class="left">A triple of three <tt>i32</tt> values</td>
				1545	</tr><tr class="layout">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1546	<td class="left">
				1547	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1548	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1549	second element is a <a href="#t_pointer">pointer</a> to a
				1550	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1551	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1552	</tr>
				1553	</table>
				1554	</div>
				1555
				1556	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1557	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1558	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1559	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1560	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1561	reference to another object, which must live in memory. Pointer types may have
				1562	an optional address space attribute defining the target-specific numbered
				1563	address space where the pointed-to object resides. The default address space is
				1564	zero.</p>
Chris Lattner	0fd4a27	2009-02-08 19:53:29 +0000	[diff] [blame]	1565
				1566	<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does
Chris Lattner	e220e8c	2009-02-08 22:21:28 +0000	[diff] [blame]	1567	it permit pointers to labels (<tt>label</tt>). Use <tt>i8</tt> instead.</p>
Chris Lattner	0fd4a27	2009-02-08 19:53:29 +0000	[diff] [blame]	1568
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1569	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1570	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1571	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1572	<table class="layout">
				1573	<tr class="layout">
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	1574	<td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1575	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1576	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1577	</tr>
				1578	<tr class="layout">
				1579	<td class="left"><tt>i32 (i32 ) </tt></td>
				1580	<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]	1581	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]	1582	<tt>i32</tt>.</td>
				1583	</tr>
				1584	<tr class="layout">
				1585	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1586	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1587	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1588	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1589	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1590	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1591
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1592	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1593	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1594	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1595
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1596	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1597
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1598	<p>A vector type is a simple derived type that represents a vector
				1599	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1600	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1601	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1602	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1603	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1604	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1605
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1606	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1607
				1608	<pre>
				1609	< <# elements> x <elementtype> >
				1610	</pre>
				1611
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1612	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1613	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1614
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1615	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1616
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1617	<table class="layout">
				1618	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1619	<td class="left"><tt><4 x i32></tt></td>
				1620	<td class="left">Vector of 4 32-bit integer values.</td>
				1621	</tr>
				1622	<tr class="layout">
				1623	<td class="left"><tt><8 x float></tt></td>
				1624	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1625	</tr>
				1626	<tr class="layout">
				1627	<td class="left"><tt><2 x i64></tt></td>
				1628	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1629	</tr>
				1630	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1631
				1632	<p>Note that the code generator does not yet support large vector types
				1633	to be used as function return types. The specific limit on how large a
				1634	vector return type codegen can currently handle is target-dependent;
				1635	currently it's often a few times longer than a hardware vector register.</p>
				1636
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1637	</div>
				1638
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1639	<!-- _______________________________________________________________________ -->
				1640	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1641	<div class="doc_text">
				1642
				1643	<h5>Overview:</h5>
				1644
				1645	<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]	1646	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]	1647	In LLVM, opaque types can eventually be resolved to any type (not just a
				1648	structure type).</p>
				1649
				1650	<h5>Syntax:</h5>
				1651
				1652	<pre>
				1653	opaque
				1654	</pre>
				1655
				1656	<h5>Examples:</h5>
				1657
				1658	<table class="layout">
				1659	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1660	<td class="left"><tt>opaque</tt></td>
				1661	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1662	</tr>
				1663	</table>
				1664	</div>
				1665
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1666	<!-- ======================================================================= -->
				1667	<div class="doc_subsection">
				1668	<a name="t_uprefs">Type Up-references</a>
				1669	</div>
				1670
				1671	<div class="doc_text">
				1672	<h5>Overview:</h5>
				1673	<p>
				1674	An "up reference" allows you to refer to a lexically enclosing type without
				1675	requiring it to have a name. For instance, a structure declaration may contain a
				1676	pointer to any of the types it is lexically a member of. Example of up
				1677	references (with their equivalent as named type declarations) include:</p>
				1678
				1679	<pre>
Chris Lattner	3060f5b	2009-02-09 10:00:56 +0000	[diff] [blame]	1680	{ \2 * } %x = type { %x* }
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1681	{ \2 }* %y = type { %y }*
				1682	\1* %z = type %z*
				1683	</pre>
				1684
				1685	<p>
				1686	An up reference is needed by the asmprinter for printing out cyclic types when
				1687	there is no declared name for a type in the cycle. Because the asmprinter does
				1688	not want to print out an infinite type string, it needs a syntax to handle
				1689	recursive types that have no names (all names are optional in llvm IR).
				1690	</p>
				1691
				1692	<h5>Syntax:</h5>
				1693	<pre>
				1694	\<level>
				1695	</pre>
				1696
				1697	<p>
				1698	The level is the count of the lexical type that is being referred to.
				1699	</p>
				1700
				1701	<h5>Examples:</h5>
				1702
				1703	<table class="layout">
				1704	<tr class="layout">
				1705	<td class="left"><tt>\1*</tt></td>
				1706	<td class="left">Self-referential pointer.</td>
				1707	</tr>
				1708	<tr class="layout">
				1709	<td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
				1710	<td class="left">Recursive structure where the upref refers to the out-most
				1711	structure.</td>
				1712	</tr>
				1713	</table>
				1714	</div>
				1715
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1716
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1717	<!-- *********************************************************************** -->
				1718	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1719	<!-- *********************************************************************** -->
				1720
				1721	<div class="doc_text">
				1722
				1723	<p>LLVM has several different basic types of constants. This section describes
				1724	them all and their syntax.</p>
				1725
				1726	</div>
				1727
				1728	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1729	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1730
				1731	<div class="doc_text">
				1732
				1733	<dl>
				1734	<dt><b>Boolean constants</b></dt>
				1735
				1736	<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]	1737	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1738	</dd>
				1739
				1740	<dt><b>Integer constants</b></dt>
				1741
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1742	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1743	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1744	integer types.
				1745	</dd>
				1746
				1747	<dt><b>Floating point constants</b></dt>
				1748
				1749	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1750	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1751	notation (see below). The assembler requires the exact decimal value of
				1752	a floating-point constant. For example, the assembler accepts 1.25 but
				1753	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1754	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]	1755
				1756	<dt><b>Null pointer constants</b></dt>
				1757
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1758	<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]	1759	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1760
				1761	</dl>
				1762
Dale Johannesen	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1763	<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1764	of floating point constants. For example, the form '<tt>double
				1765	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1766	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]	1767	(and the only time that they are generated by the disassembler) is when a
				1768	floating point constant must be emitted but it cannot be represented as a
Dale Johannesen	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1769	decimal floating point number in a reasonable number of digits. For example,
				1770	NaN's, infinities, and other
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1771	special values are represented in their IEEE hexadecimal format so that
				1772	assembly and disassembly do not cause any bits to change in the constants.</p>
Dale Johannesen	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1773	<p>When using the hexadecimal form, constants of types float and double are
				1774	represented using the 16-digit form shown above (which matches the IEEE754
				1775	representation for double); float values must, however, be exactly representable
				1776	as IEE754 single precision.
				1777	Hexadecimal format is always used for long
				1778	double, and there are three forms of long double. The 80-bit
				1779	format used by x86 is represented as <tt>0xK</tt>
				1780	followed by 20 hexadecimal digits.
				1781	The 128-bit format used by PowerPC (two adjacent doubles) is represented
				1782	by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
				1783	format is represented
				1784	by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
				1785	target uses this format. Long doubles will only work if they match
				1786	the long double format on your target. All hexadecimal formats are big-endian
				1787	(sign bit at the left).</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1788	</div>
				1789
				1790	<!-- ======================================================================= -->
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame^]	1791	<div class="doc_subsection">
				1792	<a name="aggregateconstants"> <!-- old anchor -->
				1793	<a name="complexconstants">Complex Constants</a></a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1794	</div>
				1795
				1796	<div class="doc_text">
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame^]	1797	<p>Complex constants are a (potentially recursive) combination of simple
				1798	constants and smaller complex constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1799
				1800	<dl>
				1801	<dt><b>Structure constants</b></dt>
				1802
				1803	<dd>Structure constants are represented with notation similar to structure
				1804	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1805	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1806	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]	1807	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]	1808	types of elements must match those specified by the type.
				1809	</dd>
				1810
				1811	<dt><b>Array constants</b></dt>
				1812
				1813	<dd>Array constants are represented with notation similar to array type
				1814	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1815	(<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]	1816	constants must have <a href="#t_array">array type</a>, and the number and
				1817	types of elements must match those specified by the type.
				1818	</dd>
				1819
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1820	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1821
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1822	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1823	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1824	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1825	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1826	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]	1827	match those specified by the type.
				1828	</dd>
				1829
				1830	<dt><b>Zero initialization</b></dt>
				1831
				1832	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1833	value to zero of <em>any</em> type, including scalar and aggregate types.
				1834	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]	1835	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1836	initializers.
				1837	</dd>
				1838	</dl>
				1839
				1840	</div>
				1841
				1842	<!-- ======================================================================= -->
				1843	<div class="doc_subsection">
				1844	<a name="globalconstants">Global Variable and Function Addresses</a>
				1845	</div>
				1846
				1847	<div class="doc_text">
				1848
				1849	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1850	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1851	constants. These constants are explicitly referenced when the <a
				1852	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]	1853	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1854	file:</p>
				1855
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1856	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1857	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1858	@X = global i32 17
				1859	@Y = global i32 42
				1860	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1861	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1862	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1863
				1864	</div>
				1865
				1866	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1867	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1868	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1869	<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]	1870	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]	1871	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1872
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1873	<p>Undefined values indicate to the compiler that the program is well defined
				1874	no matter what value is used, giving the compiler more freedom to optimize.
				1875	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1876	</div>
				1877
				1878	<!-- ======================================================================= -->
				1879	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1880	</div>
				1881
				1882	<div class="doc_text">
				1883
				1884	<p>Constant expressions are used to allow expressions involving other constants
				1885	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1886	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]	1887	that does not have side effects (e.g. load and call are not supported). The
				1888	following is the syntax for constant expressions:</p>
				1889
				1890	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1891	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1892	<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]	1893	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1894
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1895	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1896	<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]	1897	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]	1898
				1899	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1900	<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]	1901	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]	1902
				1903	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1904	<dd>Truncate a floating point constant to another floating point type. The
				1905	size of CST must be larger than the size of TYPE. Both types must be
				1906	floating point.</dd>
				1907
				1908	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1909	<dd>Floating point extend a constant to another type. The size of CST must be
				1910	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1911
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1912	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1913	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1914	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1915	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1916	of the same number of elements. If the value won't fit in the integer type,
				1917	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1918
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1919	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1920	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1921	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1922	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1923	of the same number of elements. If the value won't fit in the integer type,
				1924	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1925
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1926	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1927	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1928	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1929	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1930	of the same number of elements. If the value won't fit in the floating point
				1931	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1932
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1933	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1934	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1935	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1936	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1937	of the same number of elements. If the value won't fit in the floating point
				1938	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1939
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1940	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1941	<dd>Convert a pointer typed constant to the corresponding integer constant
				1942	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1943	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1944
				1945	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1946	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1947	pointer type. CST must be of integer type. The CST value is zero extended,
				1948	truncated, or unchanged to make it fit in a pointer size. This one is
				1949	<i>really</i> dangerous!</dd>
				1950
				1951	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner	03bbad6	2009-02-28 18:27:03 +0000	[diff] [blame]	1952	<dd>Convert a constant, CST, to another TYPE. The constraints of the operands
				1953	are the same as those for the <a href="#i_bitcast">bitcast
				1954	instruction</a>.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1955
				1956	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1957
				1958	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1959	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1960	instruction, the index list may have zero or more indexes, which are required
				1961	to make sense for the type of "CSTPTR".</dd>
				1962
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1963	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1964
				1965	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1966	constants.</dd>
				1967
				1968	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1969	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1970
				1971	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1972	<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]	1973
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	1974	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1975	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1976
				1977	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1978	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1979
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1980	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1981
				1982	<dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	1983	operation</a> on constants.</dd>
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1984
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1985	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				1986
				1987	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1988	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1989
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1990
				1991	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				1992
				1993	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1994	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1995
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1996	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				1997
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1998	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				1999	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]	2000	binary</a> operations. The constraints on operands are the same as those for
				2001	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2002	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2003	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2004	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	2005
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2006	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2007	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				2008	<!-- *********************************************************************** -->
				2009
				2010	<!-- ======================================================================= -->
				2011	<div class="doc_subsection">
				2012	<a name="inlineasm">Inline Assembler Expressions</a>
				2013	</div>
				2014
				2015	<div class="doc_text">
				2016
				2017	<p>
				2018	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				2019	Module-Level Inline Assembly</a>) through the use of a special value. This
				2020	value represents the inline assembler as a string (containing the instructions
				2021	to emit), a list of operand constraints (stored as a string), and a flag that
				2022	indicates whether or not the inline asm expression has side effects. An example
				2023	inline assembler expression is:
				2024	</p>
				2025
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2026	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2027	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2028	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2029	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2030	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2031
				2032	<p>
				2033	Inline assembler expressions may <b>only</b> be used as the callee operand of
				2034	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				2035	</p>
				2036
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2037	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2038	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2039	%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]	2040	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2041	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2042
				2043	<p>
				2044	Inline asms with side effects not visible in the constraint list must be marked
				2045	as having side effects. This is done through the use of the
				2046	'<tt>sideeffect</tt>' keyword, like so:
				2047	</p>
				2048
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2049	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2050	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2051	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2052	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2053	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2054
				2055	<p>TODO: The format of the asm and constraints string still need to be
				2056	documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattner	4f99335	2008-10-04 18:36:02 +0000	[diff] [blame]	2057	need to be documented). This is probably best done by reference to another
				2058	document that covers inline asm from a holistic perspective.
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2059	</p>
				2060
				2061	</div>
				2062
				2063	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2064	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				2065	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2066
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2067	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2068
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2069	<p>The LLVM instruction set consists of several different
				2070	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	2071	instructions</a>, <a href="#binaryops">binary instructions</a>,
				2072	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2073	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				2074	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2075
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2076	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2077
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2078	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2079	<div class="doc_subsection"> <a name="terminators">Terminator
				2080	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2081
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2082	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2083
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2084	<p>As mentioned <a href="#functionstructure">previously</a>, every
				2085	basic block in a program ends with a "Terminator" instruction, which
				2086	indicates which block should be executed after the current block is
				2087	finished. These terminator instructions typically yield a '<tt>void</tt>'
				2088	value: they produce control flow, not values (the one exception being
				2089	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2090	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2091	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				2092	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2093	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				2094	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				2095	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2096
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2097	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2098
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2099	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2100	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				2101	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2102	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2103	<h5>Syntax:</h5>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2104	<pre>
				2105	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]	2106	ret void <i>; Return from void function</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2107	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2108
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2109	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2110
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2111	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				2112	optionally a value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	2113	<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2114	returns a value and then causes control flow, and one that just causes
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2115	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2116
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2117	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2118
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2119	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				2120	the return value. The type of the return value must be a
				2121	'<a href="#t_firstclass">first class</a>' type.</p>
				2122
				2123	<p>A function is not <a href="#wellformed">well formed</a> if
				2124	it it has a non-void return type and contains a '<tt>ret</tt>'
				2125	instruction with no return value or a return value with a type that
				2126	does not match its type, or if it has a void return type and contains
				2127	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2128
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2129	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2130
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2131	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				2132	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]	2133	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2134	the instruction after the call. If the caller was an "<a
				2135	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2136	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2137	returns a value, that value shall set the call or invoke instruction's
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2138	return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2139
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2140	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2141
				2142	<pre>
				2143	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	2144	ret void <i>; Return from a void function</i>
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame^]	2145	ret { i32, i8 } { i32 4, i8 2 } <i>; Return an struct of values 4 and 2</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2146	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2147
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	2148	<p>Note that the code generator does not yet fully support large
				2149	return values. The specific sizes that are currently supported are
				2150	dependent on the target. For integers, on 32-bit targets the limit
				2151	is often 64 bits, and on 64-bit targets the limit is often 128 bits.
