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

blob: 416b105cd7286d436092b25f3099b7205482933e [file] [log] [blame]

Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1	<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
				2	"http://www.w3.org/TR/html4/strict.dtd">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3	<html>
				4	<head>
				5	<title>LLVM Assembly Language Reference Manual</title>
Reid Spencer	3921c74	2004-08-26 20:44:00 +0000	[diff] [blame]	6	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
				7	<meta name="author" content="Chris Lattner">
				8	<meta name="description"
				9	content="LLVM Assembly Language Reference Manual.">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	10	<link rel="stylesheet" href="llvm.css" type="text/css">
				11	</head>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	12
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	13	<body>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	14
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	15	<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	16	<ol>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	17	<li><a href="#abstract">Abstract</a></li>
				18	<li><a href="#introduction">Introduction</a></li>
				19	<li><a href="#identifiers">Identifiers</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	20	<li><a href="#highlevel">High Level Structure</a>
				21	<ol>
				22	<li><a href="#modulestructure">Module Structure</a></li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	23	<li><a href="#linkage">Linkage Types</a></li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	24	<li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner	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>
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	44	<li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	45	</ol>
				46	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	47	<li><a href="#t_derived">Derived Types</a>
				48	<ol>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	49	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	50	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	51	<li><a href="#t_function">Function Type</a></li>
				52	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	53	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	54	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	55	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	56	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	57	</ol>
				58	</li>
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	59	<li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	60	</ol>
				61	</li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	62	<li><a href="#constants">Constants</a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	63	<ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	64	<li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	65	<li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	66	<li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
				67	<li><a href="#undefvalues">Undefined Values</a></li>
				68	<li><a href="#constantexprs">Constant Expressions</a></li>
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	69	<li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	70	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	71	</li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	72	<li><a href="#othervalues">Other Values</a>
				73	<ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	74	<li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	75	</ol>
				76	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	77	<li><a href="#instref">Instruction Reference</a>
				78	<ol>
				79	<li><a href="#terminators">Terminator Instructions</a>
				80	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	81	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				82	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	83	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				84	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	85	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	86	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	87	</ol>
				88	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	89	<li><a href="#binaryops">Binary Operations</a>
				90	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	91	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	92	<li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	93	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	94	<li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	95	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	96	<li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	97	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				98	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				99	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	100	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				101	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				102	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	103	</ol>
				104	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	105	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				106	<ol>
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	107	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				108	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				109	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	110	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	111	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	112	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	113	</ol>
				114	</li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	115	<li><a href="#vectorops">Vector Operations</a>
				116	<ol>
				117	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				118	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				119	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	120	</ol>
				121	</li>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	122	<li><a href="#aggregateops">Aggregate Operations</a>
				123	<ol>
				124	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				125	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				126	</ol>
				127	</li>
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	128	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	129	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	130	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				131	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				132	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	133	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				134	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				135	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	136	</ol>
				137	</li>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	138	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	139	<ol>
				140	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				141	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				142	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				144	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	145	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				146	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				147	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				148	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	149	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				150	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	151	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	152	</ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	153	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	154	<li><a href="#otherops">Other Operations</a>
				155	<ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	156	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				157	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	158	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	159	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	160	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	161	<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]	162	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	163	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	164	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	165	</li>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	166	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	167	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	168	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				169	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	170	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				171	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				172	<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]	173	</ol>
				174	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	175	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				176	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	177	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				178	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				179	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	180	</ol>
				181	</li>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	182	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				183	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	184	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				185	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				186	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				187	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				188	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				189	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				190	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	7123e27	2004-04-09 16:43:20 +0000	[diff] [blame]	191	</ol>
				192	</li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	193	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				194	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	195	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				196	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				197	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				198	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				199	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	200	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				201	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				202	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	203	</ol>
				204	</li>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	205	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	206	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	207	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	208	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				209	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				210	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	211	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				212	<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]	213	</ol>
				214	</li>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	215	<li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
				216	<ol>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	217	<li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
				218	<li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
				219	<li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
				220	<li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
				221	<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]	222	<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]	223	</ol>
				224	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	225	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	226	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	227	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	228	<ol>
				229	<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]	230	</ol>
				231	</li>
Bill Wendling	3c44f5b	2008-11-18 22:10:53 +0000	[diff] [blame]	232	<li><a href="#int_atomics">Atomic intrinsics</a>
				233	<ol>
				234	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
				235	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
				236	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
				237	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				238	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				239	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				240	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				241	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				242	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				243	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				244	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				245	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				246	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
				247	</ol>
				248	</li>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	249	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	250	<ol>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	251	<li><a href="#int_var_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	252	'<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	253	<li><a href="#int_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	254	'<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	255	<li><a href="#int_trap">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	256	'<tt>llvm.trap</tt>' Intrinsic</a></li>
				257	<li><a href="#int_stackprotector">
				258	'<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	259	</ol>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	260	</li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	261	</ol>
				262	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	263	</ol>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	264
				265	<div class="doc_author">
				266	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				267	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	268	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	269
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	270	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	271	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				272	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	273
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	274	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	275	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	837f39b	2008-08-05 22:29:16 +0000	[diff] [blame]	276	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	277	type safety, low-level operations, flexibility, and the capability of
				278	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	279	representation used throughout all phases of the LLVM compilation
				280	strategy.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	281	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	282
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	283	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	284	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				285	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	286
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	287	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	288
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	289	<p>The LLVM code representation is designed to be used in three
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	290	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]	291	representation (suitable for fast loading by a Just-In-Time compiler),
				292	and as a human readable assembly language representation. This allows
				293	LLVM to provide a powerful intermediate representation for efficient
				294	compiler transformations and analysis, while providing a natural means
				295	to debug and visualize the transformations. The three different forms
				296	of LLVM are all equivalent. This document describes the human readable
				297	representation and notation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	298
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	299	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	300	while being expressive, typed, and extensible at the same time. It
				301	aims to be a "universal IR" of sorts, by being at a low enough level
				302	that high-level ideas may be cleanly mapped to it (similar to how
				303	microprocessors are "universal IR's", allowing many source languages to
				304	be mapped to them). By providing type information, LLVM can be used as
				305	the target of optimizations: for example, through pointer analysis, it
				306	can be proven that a C automatic variable is never accessed outside of
				307	the current function... allowing it to be promoted to a simple SSA
				308	value instead of a memory location.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	309
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	310	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	311
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	312	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	313	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	314
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	315	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	316
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	317	<p>It is important to note that this document describes 'well formed'
				318	LLVM assembly language. There is a difference between what the parser
				319	accepts and what is considered 'well formed'. For example, the
				320	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	321
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	322	<div class="doc_code">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	323	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	324	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	325	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	326	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	327
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	328	<p>...because the definition of <tt>%x</tt> does not dominate all of
				329	its uses. The LLVM infrastructure provides a verification pass that may
				330	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]	331	automatically run by the parser after parsing input assembly and by
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	332	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	333	by the verifier pass indicate bugs in transformation passes or input to
				334	the parser.</p>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	335	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	336
Chris Lattner	cc68939	2007-10-03 17:34:29 +0000	[diff] [blame]	337	<!-- Describe the typesetting conventions here. -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	338
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	339	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	340	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	341	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	342
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	343	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	344
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	345	<p>LLVM identifiers come in two basic types: global and local. Global
				346	identifiers (functions, global variables) begin with the @ character. Local
				347	identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	348	there are three different formats for identifiers, for different purposes:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	349
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	350	<ol>
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	351	<li>Named values are represented as a string of characters with their prefix.
				352	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				353	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]	354	Identifiers which require other characters in their names can be surrounded
Daniel Dunbar	76dea95	2008-10-14 23:51:43 +0000	[diff] [blame]	355	with quotes. Special characters may be escaped using "\xx" where xx is the
				356	ASCII code for the character in hexadecimal. In this way, any character can
				357	be used in a name value, even quotes themselves.
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	358
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	359	<li>Unnamed values are represented as an unsigned numeric value with their
				360	prefix. For example, %12, @2, %44.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	361
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	362	<li>Constants, which are described in a <a href="#constants">section about
				363	constants</a>, below.</li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	364	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	365
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	366	<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]	367	don't need to worry about name clashes with reserved words, and the set of
				368	reserved words may be expanded in the future without penalty. Additionally,
				369	unnamed identifiers allow a compiler to quickly come up with a temporary
				370	variable without having to avoid symbol table conflicts.</p>
				371
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	372	<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]	373	languages. There are keywords for different opcodes
				374	('<tt><a href="#i_add">add</a></tt>',
				375	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				376	'<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]	377	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]	378	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	379	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	380
				381	<p>Here is an example of LLVM code to multiply the integer variable
				382	'<tt>%X</tt>' by 8:</p>
				383
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	384	<p>The easy way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	385
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	386	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	387	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	388	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	389	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	390	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	391
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	392	<p>After strength reduction:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	393
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	394	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	395	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	396	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	397	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	398	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	399
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	400	<p>And the hard way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	401
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	402	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	403	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	404	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				405	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				406	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	407	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	408	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	409
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	410	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				411	important lexical features of LLVM:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	412
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	413	<ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	414
				415	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				416	line.</li>
				417
				418	<li>Unnamed temporaries are created when the result of a computation is not
				419	assigned to a named value.</li>
				420
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	421	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	422
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	423	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	424
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	425	<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]	426	demonstrating instructions, we will follow an instruction with a comment that
				427	defines the type and name of value produced. Comments are shown in italic
				428	text.</p>
				429
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	430	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	431
				432	<!-- *********************************************************************** -->
				433	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				434	<!-- *********************************************************************** -->
				435
				436	<!-- ======================================================================= -->
				437	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				438	</div>
				439
				440	<div class="doc_text">
				441
				442	<p>LLVM programs are composed of "Module"s, each of which is a
				443	translation unit of the input programs. Each module consists of
				444	functions, global variables, and symbol table entries. Modules may be
				445	combined together with the LLVM linker, which merges function (and
				446	global variable) definitions, resolves forward declarations, and merges
				447	symbol table entries. Here is an example of the "hello world" module:</p>
				448
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	449	<div class="doc_code">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	450	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	451	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				452	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]	453
				454	<i>; External declaration of the puts function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	455	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	456
				457	<i>; Definition of main function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	458	define i32 @main() { <i>; i32()* </i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	459	<i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	460	%cast210 = <a
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	461	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]	462
				463	<i>; Call puts function to write out the string to stdout...</i>
				464	<a
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	465	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	466	<a
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	467	href="#i_ret">ret</a> i32 0<br>}<br>
				468	</pre>
				469	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	470
				471	<p>This example is made up of a <a href="#globalvars">global variable</a>
				472	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				473	function, and a <a href="#functionstructure">function definition</a>
				474	for "<tt>main</tt>".</p>
				475
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	476	<p>In general, a module is made up of a list of global values,
				477	where both functions and global variables are global values. Global values are
				478	represented by a pointer to a memory location (in this case, a pointer to an
				479	array of char, and a pointer to a function), and have one of the following <a
				480	href="#linkage">linkage types</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	481
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	482	</div>
				483
				484	<!-- ======================================================================= -->
				485	<div class="doc_subsection">
				486	<a name="linkage">Linkage Types</a>
				487	</div>
				488
				489	<div class="doc_text">
				490
				491	<p>
				492	All Global Variables and Functions have one of the following types of linkage:
				493	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	494
				495	<dl>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	496
Rafael Espindola	bb46f52	2009-01-15 20:18:42 +0000	[diff] [blame]	497	<dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
				498
				499	<dd>Global values with private linkage are only directly accessible by
				500	objects in the current module. In particular, linking code into a module with
				501	an private global value may cause the private to be renamed as necessary to
				502	avoid collisions. Because the symbol is private to the module, all
				503	references can be updated. This doesn't show up in any symbol table in the
				504	object file.
				505	</dd>
				506
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	507	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	508
Duncan Sands	81d05c2	2009-01-16 09:29:46 +0000	[diff] [blame]	509	<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]	510	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]	511	'<tt>static</tt>' keyword in C.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	512	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	513
Chris Lattner	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame]	514	<dt><tt><b><a name="available_externally">available_externally</a></b></tt>:
				515	</dt>
				516
				517	<dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
				518	into the object file corresponding to the LLVM module. They exist to
				519	allow inlining and other optimizations to take place given knowledge of the
				520	definition of the global, which is known to be somewhere outside the module.