				2152	For aggregate types, the current limits are dependent on the element
				2153	types; for example targets are often limited to 2 total integer
				2154	elements and 2 total floating-point elements.</p>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2155
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2156	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2157	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2158	<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]	2159	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2160	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2161	<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]	2162	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2163	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2164	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				2165	transfer to a different basic block in the current function. There are
				2166	two forms of this instruction, corresponding to a conditional branch
				2167	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2168	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2169	<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]	2170	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	2171	unconditional form of the '<tt>br</tt>' instruction takes a single
				2172	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2173	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2174	<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]	2175	argument is evaluated. If the value is <tt>true</tt>, control flows
				2176	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				2177	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2178	<h5>Example:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2179	<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]	2180	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]	2181	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2182	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2183	<div class="doc_subsubsection">
				2184	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				2185	</div>
				2186
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2187	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2188	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2189
				2190	<pre>
				2191	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2192	</pre>
				2193
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2194	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2195
				2196	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2197	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2198	instruction, allowing a branch to occur to one of many possible
				2199	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2200
				2201
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2202	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2203
				2204	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2205	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2206	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2207	table is not allowed to contain duplicate constant entries.</p>
				2208
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2209	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2210
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2211	<p>The <tt>switch</tt> instruction specifies a table of values and
				2212	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2213	table is searched for the given value. If the value is found, control flow is
				2214	transfered to the corresponding destination; otherwise, control flow is
				2215	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2216
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2217	<h5>Implementation:</h5>
				2218
				2219	<p>Depending on properties of the target machine and the particular
				2220	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2221	ways. For example, it could be generated as a series of chained conditional
				2222	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2223
				2224	<h5>Example:</h5>
				2225
				2226	<pre>
				2227	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2228	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2229	switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2230
				2231	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2232	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2233
				2234	<i>; Implement a jump table:</i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2235	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2236	i32 1, label %onone
				2237	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2238	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2239	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2240
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2241	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2242	<div class="doc_subsubsection">
				2243	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2244	</div>
				2245
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2246	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2247
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2248	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2249
				2250	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2251	<result> = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ptr to function ty> <function ptr val>(<function args>) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner	76b8a33	2006-05-14 18:23:06 +0000	[diff] [blame]	2252	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2253	</pre>
				2254
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	2255	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2256
				2257	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2258	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2259	'<tt>normal</tt>' label or the
				2260	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2261	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2262	"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]	2263	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2264	continued at the dynamically nearest "exception" label.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2265
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2266	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2267
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2268	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2269
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2270	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2271	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	2272	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2273	convention</a> the call should use. If none is specified, the call defaults
				2274	to using C calling conventions.
				2275	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2276
				2277	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2278	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2279	and '<tt>inreg</tt>' attributes are valid here.</li>
				2280
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2281	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2282	function value being invoked. In most cases, this is a direct function
				2283	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2284	an arbitrary pointer to function value.
				2285	</li>
				2286
				2287	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2288	function to be invoked. </li>
				2289
				2290	<li>'<tt>function args</tt>': argument list whose types match the function
				2291	signature argument types. If the function signature indicates the function
				2292	accepts a variable number of arguments, the extra arguments can be
				2293	specified. </li>
				2294
				2295	<li>'<tt>normal label</tt>': the label reached when the called function
				2296	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2297
				2298	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2299	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2300
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2301	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2302	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2303	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2304	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2305
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2306	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2307
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2308	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2309	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2310	difference is that it establishes an association with a label, which is used by
				2311	the runtime library to unwind the stack.</p>
				2312
				2313	<p>This instruction is used in languages with destructors to ensure that proper
				2314	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2315	exception. Additionally, this is important for implementation of
				2316	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2317
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2318	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2319	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2320	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2321	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2322	%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]	2323	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2324	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2325	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2326
				2327
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2328	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2329
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2330	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2331	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2332
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2333	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2334
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2335	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2336	<pre>
				2337	unwind
				2338	</pre>
				2339
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2340	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2341
				2342	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2343	at the first callee in the dynamic call stack which used an <a
				2344	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2345	primarily used to implement exception handling.</p>
				2346
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2347	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2348
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2349	<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]	2350	immediately halt. The dynamic call stack is then searched for the first <a
				2351	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2352	execution continues at the "exceptional" destination block specified by the
				2353	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2354	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2355	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2356
				2357	<!-- _______________________________________________________________________ -->
				2358
				2359	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2360	Instruction</a> </div>
				2361
				2362	<div class="doc_text">
				2363
				2364	<h5>Syntax:</h5>
				2365	<pre>
				2366	unreachable
				2367	</pre>
				2368
				2369	<h5>Overview:</h5>
				2370
				2371	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2372	instruction is used to inform the optimizer that a particular portion of the
				2373	code is not reachable. This can be used to indicate that the code after a
				2374	no-return function cannot be reached, and other facts.</p>
				2375
				2376	<h5>Semantics:</h5>
				2377
				2378	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2379	</div>
				2380
				2381
				2382
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2383	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2384	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2385	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2386	<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]	2387	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]	2388	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2389	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]	2390	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2391	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2392	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2393	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2394	<div class="doc_subsubsection">
				2395	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2396	</div>
				2397
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2398	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2399
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2400	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2401
				2402	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2403	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2404	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2405
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2406	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2407
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2408	<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]	2409
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2410	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2411
				2412	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2413	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2414	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2415	types.</p>
				2416
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2417	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2418
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2419	<p>The value produced is the integer or floating point sum of the two
				2420	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2421
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2422	<p>If an integer sum has unsigned overflow, the result returned is the
				2423	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2424	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2425
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2426	<p>Because LLVM integers use a two's complement representation, this
				2427	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2428
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2429	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2430
				2431	<pre>
				2432	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2433	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2434	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2435	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2436	<div class="doc_subsubsection">
				2437	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2438	</div>
				2439
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2440	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2441
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2442	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2443
				2444	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2445	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2446	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2447
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2448	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2449
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2450	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2451	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2452
				2453	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2454	'<tt>neg</tt>' instruction present in most other intermediate
				2455	representations.</p>
				2456
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2457	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2458
				2459	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2460	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2461	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2462	types.</p>
				2463
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2464	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2465
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2466	<p>The value produced is the integer or floating point difference of
				2467	the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2468
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2469	<p>If an integer difference has unsigned overflow, the result returned is the
				2470	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2471	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2472
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2473	<p>Because LLVM integers use a two's complement representation, this
				2474	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2475
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2476	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2477	<pre>
				2478	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2479	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2480	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2481	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2482
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2483	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2484	<div class="doc_subsubsection">
				2485	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2486	</div>
				2487
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2488	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2489
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2490	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2491	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2492	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2493	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2494	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2495	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2496
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2497	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2498
				2499	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2500	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2501	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2502	types.</p>
				2503
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2504	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2505
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2506	<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]	2507	two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2508
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2509	<p>If the result of an integer multiplication has unsigned overflow,
				2510	the result returned is the mathematical result modulo
				2511	2<sup>n</sup>, where n is the bit width of the result.</p>
				2512	<p>Because LLVM integers use a two's complement representation, and the
				2513	result is the same width as the operands, this instruction returns the
				2514	correct result for both signed and unsigned integers. If a full product
				2515	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2516	should be sign-extended or zero-extended as appropriate to the
				2517	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2518	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2519	<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]	2520	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2521	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2522
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2523	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2524	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2525	</a></div>
				2526	<div class="doc_text">
				2527	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2528	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2529	</pre>
				2530	<h5>Overview:</h5>
				2531	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2532	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2533
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2534	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2535
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2536	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2537	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2538	values. Both arguments must have identical types.</p>
				2539
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2540	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2541
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2542	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2543	<p>Note that unsigned integer division and signed integer division are distinct
				2544	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2545	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2546	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2547	<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]	2548	</pre>
				2549	</div>
				2550	<!-- _______________________________________________________________________ -->
				2551	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2552	</a> </div>
				2553	<div class="doc_text">
				2554	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2555	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2556	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2557	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2558
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2559	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2560
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2561	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2562	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2563
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2564	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2565
				2566	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2567	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2568	values. Both arguments must have identical types.</p>
				2569
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2570	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2571	<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]	2572	<p>Note that signed integer division and unsigned integer division are distinct
				2573	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2574	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2575	undefined behavior; this is a rare case, but can occur, for example,
				2576	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2577	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2578	<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]	2579	</pre>
				2580	</div>
				2581	<!-- _______________________________________________________________________ -->
				2582	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2583	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2584	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2585	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2586	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2587	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2588	</pre>
				2589	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2590
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2591	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2592	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2593
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2594	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2595
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2596	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2597	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2598	of floating point values. Both arguments must have identical types.</p>
				2599
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2600	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2601
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2602	<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]	2603
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2604	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2605
				2606	<pre>
				2607	<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]	2608	</pre>
				2609	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2610
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2611	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2612	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2613	</div>
				2614	<div class="doc_text">
				2615	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2616	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2617	</pre>
				2618	<h5>Overview:</h5>
				2619	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2620	unsigned division of its two arguments.</p>
				2621	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2622	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2623	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2624	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2625	<h5>Semantics:</h5>
				2626	<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]	2627	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2628	<p>Note that unsigned integer remainder and signed integer remainder are
				2629	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2630	<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]	2631	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2632	<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]	2633	</pre>
				2634
				2635	</div>
				2636	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2637	<div class="doc_subsubsection">
				2638	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2639	</div>
				2640
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2641	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2642
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2643	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2644
				2645	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2646	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2647	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2648
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2649	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2650
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2651	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2652	signed division of its two operands. This instruction can also take
				2653	<a href="#t_vector">vector</a> versions of the values in which case
				2654	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2655
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2656	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2657
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2658	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2659	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2660	values. Both arguments must have identical types.</p>
				2661
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2662	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2663
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2664	<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2665	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2666	operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2667	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2668	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]	2669	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]	2670	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2671	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2672	<p>Note that signed integer remainder and unsigned integer remainder are
				2673	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2674	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2675	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2676	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2677	(The remainder doesn't actually overflow, but this rule lets srem be
				2678	implemented using instructions that return both the result of the division
				2679	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2680	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2681	<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]	2682	</pre>
				2683
				2684	</div>
				2685	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2686	<div class="doc_subsubsection">
				2687	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2688
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2689	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2690
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2691	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2692	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2693	</pre>
				2694	<h5>Overview:</h5>
				2695	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2696	division of its two operands.</p>
				2697	<h5>Arguments:</h5>
				2698	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2699	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2700	of floating point values. Both arguments must have identical types.</p>
				2701
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2702	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2703
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2704	<p>This instruction returns the <i>remainder</i> of a division.
				2705	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2706
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2707	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2708
				2709	<pre>
				2710	<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]	2711	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2712	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2713
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2714	<!-- ======================================================================= -->
				2715	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2716	Operations</a> </div>
				2717	<div class="doc_text">
				2718	<p>Bitwise binary operators are used to do various forms of
				2719	bit-twiddling in a program. They are generally very efficient
				2720	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2721	instructions. They require two operands of the same type, execute an operation on them,
				2722	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]	2723	</div>
				2724
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2725	<!-- _______________________________________________________________________ -->
				2726	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2727	Instruction</a> </div>
				2728	<div class="doc_text">
				2729	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2730	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2731	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2732
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2733	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2734
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2735	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2736	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2737
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2738	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2739
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2740	<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman	5bc1ea0	2008-07-29 15:49:41 +0000	[diff] [blame]	2741	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2742	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2743
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2744	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2745
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2746	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2747	where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
Mon P Wang	01f8d09	2008-12-10 08:55:09 +0000	[diff] [blame]	2748	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
				2749	If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2750	corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2751
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2752	<h5>Example:</h5><pre>
				2753	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2754	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2755	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2756	<result> = shl i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2757	<result> = shl <2 x i32> < i32 1, i32 1>, < i32 1, i32 2> <i>; yields: result=<2 x i32> < i32 2, i32 4></i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2758	</pre>
				2759	</div>
				2760	<!-- _______________________________________________________________________ -->
				2761	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2762	Instruction</a> </div>
				2763	<div class="doc_text">
				2764	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2765	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2766	</pre>
				2767
				2768	<h5>Overview:</h5>
				2769	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2770	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]	2771
				2772	<h5>Arguments:</h5>
				2773	<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman	5bc1ea0	2008-07-29 15:49:41 +0000	[diff] [blame]	2774	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2775	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2776
				2777	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2778
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2779	<p>This instruction always performs a logical shift right operation. The most
				2780	significant bits of the result will be filled with zero bits after the
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2781	shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang	01f8d09	2008-12-10 08:55:09 +0000	[diff] [blame]	2782	the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
				2783	vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
				2784	amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2785
				2786	<h5>Example:</h5>
				2787	<pre>
				2788	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2789	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2790	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2791	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2792	<result> = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2793	<result> = lshr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 2> <i>; yields: result=<2 x i32> < i32 0x7FFFFFFF, i32 1></i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2794	</pre>
				2795	</div>
				2796
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2797	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2798	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2799	Instruction</a> </div>
				2800	<div class="doc_text">
				2801
				2802	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2803	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2804	</pre>
				2805
				2806	<h5>Overview:</h5>
				2807	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2808	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]	2809
				2810	<h5>Arguments:</h5>
				2811	<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman	5bc1ea0	2008-07-29 15:49:41 +0000	[diff] [blame]	2812	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2813	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2814
				2815	<h5>Semantics:</h5>
				2816	<p>This instruction always performs an arithmetic shift right operation,
				2817	The most significant bits of the result will be filled with the sign bit
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2818	of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
Mon P Wang	01f8d09	2008-12-10 08:55:09 +0000	[diff] [blame]	2819	larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
				2820	arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2821	corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2822
				2823	<h5>Example:</h5>
				2824	<pre>
				2825	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2826	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2827	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2828	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2829	<result> = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2830	<result> = ashr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 3> <i>; yields: result=<2 x i32> < i32 -1, i32 0></i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2831	</pre>
				2832	</div>
				2833
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2834	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2835	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2836	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2837
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2838	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2839
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2840	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2841
				2842	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2843	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2844	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2845
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2846	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2847
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2848	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2849	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2850
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2851	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2852
				2853	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2854	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2855	values. Both arguments must have identical types.</p>
				2856
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2857	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2858	<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]	2859	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2860	<div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2861	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2862	<tbody>
				2863	<tr>
				2864	<td>In0</td>
				2865	<td>In1</td>
				2866	<td>Out</td>
				2867	</tr>
				2868	<tr>
				2869	<td>0</td>
				2870	<td>0</td>
				2871	<td>0</td>
				2872	</tr>
				2873	<tr>
				2874	<td>0</td>
				2875	<td>1</td>
				2876	<td>0</td>
				2877	</tr>
				2878	<tr>
				2879	<td>1</td>
				2880	<td>0</td>
				2881	<td>0</td>
				2882	</tr>
				2883	<tr>
				2884	<td>1</td>
				2885	<td>1</td>
				2886	<td>1</td>
				2887	</tr>
				2888	</tbody>
				2889	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2890	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2891	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2892	<pre>
				2893	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2894	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2895	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2896	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2897	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2898	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2899	<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]	2900	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2901	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2902	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2903	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2904	<h5>Overview:</h5>
				2905	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2906	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2907	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2908
				2909	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2910	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2911	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2912	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2913	<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]	2914	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2915	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2916	<table border="1" cellspacing="0" cellpadding="4">
				2917	<tbody>
				2918	<tr>
				2919	<td>In0</td>
				2920	<td>In1</td>
				2921	<td>Out</td>
				2922	</tr>
				2923	<tr>
				2924	<td>0</td>
				2925	<td>0</td>
				2926	<td>0</td>
				2927	</tr>
				2928	<tr>
				2929	<td>0</td>
				2930	<td>1</td>
				2931	<td>1</td>
				2932	</tr>
				2933	<tr>
				2934	<td>1</td>
				2935	<td>0</td>
				2936	<td>1</td>
				2937	</tr>
				2938	<tr>
				2939	<td>1</td>
				2940	<td>1</td>
				2941	<td>1</td>
				2942	</tr>
				2943	</tbody>
				2944	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2945	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2946	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2947	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2948	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2949	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2950	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2951	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2952	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2953	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2954	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2955	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2956	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2957	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2958	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2959	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2960	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2961	or of its two operands. The <tt>xor</tt> is used to implement the
				2962	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2963	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2964	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				2965	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2966	values. Both arguments must have identical types.</p>
				2967
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2968	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2969
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2970	<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]	2971	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2972	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2973	<table border="1" cellspacing="0" cellpadding="4">
				2974	<tbody>
				2975	<tr>
				2976	<td>In0</td>
				2977	<td>In1</td>
				2978	<td>Out</td>
				2979	</tr>
				2980	<tr>
				2981	<td>0</td>
				2982	<td>0</td>
				2983	<td>0</td>
				2984	</tr>
				2985	<tr>
				2986	<td>0</td>
				2987	<td>1</td>
				2988	<td>1</td>
				2989	</tr>
				2990	<tr>
				2991	<td>1</td>
				2992	<td>0</td>
				2993	<td>1</td>
				2994	</tr>
				2995	<tr>
				2996	<td>1</td>
				2997	<td>1</td>
				2998	<td>0</td>
				2999	</tr>
				3000	</tbody>
				3001	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3002	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3003	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3004	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3005	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				3006	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				3007	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				3008	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3009	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3010	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3011
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3012	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3013	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3014	<a name="vectorops">Vector Operations</a>
				3015	</div>
				3016
				3017	<div class="doc_text">
				3018
				3019	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3020	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3021	vector-specific operations needed to process vectors effectively. While LLVM
				3022	does directly support these vector operations, many sophisticated algorithms
				3023	will want to use target-specific intrinsics to take full advantage of a specific
				3024	target.</p>
				3025
				3026	</div>
				3027
				3028	<!-- _______________________________________________________________________ -->
				3029	<div class="doc_subsubsection">
				3030	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				3031	</div>
				3032
				3033	<div class="doc_text">
				3034
				3035	<h5>Syntax:</h5>
				3036
				3037	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3038	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3039	</pre>
				3040
				3041	<h5>Overview:</h5>
				3042
				3043	<p>
				3044	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3045	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3046	</p>
				3047
				3048
				3049	<h5>Arguments:</h5>
				3050
				3051	<p>
				3052	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3053	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]	3054	an index indicating the position from which to extract the element.
				3055	The index may be a variable.</p>
				3056
				3057	<h5>Semantics:</h5>
				3058
				3059	<p>
				3060	The result is a scalar of the same type as the element type of
				3061	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				3062	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				3063	results are undefined.
				3064	</p>
				3065
				3066	<h5>Example:</h5>
				3067
				3068	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3069	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3070	</pre>
				3071	</div>
				3072
				3073
				3074	<!-- _______________________________________________________________________ -->
				3075	<div class="doc_subsubsection">
				3076	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				3077	</div>
				3078
				3079	<div class="doc_text">
				3080
				3081	<h5>Syntax:</h5>
				3082
				3083	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	3084	<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]	3085	</pre>
				3086
				3087	<h5>Overview:</h5>
				3088
				3089	<p>
				3090	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3091	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3092	</p>
				3093
				3094
				3095	<h5>Arguments:</h5>
				3096
				3097	<p>
				3098	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3099	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]	3100	scalar value whose type must equal the element type of the first
				3101	operand. The third operand is an index indicating the position at
				3102	which to insert the value. The index may be a variable.</p>
				3103
				3104	<h5>Semantics:</h5>
				3105
				3106	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3107	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]	3108	element values are those of <tt>val</tt> except at position
				3109	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				3110	exceeds the length of <tt>val</tt>, the results are undefined.
				3111	</p>
				3112
				3113	<h5>Example:</h5>
				3114
				3115	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3116	%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]	3117	</pre>
				3118	</div>
				3119
				3120	<!-- _______________________________________________________________________ -->
				3121	<div class="doc_subsubsection">
				3122	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				3123	</div>
				3124
				3125	<div class="doc_text">
				3126
				3127	<h5>Syntax:</h5>
				3128
				3129	<pre>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3130	<result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <m x i32> <mask> <i>; yields <m x <ty>></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3131	</pre>
				3132
				3133	<h5>Overview:</h5>
				3134
				3135	<p>
				3136	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3137	from two input vectors, returning a vector with the same element type as
				3138	the input and length that is the same as the shuffle mask.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3139	</p>
				3140
				3141	<h5>Arguments:</h5>
				3142
				3143	<p>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3144	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				3145	with types that match each other. The third argument is a shuffle mask whose
				3146	element type is always 'i32'. The result of the instruction is a vector whose
				3147	length is the same as the shuffle mask and whose element type is the same as
				3148	the element type of the first two operands.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3149	</p>
				3150
				3151	<p>
				3152	The shuffle mask operand is required to be a constant vector with either
				3153	constant integer or undef values.
				3154	</p>
				3155
				3156	<h5>Semantics:</h5>
				3157
				3158	<p>
				3159	The elements of the two input vectors are numbered from left to right across
				3160	both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3161	the result vector, which element of the two input vectors the result element
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3162	gets. The element selector may be undef (meaning "don't care") and the second
				3163	operand may be undef if performing a shuffle from only one vector.
				3164	</p>
				3165
				3166	<h5>Example:</h5>
				3167
				3168	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3169	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3170	<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]	3171	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				3172	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> - Identity shuffle.
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3173	%result = shufflevector <8 x i32> %v1, <8 x i32> undef,
				3174	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i>
				3175	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
				3176	<8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 > <i>; yields <8 x i32></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3177	</pre>
				3178	</div>
				3179
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	3180
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3181	<!-- ======================================================================= -->
				3182	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3183	<a name="aggregateops">Aggregate Operations</a>
				3184	</div>
				3185
				3186	<div class="doc_text">
				3187
				3188	<p>LLVM supports several instructions for working with aggregate values.
				3189	</p>
				3190
				3191	</div>
				3192
				3193	<!-- _______________________________________________________________________ -->
				3194	<div class="doc_subsubsection">
				3195	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				3196	</div>
				3197
				3198	<div class="doc_text">
				3199
				3200	<h5>Syntax:</h5>
				3201
				3202	<pre>
				3203	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3204	</pre>
				3205
				3206	<h5>Overview:</h5>
				3207
				3208	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3209	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3210	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3211	</p>
				3212
				3213
				3214	<h5>Arguments:</h5>
				3215
				3216	<p>
				3217	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3218	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]	3219	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3220	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3221	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3222	</p>
				3223
				3224	<h5>Semantics:</h5>
				3225
				3226	<p>
				3227	The result is the value at the position in the aggregate specified by
				3228	the index operands.
				3229	</p>
				3230
				3231	<h5>Example:</h5>
				3232
				3233	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3234	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3235	</pre>
				3236	</div>
				3237
				3238
				3239	<!-- _______________________________________________________________________ -->
				3240	<div class="doc_subsubsection">
				3241	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3242	</div>
				3243
				3244	<div class="doc_text">
				3245
				3246	<h5>Syntax:</h5>
				3247
				3248	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3249	<result> = insertvalue <aggregate type> <val>, <ty> <val>, <idx> <i>; yields <n x <ty>></i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3250	</pre>
				3251
				3252	<h5>Overview:</h5>
				3253
				3254	<p>
				3255	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3256	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3257	</p>
				3258
				3259
				3260	<h5>Arguments:</h5>
				3261
				3262	<p>
				3263	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3264	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3265	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	3266	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3267	indicating the position at which to insert the value in a similar manner as
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3268	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3269	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3270	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]	3271	by the indices.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3272	</p>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3273
				3274	<h5>Semantics:</h5>
				3275
				3276	<p>
				3277	The result is an aggregate of the same type as <tt>val</tt>. Its
				3278	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]	3279	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3280	</p>
				3281
				3282	<h5>Example:</h5>
				3283
				3284	<pre>
Dan Gohman	52bb2db	2008-06-23 15:26:37 +0000	[diff] [blame]	3285	%result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3286	</pre>
				3287	</div>
				3288
				3289
				3290	<!-- ======================================================================= -->
				3291	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3292	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3293	</div>
				3294
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3295	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3296
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3297	<p>A key design point of an SSA-based representation is how it
				3298	represents memory. In LLVM, no memory locations are in SSA form, which
				3299	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3300	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3301
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3302	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3303
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3304	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3305	<div class="doc_subsubsection">
				3306	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3307	</div>
				3308
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3309	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3310
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3311	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3312
				3313	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3314	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3315	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3316
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3317	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3318
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3319	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3320	heap and returns a pointer to it. The object is always allocated in the generic
				3321	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3322
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3323	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3324
				3325	<p>The '<tt>malloc</tt>' instruction allocates
				3326	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3327	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]	3328	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3329	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3330	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]	3331	be aligned to at least that boundary. If not specified, or if zero, the target can
				3332	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3333
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3334	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3335
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3336	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3337
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3338	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	3339	a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3340	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3341
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3342	<h5>Example:</h5>
				3343
				3344	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3345	%array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3346
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3347	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3348	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3349	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3350	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3351	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3352	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	3353
				3354	<p>Note that the code generator does not yet respect the
				3355	alignment value.</p>
				3356
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3357	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3358
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3359	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3360	<div class="doc_subsubsection">
				3361	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3362	</div>
				3363
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3364	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3365
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3366	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3367
				3368	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3369	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3370	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3371
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3372	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3373
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3374	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3375	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3376
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3377	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3378
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3379	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3380	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3381	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3382
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3383	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3384
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3385	<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]	3386	after this instruction executes. If the pointer is null, the operation
				3387	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3388
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3389	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3390
				3391	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3392	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3393	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3394	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3395	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3396
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3397	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3398	<div class="doc_subsubsection">
				3399	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3400	</div>
				3401
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3402	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3403
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3404	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3405
				3406	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3407	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3408	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3409
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3410	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3411
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3412	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3413	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3414	returns to its caller. The object is always allocated in the generic address
				3415	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3416
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3417	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3418
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3419	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3420	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3421	appropriate type to the program. If "NumElements" is specified, it is the
				3422	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3423	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]	3424	to be aligned to at least that boundary. If not specified, or if zero, the target
				3425	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3426
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3427	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3428
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3429	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3430
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3431	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3432	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3433	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3434	instruction is commonly used to represent automatic variables that must
				3435	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]	3436	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]	3437	instructions), the memory is reclaimed. Allocating zero bytes
				3438	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3439
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3440	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3441
				3442	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3443	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
				3444	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3445	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
				3446	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3447	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3448	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3449
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3450	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3451	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3452	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3453	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3454	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3455	<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]	3456	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3457	<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]	3458	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3459	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3460	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3461	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]	3462	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]	3463	the number or order of execution of this <tt>load</tt> with other
				3464	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3465	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3466	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3467	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3468	(that is, the alignment of the memory address). A value of 0 or an
				3469	omitted "align" argument means that the operation has the preferential
				3470	alignment for the target. It is the responsibility of the code emitter
				3471	to ensure that the alignment information is correct. Overestimating
				3472	the alignment results in an undefined behavior. Underestimating the
				3473	alignment may produce less efficient code. An alignment of 1 is always
				3474	safe.
				3475	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3476	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3477	<p>The location of memory pointed to is loaded.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3478	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3479	<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]	3480	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3481	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3482	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3483	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3484	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3485	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3486	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3487	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3488	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3489	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3490	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3491	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3492	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3493	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3494	<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]	3495	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3496	<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]	3497	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]	3498	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3499	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3500	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]	3501	optimizer is not allowed to modify the number or order of execution of
				3502	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3503	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3504	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3505	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3506	(that is, the alignment of the memory address). A value of 0 or an
				3507	omitted "align" argument means that the operation has the preferential
				3508	alignment for the target. It is the responsibility of the code emitter
				3509	to ensure that the alignment information is correct. Overestimating
				3510	the alignment results in an undefined behavior. Underestimating the
				3511	alignment may produce less efficient code. An alignment of 1 is always
				3512	safe.
				3513	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3514	<h5>Semantics:</h5>
				3515	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3516	at the location specified by the '<tt><pointer></tt>' operand.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3517	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3518	<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]	3519	store i32 3, i32* %ptr <i>; yields {void}</i>
				3520	%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]	3521	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3522	</div>
				3523
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3524	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3525	<div class="doc_subsubsection">
				3526	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3527	</div>
				3528
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3529	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3530	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3531	<pre>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3532	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3533	</pre>
				3534
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3535	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3536
				3537	<p>
				3538	The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3539	subelement of an aggregate data structure. It performs address calculation only
				3540	and does not access memory.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3541
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3542	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3543
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3544	<p>The first argument is always a pointer, and forms the basis of the
				3545	calculation. The remaining arguments are indices, that indicate which of the
				3546	elements of the aggregate object are indexed. The interpretation of each index
				3547	is dependent on the type being indexed into. The first index always indexes the
				3548	pointer value given as the first argument, the second index indexes a value of
				3549	the type pointed to (not necessarily the value directly pointed to, since the
				3550	first index can be non-zero), etc. The first type indexed into must be a pointer
				3551	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3552	types being indexed into can never be pointers, since that would require loading
				3553	the pointer before continuing calculation.</p>
				3554
				3555	<p>The type of each index argument depends on the type it is indexing into.