				521	Globals with <tt>available_externally</tt> linkage are allowed to be discarded
				522	at will, and are otherwise the same as <tt>linkonce_odr</tt>. This linkage
				523	type is only allowed on definitions, not declarations.</dd>
				524
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	525	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	526
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	527	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				528	the same name when linkage occurs. This is typically used to implement
				529	inline functions, templates, or other code which must be generated in each
				530	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				531	allowed to be discarded.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	532	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	533
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	534	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				535
				536	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				537	linkage, except that unreferenced <tt>common</tt> globals may not be
				538	discarded. This is used for globals that may be emitted in multiple
				539	translation units, but that are not guaranteed to be emitted into every
				540	translation unit that uses them. One example of this is tentative
				541	definitions in C, such as "<tt>int X;</tt>" at global scope.
				542	</dd>
				543
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	544	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	545
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	546	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				547	that some targets may choose to emit different assembly sequences for them
				548	for target-dependent reasons. This is used for globals that are declared
				549	"weak" in C source code.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	550	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	551
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	552	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	553
				554	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				555	pointer to array type. When two global variables with appending linkage are
				556	linked together, the two global arrays are appended together. This is the
				557	LLVM, typesafe, equivalent of having the system linker append together
				558	"sections" with identical names when .o files are linked.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	559	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	560
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	561	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	562
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	563	<dd>The semantics of this linkage follow the ELF object file model: the
				564	symbol is weak until linked, if not linked, the symbol becomes null instead
				565	of being an undefined reference.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	566	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	567
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	568	<dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	569	<dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Chris Lattner	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame]	570	<dd>Some languages allow differing globals to be merged, such as two
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	571	functions with different semantics. Other languages, such as <tt>C++</tt>,
				572	ensure that only equivalent globals are ever merged (the "one definition
Chris Lattner	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame]	573	rule" - "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Duncan Sands	4dc2b39	2009-03-11 20:14:15 +0000	[diff] [blame]	574	and <tt>weak_odr</tt> linkage types to indicate that the global will only
				575	be merged with equivalent globals. These linkage types are otherwise the
				576	same as their non-<tt>odr</tt> versions.
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	577	</dd>
				578
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	579	<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]	580
				581	<dd>If none of the above identifiers are used, the global is externally
				582	visible, meaning that it participates in linkage and can be used to resolve
				583	external symbol references.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	584	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	585	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	586
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	587	<p>
				588	The next two types of linkage are targeted for Microsoft Windows platform
				589	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	590	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	591	</p>
				592
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	593	<dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	594	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				595
				596	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				597	or variable via a global pointer to a pointer that is set up by the DLL
				598	exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman	7956412	2009-01-12 21:35:55 +0000	[diff] [blame]	599	formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	600	</dd>
				601
				602	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				603
				604	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				605	pointer to a pointer in a DLL, so that it can be referenced with the
				606	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman	7956412	2009-01-12 21:35:55 +0000	[diff] [blame]	607	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]	608	name.
				609	</dd>
				610
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	611	</dl>
				612
Dan Gohman	f003276	2008-11-24 17:18:39 +0000	[diff] [blame]	613	<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	614	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				615	variable and was linked with this one, one of the two would be renamed,
				616	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				617	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	ac8d276	2007-01-05 00:59:10 +0000	[diff] [blame]	618	outside of the current module.</p>
				619	<p>It is illegal for a function <i>declaration</i>
Duncan Sands	5f4ee1f	2009-03-11 08:08:06 +0000	[diff] [blame]	620	to have any linkage type other than "externally visible", <tt>dllimport</tt>
				621	or <tt>extern_weak</tt>.</p>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	622	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
				623	or <tt>weak_odr</tt> linkages.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	624	</div>
				625
				626	<!-- ======================================================================= -->
				627	<div class="doc_subsection">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	628	<a name="callingconv">Calling Conventions</a>
				629	</div>
				630
				631	<div class="doc_text">
				632
				633	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				634	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				635	specified for the call. The calling convention of any pair of dynamic
				636	caller/callee must match, or the behavior of the program is undefined. The
				637	following calling conventions are supported by LLVM, and more may be added in
				638	the future:</p>
				639
				640	<dl>
				641	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				642
				643	<dd>This calling convention (the default if no other calling convention is
				644	specified) matches the target C calling conventions. This calling convention
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	645	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	646	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	647	</dd>
				648
				649	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				650
				651	<dd>This calling convention attempts to make calls as fast as possible
				652	(e.g. by passing things in registers). This calling convention allows the
				653	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]	654	without having to conform to an externally specified ABI (Application Binary
				655	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	9097d14	2008-05-14 09:17:12 +0000	[diff] [blame]	656	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				657	supported. This calling convention does not support varargs and requires the
				658	prototype of all callees to exactly match the prototype of the function
				659	definition.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	660	</dd>
				661
				662	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				663
				664	<dd>This calling convention attempts to make code in the caller as efficient
				665	as possible under the assumption that the call is not commonly executed. As
				666	such, these calls often preserve all registers so that the call does not break
				667	any live ranges in the caller side. This calling convention does not support
				668	varargs and requires the prototype of all callees to exactly match the
				669	prototype of the function definition.
				670	</dd>
				671
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	672	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	673
				674	<dd>Any calling convention may be specified by number, allowing
				675	target-specific calling conventions to be used. Target specific calling
				676	conventions start at 64.
				677	</dd>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	678	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	679
				680	<p>More calling conventions can be added/defined on an as-needed basis, to
				681	support pascal conventions or any other well-known target-independent
				682	convention.</p>
				683
				684	</div>
				685
				686	<!-- ======================================================================= -->
				687	<div class="doc_subsection">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	688	<a name="visibility">Visibility Styles</a>
				689	</div>
				690
				691	<div class="doc_text">
				692
				693	<p>
				694	All Global Variables and Functions have one of the following visibility styles:
				695	</p>
				696
				697	<dl>
				698	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				699
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	700	<dd>On targets that use the ELF object file format, default visibility means
				701	that the declaration is visible to other
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	702	modules and, in shared libraries, means that the declared entity may be
				703	overridden. On Darwin, default visibility means that the declaration is
				704	visible to other modules. Default visibility corresponds to "external
				705	linkage" in the language.
				706	</dd>
				707
				708	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				709
				710	<dd>Two declarations of an object with hidden visibility refer to the same
				711	object if they are in the same shared object. Usually, hidden visibility
				712	indicates that the symbol will not be placed into the dynamic symbol table,
				713	so no other module (executable or shared library) can reference it
				714	directly.
				715	</dd>
				716
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	717	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				718
				719	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				720	the dynamic symbol table, but that references within the defining module will
				721	bind to the local symbol. That is, the symbol cannot be overridden by another
				722	module.
				723	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	724	</dl>
				725
				726	</div>
				727
				728	<!-- ======================================================================= -->
				729	<div class="doc_subsection">
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	730	<a name="namedtypes">Named Types</a>
				731	</div>
				732
				733	<div class="doc_text">
				734
				735	<p>LLVM IR allows you to specify name aliases for certain types. This can make
				736	it easier to read the IR and make the IR more condensed (particularly when
				737	recursive types are involved). An example of a name specification is:
				738	</p>
				739
				740	<div class="doc_code">
				741	<pre>
				742	%mytype = type { %mytype*, i32 }
				743	</pre>
				744	</div>
				745
				746	<p>You may give a name to any <a href="#typesystem">type</a> except "<a
				747	href="t_void">void</a>". Type name aliases may be used anywhere a type is
				748	expected with the syntax "%mytype".</p>
				749
				750	<p>Note that type names are aliases for the structural type that they indicate,
				751	and that you can therefore specify multiple names for the same type. This often
				752	leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
				753	structural typing, the name is not part of the type. When printing out LLVM IR,
				754	the printer will pick <em>one name</em> to render all types of a particular
				755	shape. This means that if you have code where two different source types end up
				756	having the same LLVM type, that the dumper will sometimes print the "wrong" or
				757	unexpected type. This is an important design point and isn't going to
				758	change.</p>
				759
				760	</div>
				761
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	762	<!-- ======================================================================= -->
				763	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	764	<a name="globalvars">Global Variables</a>
				765	</div>
				766
				767	<div class="doc_text">
				768
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	769	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	770	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	771	an explicit section to be placed in, and may have an optional explicit alignment
				772	specified. A variable may be defined as "thread_local", which means that it
				773	will not be shared by threads (each thread will have a separated copy of the
				774	variable). A variable may be defined as a global "constant," which indicates
				775	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]	776	optimization, allowing the global data to be placed in the read-only section of
				777	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	778	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]	779
				780	<p>
				781	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				782	constant, even if the final definition of the global is not. This capability
				783	can be used to enable slightly better optimization of the program, but requires
				784	the language definition to guarantee that optimizations based on the
				785	'constantness' are valid for the translation units that do not include the
				786	definition.
				787	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	788
				789	<p>As SSA values, global variables define pointer values that are in
				790	scope (i.e. they dominate) all basic blocks in the program. Global
				791	variables always define a pointer to their "content" type because they
				792	describe a region of memory, and all memory objects in LLVM are
				793	accessed through pointers.</p>
				794
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	795	<p>A global variable may be declared to reside in a target-specifc numbered
				796	address space. For targets that support them, address spaces may affect how
				797	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	798	the variable. The default address space is zero. The address space qualifier
				799	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	800
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	801	<p>LLVM allows an explicit section to be specified for globals. If the target
				802	supports it, it will emit globals to the section specified.</p>
				803
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	804	<p>An explicit alignment may be specified for a global. If not present, or if
				805	the alignment is set to zero, the alignment of the global is set by the target
				806	to whatever it feels convenient. If an explicit alignment is specified, the
				807	global is forced to have at least that much alignment. All alignments must be
				808	a power of 2.</p>
				809
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	810	<p>For example, the following defines a global in a numbered address space with
				811	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	812
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	813	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	814	<pre>
Dan Gohman	398873c	2009-01-11 00:40:00 +0000	[diff] [blame]	815	@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	816	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	817	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	818
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	819	</div>
				820
				821
				822	<!-- ======================================================================= -->
				823	<div class="doc_subsection">
				824	<a name="functionstructure">Functions</a>
				825	</div>
				826
				827	<div class="doc_text">
				828
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	829	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				830	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	831	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	832	<a href="#callingconv">calling convention</a>, a return type, an optional
				833	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				834	name, a (possibly empty) argument list (each with optional
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	835	<a href="#paramattrs">parameter attributes</a>), optional
				836	<a href="#fnattrs">function attributes</a>, an optional section,
				837	an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	0c46a7d	2008-10-04 18:10:21 +0000	[diff] [blame]	838	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]	839
				840	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				841	optional <a href="#linkage">linkage type</a>, an optional
				842	<a href="#visibility">visibility style</a>, an optional
				843	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	844	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	845	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]	846	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	847
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	848	<p>A function definition contains a list of basic blocks, forming the CFG
				849	(Control Flow Graph) for
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	850	the function. Each basic block may optionally start with a label (giving the
				851	basic block a symbol table entry), contains a list of instructions, and ends
				852	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				853	function return).</p>
				854
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	855	<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]	856	executed on entrance to the function, and it is not allowed to have predecessor
				857	basic blocks (i.e. there can not be any branches to the entry block of a
				858	function). Because the block can have no predecessors, it also cannot have any
				859	<a href="#i_phi">PHI nodes</a>.</p>
				860
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	861	<p>LLVM allows an explicit section to be specified for functions. If the target
				862	supports it, it will emit functions to the section specified.</p>
				863
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	864	<p>An explicit alignment may be specified for a function. If not present, or if
				865	the alignment is set to zero, the alignment of the function is set by the target
				866	to whatever it feels convenient. If an explicit alignment is specified, the
				867	function is forced to have at least that much alignment. All alignments must be
				868	a power of 2.</p>
				869
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	870	<h5>Syntax:</h5>
				871
				872	<div class="doc_code">
Chris Lattner	50ad45c	2008-10-13 16:55:18 +0000	[diff] [blame]	873	<tt>
				874	define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
				875	[<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
				876	<ResultType> @<FunctionName> ([argument list])
				877	[<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
				878	[<a href="#gc">gc</a>] { ... }
				879	</tt>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	880	</div>
				881
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	882	</div>
				883
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	884
				885	<!-- ======================================================================= -->
				886	<div class="doc_subsection">
				887	<a name="aliasstructure">Aliases</a>
				888	</div>
				889	<div class="doc_text">
				890	<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]	891	function, global variable, another alias or bitcast of global value). Aliases
				892	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	893	optional <a href="#visibility">visibility style</a>.</p>
				894
				895	<h5>Syntax:</h5>
				896
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	897	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	898	<pre>
Duncan Sands	0b23ac1	2008-09-12 20:48:21 +0000	[diff] [blame]	899	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	900	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	901	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	902
				903	</div>
				904
				905
				906
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	907	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	908	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				909	<div class="doc_text">
				910	<p>The return type and each parameter of a function type may have a set of
				911	<i>parameter attributes</i> associated with them. Parameter attributes are
				912	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	913	a function. Parameter attributes are considered to be part of the function,
				914	not of the function type, so functions with different parameter attributes
				915	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	916
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	917	<p>Parameter attributes are simple keywords that follow the type specified. If
				918	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	919	example:</p>
				920
				921	<div class="doc_code">
				922	<pre>
Nick Lewycky	b6a7d25	2009-02-15 23:06:14 +0000	[diff] [blame]	923	declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	924	declare i32 @atoi(i8 zeroext)
				925	declare signext i8 @returns_signed_char()
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	926	</pre>
				927	</div>
				928
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	929	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				930	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	931
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	932	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	933	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	934	<dt><tt>zeroext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	935	<dd>This indicates to the code generator that the parameter or return value
				936	should be zero-extended to a 32-bit value by the caller (for a parameter)
				937	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	938
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	939	<dt><tt>signext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	940	<dd>This indicates to the code generator that the parameter or return value
				941	should be sign-extended to a 32-bit value by the caller (for a parameter)
				942	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	943
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	944	<dt><tt>inreg</tt></dt>
Dale Johannesen	c9c6da6	2008-09-25 20:47:45 +0000	[diff] [blame]	945	<dd>This indicates that this parameter or return value should be treated
				946	in a special target-dependent fashion during while emitting code for a
				947	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]	948	to memory, though some targets use it to distinguish between two different
				949	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	950
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	951	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	952	<dd>This indicates that the pointer parameter should really be passed by
				953	value to the function. The attribute implies that a hidden copy of the
				954	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]	955	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]	956	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	957	value, but is also valid on pointers to scalars. The copy is considered to
				958	belong to the caller not the callee (for example,
				959	<tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	960	<tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattner	ce459b1	2009-02-05 05:42:28 +0000	[diff] [blame]	961	values. The byval attribute also supports specifying an alignment with the
				962	align attribute. This has a target-specific effect on the code generator
				963	that usually indicates a desired alignment for the synthesized stack
				964	slot.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	965
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	966	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	967	<dd>This indicates that the pointer parameter specifies the address of a
				968	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]	969	This pointer must be guaranteed by the caller to be valid: loads and stores
				970	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]	971	be applied to the first parameter. This is not a valid attribute for
				972	return values. </dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	973
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	974	<dt><tt>noalias</tt></dt>
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	975	<dd>This indicates that the pointer does not alias any global or any other
				976	parameter. The caller is responsible for ensuring that this is the
Nick Lewycky	b2b32fd	2008-11-24 05:00:44 +0000	[diff] [blame]	977	case. On a function return value, <tt>noalias</tt> additionally indicates
				978	that the pointer does not alias any other pointers visible to the
Nick Lewycky	f23d0d3	2008-12-19 06:39:12 +0000	[diff] [blame]	979	caller. For further details, please see the discussion of the NoAlias
				980	response in
				981	<a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
				982	analysis</a>.</dd>
				983
				984	<dt><tt>nocapture</tt></dt>
				985	<dd>This indicates that the callee does not make any copies of the pointer
				986	that outlive the callee itself. This is not a valid attribute for return
				987	values.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	988
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	989	<dt><tt>nest</tt></dt>
Duncan Sands	0789b8b	2008-07-08 09:27:25 +0000	[diff] [blame]	990	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	991	<a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
				992	attribute for return values.</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	993	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	994
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	995	</div>
				996
				997	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	998	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	999	<a name="gc">Garbage Collector Names</a>
				1000	</div>
				1001
				1002	<div class="doc_text">
				1003	<p>Each function may specify a garbage collector name, which is simply a
				1004	string.</p>
				1005
				1006	<div class="doc_code"><pre
				1007	>define void @f() gc "name" { ...</pre></div>
				1008
				1009	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				1010	collector which will cause the compiler to alter its output in order to support
				1011	the named garbage collection algorithm.</p>
				1012	</div>
				1013
				1014	<!-- ======================================================================= -->
				1015	<div class="doc_subsection">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1016	<a name="fnattrs">Function Attributes</a>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1017	</div>
				1018
				1019	<div class="doc_text">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1020
				1021	<p>Function attributes are set to communicate additional information about
				1022	a function. Function attributes are considered to be part of the function,
				1023	not of the function type, so functions with different parameter attributes
				1024	can have the same function type.</p>
				1025
				1026	<p>Function attributes are simple keywords that follow the type specified. If
				1027	multiple attributes are needed, they are space separated. For
				1028	example:</p>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1029
				1030	<div class="doc_code">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1031	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1032	define void @f() noinline { ... }
				1033	define void @f() alwaysinline { ... }
				1034	define void @f() alwaysinline optsize { ... }
				1035	define void @f() optsize
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1036	</pre>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1037	</div>
				1038
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1039	<dl>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1040	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1041	<dd>This attribute indicates that the inliner should attempt to inline this
				1042	function into callers whenever possible, ignoring any active inlining size
				1043	threshold for this caller.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1044
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1045	<dt><tt>noinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1046	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	94b5f7d	2008-10-05 17:14:59 +0000	[diff] [blame]	1047	in any situation. This attribute may not be used together with the
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1048	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1049
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1050	<dt><tt>optsize</tt></dt>
Devang Patel	66c6c65	2008-09-29 18:34:44 +0000	[diff] [blame]	1051	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1052	make choices that keep the code size of this function low, and otherwise do
				1053	optimizations specifically to reduce code size.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1054
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1055	<dt><tt>noreturn</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1056	<dd>This function attribute indicates that the function never returns normally.
				1057	This produces undefined behavior at runtime if the function ever does
				1058	dynamically return.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1059
				1060	<dt><tt>nounwind</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1061	<dd>This function attribute indicates that the function never returns with an
				1062	unwind or exceptional control flow. If the function does unwind, its runtime
				1063	behavior is undefined.</dd>
				1064
				1065	<dt><tt>readnone</tt></dt>
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1066	<dd>This attribute indicates that the function computes its result (or decides to
				1067	unwind an exception) based strictly on its arguments, without dereferencing any
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	1068	pointer arguments or otherwise accessing any mutable state (e.g. memory, control
				1069	registers, etc) visible to caller functions. It does not write through any
				1070	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1071	never changes any state visible to callers. This means that it cannot unwind
				1072	exceptions by calling the <tt>C++</tt> exception throwing methods, but could
				1073	use the <tt>unwind</tt> instruction.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1074
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	1075	<dt><tt><a name="readonly">readonly</a></tt></dt>
				1076	<dd>This attribute indicates that the function does not write through any
				1077	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
				1078	or otherwise modify any state (e.g. memory, control registers, etc) visible to
				1079	caller functions. It may dereference pointer arguments and read state that may
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1080	be set in the caller. A readonly function always returns the same value (or
				1081	unwinds an exception identically) when called with the same set of arguments
				1082	and global state. It cannot unwind an exception by calling the <tt>C++</tt>
				1083	exception throwing methods, but may use the <tt>unwind</tt> instruction.</dd>
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1084
				1085	<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1086	<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1087	protector. It is in the form of a "canary"—a random value placed on the
				1088	stack before the local variables that's checked upon return from the function to
				1089	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]	1090	needs stack protectors or not.
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1091
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1092	<br><br>If a function that has an <tt>ssp</tt> attribute is inlined into a function
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1093	that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1094	have an <tt>ssp</tt> attribute.</dd>
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1095
				1096	<dt><tt>sspreq</tt></dt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1097	<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]	1098	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]	1099	function attribute.
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1100
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1101	If a function that has an <tt>sspreq</tt> attribute is inlined into a
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1102	function that doesn't have an <tt>sspreq</tt> attribute or which has
				1103	an <tt>ssp</tt> attribute, then the resulting function will have
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1104	an <tt>sspreq</tt> attribute.</dd>
				1105
				1106	<dt><tt>noredzone</tt></dt>
Dan Gohman	2185f9e	2009-06-15 17:37:09 +0000	[diff] [blame]	1107	<dd>This attribute indicates that the code generator should not use a
Dan Gohman	125473b	2009-06-15 21:18:01 +0000	[diff] [blame]	1108	red zone, even if the target-specific ABI normally permits it.
Dan Gohman	2185f9e	2009-06-15 17:37:09 +0000	[diff] [blame]	1109	</dd>
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1110
				1111	<dt><tt>noimplicitfloat</tt></dt>
				1112	<dd>This attributes disables implicit floating point instructions.</dd>
				1113
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1114	</dl>
				1115
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1116	</div>
				1117
				1118	<!-- ======================================================================= -->
				1119	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	1120	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1121	</div>
				1122
				1123	<div class="doc_text">
				1124	<p>
				1125	Modules may contain "module-level inline asm" blocks, which corresponds to the
				1126	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				1127	LLVM and treated as a single unit, but may be separated in the .ll file if
				1128	desired. The syntax is very simple:
				1129	</p>
				1130
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1131	<div class="doc_code">
				1132	<pre>
				1133	module asm "inline asm code goes here"
				1134	module asm "more can go here"
				1135	</pre>
				1136	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1137
				1138	<p>The strings can contain any character by escaping non-printable characters.
				1139	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1140	for the number.
				1141	</p>
				1142
				1143	<p>
				1144	The inline asm code is simply printed to the machine code .s file when
				1145	assembly code is generated.
				1146	</p>
				1147	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1148
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1149	<!-- ======================================================================= -->
				1150	<div class="doc_subsection">
				1151	<a name="datalayout">Data Layout</a>
				1152	</div>
				1153
				1154	<div class="doc_text">
				1155	<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]	1156	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1157	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1158	<p>The <i>layout specification</i> consists of a list of specifications
				1159	separated by the minus sign character ('-'). Each specification starts with a
				1160	letter and may include other information after the letter to define some
				1161	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1162	<dl>
				1163	<dt><tt>E</tt></dt>
				1164	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1165	bits with the most significance have the lowest address location.</dd>
				1166	<dt><tt>e</tt></dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1167	<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]	1168	the bits with the least significance have the lowest address location.</dd>
				1169	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1170	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1171	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1172	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1173	too.</dd>
				1174	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1175	<dd>This specifies the alignment for an integer type of a given bit
				1176	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1177	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1178	<dd>This specifies the alignment for a vector type of a given bit
				1179	<i>size</i>.</dd>
				1180	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1181	<dd>This specifies the alignment for a floating point type of a given bit
				1182	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1183	(double).</dd>
				1184	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1185	<dd>This specifies the alignment for an aggregate type of a given bit
				1186	<i>size</i>.</dd>
Daniel Dunbar	87bde0b	2009-06-08 22:17:53 +0000	[diff] [blame]	1187	<dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1188	<dd>This specifies the alignment for a stack object of a given bit
				1189	<i>size</i>.</dd>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1190	</dl>
				1191	<p>When constructing the data layout for a given target, LLVM starts with a
				1192	default set of specifications which are then (possibly) overriden by the
				1193	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1194	are given in this list:</p>
				1195	<ul>
				1196	<li><tt>E</tt> - big endian</li>
				1197	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1198	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1199	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1200	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1201	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1202	<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]	1203	alignment of 64-bits</li>
				1204	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1205	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1206	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1207	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1208	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar	87bde0b	2009-06-08 22:17:53 +0000	[diff] [blame]	1209	<li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1210	</ul>
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	1211	<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]	1212	following rules:</p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1213	<ol>
				1214	<li>If the type sought is an exact match for one of the specifications, that
				1215	specification is used.</li>
				1216	<li>If no match is found, and the type sought is an integer type, then the
				1217	smallest integer type that is larger than the bitwidth of the sought type is
				1218	used. If none of the specifications are larger than the bitwidth then the the
				1219	largest integer type is used. For example, given the default specifications
				1220	above, the i7 type will use the alignment of i8 (next largest) while both
				1221	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1222	<li>If no match is found, and the type sought is a vector type, then the
				1223	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]	1224	as a fall back. This happens because <128 x double> can be implemented
				1225	in terms of 64 <2 x double>, for example.</li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1226	</ol>
				1227	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1228
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1229	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1230	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1231	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1232
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1233	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1234
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1235	<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]	1236	intermediate representation. Being typed enables a number of
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1237	optimizations to be performed on the intermediate representation directly,
				1238	without having to do
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1239	extra analyses on the side before the transformation. A strong type
				1240	system makes it easier to read the generated code and enables novel
				1241	analyses and transformations that are not feasible to perform on normal
				1242	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1243
				1244	</div>
				1245
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1246	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1247	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1248	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1249	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1250	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1251	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1252
				1253	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1254	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1255	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1256	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1257	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1258	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1259	</tr>
				1260	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1261	<td><a href="#t_floating">floating point</a></td>
				1262	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1263	</tr>
				1264	<tr>
				1265	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1266	<td><a href="#t_integer">integer</a>,
				1267	<a href="#t_floating">floating point</a>,
				1268	<a href="#t_pointer">pointer</a>,
Dan Gohman	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame]	1269	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1270	<a href="#t_struct">structure</a>,
				1271	<a href="#t_array">array</a>,
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1272	<a href="#t_label">label</a>,
				1273	<a href="#t_metadata">metadata</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1274	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1275	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1276	<tr>
				1277	<td><a href="#t_primitive">primitive</a></td>
				1278	<td><a href="#t_label">label</a>,
				1279	<a href="#t_void">void</a>,
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1280	<a href="#t_floating">floating point</a>,
				1281	<a href="#t_metadata">metadata</a>.</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1282	</tr>
				1283	<tr>
				1284	<td><a href="#t_derived">derived</a></td>
				1285	<td><a href="#t_integer">integer</a>,
				1286	<a href="#t_array">array</a>,
				1287	<a href="#t_function">function</a>,
				1288	<a href="#t_pointer">pointer</a>,
				1289	<a href="#t_struct">structure</a>,
				1290	<a href="#t_pstruct">packed structure</a>,
				1291	<a href="#t_vector">vector</a>,
				1292	<a href="#t_opaque">opaque</a>.