				3556	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3557	<b>constants</b> are allowed. When indexing into an array, pointer or vector,
				3558	only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
				3559	will be sign extended to 64-bits if required.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3560
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3561	<p>For example, let's consider a C code fragment and how it gets
				3562	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3563
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3564	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3565	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3566	struct RT {
				3567	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3568	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3569	char C;
				3570	};
				3571	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3572	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3573	double Y;
				3574	struct RT Z;
				3575	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3576
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3577	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3578	return &s[1].Z.B[5][13];
				3579	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3580	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3581	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3582
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3583	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3584
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3585	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3586	<pre>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	3587	%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
				3588	%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3589
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3590	define i32* %foo(%ST* %s) {
				3591	entry:
				3592	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3593	ret i32* %reg
				3594	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3595	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3596	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3597
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3598	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3599
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3600	<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]	3601	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]	3602	}</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]	3603	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3604	i8 }</tt>' type, another structure. The third index indexes into the second
				3605	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]	3606	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3607	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3608	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]	3609
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3610	<p>Note that it is perfectly legal to index partially through a
				3611	structure, returning a pointer to an inner element. Because of this,
				3612	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3613
				3614	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3615	define i32* %foo(%ST* %s) {
				3616	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3617	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3618	%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]	3619	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3620	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3621	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3622	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3623	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3624
				3625	<p>Note that it is undefined to access an array out of bounds: array and
				3626	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]	3627	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]	3628	defined to be accessible as variable length arrays, which requires access
				3629	beyond the zero'th element.</p>
				3630
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3631	<p>The getelementptr instruction is often confusing. For some more insight
				3632	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3633	FAQ</a>.</p>
				3634
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3635	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3636
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3637	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3638	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3639	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3640	<i>; yields i8*:vptr</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3641	%vptr = getelementptr {i32, <2 x i8>}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3642	<i>; yields i8*:eptr</i>
				3643	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3644	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3645	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3646
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3647	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3648	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3649	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3650	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3651	<p>The instructions in this category are the conversion instructions (casting)
				3652	which all take a single operand and a type. They perform various bit conversions
				3653	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3654	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3655
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3656	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3657	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3658	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3659	</div>
				3660	<div class="doc_text">
				3661
				3662	<h5>Syntax:</h5>
				3663	<pre>
				3664	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3665	</pre>
				3666
				3667	<h5>Overview:</h5>
				3668	<p>
				3669	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3670	</p>
				3671
				3672	<h5>Arguments:</h5>
				3673	<p>
				3674	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3675	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]	3676	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]	3677	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3678	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3679
				3680	<h5>Semantics:</h5>
				3681	<p>
				3682	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]	3683	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3684	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3685	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3686
				3687	<h5>Example:</h5>
				3688	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3689	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3690	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3691	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3692	</pre>
				3693	</div>
				3694
				3695	<!-- _______________________________________________________________________ -->
				3696	<div class="doc_subsubsection">
				3697	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3698	</div>
				3699	<div class="doc_text">
				3700
				3701	<h5>Syntax:</h5>
				3702	<pre>
				3703	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3704	</pre>
				3705
				3706	<h5>Overview:</h5>
				3707	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3708	<tt>ty2</tt>.</p>
				3709
				3710
				3711	<h5>Arguments:</h5>
				3712	<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]	3713	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3714	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]	3715	<tt>value</tt> must be smaller than the bit size of the destination type,
				3716	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3717
				3718	<h5>Semantics:</h5>
				3719	<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]	3720	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]	3721
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3722	<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]	3723
				3724	<h5>Example:</h5>
				3725	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3726	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3727	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3728	</pre>
				3729	</div>
				3730
				3731	<!-- _______________________________________________________________________ -->
				3732	<div class="doc_subsubsection">
				3733	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3734	</div>
				3735	<div class="doc_text">
				3736
				3737	<h5>Syntax:</h5>
				3738	<pre>
				3739	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3740	</pre>
				3741
				3742	<h5>Overview:</h5>
				3743	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3744
				3745	<h5>Arguments:</h5>
				3746	<p>
				3747	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]	3748	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3749	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]	3750	<tt>value</tt> must be smaller than the bit size of the destination type,
				3751	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3752
				3753	<h5>Semantics:</h5>
				3754	<p>
				3755	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3756	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]	3757	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3758
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3759	<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]	3760
				3761	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3762	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3763	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3764	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3765	</pre>
				3766	</div>
				3767
				3768	<!-- _______________________________________________________________________ -->
				3769	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3770	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3771	</div>
				3772
				3773	<div class="doc_text">
				3774
				3775	<h5>Syntax:</h5>
				3776
				3777	<pre>
				3778	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3779	</pre>
				3780
				3781	<h5>Overview:</h5>
				3782	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3783	<tt>ty2</tt>.</p>
				3784
				3785
				3786	<h5>Arguments:</h5>
				3787	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3788	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3789	cast it to. The size of <tt>value</tt> must be larger than the size of
				3790	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3791	<i>no-op cast</i>.</p>
				3792
				3793	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3794	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3795	<a href="#t_floating">floating point</a> type to a smaller
				3796	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3797	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3798
				3799	<h5>Example:</h5>
				3800	<pre>
				3801	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3802	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3803	</pre>
				3804	</div>
				3805
				3806	<!-- _______________________________________________________________________ -->
				3807	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3808	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3809	</div>
				3810	<div class="doc_text">
				3811
				3812	<h5>Syntax:</h5>
				3813	<pre>
				3814	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3815	</pre>
				3816
				3817	<h5>Overview:</h5>
				3818	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3819	floating point value.</p>
				3820
				3821	<h5>Arguments:</h5>
				3822	<p>The '<tt>fpext</tt>' instruction takes a
				3823	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3824	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3825	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3826
				3827	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3828	<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]	3829	<a href="#t_floating">floating point</a> type to a larger
				3830	<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]	3831	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]	3832	<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]	3833
				3834	<h5>Example:</h5>
				3835	<pre>
				3836	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3837	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3838	</pre>
				3839	</div>
				3840
				3841	<!-- _______________________________________________________________________ -->
				3842	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	3843	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3844	</div>
				3845	<div class="doc_text">
				3846
				3847	<h5>Syntax:</h5>
				3848	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3849	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3850	</pre>
				3851
				3852	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3853	<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]	3854	unsigned integer equivalent of type <tt>ty2</tt>.
				3855	</p>
				3856
				3857	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3858	<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]	3859	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3860	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3861	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3862	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]	3863
				3864	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3865	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3866	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3867	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3868	the results are undefined.</p>
				3869
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3870	<h5>Example:</h5>
				3871	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3872	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3873	%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]	3874	%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]	3875	</pre>
				3876	</div>
				3877
				3878	<!-- _______________________________________________________________________ -->
				3879	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3880	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3881	</div>
				3882	<div class="doc_text">
				3883
				3884	<h5>Syntax:</h5>
				3885	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3886	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3887	</pre>
				3888
				3889	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3890	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3891	<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]	3892	</p>
				3893
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3894	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3895	<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]	3896	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3897	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3898	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3899	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]	3900
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3901	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3902	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3903	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3904	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3905	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3906
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3907	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3908	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3909	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3910	%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]	3911	%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]	3912	</pre>
				3913	</div>
				3914
				3915	<!-- _______________________________________________________________________ -->
				3916	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3917	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3918	</div>
				3919	<div class="doc_text">
				3920
				3921	<h5>Syntax:</h5>
				3922	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3923	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3924	</pre>
				3925
				3926	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3927	<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]	3928	integer and converts that value to the <tt>ty2</tt> type.</p>
				3929
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3930	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3931	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3932	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3933	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3934	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3935	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]	3936
				3937	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3938	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3939	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3940	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]	3941
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3942	<h5>Example:</h5>
				3943	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3944	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3945	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3946	</pre>
				3947	</div>
				3948
				3949	<!-- _______________________________________________________________________ -->
				3950	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3951	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3952	</div>
				3953	<div class="doc_text">
				3954
				3955	<h5>Syntax:</h5>
				3956	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3957	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3958	</pre>
				3959
				3960	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3961	<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]	3962	integer and converts that value to the <tt>ty2</tt> type.</p>
				3963
				3964	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3965	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3966	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3967	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3968	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3969	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]	3970
				3971	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3972	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3973	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3974	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]	3975
				3976	<h5>Example:</h5>
				3977	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3978	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3979	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3980	</pre>
				3981	</div>
				3982
				3983	<!-- _______________________________________________________________________ -->
				3984	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3985	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				3986	</div>
				3987	<div class="doc_text">
				3988
				3989	<h5>Syntax:</h5>
				3990	<pre>
				3991	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				3992	</pre>
				3993
				3994	<h5>Overview:</h5>
				3995	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				3996	the integer type <tt>ty2</tt>.</p>
				3997
				3998	<h5>Arguments:</h5>
				3999	<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]	4000	must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4001	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4002
				4003	<h5>Semantics:</h5>
				4004	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				4005	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				4006	truncating or zero extending that value to the size of the integer type. If
				4007	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				4008	<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]	4009	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				4010	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4011
				4012	<h5>Example:</h5>
				4013	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4014	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				4015	%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]	4016	</pre>
				4017	</div>
				4018
				4019	<!-- _______________________________________________________________________ -->
				4020	<div class="doc_subsubsection">
				4021	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				4022	</div>
				4023	<div class="doc_text">
				4024
				4025	<h5>Syntax:</h5>
				4026	<pre>
				4027	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				4028	</pre>
				4029
				4030	<h5>Overview:</h5>
				4031	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				4032	a pointer type, <tt>ty2</tt>.</p>
				4033
				4034	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4035	<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]	4036	value to cast, and a type to cast it to, which must be a
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4037	<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4038
				4039	<h5>Semantics:</h5>
				4040	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				4041	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				4042	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				4043	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				4044	the size of a pointer then a zero extension is done. If they are the same size,
				4045	nothing is done (<i>no-op cast</i>).</p>
				4046
				4047	<h5>Example:</h5>
				4048	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4049	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				4050	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				4051	%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]	4052	</pre>
				4053	</div>
				4054
				4055	<!-- _______________________________________________________________________ -->
				4056	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4057	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4058	</div>
				4059	<div class="doc_text">
				4060
				4061	<h5>Syntax:</h5>
				4062	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4063	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4064	</pre>
				4065
				4066	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4067
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4068	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4069	<tt>ty2</tt> without changing any bits.</p>
				4070
				4071	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4072
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4073	<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman	500233a	2008-09-08 16:45:59 +0000	[diff] [blame]	4074	a non-aggregate first class value, and a type to cast it to, which must also be
				4075	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				4076	<tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	4077	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]	4078	type is a pointer, the destination type must also be a pointer. This
				4079	instruction supports bitwise conversion of vectors to integers and to vectors
				4080	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4081
				4082	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4083	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4084	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				4085	this conversion. The conversion is done as if the <tt>value</tt> had been
				4086	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				4087	converted to other pointer types with this instruction. To convert pointers to
				4088	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				4089	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4090
				4091	<h5>Example:</h5>
				4092	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4093	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4094	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4095	%Z = bitcast <2 x int> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	4096	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4097	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4098
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4099	<!-- ======================================================================= -->
				4100	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				4101	<div class="doc_text">
				4102	<p>The instructions in this category are the "miscellaneous"
				4103	instructions, which defy better classification.</p>
				4104	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4105
				4106	<!-- _______________________________________________________________________ -->
				4107	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				4108	</div>
				4109	<div class="doc_text">
				4110	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4111	<pre> <result> = icmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4112	</pre>
				4113	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4114	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				4115	a vector of boolean values based on comparison
				4116	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4117	<h5>Arguments:</h5>
				4118	<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]	4119	the condition code indicating the kind of comparison to perform. It is not
				4120	a value, just a keyword. The possible condition code are:
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4121	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4122	<ol>
				4123	<li><tt>eq</tt>: equal</li>
				4124	<li><tt>ne</tt>: not equal </li>
				4125	<li><tt>ugt</tt>: unsigned greater than</li>
				4126	<li><tt>uge</tt>: unsigned greater or equal</li>
				4127	<li><tt>ult</tt>: unsigned less than</li>
				4128	<li><tt>ule</tt>: unsigned less or equal</li>
				4129	<li><tt>sgt</tt>: signed greater than</li>
				4130	<li><tt>sge</tt>: signed greater or equal</li>
				4131	<li><tt>slt</tt>: signed less than</li>
				4132	<li><tt>sle</tt>: signed less or equal</li>
				4133	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	4134	<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4135	<a href="#t_pointer">pointer</a>
				4136	or integer <a href="#t_vector">vector</a> typed.
				4137	They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4138	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4139	<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4140	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4141	yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4142	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4143	<ol>
				4144	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				4145	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				4146	</li>
				4147	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4148	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4149	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4150	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4151	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4152	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4153	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4154	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4155	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4156	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4157	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4158	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4159	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4160	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4161	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4162	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4163	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4164	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4165	</ol>
				4166	<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]	4167	values are compared as if they were integers.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4168	<p>If the operands are integer vectors, then they are compared
				4169	element by element. The result is an <tt>i1</tt> vector with
				4170	the same number of elements as the values being compared.
				4171	Otherwise, the result is an <tt>i1</tt>.
				4172	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4173
				4174	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4175	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				4176	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				4177	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				4178	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				4179	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				4180	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4181	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4182
				4183	<p>Note that the code generator does not yet support vector types with
				4184	the <tt>icmp</tt> instruction.</p>
				4185
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4186	</div>
				4187
				4188	<!-- _______________________________________________________________________ -->
				4189	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				4190	</div>
				4191	<div class="doc_text">
				4192	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4193	<pre> <result> = fcmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4194	</pre>
				4195	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4196	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				4197	or vector of boolean values based on comparison
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4198	of its operands.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4199	<p>
				4200	If the operands are floating point scalars, then the result
				4201	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				4202	</p>
				4203	<p>If the operands are floating point vectors, then the result type
				4204	is a vector of boolean with the same number of elements as the
				4205	operands being compared.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4206	<h5>Arguments:</h5>
				4207	<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]	4208	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4209	a value, just a keyword. The possible condition code are:</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4210	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4211	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4212	<li><tt>oeq</tt>: ordered and equal</li>
				4213	<li><tt>ogt</tt>: ordered and greater than </li>
				4214	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4215	<li><tt>olt</tt>: ordered and less than </li>
				4216	<li><tt>ole</tt>: ordered and less than or equal</li>
				4217	<li><tt>one</tt>: ordered and not equal</li>
				4218	<li><tt>ord</tt>: ordered (no nans)</li>
				4219	<li><tt>ueq</tt>: unordered or equal</li>
				4220	<li><tt>ugt</tt>: unordered or greater than </li>
				4221	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4222	<li><tt>ult</tt>: unordered or less than </li>
				4223	<li><tt>ule</tt>: unordered or less than or equal</li>
				4224	<li><tt>une</tt>: unordered or not equal</li>
				4225	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4226	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4227	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4228	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	4229	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4230	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4231	either a <a href="#t_floating">floating point</a> type
				4232	or a <a href="#t_vector">vector</a> of floating point type.
				4233	They must have identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4234	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4235	<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4236	according to the condition code given as <tt>cond</tt>.
				4237	If the operands are vectors, then the vectors are compared
				4238	element by element.
				4239	Each comparison performed
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4240	always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4241	<ol>
				4242	<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]	4243	<li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4244	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4245	<li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4246	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4247	<li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4248	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4249	<li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4250	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4251	<li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4252	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4253	<li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4254	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4255	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4256	<li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4257	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4258	<li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4259	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4260	<li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4261	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4262	<li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4263	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4264	<li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4265	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4266	<li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4267	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4268	<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]	4269	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4270	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4271
				4272	<h5>Example:</h5>
				4273	<pre> <result> = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4274	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4275	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4276	<result> = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4277	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4278
				4279	<p>Note that the code generator does not yet support vector types with
				4280	the <tt>fcmp</tt> instruction.</p>
				4281
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4282	</div>
				4283
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4284	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4285	<div class="doc_subsubsection">
				4286	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4287	</div>
				4288	<div class="doc_text">
				4289	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4290	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4291	</pre>
				4292	<h5>Overview:</h5>
				4293	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4294	element-wise comparison of its two integer vector operands.</p>
				4295	<h5>Arguments:</h5>
				4296	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4297	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4298	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4299	<ol>
				4300	<li><tt>eq</tt>: equal</li>
				4301	<li><tt>ne</tt>: not equal </li>
				4302	<li><tt>ugt</tt>: unsigned greater than</li>
				4303	<li><tt>uge</tt>: unsigned greater or equal</li>
				4304	<li><tt>ult</tt>: unsigned less than</li>
				4305	<li><tt>ule</tt>: unsigned less or equal</li>
				4306	<li><tt>sgt</tt>: signed greater than</li>
				4307	<li><tt>sge</tt>: signed greater or equal</li>
				4308	<li><tt>slt</tt>: signed less than</li>
				4309	<li><tt>sle</tt>: signed less or equal</li>
				4310	</ol>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4311	<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4312	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4313	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4314	<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4315	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4316	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4317	identical type as the values being compared. The most significant bit in each
				4318	element is 1 if the element-wise comparison evaluates to true, and is 0
				4319	otherwise. All other bits of the result are undefined. The condition codes
				4320	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4321	instruction</a>.</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4322
				4323	<h5>Example:</h5>
				4324	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4325	<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>
				4326	<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]	4327	</pre>
				4328	</div>
				4329
				4330	<!-- _______________________________________________________________________ -->
				4331	<div class="doc_subsubsection">
				4332	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4333	</div>
				4334	<div class="doc_text">
				4335	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4336	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4337	<h5>Overview:</h5>
				4338	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4339	element-wise comparison of its two floating point vector operands. The output
				4340	elements have the same width as the input elements.</p>
				4341	<h5>Arguments:</h5>
				4342	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4343	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4344	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4345	<ol>
				4346	<li><tt>false</tt>: no comparison, always returns false</li>
				4347	<li><tt>oeq</tt>: ordered and equal</li>
				4348	<li><tt>ogt</tt>: ordered and greater than </li>
				4349	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4350	<li><tt>olt</tt>: ordered and less than </li>
				4351	<li><tt>ole</tt>: ordered and less than or equal</li>
				4352	<li><tt>one</tt>: ordered and not equal</li>
				4353	<li><tt>ord</tt>: ordered (no nans)</li>
				4354	<li><tt>ueq</tt>: unordered or equal</li>
				4355	<li><tt>ugt</tt>: unordered or greater than </li>
				4356	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4357	<li><tt>ult</tt>: unordered or less than </li>
				4358	<li><tt>ule</tt>: unordered or less than or equal</li>
				4359	<li><tt>une</tt>: unordered or not equal</li>
				4360	<li><tt>uno</tt>: unordered (either nans)</li>
				4361	<li><tt>true</tt>: no comparison, always returns true</li>
				4362	</ol>
				4363	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4364	<a href="#t_floating">floating point</a> typed. They must also be identical
				4365	types.</p>
				4366	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4367	<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4368	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4369	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4370	an identical number of elements as the values being compared, and each element
				4371	having identical with to the width of the floating point elements. The most
				4372	significant bit in each element is 1 if the element-wise comparison evaluates to
				4373	true, and is 0 otherwise. All other bits of the result are undefined. The
				4374	condition codes are evaluated identically to the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4375	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4376
				4377	<h5>Example:</h5>
				4378	<pre>
Chris Lattner	50ad45c	2008-10-13 16:55:18 +0000	[diff] [blame]	4379	<i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4380	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 >
				4381
				4382	<i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
				4383	<result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4384	</pre>
				4385	</div>
				4386
				4387	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4388	<div class="doc_subsubsection">
				4389	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4390	</div>
				4391
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4392	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4393
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4394	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4395
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4396	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4397	<h5>Overview:</h5>
				4398	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4399	the SSA graph representing the function.</p>
				4400	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4401
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4402	<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]	4403	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4404	as arguments, with one pair for each predecessor basic block of the
				4405	current block. Only values of <a href="#t_firstclass">first class</a>
				4406	type may be used as the value arguments to the PHI node. Only labels
				4407	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4408
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4409	<p>There must be no non-phi instructions between the start of a basic
				4410	block and the PHI instructions: i.e. PHI instructions must be first in
				4411	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4412
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4413	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4414
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4415	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4416	specified by the pair corresponding to the predecessor basic block that executed
				4417	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4418
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4419	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4420	<pre>
				4421	Loop: ; Infinite loop that counts from 0 on up...
				4422	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4423	%nextindvar = add i32 %indvar, 1
				4424	br label %Loop
				4425	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4426	</div>
				4427
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4428	<!-- _______________________________________________________________________ -->
				4429	<div class="doc_subsubsection">
				4430	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4431	</div>
				4432
				4433	<div class="doc_text">
				4434
				4435	<h5>Syntax:</h5>
				4436
				4437	<pre>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4438	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4439
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4440	<i>selty</i> is either i1 or {<N x i1>}
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4441	</pre>
				4442
				4443	<h5>Overview:</h5>
				4444
				4445	<p>
				4446	The '<tt>select</tt>' instruction is used to choose one value based on a
				4447	condition, without branching.