Dan Gohman	01ac101	2008-10-14 16:32:04 +0000	[diff] [blame]	1293	</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1294	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1295	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1296	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1297
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1298	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1299	most important. Values of these types are the only ones which can be
				1300	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1301	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1302	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1303
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1304	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1305	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1306
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1307	<div class="doc_text">
				1308	<p>The primitive types are the fundamental building blocks of the LLVM
				1309	system.</p>
				1310
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1311	</div>
				1312
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1313	<!-- _______________________________________________________________________ -->
				1314	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1315
				1316	<div class="doc_text">
				1317	<table>
				1318	<tbody>
				1319	<tr><th>Type</th><th>Description</th></tr>
				1320	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1321	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1322	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1323	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1324	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1325	</tbody>
				1326	</table>
				1327	</div>
				1328
				1329	<!-- _______________________________________________________________________ -->
				1330	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1331
				1332	<div class="doc_text">
				1333	<h5>Overview:</h5>
				1334	<p>The void type does not represent any value and has no size.</p>
				1335
				1336	<h5>Syntax:</h5>
				1337
				1338	<pre>
				1339	void
				1340	</pre>
				1341	</div>
				1342
				1343	<!-- _______________________________________________________________________ -->
				1344	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1345
				1346	<div class="doc_text">
				1347	<h5>Overview:</h5>
				1348	<p>The label type represents code labels.</p>
				1349
				1350	<h5>Syntax:</h5>
				1351
				1352	<pre>
				1353	label
				1354	</pre>
				1355	</div>
				1356
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1357	<!-- _______________________________________________________________________ -->
				1358	<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
				1359
				1360	<div class="doc_text">
				1361	<h5>Overview:</h5>
				1362	<p>The metadata type represents embedded metadata. The only derived type that
				1363	may contain metadata is <tt>metadata*</tt> or a function type that returns or
				1364	takes metadata typed parameters, but not pointer to metadata types.</p>
				1365
				1366	<h5>Syntax:</h5>
				1367
				1368	<pre>
				1369	metadata
				1370	</pre>
				1371	</div>
				1372
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1373
				1374	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1375	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1376
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1377	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1378
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1379	<p>The real power in LLVM comes from the derived types in the system.
				1380	This is what allows a programmer to represent arrays, functions,
				1381	pointers, and other useful types. Note that these derived types may be
				1382	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]	1383
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1384	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1385
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1386	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1387	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1388
				1389	<div class="doc_text">
				1390
				1391	<h5>Overview:</h5>
				1392	<p>The integer type is a very simple derived type that simply specifies an
				1393	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1394	2^23-1 (about 8 million) can be specified.</p>
				1395
				1396	<h5>Syntax:</h5>
				1397
				1398	<pre>
				1399	iN
				1400	</pre>
				1401
				1402	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1403	value.</p>
				1404
				1405	<h5>Examples:</h5>
				1406	<table class="layout">
Nick Lewycky	86c4864	2009-05-24 02:46:06 +0000	[diff] [blame]	1407	<tr class="layout">
				1408	<td class="left"><tt>i1</tt></td>
				1409	<td class="left">a single-bit integer.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1410	</tr>
Nick Lewycky	86c4864	2009-05-24 02:46:06 +0000	[diff] [blame]	1411	<tr class="layout">
				1412	<td class="left"><tt>i32</tt></td>
				1413	<td class="left">a 32-bit integer.</td>
				1414	</tr>
				1415	<tr class="layout">
				1416	<td class="left"><tt>i1942652</tt></td>
				1417	<td class="left">a really big integer of over 1 million bits.</td>
				1418	</tr>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1419	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1420
				1421	<p>Note that the code generator does not yet support large integer types
				1422	to be used as function return types. The specific limit on how large a
				1423	return type the code generator can currently handle is target-dependent;
				1424	currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
				1425	targets.</p>
				1426
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1427	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1428
				1429	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1430	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1431
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1432	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1433
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1434	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1435
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1436	<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]	1437	sequentially in memory. The array type requires a size (number of
				1438	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1439
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1440	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1441
				1442	<pre>
				1443	[<# elements> x <elementtype>]
				1444	</pre>
				1445
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1446	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1447	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1448
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1449	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1450	<table class="layout">
				1451	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1452	<td class="left"><tt>[40 x i32]</tt></td>
				1453	<td class="left">Array of 40 32-bit integer values.</td>
				1454	</tr>
				1455	<tr class="layout">
				1456	<td class="left"><tt>[41 x i32]</tt></td>
				1457	<td class="left">Array of 41 32-bit integer values.</td>
				1458	</tr>
				1459	<tr class="layout">
				1460	<td class="left"><tt>[4 x i8]</tt></td>
				1461	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1462	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1463	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1464	<p>Here are some examples of multidimensional arrays:</p>
				1465	<table class="layout">
				1466	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1467	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1468	<td class="left">3x4 array of 32-bit integer values.</td>
				1469	</tr>
				1470	<tr class="layout">
				1471	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1472	<td class="left">12x10 array of single precision floating point values.</td>
				1473	</tr>
				1474	<tr class="layout">
				1475	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1476	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1477	</tr>
				1478	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1479
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1480	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1481	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]	1482	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1483	As a special case, however, zero length arrays are recognized to be variable
				1484	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1485	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1486
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1487	<p>Note that the code generator does not yet support large aggregate types
				1488	to be used as function return types. The specific limit on how large an
				1489	aggregate return type the code generator can currently handle is
				1490	target-dependent, and also dependent on the aggregate element types.</p>
				1491
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1492	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1493
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1494	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1495	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1496	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1497
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1498	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1499
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1500	<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]	1501	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]	1502	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]	1503	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]	1504	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1505
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1506	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1507
				1508	<pre>
				1509	<returntype list> (<parameter list>)
				1510	</pre>
				1511
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1512	<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]	1513	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1514	which indicates that the function takes a variable number of arguments.
				1515	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1516	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1517	'<tt><returntype list></tt>' is a comma-separated list of
				1518	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1519
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1520	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1521	<table class="layout">
				1522	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1523	<td class="left"><tt>i32 (i32)</tt></td>
				1524	<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]	1525	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1526	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1527	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1528	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1529	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1530	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1531	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1532	<tt>float</tt>.
				1533	</td>
				1534	</tr><tr class="layout">
				1535	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1536	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1537	<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]	1538	which returns an integer. This is the signature for <tt>printf</tt> in
				1539	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1540	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1541	</tr><tr class="layout">
				1542	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukman	b0a57aa	2008-11-27 06:41:20 +0000	[diff] [blame]	1543	<td class="left">A function taking an <tt>i32</tt>, returning two
				1544	<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]	1545	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1546	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1547	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1548
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1549	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1550	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1551	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1552	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1553	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1554	<p>The structure type is used to represent a collection of data members
				1555	together in memory. The packing of the field types is defined to match
				1556	the ABI of the underlying processor. The elements of a structure may
				1557	be any type that has a size.</p>
				1558	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1559	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1560	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1561	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1562	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1563	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1564	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1565	<table class="layout">
				1566	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1567	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1568	<td class="left">A triple of three <tt>i32</tt> values</td>
				1569	</tr><tr class="layout">
				1570	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1571	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1572	second element is a <a href="#t_pointer">pointer</a> to a
				1573	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1574	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1575	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1576	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1577
				1578	<p>Note that the code generator does not yet support large aggregate types
				1579	to be used as function return types. The specific limit on how large an
				1580	aggregate return type the code generator can currently handle is
				1581	target-dependent, and also dependent on the aggregate element types.</p>
				1582
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1583	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1584
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1585	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1586	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1587	</div>
				1588	<div class="doc_text">
				1589	<h5>Overview:</h5>
				1590	<p>The packed structure type is used to represent a collection of data members
				1591	together in memory. There is no padding between fields. Further, the alignment
				1592	of a packed structure is 1 byte. The elements of a packed structure may
				1593	be any type that has a size.</p>
				1594	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1595	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1596	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1597	instruction.</p>
				1598	<h5>Syntax:</h5>
				1599	<pre> < { <type list> } > <br></pre>
				1600	<h5>Examples:</h5>
				1601	<table class="layout">
				1602	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1603	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1604	<td class="left">A triple of three <tt>i32</tt> values</td>
				1605	</tr><tr class="layout">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1606	<td class="left">
				1607	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1608	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1609	second element is a <a href="#t_pointer">pointer</a> to a
				1610	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1611	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1612	</tr>
				1613	</table>
				1614	</div>
				1615
				1616	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1617	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1618	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1619	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1620	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1621	reference to another object, which must live in memory. Pointer types may have
				1622	an optional address space attribute defining the target-specific numbered
				1623	address space where the pointed-to object resides. The default address space is
				1624	zero.</p>
Chris Lattner	0fd4a27	2009-02-08 19:53:29 +0000	[diff] [blame]	1625
				1626	<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]	1627	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]	1628
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1629	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1630	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1631	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1632	<table class="layout">
				1633	<tr class="layout">
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	1634	<td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1635	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1636	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1637	</tr>
				1638	<tr class="layout">
				1639	<td class="left"><tt>i32 (i32 ) </tt></td>
				1640	<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]	1641	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]	1642	<tt>i32</tt>.</td>
				1643	</tr>
				1644	<tr class="layout">
				1645	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1646	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1647	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1648	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1649	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1650	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1651
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1652	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1653	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1654	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1655
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1656	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1657
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1658	<p>A vector type is a simple derived type that represents a vector
				1659	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1660	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1661	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1662	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1663	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1664	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1665
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1666	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1667
				1668	<pre>
				1669	< <# elements> x <elementtype> >
				1670	</pre>
				1671
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1672	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1673	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1674
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1675	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1676
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1677	<table class="layout">
				1678	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1679	<td class="left"><tt><4 x i32></tt></td>
				1680	<td class="left">Vector of 4 32-bit integer values.</td>
				1681	</tr>
				1682	<tr class="layout">
				1683	<td class="left"><tt><8 x float></tt></td>
				1684	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1685	</tr>
				1686	<tr class="layout">
				1687	<td class="left"><tt><2 x i64></tt></td>
				1688	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1689	</tr>
				1690	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1691
				1692	<p>Note that the code generator does not yet support large vector types
				1693	to be used as function return types. The specific limit on how large a
				1694	vector return type codegen can currently handle is target-dependent;
				1695	currently it's often a few times longer than a hardware vector register.</p>
				1696
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1697	</div>
				1698
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1699	<!-- _______________________________________________________________________ -->
				1700	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1701	<div class="doc_text">
				1702
				1703	<h5>Overview:</h5>
				1704
				1705	<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]	1706	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]	1707	In LLVM, opaque types can eventually be resolved to any type (not just a
				1708	structure type).</p>
				1709
				1710	<h5>Syntax:</h5>
				1711
				1712	<pre>
				1713	opaque
				1714	</pre>
				1715
				1716	<h5>Examples:</h5>
				1717
				1718	<table class="layout">
				1719	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1720	<td class="left"><tt>opaque</tt></td>
				1721	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1722	</tr>
				1723	</table>
				1724	</div>
				1725
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1726	<!-- ======================================================================= -->
				1727	<div class="doc_subsection">
				1728	<a name="t_uprefs">Type Up-references</a>
				1729	</div>
				1730
				1731	<div class="doc_text">
				1732	<h5>Overview:</h5>
				1733	<p>
				1734	An "up reference" allows you to refer to a lexically enclosing type without
				1735	requiring it to have a name. For instance, a structure declaration may contain a
				1736	pointer to any of the types it is lexically a member of. Example of up
				1737	references (with their equivalent as named type declarations) include:</p>
				1738
				1739	<pre>
Chris Lattner	3060f5b	2009-02-09 10:00:56 +0000	[diff] [blame]	1740	{ \2 * } %x = type { %x* }
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1741	{ \2 }* %y = type { %y }*
				1742	\1* %z = type %z*
				1743	</pre>
				1744
				1745	<p>
				1746	An up reference is needed by the asmprinter for printing out cyclic types when
				1747	there is no declared name for a type in the cycle. Because the asmprinter does
				1748	not want to print out an infinite type string, it needs a syntax to handle
				1749	recursive types that have no names (all names are optional in llvm IR).
				1750	</p>
				1751
				1752	<h5>Syntax:</h5>
				1753	<pre>
				1754	\<level>
				1755	</pre>
				1756
				1757	<p>
				1758	The level is the count of the lexical type that is being referred to.
				1759	</p>
				1760
				1761	<h5>Examples:</h5>
				1762
				1763	<table class="layout">
				1764	<tr class="layout">
				1765	<td class="left"><tt>\1*</tt></td>
				1766	<td class="left">Self-referential pointer.</td>
				1767	</tr>
				1768	<tr class="layout">
				1769	<td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
				1770	<td class="left">Recursive structure where the upref refers to the out-most
				1771	structure.</td>
				1772	</tr>
				1773	</table>
				1774	</div>
				1775
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1776
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1777	<!-- *********************************************************************** -->
				1778	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1779	<!-- *********************************************************************** -->
				1780
				1781	<div class="doc_text">
				1782
				1783	<p>LLVM has several different basic types of constants. This section describes
				1784	them all and their syntax.</p>
				1785
				1786	</div>
				1787
				1788	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1789	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1790
				1791	<div class="doc_text">
				1792
				1793	<dl>
				1794	<dt><b>Boolean constants</b></dt>
				1795
				1796	<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]	1797	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1798	</dd>
				1799
				1800	<dt><b>Integer constants</b></dt>
				1801
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1802	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1803	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1804	integer types.
				1805	</dd>
				1806
				1807	<dt><b>Floating point constants</b></dt>
				1808
				1809	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1810	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1811	notation (see below). The assembler requires the exact decimal value of
				1812	a floating-point constant. For example, the assembler accepts 1.25 but
				1813	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1814	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]	1815
				1816	<dt><b>Null pointer constants</b></dt>
				1817
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1818	<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]	1819	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1820
				1821	</dl>
				1822
Dale Johannesen	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1823	<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1824	of floating point constants. For example, the form '<tt>double
				1825	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1826	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]	1827	(and the only time that they are generated by the disassembler) is when a
				1828	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]	1829	decimal floating point number in a reasonable number of digits. For example,
				1830	NaN's, infinities, and other
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1831	special values are represented in their IEEE hexadecimal format so that
				1832	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]	1833	<p>When using the hexadecimal form, constants of types float and double are
				1834	represented using the 16-digit form shown above (which matches the IEEE754
				1835	representation for double); float values must, however, be exactly representable
				1836	as IEE754 single precision.
				1837	Hexadecimal format is always used for long
				1838	double, and there are three forms of long double. The 80-bit
				1839	format used by x86 is represented as <tt>0xK</tt>
				1840	followed by 20 hexadecimal digits.
				1841	The 128-bit format used by PowerPC (two adjacent doubles) is represented
				1842	by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
				1843	format is represented
				1844	by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
				1845	target uses this format. Long doubles will only work if they match
				1846	the long double format on your target. All hexadecimal formats are big-endian
				1847	(sign bit at the left).</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1848	</div>
				1849
				1850	<!-- ======================================================================= -->
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	1851	<div class="doc_subsection">
				1852	<a name="aggregateconstants"> <!-- old anchor -->
				1853	<a name="complexconstants">Complex Constants</a></a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1854	</div>
				1855
				1856	<div class="doc_text">
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	1857	<p>Complex constants are a (potentially recursive) combination of simple
				1858	constants and smaller complex constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1859
				1860	<dl>
				1861	<dt><b>Structure constants</b></dt>
				1862
				1863	<dd>Structure constants are represented with notation similar to structure
				1864	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1865	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1866	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]	1867	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]	1868	types of elements must match those specified by the type.
				1869	</dd>
				1870
				1871	<dt><b>Array constants</b></dt>
				1872
				1873	<dd>Array constants are represented with notation similar to array type
				1874	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1875	(<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]	1876	constants must have <a href="#t_array">array type</a>, and the number and
				1877	types of elements must match those specified by the type.
				1878	</dd>
				1879
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1880	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1881
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1882	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1883	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1884	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1885	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1886	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]	1887	match those specified by the type.
				1888	</dd>
				1889
				1890	<dt><b>Zero initialization</b></dt>
				1891
				1892	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1893	value to zero of <em>any</em> type, including scalar and aggregate types.
				1894	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]	1895	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1896	initializers.
				1897	</dd>
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	1898
				1899	<dt><b>Metadata node</b></dt>
				1900
Nick Lewycky	1e8c7a6	2009-05-30 16:08:30 +0000	[diff] [blame]	1901	<dd>A metadata node is a structure-like constant with
				1902	<a href="#t_metadata">metadata type</a>. For example:
				1903	"<tt>metadata !{ i32 0, metadata !"test" }</tt>". Unlike other constants
				1904	that are meant to be interpreted as part of the instruction stream, metadata
				1905	is a place to attach additional information such as debug info.
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	1906	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1907	</dl>
				1908
				1909	</div>
				1910
				1911	<!-- ======================================================================= -->
				1912	<div class="doc_subsection">
				1913	<a name="globalconstants">Global Variable and Function Addresses</a>
				1914	</div>
				1915
				1916	<div class="doc_text">
				1917
				1918	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1919	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1920	constants. These constants are explicitly referenced when the <a
				1921	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]	1922	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1923	file:</p>
				1924
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1925	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1926	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1927	@X = global i32 17
				1928	@Y = global i32 42
				1929	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1930	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1931	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1932
				1933	</div>
				1934
				1935	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1936	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1937	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1938	<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]	1939	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]	1940	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1941
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1942	<p>Undefined values indicate to the compiler that the program is well defined
				1943	no matter what value is used, giving the compiler more freedom to optimize.
				1944	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1945	</div>
				1946
				1947	<!-- ======================================================================= -->
				1948	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1949	</div>
				1950
				1951	<div class="doc_text">
				1952
				1953	<p>Constant expressions are used to allow expressions involving other constants
				1954	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1955	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]	1956	that does not have side effects (e.g. load and call are not supported). The
				1957	following is the syntax for constant expressions:</p>
				1958
				1959	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1960	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1961	<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]	1962	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1963
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1964	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1965	<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]	1966	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]	1967
				1968	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1969	<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]	1970	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]	1971
				1972	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1973	<dd>Truncate a floating point constant to another floating point type. The
				1974	size of CST must be larger than the size of TYPE. Both types must be
				1975	floating point.</dd>
				1976
				1977	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1978	<dd>Floating point extend a constant to another type. The size of CST must be
				1979	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1980
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1981	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1982	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1983	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1984	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1985	of the same number of elements. If the value won't fit in the integer type,
				1986	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1987
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1988	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1989	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1990	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1991	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1992	of the same number of elements. If the value won't fit in the integer type,
				1993	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1994
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1995	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1996	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1997	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1998	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1999	of the same number of elements. If the value won't fit in the floating point
				2000	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2001
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	2002	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2003	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	2004	constant. TYPE must be a scalar or vector floating point type. CST must be of
				2005	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				2006	of the same number of elements. If the value won't fit in the floating point
				2007	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2008
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	2009	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				2010	<dd>Convert a pointer typed constant to the corresponding integer constant
				2011	TYPE must be an integer type. CST must be of pointer type. The CST value is
				2012	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				2013
				2014	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				2015	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				2016	pointer type. CST must be of integer type. The CST value is zero extended,
				2017	truncated, or unchanged to make it fit in a pointer size. This one is
				2018	<i>really</i> dangerous!</dd>
				2019
				2020	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner	03bbad6	2009-02-28 18:27:03 +0000	[diff] [blame]	2021	<dd>Convert a constant, CST, to another TYPE. The constraints of the operands
				2022	are the same as those for the <a href="#i_bitcast">bitcast
				2023	instruction</a>.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2024
				2025	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				2026
				2027	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				2028	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				2029	instruction, the index list may have zero or more indexes, which are required
				2030	to make sense for the type of "CSTPTR".</dd>
				2031
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2032	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				2033
				2034	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2035	constants.</dd>
				2036
				2037	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				2038	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				2039
				2040	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2041	<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]	2042
				2043	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				2044
				2045	<dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2046	operation</a> on constants.</dd>
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2047
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2048	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				2049
				2050	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2051	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2052
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2053
				2054	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				2055
				2056	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2057	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2058
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2059	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				2060
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	2061	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				2062	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]	2063	binary</a> operations. The constraints on operands are the same as those for
				2064	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2065	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2066	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2067	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	2068
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2069	<!-- ======================================================================= -->
				2070	<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
				2071	</div>
				2072
				2073	<div class="doc_text">
				2074
				2075	<p>Embedded metadata provides a way to attach arbitrary data to the
				2076	instruction stream without affecting the behaviour of the program. There are
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	2077	two metadata primitives, strings and nodes. All metadata has the
				2078	<tt>metadata</tt> type and is identified in syntax by a preceding exclamation
				2079	point ('<tt>!</tt>').
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2080	</p>
				2081
				2082	<p>A metadata string is a string surrounded by double quotes. It can contain
				2083	any character by escaping non-printable characters with "\xx" where "xx" is
				2084	the two digit hex code. For example: "<tt>!"test\00"</tt>".
				2085	</p>
				2086
				2087	<p>Metadata nodes are represented with notation similar to structure constants
				2088	(a comma separated list of elements, surrounded by braces and preceeded by an
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	2089	exclamation point). For example: "<tt>!{ metadata !"test\00", i32 10}</tt>".
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2090	</p>
				2091
Nick Lewycky	cb33799	2009-05-10 20:57:05 +0000	[diff] [blame]	2092	<p>A metadata node will attempt to track changes to the values it holds. In
				2093	the event that a value is deleted, it will be replaced with a typeless
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	2094	"<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewycky	cb33799	2009-05-10 20:57:05 +0000	[diff] [blame]	2095
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2096	<p>Optimizations may rely on metadata to provide additional information about
				2097	the program that isn't available in the instructions, or that isn't easily
				2098	computable. Similarly, the code generator may expect a certain metadata format
				2099	to be used to express debugging information.</p>
				2100	</div>
				2101
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2102	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2103	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				2104	<!-- *********************************************************************** -->
				2105
				2106	<!-- ======================================================================= -->
				2107	<div class="doc_subsection">
				2108	<a name="inlineasm">Inline Assembler Expressions</a>
				2109	</div>
				2110
				2111	<div class="doc_text">
				2112
				2113	<p>
				2114	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				2115	Module-Level Inline Assembly</a>) through the use of a special value. This
				2116	value represents the inline assembler as a string (containing the instructions
				2117	to emit), a list of operand constraints (stored as a string), and a flag that
				2118	indicates whether or not the inline asm expression has side effects. An example
				2119	inline assembler expression is:
				2120	</p>
				2121
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2122	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2123	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2124	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2125	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2126	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2127
				2128	<p>
				2129	Inline assembler expressions may <b>only</b> be used as the callee operand of
				2130	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				2131	</p>
				2132
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2133	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2134	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2135	%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]	2136	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2137	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2138
				2139	<p>
				2140	Inline asms with side effects not visible in the constraint list must be marked
				2141	as having side effects. This is done through the use of the
				2142	'<tt>sideeffect</tt>' keyword, like so:
				2143	</p>
				2144
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2145	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2146	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2147	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2148	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2149	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2150
				2151	<p>TODO: The format of the asm and constraints string still need to be
				2152	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]	2153	need to be documented). This is probably best done by reference to another
				2154	document that covers inline asm from a holistic perspective.