				4448	</p>
				4449
				4450
				4451	<h5>Arguments:</h5>
				4452
				4453	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4454	The '<tt>select</tt>' instruction requires an 'i1' value or
				4455	a vector of 'i1' values indicating the
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4456	condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4457	type. If the val1/val2 are vectors and
				4458	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4459	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4460	</p>
				4461
				4462	<h5>Semantics:</h5>
				4463
				4464	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4465	If the condition is an i1 and it evaluates to 1, the instruction returns the first
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4466	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4467	</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4468	<p>
				4469	If the condition is a vector of i1, then the value arguments must
				4470	be vectors of the same size, and the selection is done element
				4471	by element.
				4472	</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4473
				4474	<h5>Example:</h5>
				4475
				4476	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4477	%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]	4478	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4479
				4480	<p>Note that the code generator does not yet support conditions
				4481	with vector type.</p>
				4482
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4483	</div>
				4484
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4485
				4486	<!-- _______________________________________________________________________ -->
				4487	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4488	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4489	</div>
				4490
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4491	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4492
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4493	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4494	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4495	<result> = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ty> [<fnty>*] <fnptrval>(<function args>) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4496	</pre>
				4497
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4498	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4499
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4500	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4501
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4502	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4503
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4504	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4505
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4506	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4507	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4508	<p>The optional "tail" marker indicates whether the callee function accesses
				4509	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]	4510	function call is eligible for tail call optimization. Note that calls may
				4511	be marked "tail" even if they do not occur before a <a
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4512	href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4513	</li>
				4514	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4515	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4516	convention</a> the call should use. If none is specified, the call defaults
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4517	to using C calling conventions.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4518	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4519
				4520	<li>
				4521	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4522	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4523	and '<tt>inreg</tt>' attributes are valid here.</p>
				4524	</li>
				4525
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4526	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4527	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4528	the type of the return value. Functions that return no value are marked
				4529	<tt><a href="#t_void">void</a></tt>.</p>
				4530	</li>
				4531	<li>
				4532	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4533	value being invoked. The argument types must match the types implied by
				4534	this signature. This type can be omitted if the function is not varargs
				4535	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]	4536	</li>
				4537	<li>
				4538	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4539	be invoked. In most cases, this is a direct function invocation, but
				4540	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]	4541	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4542	</li>
				4543	<li>
				4544	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4545	function signature argument types. All arguments must be of
				4546	<a href="#t_firstclass">first class</a> type. If the function signature
				4547	indicates the function accepts a variable number of arguments, the extra
				4548	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4549	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4550	<li>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4551	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4552	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4553	'<tt>readnone</tt>' attributes are valid here.</p>
				4554	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4555	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4556
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4557	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4558
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4559	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4560	transfer to a specified function, with its incoming arguments bound to
				4561	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4562	instruction in the called function, control flow continues with the
				4563	instruction after the function call, and the return value of the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4564	function is bound to the result argument.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4565
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4566	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4567
				4568	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4569	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4570	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4571	%X = tail call i32 @foo() <i>; yields i32</i>
				4572	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4573	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4574
				4575	%struct.A = type { i32, i8 }
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4576	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	4577	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4578	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	85a350f	2008-10-08 06:26:11 +0000	[diff] [blame]	4579	%Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijman	cb73d19	2008-10-07 10:03:45 +0000	[diff] [blame]	4580	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4581	</pre>
				4582
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4583	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4584
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4585	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4586	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4587	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4588	</div>
				4589
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4590	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4591
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4592	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4593
				4594	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4595	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4596	</pre>
				4597
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4598	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4599
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4600	<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]	4601	the "variable argument" area of a function call. It is used to implement the
				4602	<tt>va_arg</tt> macro in C.</p>
				4603
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4604	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4605
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4606	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4607	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4608	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]	4609	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4610
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4611	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4612
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4613	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4614	type from the specified <tt>va_list</tt> and causes the
				4615	<tt>va_list</tt> to point to the next argument. For more information,
				4616	see the variable argument handling <a href="#int_varargs">Intrinsic
				4617	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4618
				4619	<p>It is legal for this instruction to be called in a function which does not
				4620	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4621	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4622
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4623	<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]	4624	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4625	argument.</p>
				4626
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4627	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4628
				4629	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4630
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	4631	<p>Note that the code generator does not yet fully support va_arg
				4632	on many targets. Also, it does not currently support va_arg with
				4633	aggregate types on any target.</p>
				4634
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4635	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4636
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4637	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4638	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4639	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4640
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4641	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4642
				4643	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4644	well known names and semantics and are required to follow certain restrictions.
				4645	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4646	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]	4647	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]	4648
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4649	<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]	4650	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4651	begin with this prefix. Intrinsic functions must always be external functions:
				4652	you cannot define the body of intrinsic functions. Intrinsic functions may
				4653	only be used in call or invoke instructions: it is illegal to take the address
				4654	of an intrinsic function. Additionally, because intrinsic functions are part
				4655	of the LLVM language, it is required if any are added that they be documented
				4656	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4657
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4658	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4659	a family of functions that perform the same operation but on different data
				4660	types. Because LLVM can represent over 8 million different integer types,
				4661	overloading is used commonly to allow an intrinsic function to operate on any
				4662	integer type. One or more of the argument types or the result type can be
				4663	overloaded to accept any integer type. Argument types may also be defined as
				4664	exactly matching a previous argument's type or the result type. This allows an
				4665	intrinsic function which accepts multiple arguments, but needs all of them to
				4666	be of the same type, to only be overloaded with respect to a single argument or
				4667	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4668
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4669	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4670	encoded into its function name, each preceded by a period. Only those types
				4671	which are overloaded result in a name suffix. Arguments whose type is matched
				4672	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4673	take an integer of any width and returns an integer of exactly the same integer
				4674	width. This leads to a family of functions such as
				4675	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4676	Only one type, the return type, is overloaded, and only one type suffix is
				4677	required. Because the argument's type is matched against the return type, it
				4678	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4679
				4680	<p>To learn how to add an intrinsic function, please see the
				4681	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4682	</p>
				4683
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4684	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4685
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4686	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4687	<div class="doc_subsection">
				4688	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4689	</div>
				4690
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4691	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4692
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4693	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4694	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]	4695	intrinsic functions. These functions are related to the similarly
				4696	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4697
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4698	<p>All of these functions operate on arguments that use a
				4699	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4700	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4701	transformations should be prepared to handle these functions regardless of
				4702	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4703
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4704	<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]	4705	instruction and the variable argument handling intrinsic functions are
				4706	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4707
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4708	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4709	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4710	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4711	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4712	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4713	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4714	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4715
				4716	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4717	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4718
				4719	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4720	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4721	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4722	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4723	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4724
				4725	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4726	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4727	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4728	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4729
				4730	declare void @llvm.va_start(i8*)
				4731	declare void @llvm.va_copy(i8, i8)
				4732	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4733	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4734	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4735
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4736	</div>
				4737
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4738	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4739	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4740	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4741	</div>
				4742
				4743
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4744	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4745	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4746	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4747	<h5>Overview:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4748	<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4749	<tt>*<arglist></tt> for subsequent use by <tt><a
				4750	href="#i_va_arg">va_arg</a></tt>.</p>
				4751
				4752	<h5>Arguments:</h5>
				4753
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4754	<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4755
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4756	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4757
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4758	<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4759	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4760	<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]	4761	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4762	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]	4763	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]	4764
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4765	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4766
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4767	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4768	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4769	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4770	</div>
				4771
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4772	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4773	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4774	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4775	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4776
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4777	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4778	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]	4779	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]	4780
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4781	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4782
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4783	<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]	4784
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4785	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4786
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4787	<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]	4788	macro available in C. In a target-dependent way, it destroys the
				4789	<tt>va_list</tt> element to which the argument points. Calls to <a
				4790	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4791	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4792	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4793
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4794	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4795
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4796	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4797	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4798	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4799	</div>
				4800
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4801	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4802
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4803	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4804
				4805	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4806	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4807	</pre>
				4808
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4809	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4810
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4811	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4812	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4813
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4814	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4815
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4816	<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]	4817	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]	4818
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4819
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4820	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4821
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4822	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4823	macro available in C. In a target-dependent way, it copies the source
				4824	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4825	intrinsic is necessary because the <tt><a href="#int_va_start">
				4826	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4827	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4828
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4829	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4830
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4831	<!-- ======================================================================= -->
				4832	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4833	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4834	</div>
				4835
				4836	<div class="doc_text">
				4837
				4838	<p>
				4839	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	4840	Collection</a> (GC) requires the implementation and generation of these
				4841	intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4842	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]	4843	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4844	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]	4845	Front-ends for type-safe garbage collected languages should generate these
				4846	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4847	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4848	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4849
				4850	<p>The garbage collection intrinsics only operate on objects in the generic
				4851	address space (address space zero).</p>
				4852
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4853	</div>
				4854
				4855	<!-- _______________________________________________________________________ -->
				4856	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4857	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4858	</div>
				4859
				4860	<div class="doc_text">
				4861
				4862	<h5>Syntax:</h5>
				4863
				4864	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4865	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4866	</pre>
				4867
				4868	<h5>Overview:</h5>
				4869
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4870	<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]	4871	the code generator, and allows some metadata to be associated with it.</p>
				4872
				4873	<h5>Arguments:</h5>
				4874
				4875	<p>The first argument specifies the address of a stack object that contains the
				4876	root pointer. The second pointer (which must be either a constant or a global
				4877	value address) contains the meta-data to be associated with the root.</p>
				4878
				4879	<h5>Semantics:</h5>
				4880
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	4881	<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]	4882	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4883	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4884	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4885	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4886
				4887	</div>
				4888
				4889
				4890	<!-- _______________________________________________________________________ -->
				4891	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4892	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4893	</div>
				4894
				4895	<div class="doc_text">
				4896
				4897	<h5>Syntax:</h5>
				4898
				4899	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4900	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4901	</pre>
				4902
				4903	<h5>Overview:</h5>
				4904
				4905	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4906	locations, allowing garbage collector implementations that require read
				4907	barriers.</p>
				4908
				4909	<h5>Arguments:</h5>
				4910
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4911	<p>The second argument is the address to read from, which should be an address
				4912	allocated from the garbage collector. The first object is a pointer to the
				4913	start of the referenced object, if needed by the language runtime (otherwise
				4914	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4915
				4916	<h5>Semantics:</h5>
				4917
				4918	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4919	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4920	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4921	may only be used in a function which <a href="#gc">specifies a GC
				4922	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4923
				4924	</div>
				4925
				4926
				4927	<!-- _______________________________________________________________________ -->
				4928	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4929	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4930	</div>
				4931
				4932	<div class="doc_text">
				4933
				4934	<h5>Syntax:</h5>
				4935
				4936	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4937	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4938	</pre>
				4939
				4940	<h5>Overview:</h5>
				4941
				4942	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4943	locations, allowing garbage collector implementations that require write
				4944	barriers (such as generational or reference counting collectors).</p>
				4945
				4946	<h5>Arguments:</h5>
				4947
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4948	<p>The first argument is the reference to store, the second is the start of the
				4949	object to store it to, and the third is the address of the field of Obj to
				4950	store to. If the runtime does not require a pointer to the object, Obj may be
				4951	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4952
				4953	<h5>Semantics:</h5>
				4954
				4955	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4956	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4957	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4958	may only be used in a function which <a href="#gc">specifies a GC
				4959	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4960
				4961	</div>
				4962
				4963
				4964
				4965	<!-- ======================================================================= -->
				4966	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4967	<a name="int_codegen">Code Generator Intrinsics</a>
				4968	</div>
				4969
				4970	<div class="doc_text">
				4971	<p>
				4972	These intrinsics are provided by LLVM to expose special features that may only
				4973	be implemented with code generator support.
				4974	</p>
				4975
				4976	</div>
				4977
				4978	<!-- _______________________________________________________________________ -->
				4979	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4980	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4981	</div>
				4982
				4983	<div class="doc_text">
				4984
				4985	<h5>Syntax:</h5>
				4986	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4987	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4988	</pre>
				4989
				4990	<h5>Overview:</h5>
				4991
				4992	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4993	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				4994	target-specific value indicating the return address of the current function
				4995	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4996	</p>
				4997
				4998	<h5>Arguments:</h5>
				4999
				5000	<p>
				5001	The argument to this intrinsic indicates which function to return the address
				5002	for. Zero indicates the calling function, one indicates its caller, etc. The
				5003	argument is <b>required</b> to be a constant integer value.
				5004	</p>
				5005
				5006	<h5>Semantics:</h5>
				5007
				5008	<p>
				5009	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				5010	the return address of the specified call frame, or zero if it cannot be
				5011	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5012	for arguments other than zero, so it should only be used for debugging purposes.
				5013	</p>
				5014
				5015	<p>
				5016	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5017	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]	5018	source-language caller.
				5019	</p>
				5020	</div>
				5021
				5022
				5023	<!-- _______________________________________________________________________ -->
				5024	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5025	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5026	</div>
				5027
				5028	<div class="doc_text">
				5029
				5030	<h5>Syntax:</h5>
				5031	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5032	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5033	</pre>
				5034
				5035	<h5>Overview:</h5>
				5036
				5037	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5038	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				5039	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5040	</p>
				5041
				5042	<h5>Arguments:</h5>
				5043
				5044	<p>
				5045	The argument to this intrinsic indicates which function to return the frame
				5046	pointer for. Zero indicates the calling function, one indicates its caller,
				5047	etc. The argument is <b>required</b> to be a constant integer value.
				5048	</p>
				5049
				5050	<h5>Semantics:</h5>
				5051
				5052	<p>
				5053	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				5054	the frame address of the specified call frame, or zero if it cannot be
				5055	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5056	for arguments other than zero, so it should only be used for debugging purposes.
				5057	</p>
				5058
				5059	<p>
				5060	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5061	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]	5062	source-language caller.
				5063	</p>
				5064	</div>
				5065
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5066	<!-- _______________________________________________________________________ -->
				5067	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5068	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5069	</div>
				5070
				5071	<div class="doc_text">
				5072
				5073	<h5>Syntax:</h5>
				5074	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5075	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5076	</pre>
				5077
				5078	<h5>Overview:</h5>
				5079
				5080	<p>
				5081	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]	5082	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5083	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				5084	features like scoped automatic variable sized arrays in C99.