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2155	</p>
				2156
				2157	</div>
				2158
				2159	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2160	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				2161	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2162
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2163	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2164
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2165	<p>The LLVM instruction set consists of several different
				2166	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	2167	instructions</a>, <a href="#binaryops">binary instructions</a>,
				2168	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2169	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				2170	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2171
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2172	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2173
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2174	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2175	<div class="doc_subsection"> <a name="terminators">Terminator
				2176	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2177
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2178	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2179
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2180	<p>As mentioned <a href="#functionstructure">previously</a>, every
				2181	basic block in a program ends with a "Terminator" instruction, which
				2182	indicates which block should be executed after the current block is
				2183	finished. These terminator instructions typically yield a '<tt>void</tt>'
				2184	value: they produce control flow, not values (the one exception being
				2185	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2186	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2187	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				2188	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2189	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				2190	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				2191	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2192
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2193	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2194
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2195	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2196	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				2197	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2198	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2199	<h5>Syntax:</h5>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2200	<pre>
				2201	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]	2202	ret void <i>; Return from void function</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2203	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2204
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2205	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2206
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2207	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				2208	optionally a value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	2209	<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]	2210	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]	2211	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2212
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2213	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2214
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2215	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				2216	the return value. The type of the return value must be a
				2217	'<a href="#t_firstclass">first class</a>' type.</p>
				2218
				2219	<p>A function is not <a href="#wellformed">well formed</a> if
				2220	it it has a non-void return type and contains a '<tt>ret</tt>'
				2221	instruction with no return value or a return value with a type that
				2222	does not match its type, or if it has a void return type and contains
				2223	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2224
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2225	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2226
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2227	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				2228	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]	2229	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2230	the instruction after the call. If the caller was an "<a
				2231	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2232	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2233	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]	2234	return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2235
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2236	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2237
				2238	<pre>
				2239	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	2240	ret void <i>; Return from a void function</i>
Bill Wendling	0a4bbbf	2009-02-28 22:12:54 +0000	[diff] [blame]	2241	ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2242	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2243
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	2244	<p>Note that the code generator does not yet fully support large
				2245	return values. The specific sizes that are currently supported are
				2246	dependent on the target. For integers, on 32-bit targets the limit
				2247	is often 64 bits, and on 64-bit targets the limit is often 128 bits.
				2248	For aggregate types, the current limits are dependent on the element
				2249	types; for example targets are often limited to 2 total integer
				2250	elements and 2 total floating-point elements.</p>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2251
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2252	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2253	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2254	<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]	2255	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2256	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2257	<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]	2258	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2259	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2260	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				2261	transfer to a different basic block in the current function. There are
				2262	two forms of this instruction, corresponding to a conditional branch
				2263	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2264	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2265	<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]	2266	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	2267	unconditional form of the '<tt>br</tt>' instruction takes a single
				2268	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2269	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2270	<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]	2271	argument is evaluated. If the value is <tt>true</tt>, control flows
				2272	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				2273	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2274	<h5>Example:</h5>
Chris Lattner	60150a3	2009-05-09 18:11:50 +0000	[diff] [blame]	2275	<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]	2276	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]	2277	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2278	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2279	<div class="doc_subsubsection">
				2280	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				2281	</div>
				2282
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2283	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2284	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2285
				2286	<pre>
				2287	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2288	</pre>
				2289
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2290	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2291
				2292	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2293	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2294	instruction, allowing a branch to occur to one of many possible
				2295	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2296
				2297
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2298	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2299
				2300	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2301	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2302	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2303	table is not allowed to contain duplicate constant entries.</p>
				2304
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2305	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2306
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2307	<p>The <tt>switch</tt> instruction specifies a table of values and
				2308	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2309	table is searched for the given value. If the value is found, control flow is
				2310	transfered to the corresponding destination; otherwise, control flow is
				2311	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2312
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2313	<h5>Implementation:</h5>
				2314
				2315	<p>Depending on properties of the target machine and the particular
				2316	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2317	ways. For example, it could be generated as a series of chained conditional
				2318	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2319
				2320	<h5>Example:</h5>
				2321
				2322	<pre>
				2323	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2324	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2325	switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2326
				2327	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2328	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2329
				2330	<i>; Implement a jump table:</i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2331	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2332	i32 1, label %onone
				2333	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2334	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2335	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2336
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2337	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2338	<div class="doc_subsubsection">
				2339	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2340	</div>
				2341
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2342	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2343
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2344	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2345
				2346	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2347	<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]	2348	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2349	</pre>
				2350
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	2351	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2352
				2353	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2354	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2355	'<tt>normal</tt>' label or the
				2356	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2357	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2358	"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]	2359	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2360	continued at the dynamically nearest "exception" label.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2361
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2362	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2363
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2364	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2365
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2366	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2367	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	2368	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2369	convention</a> the call should use. If none is specified, the call defaults
				2370	to using C calling conventions.
				2371	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2372
				2373	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2374	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2375	and '<tt>inreg</tt>' attributes are valid here.</li>
				2376
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2377	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2378	function value being invoked. In most cases, this is a direct function
				2379	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2380	an arbitrary pointer to function value.
				2381	</li>
				2382
				2383	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2384	function to be invoked. </li>
				2385
				2386	<li>'<tt>function args</tt>': argument list whose types match the function
				2387	signature argument types. If the function signature indicates the function
				2388	accepts a variable number of arguments, the extra arguments can be
				2389	specified. </li>
				2390
				2391	<li>'<tt>normal label</tt>': the label reached when the called function
				2392	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2393
				2394	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2395	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2396
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2397	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2398	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2399	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2400	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2401
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2402	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2403
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2404	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2405	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2406	difference is that it establishes an association with a label, which is used by
				2407	the runtime library to unwind the stack.</p>
				2408
				2409	<p>This instruction is used in languages with destructors to ensure that proper
				2410	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2411	exception. Additionally, this is important for implementation of
				2412	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2413
Jay Foad	d244909	2009-06-03 10:20:10 +0000	[diff] [blame]	2414	<p>For the purposes of the SSA form, the definition of the value
				2415	returned by the '<tt>invoke</tt>' instruction is deemed to occur on
				2416	the edge from the current block to the "normal" label. If the callee
				2417	unwinds then no return value is available.</p>
Dan Gohman	f96a499	2009-05-22 21:47:08 +0000	[diff] [blame]	2418
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2419	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2420	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2421	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2422	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2423	%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]	2424	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2425	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2426	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2427
				2428
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2429	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2430
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2431	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2432	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2433
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2434	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2435
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2436	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2437	<pre>
				2438	unwind
				2439	</pre>
				2440
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2441	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2442
				2443	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2444	at the first callee in the dynamic call stack which used an <a
				2445	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2446	primarily used to implement exception handling.</p>
				2447
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2448	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2449
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2450	<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]	2451	immediately halt. The dynamic call stack is then searched for the first <a
				2452	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2453	execution continues at the "exceptional" destination block specified by the
				2454	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2455	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2456	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2457
				2458	<!-- _______________________________________________________________________ -->
				2459
				2460	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2461	Instruction</a> </div>
				2462
				2463	<div class="doc_text">
				2464
				2465	<h5>Syntax:</h5>
				2466	<pre>
				2467	unreachable
				2468	</pre>
				2469
				2470	<h5>Overview:</h5>
				2471
				2472	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2473	instruction is used to inform the optimizer that a particular portion of the
				2474	code is not reachable. This can be used to indicate that the code after a
				2475	no-return function cannot be reached, and other facts.</p>
				2476
				2477	<h5>Semantics:</h5>
				2478
				2479	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2480	</div>
				2481
				2482
				2483
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2484	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2485	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2486	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2487	<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]	2488	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]	2489	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2490	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]	2491	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2492	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2493	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2494	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2495	<div class="doc_subsubsection">
				2496	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2497	</div>
				2498
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2499	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2500
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2501	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2502
				2503	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2504	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2505	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2506
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2507	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2508
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2509	<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]	2510
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2511	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2512
				2513	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2514	href="#t_integer">integer</a> or
				2515	<a href="#t_vector">vector</a> of integer values. Both arguments must
				2516	have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2517
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2518	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2519
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2520	<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2521
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2522	<p>If the sum has unsigned overflow, the result returned is the
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2523	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2524	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2525
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2526	<p>Because LLVM integers use a two's complement representation, this
				2527	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2528
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2529	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2530
				2531	<pre>
				2532	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2533	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2534	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2535	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2536	<div class="doc_subsubsection">
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2537	<a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
				2538	</div>
				2539
				2540	<div class="doc_text">
				2541
				2542	<h5>Syntax:</h5>
				2543
				2544	<pre>
				2545	<result> = fadd <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2546	</pre>
				2547
				2548	<h5>Overview:</h5>
				2549
				2550	<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
				2551
				2552	<h5>Arguments:</h5>
				2553
				2554	<p>The two arguments to the '<tt>fadd</tt>' instruction must be
				2555	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
				2556	floating point values. Both arguments must have identical types.</p>
				2557
				2558	<h5>Semantics:</h5>
				2559
				2560	<p>The value produced is the floating point sum of the two operands.</p>
				2561
				2562	<h5>Example:</h5>
				2563
				2564	<pre>
				2565	<result> = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
				2566	</pre>
				2567	</div>
				2568	<!-- _______________________________________________________________________ -->
				2569	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2570	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2571	</div>
				2572
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2573	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2574
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2575	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2576
				2577	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2578	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2579	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2580
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2581	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2582
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2583	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2584	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2585
				2586	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2587	'<tt>neg</tt>' instruction present in most other intermediate
				2588	representations.</p>
				2589
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2590	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2591
				2592	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2593	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
				2594	integer values. Both arguments must have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2595
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2596	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2597
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2598	<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2599
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2600	<p>If the difference has unsigned overflow, the result returned is the
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2601	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2602	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2603
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2604	<p>Because LLVM integers use a two's complement representation, this
				2605	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2606
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2607	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2608	<pre>
				2609	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2610	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2611	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2612	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2613
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2614	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2615	<div class="doc_subsubsection">
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2616	<a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
				2617	</div>
				2618
				2619	<div class="doc_text">
				2620
				2621	<h5>Syntax:</h5>
				2622
				2623	<pre>
				2624	<result> = fsub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2625	</pre>
				2626
				2627	<h5>Overview:</h5>
				2628
				2629	<p>The '<tt>fsub</tt>' instruction returns the difference of its two
				2630	operands.</p>
				2631
				2632	<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
				2633	'<tt>fneg</tt>' instruction present in most other intermediate
				2634	representations.</p>
				2635
				2636	<h5>Arguments:</h5>
				2637
				2638	<p>The two arguments to the '<tt>fsub</tt>' instruction must be <a
				2639	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2640	of floating point values. Both arguments must have identical types.</p>
				2641
				2642	<h5>Semantics:</h5>
				2643
				2644	<p>The value produced is the floating point difference of the two operands.</p>
				2645
				2646	<h5>Example:</h5>
				2647	<pre>
				2648	<result> = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
				2649	<result> = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
				2650	</pre>
				2651	</div>
				2652
				2653	<!-- _______________________________________________________________________ -->
				2654	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2655	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2656	</div>
				2657
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2658	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2659
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2660	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2661	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2662	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2663	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2664	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2665	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2666
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2667	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2668
				2669	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2670	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2671	values. Both arguments must have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2672
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2673	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2674
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2675	<p>The value produced is the integer product of the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2676
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2677	<p>If the result of the multiplication has unsigned overflow,
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2678	the result returned is the mathematical result modulo
				2679	2<sup>n</sup>, where n is the bit width of the result.</p>
				2680	<p>Because LLVM integers use a two's complement representation, and the
				2681	result is the same width as the operands, this instruction returns the
				2682	correct result for both signed and unsigned integers. If a full product
				2683	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2684	should be sign-extended or zero-extended as appropriate to the