				5085	</p>
				5086
				5087	<h5>Semantics:</h5>
				5088
				5089	<p>
				5090	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]	5091	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5092	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				5093	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				5094	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				5095	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				5096	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				5097	</p>
				5098
				5099	</div>
				5100
				5101	<!-- _______________________________________________________________________ -->
				5102	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5103	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5104	</div>
				5105
				5106	<div class="doc_text">
				5107
				5108	<h5>Syntax:</h5>
				5109	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5110	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5111	</pre>
				5112
				5113	<h5>Overview:</h5>
				5114
				5115	<p>
				5116	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				5117	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]	5118	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5119	useful for implementing language features like scoped automatic variable sized
				5120	arrays in C99.
				5121	</p>
				5122
				5123	<h5>Semantics:</h5>
				5124
				5125	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5126	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]	5127	</p>
				5128
				5129	</div>
				5130
				5131
				5132	<!-- _______________________________________________________________________ -->
				5133	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5134	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5135	</div>
				5136
				5137	<div class="doc_text">
				5138
				5139	<h5>Syntax:</h5>
				5140	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5141	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5142	</pre>
				5143
				5144	<h5>Overview:</h5>
				5145
				5146
				5147	<p>
				5148	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]	5149	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				5150	no
				5151	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	5152	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5153	</p>
				5154
				5155	<h5>Arguments:</h5>
				5156
				5157	<p>
				5158	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				5159	determining if the fetch should be for a read (0) or write (1), and
				5160	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	5161	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]	5162	<tt>locality</tt> arguments must be constant integers.
				5163	</p>
				5164
				5165	<h5>Semantics:</h5>
				5166
				5167	<p>
				5168	This intrinsic does not modify the behavior of the program. In particular,
				5169	prefetches cannot trap and do not produce a value. On targets that support this
				5170	intrinsic, the prefetch can provide hints to the processor cache for better
				5171	performance.
				5172	</p>
				5173
				5174	</div>
				5175
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5176	<!-- _______________________________________________________________________ -->
				5177	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5178	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5179	</div>
				5180
				5181	<div class="doc_text">
				5182
				5183	<h5>Syntax:</h5>
				5184	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5185	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5186	</pre>
				5187
				5188	<h5>Overview:</h5>
				5189
				5190
				5191	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5192	The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	5193	(PC) in a region of
				5194	code to simulators and other tools. The method is target specific, but it is
				5195	expected that the marker will use exported symbols to transmit the PC of the
				5196	marker.
				5197	The marker makes no guarantees that it will remain with any specific instruction
				5198	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]	5199	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5200	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5201	</p>
				5202
				5203	<h5>Arguments:</h5>
				5204
				5205	<p>
				5206	<tt>id</tt> is a numerical id identifying the marker.
				5207	</p>
				5208
				5209	<h5>Semantics:</h5>
				5210
				5211	<p>
				5212	This intrinsic does not modify the behavior of the program. Backends that do not
				5213	support this intrinisic may ignore it.
				5214	</p>
				5215
				5216	</div>
				5217
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5218	<!-- _______________________________________________________________________ -->
				5219	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5220	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5221	</div>
				5222
				5223	<div class="doc_text">
				5224
				5225	<h5>Syntax:</h5>
				5226	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5227	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5228	</pre>
				5229
				5230	<h5>Overview:</h5>
				5231
				5232
				5233	<p>
				5234	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5235	counter register (or similar low latency, high accuracy clocks) on those targets
				5236	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5237	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5238	should only be used for small timings.
				5239	</p>
				5240
				5241	<h5>Semantics:</h5>
				5242
				5243	<p>
				5244	When directly supported, reading the cycle counter should not modify any memory.
				5245	Implementations are allowed to either return a application specific value or a
				5246	system wide value. On backends without support, this is lowered to a constant 0.
				5247	</p>
				5248
				5249	</div>
				5250
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5251	<!-- ======================================================================= -->
				5252	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5253	<a name="int_libc">Standard C Library Intrinsics</a>
				5254	</div>
				5255
				5256	<div class="doc_text">
				5257	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5258	LLVM provides intrinsics for a few important standard C library functions.
				5259	These intrinsics allow source-language front-ends to pass information about the
				5260	alignment of the pointer arguments to the code generator, providing opportunity
				5261	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5262	</p>
				5263
				5264	</div>
				5265
				5266	<!-- _______________________________________________________________________ -->
				5267	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5268	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5269	</div>
				5270
				5271	<div class="doc_text">
				5272
				5273	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5274	<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
				5275	width. Not all targets support all bit widths however.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5276	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5277	declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>,
				5278	i8 <len>, i32 <align>)
				5279	declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>,
				5280	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5281	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5282	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5283	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5284	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5285	</pre>
				5286
				5287	<h5>Overview:</h5>
				5288
				5289	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5290	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]	5291	location to the destination location.
				5292	</p>
				5293
				5294	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5295	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5296	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5297	</p>
				5298
				5299	<h5>Arguments:</h5>
				5300
				5301	<p>
				5302	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]	5303	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5304	specifying the number of bytes to copy, and the fourth argument is the alignment
				5305	of the source and destination locations.
				5306	</p>
				5307
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5308	<p>
				5309	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]	5310	the caller guarantees that both the source and destination pointers are aligned
				5311	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5312	</p>
				5313
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5314	<h5>Semantics:</h5>
				5315
				5316	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5317	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]	5318	location to the destination location, which are not allowed to overlap. It
				5319	copies "len" bytes of memory over. If the argument is known to be aligned to
				5320	some boundary, this can be specified as the fourth argument, otherwise it should
				5321	be set to 0 or 1.
				5322	</p>
				5323	</div>
				5324
				5325
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5326	<!-- _______________________________________________________________________ -->
				5327	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5328	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5329	</div>
				5330
				5331	<div class="doc_text">
				5332
				5333	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5334	<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
				5335	width. Not all targets support all bit widths however.</p>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5336	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5337	declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>,
				5338	i8 <len>, i32 <align>)
				5339	declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>,
				5340	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5341	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5342	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5343	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5344	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5345	</pre>
				5346
				5347	<h5>Overview:</h5>
				5348
				5349	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5350	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5351	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5352	'<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]	5353	</p>
				5354
				5355	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5356	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5357	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5358	</p>
				5359
				5360	<h5>Arguments:</h5>
				5361
				5362	<p>
				5363	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]	5364	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5365	specifying the number of bytes to copy, and the fourth argument is the alignment
				5366	of the source and destination locations.
				5367	</p>
				5368
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5369	<p>
				5370	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]	5371	the caller guarantees that the source and destination pointers are aligned to
				5372	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5373	</p>
				5374
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5375	<h5>Semantics:</h5>
				5376
				5377	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5378	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]	5379	location to the destination location, which may overlap. It
				5380	copies "len" bytes of memory over. If the argument is known to be aligned to
				5381	some boundary, this can be specified as the fourth argument, otherwise it should
				5382	be set to 0 or 1.
				5383	</p>
				5384	</div>
				5385
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5386
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5387	<!-- _______________________________________________________________________ -->
				5388	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5389	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5390	</div>
				5391
				5392	<div class="doc_text">
				5393
				5394	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5395	<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
				5396	width. Not all targets support all bit widths however.</p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5397	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5398	declare void @llvm.memset.i8(i8 * <dest>, i8 <val>,
				5399	i8 <len>, i32 <align>)
				5400	declare void @llvm.memset.i16(i8 * <dest>, i8 <val>,
				5401	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5402	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5403	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5404	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5405	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5406	</pre>
				5407
				5408	<h5>Overview:</h5>
				5409
				5410	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5411	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]	5412	byte value.
				5413	</p>
				5414
				5415	<p>
				5416	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5417	does not return a value, and takes an extra alignment argument.
				5418	</p>
				5419
				5420	<h5>Arguments:</h5>
				5421
				5422	<p>
				5423	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]	5424	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5425	argument specifying the number of bytes to fill, and the fourth argument is the
				5426	known alignment of destination location.
				5427	</p>
				5428
				5429	<p>
				5430	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]	5431	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5432	</p>
				5433
				5434	<h5>Semantics:</h5>
				5435
				5436	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5437	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5438	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5439	destination location. If the argument is known to be aligned to some boundary,
				5440	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5441	1.
				5442	</p>
				5443	</div>
				5444
				5445
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5446	<!-- _______________________________________________________________________ -->
				5447	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5448	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5449	</div>
				5450
				5451	<div class="doc_text">
				5452
				5453	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5454	<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]	5455	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5456	types however.</p>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5457	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5458	declare float @llvm.sqrt.f32(float %Val)
				5459	declare double @llvm.sqrt.f64(double %Val)
				5460	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5461	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5462	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5463	</pre>
				5464
				5465	<h5>Overview:</h5>
				5466
				5467	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5468	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]	5469	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]	5470	<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]	5471	negative numbers other than -0.0 (which allows for better optimization, because
				5472	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5473	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5474	</p>
				5475
				5476	<h5>Arguments:</h5>
				5477
				5478	<p>
				5479	The argument and return value are floating point numbers of the same type.
				5480	</p>
				5481
				5482	<h5>Semantics:</h5>
				5483
				5484	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5485	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]	5486	floating point number.
				5487	</p>
				5488	</div>
				5489
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5490	<!-- _______________________________________________________________________ -->
				5491	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5492	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5493	</div>
				5494
				5495	<div class="doc_text">
				5496
				5497	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5498	<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]	5499	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5500	types however.</p>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5501	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5502	declare float @llvm.powi.f32(float %Val, i32 %power)
				5503	declare double @llvm.powi.f64(double %Val, i32 %power)
				5504	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5505	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5506	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5507	</pre>
				5508
				5509	<h5>Overview:</h5>
				5510
				5511	<p>
				5512	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5513	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5514	multiplications is not defined. When a vector of floating point type is
				5515	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5516	</p>
				5517
				5518	<h5>Arguments:</h5>
				5519
				5520	<p>
				5521	The second argument is an integer power, and the first is a value to raise to
				5522	that power.
				5523	</p>
				5524
				5525	<h5>Semantics:</h5>
				5526
				5527	<p>
				5528	This function returns the first value raised to the second power with an
				5529	unspecified sequence of rounding operations.</p>
				5530	</div>
				5531
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5532	<!-- _______________________________________________________________________ -->
				5533	<div class="doc_subsubsection">
				5534	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5535	</div>
				5536
				5537	<div class="doc_text">
				5538
				5539	<h5>Syntax:</h5>
				5540	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5541	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5542	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5543	<pre>
				5544	declare float @llvm.sin.f32(float %Val)
				5545	declare double @llvm.sin.f64(double %Val)
				5546	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5547	declare fp128 @llvm.sin.f128(fp128 %Val)
				5548	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5549	</pre>
				5550
				5551	<h5>Overview:</h5>
				5552
				5553	<p>
				5554	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5555	</p>
				5556
				5557	<h5>Arguments:</h5>
				5558
				5559	<p>
				5560	The argument and return value are floating point numbers of the same type.
				5561	</p>
				5562
				5563	<h5>Semantics:</h5>
				5564
				5565	<p>
				5566	This function returns the sine of the specified operand, returning the
				5567	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]	5568	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5569	</div>
				5570
				5571	<!-- _______________________________________________________________________ -->
				5572	<div class="doc_subsubsection">
				5573	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5574	</div>
				5575
				5576	<div class="doc_text">
				5577
				5578	<h5>Syntax:</h5>
				5579	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5580	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5581	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5582	<pre>
				5583	declare float @llvm.cos.f32(float %Val)
				5584	declare double @llvm.cos.f64(double %Val)
				5585	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5586	declare fp128 @llvm.cos.f128(fp128 %Val)
				5587	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5588	</pre>
				5589
				5590	<h5>Overview:</h5>
				5591
				5592	<p>
				5593	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5594	</p>
				5595
				5596	<h5>Arguments:</h5>
				5597
				5598	<p>
				5599	The argument and return value are floating point numbers of the same type.
				5600	</p>
				5601
				5602	<h5>Semantics:</h5>
				5603
				5604	<p>
				5605	This function returns the cosine of the specified operand, returning the
				5606	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]	5607	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5608	</div>
				5609
				5610	<!-- _______________________________________________________________________ -->
				5611	<div class="doc_subsubsection">
				5612	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5613	</div>
				5614
				5615	<div class="doc_text">
				5616
				5617	<h5>Syntax:</h5>
				5618	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5619	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5620	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5621	<pre>
				5622	declare float @llvm.pow.f32(float %Val, float %Power)
				5623	declare double @llvm.pow.f64(double %Val, double %Power)
				5624	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5625	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5626	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5627	</pre>
				5628
				5629	<h5>Overview:</h5>
				5630
				5631	<p>
				5632	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5633	specified (positive or negative) power.
				5634	</p>
				5635
				5636	<h5>Arguments:</h5>
				5637
				5638	<p>
				5639	The second argument is a floating point power, and the first is a value to
				5640	raise to that power.
				5641	</p>
				5642
				5643	<h5>Semantics:</h5>
				5644
				5645	<p>
				5646	This function returns the first value raised to the second power,
				5647	returning the
				5648	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]	5649	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5650	</div>
				5651
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5652
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5653	<!-- ======================================================================= -->
				5654	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5655	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5656	</div>
				5657
				5658	<div class="doc_text">
				5659	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5660	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5661	These allow efficient code generation for some algorithms.
				5662	</p>
				5663
				5664	</div>
				5665
				5666	<!-- _______________________________________________________________________ -->
				5667	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5668	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5669	</div>
				5670
				5671	<div class="doc_text">
				5672
				5673	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5674	<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5675	type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5676	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5677	declare i16 @llvm.bswap.i16(i16 <id>)
				5678	declare i32 @llvm.bswap.i32(i32 <id>)
				5679	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5680	</pre>
				5681
				5682	<h5>Overview:</h5>
				5683
				5684	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5685	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]	5686	values with an even number of bytes (positive multiple of 16 bits). These are
				5687	useful for performing operations on data that is not in the target's native
				5688	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5689	</p>
				5690
				5691	<h5>Semantics:</h5>
				5692
				5693	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5694	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]	5695	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5696	intrinsic returns an i32 value that has the four bytes of the input i32
				5697	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]	5698	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5699	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5700	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5701	</p>
				5702
				5703	</div>
				5704
				5705	<!-- _______________________________________________________________________ -->
				5706	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5707	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5708	</div>
				5709
				5710	<div class="doc_text">
				5711
				5712	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5713	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5714	width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5715	<pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5716	declare i8 @llvm.ctpop.i8(i8 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5717	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5718	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5719	declare i64 @llvm.ctpop.i64(i64 <src>)
				5720	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5721	</pre>
				5722
				5723	<h5>Overview:</h5>
				5724
				5725	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5726	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5727	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5728	</p>
				5729
				5730	<h5>Arguments:</h5>
				5731
				5732	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5733	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]	5734	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5735	</p>
				5736
				5737	<h5>Semantics:</h5>
				5738
				5739	<p>
				5740	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5741	</p>
				5742	</div>
				5743
				5744	<!-- _______________________________________________________________________ -->
				5745	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5746	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5747	</div>
				5748
				5749	<div class="doc_text">
				5750
				5751	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5752	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5753	integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5754	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5755	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5756	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5757	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5758	declare i64 @llvm.ctlz.i64(i64 <src>)
				5759	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5760	</pre>
				5761
				5762	<h5>Overview:</h5>
				5763
				5764	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5765	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5766	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5767	</p>
				5768
				5769	<h5>Arguments:</h5>
				5770
				5771	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5772	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]	5773	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5774	</p>
				5775
				5776	<h5>Semantics:</h5>
				5777
				5778	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5779	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5780	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]	5781	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5782	</p>
				5783	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5784
				5785
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5786
				5787	<!-- _______________________________________________________________________ -->
				5788	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5789	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5790	</div>
				5791
				5792	<div class="doc_text">
				5793
				5794	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5795	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5796	integer bit width. Not all targets support all bit widths however.</p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5797	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5798	declare i8 @llvm.cttz.i8 (i8 <src>)
				5799	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5800	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5801	declare i64 @llvm.cttz.i64(i64 <src>)
				5802	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5803	</pre>
				5804
				5805	<h5>Overview:</h5>
				5806
				5807	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5808	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5809	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5810	</p>
				5811
				5812	<h5>Arguments:</h5>
				5813
				5814	<p>
				5815	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]	5816	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5817	</p>
				5818
				5819	<h5>Semantics:</h5>
				5820
				5821	<p>
				5822	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5823	in a variable. If the src == 0 then the result is the size in bits of the type
				5824	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5825	</p>
				5826	</div>
				5827
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	5828	<!-- _______________________________________________________________________ -->
				5829	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5830	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5831	</div>
				5832
				5833	<div class="doc_text">
				5834
				5835	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5836	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5837	on any integer bit width.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5838	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5839	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5840	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5841	</pre>
				5842
				5843	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5844	<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]	5845	range of bits from an integer value and returns them in the same bit width as
				5846	the original value.</p>
				5847
				5848	<h5>Arguments:</h5>
				5849	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5850	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]	5851	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]	5852
				5853	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5854	<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]	5855	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5856	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5857	operates in forward mode.</p>
				5858	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5859	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]	5860	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5861	<ol>
				5862	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5863	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5864	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5865	to determine the number of bits to retain.</li>
				5866	<li>A mask of the retained bits is created by shifting a -1 value.</li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5867	<li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5868	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	5869	<p>In reverse mode, a similar computation is made except that the bits are
				5870	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5871	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5872	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5873	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5874	</div>
				5875
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5876	<div class="doc_subsubsection">
				5877	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5878	</div>
				5879
				5880	<div class="doc_text">
				5881
				5882	<h5>Syntax:</h5>
				5883	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5884	on any integer bit width.</p>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5885	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5886	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5887	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]	5888	</pre>
				5889
				5890	<h5>Overview:</h5>
				5891	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5892	of bits in an integer value with another integer value. It returns the integer
				5893	with the replaced bits.</p>
				5894
				5895	<h5>Arguments:</h5>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5896	<p>The first argument, <tt>%val</tt>, and the result may be integer types of
				5897	any bit width, but they must have the same bit width. <tt>%val</tt> is the value
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5898	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5899	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5900	type since they specify only a bit index.</p>
				5901
				5902	<h5>Semantics:</h5>
				5903	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5904	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5905	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5906	operates in forward mode.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5907
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5908	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5909	truncating it down to the size of the replacement area or zero extending it
				5910	up to that size.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5911
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5912	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5913	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5914	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5915	to the <tt>%hi</tt>th bit.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5916
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5917	<p>In reverse mode, a similar computation is made except that the bits are
				5918	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5919	<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5920
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5921	<h5>Examples:</h5>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5922
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5923	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5924	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5925	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5926	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5927	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5928	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	5929	</pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5930
				5931	</div>
				5932
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	5933	<!-- ======================================================================= -->
				5934	<div class="doc_subsection">
				5935	<a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
				5936	</div>
				5937
				5938	<div class="doc_text">
				5939	<p>
				5940	LLVM provides intrinsics for some arithmetic with overflow operations.
				5941	</p>
				5942
				5943	</div>
				5944
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5945	<!-- _______________________________________________________________________ -->
				5946	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	5947	<a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5948	</div>
				5949
				5950	<div class="doc_text">
				5951
				5952	<h5>Syntax:</h5>
				5953
				5954	<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	5955	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5956
				5957	<pre>
				5958	declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
				5959	declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				5960	declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
				5961	</pre>
				5962
				5963	<h5>Overview:</h5>
				5964
				5965	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				5966	a signed addition of the two arguments, and indicate whether an overflow
				5967	occurred during the signed summation.</p>
				5968
				5969	<h5>Arguments:</h5>
				5970
				5971	<p>The arguments (%a and %b) and the first element of the result structure may
				5972	be of integer types of any bit width, but they must have the same bit width. The
				5973	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				5974	and <tt>%b</tt> are the two values that will undergo signed addition.</p>
				5975
				5976	<h5>Semantics:</h5>
				5977
				5978	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				5979	a signed addition of the two variables. They return a structure — the
				5980	first element of which is the signed summation, and the second element of which
				5981	is a bit specifying if the signed summation resulted in an overflow.</p>
				5982
				5983	<h5>Examples:</h5>
				5984	<pre>
				5985	%res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				5986	%sum = extractvalue {i32, i1} %res, 0
				5987	%obit = extractvalue {i32, i1} %res, 1
				5988	br i1 %obit, label %overflow, label %normal
				5989	</pre>
				5990
				5991	</div>
				5992
				5993	<!-- _______________________________________________________________________ -->
				5994	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	5995	<a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5996	</div>
				5997
				5998	<div class="doc_text">
				5999
				6000	<h5>Syntax:</h5>
				6001
				6002	<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6003	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6004
				6005	<pre>
				6006	declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
				6007	declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6008	declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
				6009	</pre>
				6010
				6011	<h5>Overview:</h5>
				6012
				6013	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6014	an unsigned addition of the two arguments, and indicate whether a carry occurred
				6015	during the unsigned summation.</p>
				6016
				6017	<h5>Arguments:</h5>
				6018
				6019	<p>The arguments (%a and %b) and the first element of the result structure may
				6020	be of integer types of any bit width, but they must have the same bit width. The
				6021	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6022	and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
				6023
				6024	<h5>Semantics:</h5>
				6025
				6026	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6027	an unsigned addition of the two arguments. They return a structure — the
				6028	first element of which is the sum, and the second element of which is a bit
				6029	specifying if the unsigned summation resulted in a carry.</p>
				6030
				6031	<h5>Examples:</h5>
				6032	<pre>
				6033	%res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6034	%sum = extractvalue {i32, i1} %res, 0
				6035	%obit = extractvalue {i32, i1} %res, 1
				6036	br i1 %obit, label %carry, label %normal
				6037	</pre>
				6038
				6039	</div>
				6040
				6041	<!-- _______________________________________________________________________ -->
				6042	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6043	<a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6044	</div>
				6045
				6046	<div class="doc_text">
				6047
				6048	<h5>Syntax:</h5>
				6049
				6050	<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6051	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6052
				6053	<pre>
				6054	declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
				6055	declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6056	declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
				6057	</pre>
				6058
				6059	<h5>Overview:</h5>
				6060
				6061	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6062	a signed subtraction of the two arguments, and indicate whether an overflow
				6063	occurred during the signed subtraction.</p>
				6064
				6065	<h5>Arguments:</h5>
				6066
				6067	<p>The arguments (%a and %b) and the first element of the result structure may
				6068	be of integer types of any bit width, but they must have the same bit width. The
				6069	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6070	and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
				6071
				6072	<h5>Semantics:</h5>
				6073
				6074	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6075	a signed subtraction of the two arguments. They return a structure — the
				6076	first element of which is the subtraction, and the second element of which is a bit
				6077	specifying if the signed subtraction resulted in an overflow.</p>
				6078
				6079	<h5>Examples:</h5>
				6080	<pre>
				6081	%res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6082	%sum = extractvalue {i32, i1} %res, 0
				6083	%obit = extractvalue {i32, i1} %res, 1
				6084	br i1 %obit, label %overflow, label %normal
				6085	</pre>
				6086
				6087	</div>
				6088
				6089	<!-- _______________________________________________________________________ -->
				6090	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6091	<a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6092	</div>
				6093
				6094	<div class="doc_text">
				6095
				6096	<h5>Syntax:</h5>
				6097
				6098	<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6099	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6100
				6101	<pre>
				6102	declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
				6103	declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6104	declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
				6105	</pre>
				6106
				6107	<h5>Overview:</h5>
				6108
				6109	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6110	an unsigned subtraction of the two arguments, and indicate whether an overflow
				6111	occurred during the unsigned subtraction.</p>
				6112
				6113	<h5>Arguments:</h5>
				6114
				6115	<p>The arguments (%a and %b) and the first element of the result structure may
				6116	be of integer types of any bit width, but they must have the same bit width. The
				6117	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6118	and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
				6119
				6120	<h5>Semantics:</h5>
				6121
				6122	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6123	an unsigned subtraction of the two arguments. They return a structure — the
				6124	first element of which is the subtraction, and the second element of which is a bit
				6125	specifying if the unsigned subtraction resulted in an overflow.</p>
				6126
				6127	<h5>Examples:</h5>
				6128	<pre>
				6129	%res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6130	%sum = extractvalue {i32, i1} %res, 0
				6131	%obit = extractvalue {i32, i1} %res, 1
				6132	br i1 %obit, label %overflow, label %normal
				6133	</pre>
				6134
				6135	</div>
				6136
				6137	<!-- _______________________________________________________________________ -->
				6138	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6139	<a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6140	</div>
				6141
				6142	<div class="doc_text">
				6143
				6144	<h5>Syntax:</h5>
				6145
				6146	<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6147	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6148
				6149	<pre>
				6150	declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
				6151	declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6152	declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
				6153	</pre>
				6154
				6155	<h5>Overview:</h5>
				6156
				6157	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6158	a signed multiplication of the two arguments, and indicate whether an overflow
				6159	occurred during the signed multiplication.</p>
				6160
				6161	<h5>Arguments:</h5>
				6162
				6163	<p>The arguments (%a and %b) and the first element of the result structure may
				6164	be of integer types of any bit width, but they must have the same bit width. The
				6165	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6166	and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
				6167
				6168	<h5>Semantics:</h5>
				6169
				6170	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6171	a signed multiplication of the two arguments. They return a structure —
				6172	the first element of which is the multiplication, and the second element of
				6173	which is a bit specifying if the signed multiplication resulted in an
				6174	overflow.</p>
				6175
				6176	<h5>Examples:</h5>
				6177	<pre>
				6178	%res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6179	%sum = extractvalue {i32, i1} %res, 0
				6180	%obit = extractvalue {i32, i1} %res, 1
				6181	br i1 %obit, label %overflow, label %normal
				6182	</pre>
				6183
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6184	</div>
				6185
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	6186	<!-- _______________________________________________________________________ -->
				6187	<div class="doc_subsubsection">
				6188	<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
				6189	</div>
				6190
				6191	<div class="doc_text">
				6192
				6193	<h5>Syntax:</h5>
				6194
				6195	<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
				6196	on any integer bit width.</p>
				6197
				6198	<pre>
				6199	declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
				6200	declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6201	declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
				6202	</pre>
				6203
				6204	<h5>Overview:</h5>
				6205
				6206	<p><i><b>Warning:</b> '<tt>llvm.umul.with.overflow</tt>' is badly broken. It is
				6207	actively being fixed, but it should not currently be used!</i></p>
				6208
				6209	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6210	a unsigned multiplication of the two arguments, and indicate whether an overflow
				6211	occurred during the unsigned multiplication.</p>
				6212
				6213	<h5>Arguments:</h5>
				6214
				6215	<p>The arguments (%a and %b) and the first element of the result structure may
				6216	be of integer types of any bit width, but they must have the same bit width. The
				6217	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6218	and <tt>%b</tt> are the two values that will undergo unsigned
				6219	multiplication.</p>
				6220
				6221	<h5>Semantics:</h5>
				6222
				6223	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6224	an unsigned multiplication of the two arguments. They return a structure —
				6225	the first element of which is the multiplication, and the second element of
				6226	which is a bit specifying if the unsigned multiplication resulted in an
				6227	overflow.</p>
				6228
				6229	<h5>Examples:</h5>
				6230	<pre>
				6231	%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6232	%sum = extractvalue {i32, i1} %res, 0
				6233	%obit = extractvalue {i32, i1} %res, 1
				6234	br i1 %obit, label %overflow, label %normal
				6235	</pre>
				6236
				6237	</div>
				6238
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	6239	<!-- ======================================================================= -->
				6240	<div class="doc_subsection">
				6241	<a name="int_debugger">Debugger Intrinsics</a>
				6242	</div>
				6243
				6244	<div class="doc_text">
				6245	<p>
				6246	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				6247	are described in the <a
				6248	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				6249	Debugging</a> document.
				6250	</p>
				6251	</div>
				6252
				6253
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6254	<!-- ======================================================================= -->
				6255	<div class="doc_subsection">
				6256	<a name="int_eh">Exception Handling Intrinsics</a>
				6257	</div>
				6258
				6259	<div class="doc_text">
				6260	<p> The LLVM exception handling intrinsics (which all start with
				6261	<tt>llvm.eh.</tt> prefix), are described in the <a
				6262	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				6263	Handling</a> document. </p>
				6264	</div>
				6265
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6266	<!-- ======================================================================= -->
				6267	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6268	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6269	</div>
				6270
				6271	<div class="doc_text">
				6272	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6273	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6274	the <tt>nest</tt> attribute, from a function. The result is a callable
				6275	function pointer lacking the nest parameter - the caller does not need
				6276	to provide a value for it. Instead, the value to use is stored in
				6277	advance in a "trampoline", a block of memory usually allocated
				6278	on the stack, which also contains code to splice the nest value into the
				6279	argument list. This is used to implement the GCC nested function address
				6280	extension.
				6281	</p>
				6282	<p>
				6283	For example, if the function is
				6284	<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]	6285	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]	6286	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6287	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				6288	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				6289	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				6290	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6291	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	6292	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				6293	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]	6294	</div>
				6295
				6296	<!-- _______________________________________________________________________ -->
				6297	<div class="doc_subsubsection">
				6298	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				6299	</div>
				6300	<div class="doc_text">
				6301	<h5>Syntax:</h5>
				6302	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6303	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6304	</pre>
				6305	<h5>Overview:</h5>
				6306	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6307	This fills the memory pointed to by <tt>tramp</tt> with code
				6308	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6309	</p>
				6310	<h5>Arguments:</h5>
				6311	<p>
				6312	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				6313	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				6314	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]	6315	intrinsic. Note that the size and the alignment are target-specific - LLVM
				6316	currently provides no portable way of determining them, so a front-end that
				6317	generates this intrinsic needs to have some target-specific knowledge.
				6318	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]	6319	</p>
				6320	<h5>Semantics:</h5>
				6321	<p>
				6322	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]	6323	dependent code, turning it into a function. A pointer to this function is
				6324	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6325	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6326	before being called. The new function's signature is the same as that of
				6327	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				6328	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				6329	of pointer type. Calling the new function is equivalent to calling
				6330	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				6331	missing <tt>nest</tt> argument. If, after calling
				6332	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				6333	modified, then the effect of any later call to the returned function pointer is
				6334	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6335	</p>
				6336	</div>
				6337
				6338	<!-- ======================================================================= -->
				6339	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6340	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				6341	</div>
				6342
				6343	<div class="doc_text">
				6344	<p>
				6345	These intrinsic functions expand the "universal IR" of LLVM to represent
				6346	hardware constructs for atomic operations and memory synchronization. This
				6347	provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	6348	is aimed at a low enough level to allow any programming models or APIs
				6349	(Application Programming Interfaces) which
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6350	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				6351	hardware behavior. Just as hardware provides a "universal IR" for source
				6352	languages, it also provides a starting point for developing a "universal"
				6353	atomic operation and synchronization IR.
				6354	</p>
				6355	<p>
				6356	These do <em>not</em> form an API such as high-level threading libraries,
				6357	software transaction memory systems, atomic primitives, and intrinsic
				6358	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				6359	application libraries. The hardware interface provided by LLVM should allow
				6360	a clean implementation of all of these APIs and parallel programming models.
				6361	No one model or paradigm should be selected above others unless the hardware
				6362	itself ubiquitously does so.
				6363
				6364	</p>
				6365	</div>
				6366
				6367	<!-- _______________________________________________________________________ -->
				6368	<div class="doc_subsubsection">
				6369	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				6370	</div>
				6371	<div class="doc_text">
				6372	<h5>Syntax:</h5>
				6373	<pre>
				6374	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				6375	i1 <device> )
				6376
				6377	</pre>
				6378	<h5>Overview:</h5>
				6379	<p>
				6380	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				6381	specific pairs of memory access types.