				2685	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2686	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2687	<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]	2688	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2689	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2690
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2691	<!-- _______________________________________________________________________ -->
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2692	<div class="doc_subsubsection">
				2693	<a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
				2694	</div>
				2695
				2696	<div class="doc_text">
				2697
				2698	<h5>Syntax:</h5>
				2699	<pre> <result> = fmul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2700	</pre>
				2701	<h5>Overview:</h5>
				2702	<p>The '<tt>fmul</tt>' instruction returns the product of its two
				2703	operands.</p>
				2704
				2705	<h5>Arguments:</h5>
				2706
				2707	<p>The two arguments to the '<tt>fmul</tt>' instruction must be
				2708	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2709	of floating point values. Both arguments must have identical types.</p>
				2710
				2711	<h5>Semantics:</h5>
				2712
				2713	<p>The value produced is the floating point product of the two operands.</p>
				2714
				2715	<h5>Example:</h5>
				2716	<pre> <result> = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
				2717	</pre>
				2718	</div>
				2719
				2720	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2721	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2722	</a></div>
				2723	<div class="doc_text">
				2724	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2725	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2726	</pre>
				2727	<h5>Overview:</h5>
				2728	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2729	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2730
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2731	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2732
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2733	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2734	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2735	values. Both arguments must have identical types.</p>
				2736
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2737	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2738
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2739	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2740	<p>Note that unsigned integer division and signed integer division are distinct
				2741	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2742	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2743	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2744	<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]	2745	</pre>
				2746	</div>
				2747	<!-- _______________________________________________________________________ -->
				2748	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2749	</a> </div>
				2750	<div class="doc_text">
				2751	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2752	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2753	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2754	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2755
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2756	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2757
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2758	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2759	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2760
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2761	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2762
				2763	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2764	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2765	values. Both arguments must have identical types.</p>
				2766
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2767	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2768	<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]	2769	<p>Note that signed integer division and unsigned integer division are distinct
				2770	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2771	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2772	undefined behavior; this is a rare case, but can occur, for example,
				2773	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2774	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2775	<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]	2776	</pre>
				2777	</div>
				2778	<!-- _______________________________________________________________________ -->
				2779	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2780	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2781	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2782	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2783	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2784	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2785	</pre>
				2786	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2787
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2788	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2789	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2790
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2791	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2792
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2793	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2794	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2795	of floating point values. Both arguments must have identical types.</p>
				2796
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2797	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2798
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2799	<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]	2800
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2801	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2802
				2803	<pre>
				2804	<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]	2805	</pre>
				2806	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2807
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2808	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2809	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2810	</div>
				2811	<div class="doc_text">
				2812	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2813	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2814	</pre>
				2815	<h5>Overview:</h5>
				2816	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2817	unsigned division of its two arguments.</p>
				2818	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2819	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2820	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2821	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2822	<h5>Semantics:</h5>
				2823	<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]	2824	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2825	<p>Note that unsigned integer remainder and signed integer remainder are
				2826	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2827	<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]	2828	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2829	<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]	2830	</pre>
				2831
				2832	</div>
				2833	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2834	<div class="doc_subsubsection">
				2835	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2836	</div>
				2837
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2838	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2839
Chris Lattner	261efe9	2003-11-25 01:02:51 +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> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2844	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2845
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2846	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2847
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2848	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2849	signed division of its two operands. This instruction can also take
				2850	<a href="#t_vector">vector</a> versions of the values in which case
				2851	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2852
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2853	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2854
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2855	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2856	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2857	values. Both arguments must have identical types.</p>
				2858
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2859	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2860
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2861	<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]	2862	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2863	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]	2864	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2865	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]	2866	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]	2867	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2868	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2869	<p>Note that signed integer remainder and unsigned integer remainder are
				2870	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2871	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2872	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2873	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2874	(The remainder doesn't actually overflow, but this rule lets srem be
				2875	implemented using instructions that return both the result of the division
				2876	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2877	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2878	<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]	2879	</pre>
				2880
				2881	</div>
				2882	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2883	<div class="doc_subsubsection">
				2884	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2885
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2886	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2887
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2888	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2889	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2890	</pre>
				2891	<h5>Overview:</h5>
				2892	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2893	division of its two operands.</p>
				2894	<h5>Arguments:</h5>
				2895	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2896	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2897	of floating point values. Both arguments must have identical types.</p>
				2898
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2899	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2900
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2901	<p>This instruction returns the <i>remainder</i> of a division.
				2902	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2903
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2904	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2905
				2906	<pre>
				2907	<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]	2908	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2909	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2910
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2911	<!-- ======================================================================= -->
				2912	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2913	Operations</a> </div>
				2914	<div class="doc_text">
				2915	<p>Bitwise binary operators are used to do various forms of
				2916	bit-twiddling in a program. They are generally very efficient
				2917	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2918	instructions. They require two operands of the same type, execute an operation on them,
				2919	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]	2920	</div>
				2921
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2922	<!-- _______________________________________________________________________ -->
				2923	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2924	Instruction</a> </div>
				2925	<div class="doc_text">
				2926	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2927	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2928	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2929
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2930	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2931
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2932	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2933	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2934
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2935	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2936
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2937	<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]	2938	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]	2939	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2940
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2941	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2942
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2943	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2944	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]	2945	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
				2946	If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2947	corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2948
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2949	<h5>Example:</h5><pre>
				2950	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2951	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2952	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2953	<result> = shl i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2954	<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]	2955	</pre>
				2956	</div>
				2957	<!-- _______________________________________________________________________ -->
				2958	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2959	Instruction</a> </div>
				2960	<div class="doc_text">
				2961	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2962	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2963	</pre>
				2964
				2965	<h5>Overview:</h5>
				2966	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2967	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]	2968
				2969	<h5>Arguments:</h5>
				2970	<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]	2971	<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]	2972	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2973
				2974	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2975
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2976	<p>This instruction always performs a logical shift right operation. The most
				2977	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]	2978	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]	2979	the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
				2980	vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
				2981	amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2982
				2983	<h5>Example:</h5>
				2984	<pre>
				2985	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2986	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2987	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2988	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2989	<result> = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2990	<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]	2991	</pre>
				2992	</div>
				2993
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2994	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2995	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2996	Instruction</a> </div>
				2997	<div class="doc_text">
				2998
				2999	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3000	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3001	</pre>
				3002
				3003	<h5>Overview:</h5>
				3004	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3005	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]	3006
				3007	<h5>Arguments:</h5>
				3008	<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]	3009	<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]	3010	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3011
				3012	<h5>Semantics:</h5>
				3013	<p>This instruction always performs an arithmetic shift right operation,
				3014	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]	3015	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]	3016	larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
				3017	arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				3018	corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3019
				3020	<h5>Example:</h5>
				3021	<pre>
				3022	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				3023	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				3024	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				3025	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	3026	<result> = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	3027	<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]	3028	</pre>
				3029	</div>
				3030
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3031	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3032	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				3033	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3034
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3035	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3036
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3037	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3038
				3039	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3040	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3041	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3042
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3043	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3044
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3045	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				3046	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3047
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3048	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3049
				3050	<p>The two arguments to the '<tt>and</tt>' instruction must be
				3051	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3052	values. Both arguments must have identical types.</p>
				3053
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3054	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3055	<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]	3056	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3057	<div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3058	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3059	<tbody>
				3060	<tr>
				3061	<td>In0</td>
				3062	<td>In1</td>
				3063	<td>Out</td>
				3064	</tr>
				3065	<tr>
				3066	<td>0</td>
				3067	<td>0</td>
				3068	<td>0</td>
				3069	</tr>
				3070	<tr>
				3071	<td>0</td>
				3072	<td>1</td>
				3073	<td>0</td>
				3074	</tr>
				3075	<tr>
				3076	<td>1</td>
				3077	<td>0</td>
				3078	<td>0</td>
				3079	</tr>
				3080	<tr>
				3081	<td>1</td>
				3082	<td>1</td>
				3083	<td>1</td>
				3084	</tr>
				3085	</tbody>
				3086	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3087	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3088	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3089	<pre>
				3090	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3091	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				3092	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3093	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3094	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3095	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3096	<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]	3097	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3098	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3099	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3100	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3101	<h5>Overview:</h5>
				3102	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				3103	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3104	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3105
				3106	<p>The two arguments to the '<tt>or</tt>' instruction must be
				3107	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3108	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3109	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3110	<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]	3111	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3112	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3113	<table border="1" cellspacing="0" cellpadding="4">
				3114	<tbody>
				3115	<tr>
				3116	<td>In0</td>
				3117	<td>In1</td>
				3118	<td>Out</td>
				3119	</tr>
				3120	<tr>
				3121	<td>0</td>
				3122	<td>0</td>
				3123	<td>0</td>
				3124	</tr>
				3125	<tr>
				3126	<td>0</td>
				3127	<td>1</td>
				3128	<td>1</td>
				3129	</tr>
				3130	<tr>
				3131	<td>1</td>
				3132	<td>0</td>
				3133	<td>1</td>
				3134	</tr>
				3135	<tr>
				3136	<td>1</td>
				3137	<td>1</td>
				3138	<td>1</td>
				3139	</tr>
				3140	</tbody>
				3141	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3142	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3143	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3144	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				3145	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				3146	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3147	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3148	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3149	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3150	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				3151	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3152	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3153	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3154	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3155	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3156	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3157	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				3158	or of its two operands. The <tt>xor</tt> is used to implement the
				3159	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3160	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3161	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				3162	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3163	values. Both arguments must have identical types.</p>
				3164
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3165	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3166
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3167	<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]	3168	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3169	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3170	<table border="1" cellspacing="0" cellpadding="4">
				3171	<tbody>
				3172	<tr>
				3173	<td>In0</td>
				3174	<td>In1</td>
				3175	<td>Out</td>
				3176	</tr>
				3177	<tr>
				3178	<td>0</td>
				3179	<td>0</td>
				3180	<td>0</td>
				3181	</tr>
				3182	<tr>
				3183	<td>0</td>
				3184	<td>1</td>
				3185	<td>1</td>
				3186	</tr>
				3187	<tr>
				3188	<td>1</td>
				3189	<td>0</td>
				3190	<td>1</td>
				3191	</tr>
				3192	<tr>
				3193	<td>1</td>
				3194	<td>1</td>
				3195	<td>0</td>
				3196	</tr>
				3197	</tbody>
				3198	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3199	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3200	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3201	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3202	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				3203	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				3204	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				3205	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3206	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3207	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3208
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3209	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3210	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3211	<a name="vectorops">Vector Operations</a>
				3212	</div>
				3213
				3214	<div class="doc_text">
				3215
				3216	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3217	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3218	vector-specific operations needed to process vectors effectively. While LLVM
				3219	does directly support these vector operations, many sophisticated algorithms
				3220	will want to use target-specific intrinsics to take full advantage of a specific
				3221	target.</p>
				3222
				3223	</div>
				3224
				3225	<!-- _______________________________________________________________________ -->
				3226	<div class="doc_subsubsection">
				3227	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				3228	</div>
				3229
				3230	<div class="doc_text">
				3231
				3232	<h5>Syntax:</h5>
				3233
				3234	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3235	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3236	</pre>
				3237
				3238	<h5>Overview:</h5>
				3239
				3240	<p>
				3241	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3242	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3243	</p>
				3244
				3245
				3246	<h5>Arguments:</h5>
				3247
				3248	<p>
				3249	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3250	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]	3251	an index indicating the position from which to extract the element.
				3252	The index may be a variable.</p>
				3253
				3254	<h5>Semantics:</h5>
				3255
				3256	<p>
				3257	The result is a scalar of the same type as the element type of
				3258	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				3259	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				3260	results are undefined.
				3261	</p>
				3262
				3263	<h5>Example:</h5>
				3264
				3265	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3266	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3267	</pre>
				3268	</div>
				3269
				3270
				3271	<!-- _______________________________________________________________________ -->
				3272	<div class="doc_subsubsection">
				3273	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				3274	</div>
				3275
				3276	<div class="doc_text">
				3277
				3278	<h5>Syntax:</h5>
				3279
				3280	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	3281	<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]	3282	</pre>
				3283
				3284	<h5>Overview:</h5>
				3285
				3286	<p>
				3287	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3288	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3289	</p>
				3290
				3291
				3292	<h5>Arguments:</h5>
				3293
				3294	<p>
				3295	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3296	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]	3297	scalar value whose type must equal the element type of the first
				3298	operand. The third operand is an index indicating the position at
				3299	which to insert the value. The index may be a variable.</p>
				3300
				3301	<h5>Semantics:</h5>
				3302
				3303	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3304	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]	3305	element values are those of <tt>val</tt> except at position
				3306	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				3307	exceeds the length of <tt>val</tt>, the results are undefined.