				6382	</p>
				6383	<h5>Arguments:</h5>
				6384	<p>
				6385	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				6386	The first four arguments enables a specific barrier as listed below. The fith
				6387	argument specifies that the barrier applies to io or device or uncached memory.
				6388
				6389	</p>
				6390	<ul>
				6391	<li><tt>ll</tt>: load-load barrier</li>
				6392	<li><tt>ls</tt>: load-store barrier</li>
				6393	<li><tt>sl</tt>: store-load barrier</li>
				6394	<li><tt>ss</tt>: store-store barrier</li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6395	<li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6396	</ul>
				6397	<h5>Semantics:</h5>
				6398	<p>
				6399	This intrinsic causes the system to enforce some ordering constraints upon
				6400	the loads and stores of the program. This barrier does not indicate
				6401	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				6402	which they occur. For any of the specified pairs of load and store operations
				6403	(f.ex. load-load, or store-load), all of the first operations preceding the
				6404	barrier will complete before any of the second operations succeeding the
				6405	barrier begin. Specifically the semantics for each pairing is as follows:
				6406	</p>
				6407	<ul>
				6408	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				6409	after the barrier begins.</li>
				6410
				6411	<li><tt>ls</tt>: All loads before the barrier must complete before any
				6412	store after the barrier begins.</li>
				6413	<li><tt>ss</tt>: All stores before the barrier must complete before any
				6414	store after the barrier begins.</li>
				6415	<li><tt>sl</tt>: All stores before the barrier must complete before any
				6416	load after the barrier begins.</li>
				6417	</ul>
				6418	<p>
				6419	These semantics are applied with a logical "and" behavior when more than one
				6420	is enabled in a single memory barrier intrinsic.
				6421	</p>
				6422	<p>
				6423	Backends may implement stronger barriers than those requested when they do not
				6424	support as fine grained a barrier as requested. Some architectures do not
				6425	need all types of barriers and on such architectures, these become noops.
				6426	</p>
				6427	<h5>Example:</h5>
				6428	<pre>
				6429	%ptr = malloc i32
				6430	store i32 4, %ptr
				6431
				6432	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				6433	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				6434	<i>; guarantee the above finishes</i>
				6435	store i32 8, %ptr <i>; before this begins</i>
				6436	</pre>
				6437	</div>
				6438
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6439	<!-- _______________________________________________________________________ -->
				6440	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6441	<a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6442	</div>
				6443	<div class="doc_text">
				6444	<h5>Syntax:</h5>
				6445	<p>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6446	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				6447	any integer bit width and for different address spaces. Not all targets
				6448	support all bit widths however.</p>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6449
				6450	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6451	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				6452	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				6453	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				6454	declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* <ptr>, i64 <cmp>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6455
				6456	</pre>
				6457	<h5>Overview:</h5>
				6458	<p>
				6459	This loads a value in memory and compares it to a given value. If they are
				6460	equal, it stores a new value into the memory.
				6461	</p>
				6462	<h5>Arguments:</h5>
				6463	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6464	The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6465	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				6466	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				6467	this integer type. While any bit width integer may be used, targets may only
				6468	lower representations they support in hardware.
				6469
				6470	</p>
				6471	<h5>Semantics:</h5>
				6472	<p>
				6473	This entire intrinsic must be executed atomically. It first loads the value
				6474	in memory pointed to by <tt>ptr</tt> and compares it with the value
				6475	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				6476	loaded value is yielded in all cases. This provides the equivalent of an
				6477	atomic compare-and-swap operation within the SSA framework.
				6478	</p>
				6479	<h5>Examples:</h5>
				6480
				6481	<pre>
				6482	%ptr = malloc i32
				6483	store i32 4, %ptr
				6484
				6485	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6486	%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6487	<i>; yields {i32}:result1 = 4</i>
				6488	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6489	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6490
				6491	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6492	%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6493	<i>; yields {i32}:result2 = 8</i>
				6494	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				6495
				6496	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				6497	</pre>
				6498	</div>
				6499
				6500	<!-- _______________________________________________________________________ -->
				6501	<div class="doc_subsubsection">
				6502	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				6503	</div>
				6504	<div class="doc_text">
				6505	<h5>Syntax:</h5>
				6506
				6507	<p>
				6508	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				6509	integer bit width. Not all targets support all bit widths however.</p>
				6510	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6511	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				6512	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				6513	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				6514	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6515
				6516	</pre>
				6517	<h5>Overview:</h5>
				6518	<p>
				6519	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				6520	the value from memory. It then stores the value in <tt>val</tt> in the memory
				6521	at <tt>ptr</tt>.
				6522	</p>
				6523	<h5>Arguments:</h5>
				6524
				6525	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6526	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6527	<tt>val</tt> argument and the result must be integers of the same bit width.
				6528	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				6529	integer type. The targets may only lower integer representations they
				6530	support.
				6531	</p>
				6532	<h5>Semantics:</h5>
				6533	<p>
				6534	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				6535	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				6536	equivalent of an atomic swap operation within the SSA framework.
				6537
				6538	</p>
				6539	<h5>Examples:</h5>
				6540	<pre>
				6541	%ptr = malloc i32
				6542	store i32 4, %ptr
				6543
				6544	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6545	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6546	<i>; yields {i32}:result1 = 4</i>
				6547	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6548	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6549
				6550	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6551	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6552	<i>; yields {i32}:result2 = 8</i>
				6553
				6554	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				6555	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6556	</pre>
				6557	</div>
				6558
				6559	<!-- _______________________________________________________________________ -->
				6560	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6561	<a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6562
				6563	</div>
				6564	<div class="doc_text">
				6565	<h5>Syntax:</h5>
				6566	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6567	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on any
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6568	integer bit width. Not all targets support all bit widths however.</p>
				6569	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6570	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6571	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6572	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6573	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6574
				6575	</pre>
				6576	<h5>Overview:</h5>
				6577	<p>
				6578	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6579	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6580	</p>
				6581	<h5>Arguments:</h5>
				6582	<p>
				6583
				6584	The intrinsic takes two arguments, the first a pointer to an integer value
				6585	and the second an integer value. The result is also an integer value. These
				6586	integer types can have any bit width, but they must all have the same bit
				6587	width. The targets may only lower integer representations they support.
				6588	</p>
				6589	<h5>Semantics:</h5>
				6590	<p>
				6591	This intrinsic does a series of operations atomically. It first loads the
				6592	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6593	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6594	</p>
				6595
				6596	<h5>Examples:</h5>
				6597	<pre>
				6598	%ptr = malloc i32
				6599	store i32 4, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6600	%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6601	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6602	%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6603	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6604	%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6605	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6606	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6607	</pre>
				6608	</div>
				6609
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6610	<!-- _______________________________________________________________________ -->
				6611	<div class="doc_subsubsection">
				6612	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6613
				6614	</div>
				6615	<div class="doc_text">
				6616	<h5>Syntax:</h5>
				6617	<p>
				6618	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6619	any integer bit width and for different address spaces. Not all targets
				6620	support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6621	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6622	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6623	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6624	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6625	declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6626
				6627	</pre>
				6628	<h5>Overview:</h5>
				6629	<p>
				6630	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6631	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6632	</p>
				6633	<h5>Arguments:</h5>
				6634	<p>
				6635
				6636	The intrinsic takes two arguments, the first a pointer to an integer value
				6637	and the second an integer value. The result is also an integer value. These
				6638	integer types can have any bit width, but they must all have the same bit
				6639	width. The targets may only lower integer representations they support.
				6640	</p>
				6641	<h5>Semantics:</h5>
				6642	<p>
				6643	This intrinsic does a series of operations atomically. It first loads the
				6644	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6645	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6646	</p>
				6647
				6648	<h5>Examples:</h5>
				6649	<pre>
				6650	%ptr = malloc i32
				6651	store i32 8, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6652	%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6653	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6654	%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6655	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6656	%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6657	<i>; yields {i32}:result3 = 2</i>
				6658	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6659	</pre>
				6660	</div>
				6661
				6662	<!-- _______________________________________________________________________ -->
				6663	<div class="doc_subsubsection">
				6664	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6665	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6666	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6667	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6668
				6669	</div>
				6670	<div class="doc_text">
				6671	<h5>Syntax:</h5>
				6672	<p>
				6673	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6674	<tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6675	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6676	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6677	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6678	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6679	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6680	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6681	declare i64 @llvm.atomic.load.and.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6682
				6683	</pre>
				6684
				6685	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6686	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6687	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6688	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6689	declare i64 @llvm.atomic.load.or.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6690
				6691	</pre>
				6692
				6693	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6694	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6695	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6696	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6697	declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6698
				6699	</pre>
				6700
				6701	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6702	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6703	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6704	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6705	declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6706
				6707	</pre>
				6708	<h5>Overview:</h5>
				6709	<p>
				6710	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6711	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6712	at <tt>ptr</tt>.
				6713	</p>
				6714	<h5>Arguments:</h5>
				6715	<p>
				6716
				6717	These intrinsics take two arguments, the first a pointer to an integer value
				6718	and the second an integer value. The result is also an integer value. These
				6719	integer types can have any bit width, but they must all have the same bit
				6720	width. The targets may only lower integer representations they support.
				6721	</p>
				6722	<h5>Semantics:</h5>
				6723	<p>
				6724	These intrinsics does a series of operations atomically. They first load the
				6725	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6726	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6727	value stored at <tt>ptr</tt>.
				6728	</p>
				6729
				6730	<h5>Examples:</h5>
				6731	<pre>
				6732	%ptr = malloc i32
				6733	store i32 0x0F0F, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6734	%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6735	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6736	%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6737	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6738	%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6739	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6740	%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6741	<i>; yields {i32}:result3 = FF</i>
				6742	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6743	</pre>
				6744	</div>
				6745
				6746
				6747	<!-- _______________________________________________________________________ -->
				6748	<div class="doc_subsubsection">
				6749	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6750	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6751	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6752	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6753
				6754	</div>
				6755	<div class="doc_text">
				6756	<h5>Syntax:</h5>
				6757	<p>
				6758	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6759	<tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6760	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6761	address spaces. Not all targets
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6762	support all bit widths however.</p>
				6763	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6764	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6765	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6766	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6767	declare i64 @llvm.atomic.load.max.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6768
				6769	</pre>
				6770
				6771	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6772	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6773	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6774	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6775	declare i64 @llvm.atomic.load.min.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6776
				6777	</pre>
				6778
				6779	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6780	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6781	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6782	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6783	declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6784
				6785	</pre>
				6786
				6787	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6788	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6789	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6790	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6791	declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6792
				6793	</pre>
				6794	<h5>Overview:</h5>
				6795	<p>
				6796	These intrinsics takes the signed or unsigned minimum or maximum of
				6797	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6798	original value at <tt>ptr</tt>.
				6799	</p>
				6800	<h5>Arguments:</h5>
				6801	<p>
				6802
				6803	These intrinsics take two arguments, the first a pointer to an integer value
				6804	and the second an integer value. The result is also an integer value. These
				6805	integer types can have any bit width, but they must all have the same bit
				6806	width. The targets may only lower integer representations they support.
				6807	</p>
				6808	<h5>Semantics:</h5>
				6809	<p>
				6810	These intrinsics does a series of operations atomically. They first load the
				6811	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6812	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6813	the original value stored at <tt>ptr</tt>.
				6814	</p>
				6815
				6816	<h5>Examples:</h5>
				6817	<pre>
				6818	%ptr = malloc i32
				6819	store i32 7, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6820	%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6821	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6822	%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6823	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6824	%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6825	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6826	%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6827	<i>; yields {i32}:result3 = 8</i>
				6828	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6829	</pre>
				6830	</div>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6831
				6832	<!-- ======================================================================= -->
				6833	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6834	<a name="int_general">General Intrinsics</a>
				6835	</div>
				6836
				6837	<div class="doc_text">
				6838	<p> This class of intrinsics is designed to be generic and has
				6839	no specific purpose. </p>
				6840	</div>
				6841
				6842	<!-- _______________________________________________________________________ -->
				6843	<div class="doc_subsubsection">
				6844	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6845	</div>
				6846
				6847	<div class="doc_text">
				6848
				6849	<h5>Syntax:</h5>
				6850	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6851	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]	6852	</pre>
				6853
				6854	<h5>Overview:</h5>
				6855
				6856	<p>
				6857	The '<tt>llvm.var.annotation</tt>' intrinsic
				6858	</p>
				6859
				6860	<h5>Arguments:</h5>
				6861
				6862	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6863	The first argument is a pointer to a value, the second is a pointer to a
				6864	global string, the third is a pointer to a global string which is the source
				6865	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6866	</p>
				6867
				6868	<h5>Semantics:</h5>
				6869
				6870	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6871	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6872	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]	6873	annotations. These have no other defined use, they are ignored by code
				6874	generation and optimization.
				6875	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6876	</div>
				6877
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6878	<!-- _______________________________________________________________________ -->
				6879	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	6880	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6881	</div>
				6882
				6883	<div class="doc_text">
				6884
				6885	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6886	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6887	any integer bit width.
				6888	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6889	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	6890	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6891	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6892	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6893	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6894	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]	6895	</pre>
				6896
				6897	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6898
				6899	<p>
				6900	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6901	</p>
				6902
				6903	<h5>Arguments:</h5>
				6904
				6905	<p>
				6906	The first argument is an integer value (result of some expression),
				6907	the second is a pointer to a global string, the third is a pointer to a global
				6908	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]	6909	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6910	</p>
				6911
				6912	<h5>Semantics:</h5>
				6913
				6914	<p>
				6915	This intrinsic allows annotations to be put on arbitrary expressions
				6916	with arbitrary strings. This can be useful for special purpose optimizations
				6917	that want to look for these annotations. These have no other defined use, they
				6918	are ignored by code generation and optimization.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6919	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6920	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6921
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6922	<!-- _______________________________________________________________________ -->
				6923	<div class="doc_subsubsection">
				6924	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6925	</div>
				6926
				6927	<div class="doc_text">
				6928
				6929	<h5>Syntax:</h5>
				6930	<pre>
				6931	declare void @llvm.trap()
				6932	</pre>
				6933
				6934	<h5>Overview:</h5>
				6935
				6936	<p>
				6937	The '<tt>llvm.trap</tt>' intrinsic
				6938	</p>
				6939
				6940	<h5>Arguments:</h5>
				6941
				6942	<p>
				6943	None
				6944	</p>
				6945
				6946	<h5>Semantics:</h5>
				6947
				6948	<p>
				6949	This intrinsics is lowered to the target dependent trap instruction. If the
				6950	target does not have a trap instruction, this intrinsic will be lowered to the
				6951	call of the abort() function.
				6952	</p>
				6953	</div>
				6954
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	6955	<!-- _______________________________________________________________________ -->
				6956	<div class="doc_subsubsection">
Misha Brukman	dccb025	2008-11-22 23:55:29 +0000	[diff] [blame]	6957	<a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	6958	</div>
				6959	<div class="doc_text">
				6960	<h5>Syntax:</h5>
				6961	<pre>
				6962	declare void @llvm.stackprotector( i8* <guard>, i8** <slot> )
				6963
				6964	</pre>
				6965	<h5>Overview:</h5>
				6966	<p>
				6967	The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
				6968	it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
				6969	it is placed on the stack before local variables.
				6970	</p>
				6971	<h5>Arguments:</h5>
				6972	<p>
				6973	The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
				6974	first argument is the value loaded from the stack guard
				6975	<tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
				6976	has enough space to hold the value of the guard.
				6977	</p>
				6978	<h5>Semantics:</h5>
				6979	<p>
				6980	This intrinsic causes the prologue/epilogue inserter to force the position of
				6981	the <tt>AllocaInst</tt> stack slot to be before local variables on the
				6982	stack. This is to ensure that if a local variable on the stack is overwritten,
				6983	it will destroy the value of the guard. When the function exits, the guard on
				6984	the stack is checked against the original guard. If they're different, then
				6985	the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
				6986	</p>
				6987	</div>
				6988
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6989	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6990	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6991	<address>
				6992	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	6993	src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6994	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	6995	src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6996
				6997	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	6998	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6999	Last modified: $Date$
				7000	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	7001
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	7002	</body>
				7003	</html>