				3308	</p>
				3309
				3310	<h5>Example:</h5>
				3311
				3312	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3313	%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]	3314	</pre>
				3315	</div>
				3316
				3317	<!-- _______________________________________________________________________ -->
				3318	<div class="doc_subsubsection">
				3319	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				3320	</div>
				3321
				3322	<div class="doc_text">
				3323
				3324	<h5>Syntax:</h5>
				3325
				3326	<pre>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3327	<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]	3328	</pre>
				3329
				3330	<h5>Overview:</h5>
				3331
				3332	<p>
				3333	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3334	from two input vectors, returning a vector with the same element type as
				3335	the input and length that is the same as the shuffle mask.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3336	</p>
				3337
				3338	<h5>Arguments:</h5>
				3339
				3340	<p>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3341	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				3342	with types that match each other. The third argument is a shuffle mask whose
				3343	element type is always 'i32'. The result of the instruction is a vector whose
				3344	length is the same as the shuffle mask and whose element type is the same as
				3345	the element type of the first two operands.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3346	</p>
				3347
				3348	<p>
				3349	The shuffle mask operand is required to be a constant vector with either
				3350	constant integer or undef values.
				3351	</p>
				3352
				3353	<h5>Semantics:</h5>
				3354
				3355	<p>
				3356	The elements of the two input vectors are numbered from left to right across
				3357	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]	3358	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]	3359	gets. The element selector may be undef (meaning "don't care") and the second
				3360	operand may be undef if performing a shuffle from only one vector.
				3361	</p>
				3362
				3363	<h5>Example:</h5>
				3364
				3365	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3366	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3367	<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]	3368	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				3369	<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]	3370	%result = shufflevector <8 x i32> %v1, <8 x i32> undef,
				3371	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i>
				3372	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
				3373	<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]	3374	</pre>
				3375	</div>
				3376
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	3377
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3378	<!-- ======================================================================= -->
				3379	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3380	<a name="aggregateops">Aggregate Operations</a>
				3381	</div>
				3382
				3383	<div class="doc_text">
				3384
				3385	<p>LLVM supports several instructions for working with aggregate values.
				3386	</p>
				3387
				3388	</div>
				3389
				3390	<!-- _______________________________________________________________________ -->
				3391	<div class="doc_subsubsection">
				3392	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				3393	</div>
				3394
				3395	<div class="doc_text">
				3396
				3397	<h5>Syntax:</h5>
				3398
				3399	<pre>
				3400	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3401	</pre>
				3402
				3403	<h5>Overview:</h5>
				3404
				3405	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3406	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3407	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3408	</p>
				3409
				3410
				3411	<h5>Arguments:</h5>
				3412
				3413	<p>
				3414	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3415	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]	3416	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3417	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3418	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3419	</p>
				3420
				3421	<h5>Semantics:</h5>
				3422
				3423	<p>
				3424	The result is the value at the position in the aggregate specified by
				3425	the index operands.
				3426	</p>
				3427
				3428	<h5>Example:</h5>
				3429
				3430	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3431	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3432	</pre>
				3433	</div>
				3434
				3435
				3436	<!-- _______________________________________________________________________ -->
				3437	<div class="doc_subsubsection">
				3438	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3439	</div>
				3440
				3441	<div class="doc_text">
				3442
				3443	<h5>Syntax:</h5>
				3444
				3445	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3446	<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]	3447	</pre>
				3448
				3449	<h5>Overview:</h5>
				3450
				3451	<p>
				3452	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3453	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3454	</p>
				3455
				3456
				3457	<h5>Arguments:</h5>
				3458
				3459	<p>
				3460	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3461	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3462	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	3463	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3464	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]	3465	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3466	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3467	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]	3468	by the indices.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3469	</p>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3470
				3471	<h5>Semantics:</h5>
				3472
				3473	<p>
				3474	The result is an aggregate of the same type as <tt>val</tt>. Its
				3475	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]	3476	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3477	</p>
				3478
				3479	<h5>Example:</h5>
				3480
				3481	<pre>
Dan Gohman	52bb2db	2008-06-23 15:26:37 +0000	[diff] [blame]	3482	%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]	3483	</pre>
				3484	</div>
				3485
				3486
				3487	<!-- ======================================================================= -->
				3488	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3489	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3490	</div>
				3491
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3492	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3493
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3494	<p>A key design point of an SSA-based representation is how it
				3495	represents memory. In LLVM, no memory locations are in SSA form, which
				3496	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3497	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3498
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3499	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3500
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3501	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3502	<div class="doc_subsubsection">
				3503	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3504	</div>
				3505
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3506	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3507
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3508	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3509
				3510	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3511	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3512	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3513
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3514	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3515
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3516	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3517	heap and returns a pointer to it. The object is always allocated in the generic
				3518	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3519
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3520	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3521
				3522	<p>The '<tt>malloc</tt>' instruction allocates
				3523	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3524	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]	3525	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3526	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Duncan Sands	434ca80	2009-06-20 13:26:06 +0000	[diff] [blame]	3527	If a constant alignment is specified, the value result of the allocation is
				3528	guaranteed to be aligned to at least that boundary. If not specified, or if
				3529	zero, the target can choose to align the allocation on any convenient boundary
				3530	compatible with the type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3531
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3532	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3533
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3534	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3535
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3536	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	3537	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]	3538	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3539
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3540	<h5>Example:</h5>
				3541
				3542	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3543	%array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3544
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3545	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3546	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3547	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3548	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3549	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3550	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	3551
				3552	<p>Note that the code generator does not yet respect the
				3553	alignment value.</p>
				3554
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3555	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3556
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3557	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3558	<div class="doc_subsubsection">
				3559	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3560	</div>
				3561
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3562	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3563
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3564	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3565
				3566	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3567	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3568	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3569
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3570	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3571
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3572	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3573	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3574
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3575	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3576
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3577	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3578	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3579	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3580
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3581	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3582
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3583	<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]	3584	after this instruction executes. If the pointer is null, the operation
				3585	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3586
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3587	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3588
				3589	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3590	%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]	3591	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3592	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3593	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3594
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3595	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3596	<div class="doc_subsubsection">
				3597	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3598	</div>
				3599
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3600	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3601
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3602	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3603
				3604	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3605	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3606	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3607
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3608	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3609
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3610	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3611	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3612	returns to its caller. The object is always allocated in the generic address
				3613	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3614
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3615	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3616
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3617	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3618	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3619	appropriate type to the program. If "NumElements" is specified, it is the
				3620	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Duncan Sands	434ca80	2009-06-20 13:26:06 +0000	[diff] [blame]	3621	If a constant alignment is specified, the value result of the allocation is
				3622	guaranteed to be aligned to at least that boundary. If not specified, or if
				3623	zero, the target can choose to align the allocation on any convenient boundary
				3624	compatible with the type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3625
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3626	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3627
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3628	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3629
Bill Wendling	871eb0a	2009-05-08 20:49:29 +0000	[diff] [blame]	3630	<p>Memory is allocated; a pointer is returned. The operation is undefined if
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3631	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3632	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3633	instruction is commonly used to represent automatic variables that must
				3634	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]	3635	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]	3636	instructions), the memory is reclaimed. Allocating zero bytes
				3637	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3638
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3639	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3640
				3641	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3642	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
				3643	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3644	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
				3645	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3646	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3647	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3648
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3649	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3650	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3651	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3652	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3653	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3654	<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]	3655	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3656	<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]	3657	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3658	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3659	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3660	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]	3661	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]	3662	the number or order of execution of this <tt>load</tt> with other
				3663	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3664	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3665	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3666	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3667	(that is, the alignment of the memory address). A value of 0 or an
				3668	omitted "align" argument means that the operation has the preferential
				3669	alignment for the target. It is the responsibility of the code emitter
				3670	to ensure that the alignment information is correct. Overestimating
				3671	the alignment results in an undefined behavior. Underestimating the
				3672	alignment may produce less efficient code. An alignment of 1 is always
				3673	safe.
				3674	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3675	<h5>Semantics:</h5>
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3676	<p>The location of memory pointed to is loaded. If the value being loaded
				3677	is of scalar type then the number of bytes read does not exceed the minimum
				3678	number of bytes needed to hold all bits of the type. For example, loading an
				3679	<tt>i24</tt> reads at most three bytes. When loading a value of a type like
				3680	<tt>i20</tt> with a size that is not an integral number of bytes, the result
				3681	is undefined if the value was not originally written using a store of the
				3682	same type.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3683	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3684	<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]	3685	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3686	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3687	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3688	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3689	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3690	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3691	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3692	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3693	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3694	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3695	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3696	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3697	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3698	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3699	<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]	3700	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3701	<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]	3702	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]	3703	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3704	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3705	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]	3706	optimizer is not allowed to modify the number or order of execution of
				3707	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3708	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3709	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3710	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3711	(that is, the alignment of the memory address). A value of 0 or an
				3712	omitted "align" argument means that the operation has the preferential
				3713	alignment for the target. It is the responsibility of the code emitter
				3714	to ensure that the alignment information is correct. Overestimating
				3715	the alignment results in an undefined behavior. Underestimating the
				3716	alignment may produce less efficient code. An alignment of 1 is always
				3717	safe.
				3718	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3719	<h5>Semantics:</h5>
				3720	<p>The contents of memory are updated to contain '<tt><value></tt>'
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3721	at the location specified by the '<tt><pointer></tt>' operand.
				3722	If '<tt><value></tt>' is of scalar type then the number of bytes
				3723	written does not exceed the minimum number of bytes needed to hold all
				3724	bits of the type. For example, storing an <tt>i24</tt> writes at most
				3725	three bytes. When writing a value of a type like <tt>i20</tt> with a
				3726	size that is not an integral number of bytes, it is unspecified what
				3727	happens to the extra bits that do not belong to the type, but they will
				3728	typically be overwritten.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3729	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3730	<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]	3731	store i32 3, i32* %ptr <i>; yields {void}</i>
				3732	%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]	3733	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3734	</div>
				3735
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3736	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3737	<div class="doc_subsubsection">
				3738	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3739	</div>
				3740
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3741	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3742	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3743	<pre>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3744	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3745	</pre>
				3746
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3747	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3748
				3749	<p>
				3750	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]	3751	subelement of an aggregate data structure. It performs address calculation only
				3752	and does not access memory.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3753
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3754	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3755
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3756	<p>The first argument is always a pointer, and forms the basis of the
				3757	calculation. The remaining arguments are indices, that indicate which of the
				3758	elements of the aggregate object are indexed. The interpretation of each index
				3759	is dependent on the type being indexed into. The first index always indexes the
				3760	pointer value given as the first argument, the second index indexes a value of
				3761	the type pointed to (not necessarily the value directly pointed to, since the
				3762	first index can be non-zero), etc. The first type indexed into must be a pointer
				3763	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3764	types being indexed into can never be pointers, since that would require loading
				3765	the pointer before continuing calculation.</p>
				3766
				3767	<p>The type of each index argument depends on the type it is indexing into.
				3768	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3769	<b>constants</b> are allowed. When indexing into an array, pointer or vector,
Sanjiv Gupta	23c70f4	2009-04-27 03:21:00 +0000	[diff] [blame]	3770	integers of any width are allowed (also non-constants).</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3771
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3772	<p>For example, let's consider a C code fragment and how it gets
				3773	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3774
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3775	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3776	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3777	struct RT {
				3778	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3779	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3780	char C;
				3781	};
				3782	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3783	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3784	double Y;
				3785	struct RT Z;
				3786	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3787
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3788	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3789	return &s[1].Z.B[5][13];
				3790	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3791	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3792	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3793
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3794	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3795
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3796	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3797	<pre>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	3798	%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
				3799	%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3800
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3801	define i32* %foo(%ST* %s) {
				3802	entry:
				3803	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3804	ret i32* %reg
				3805	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3806	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3807	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3808
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3809	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3810
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3811	<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]	3812	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]	3813	}</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]	3814	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3815	i8 }</tt>' type, another structure. The third index indexes into the second
				3816	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]	3817	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3818	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3819	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]	3820
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3821	<p>Note that it is perfectly legal to index partially through a
				3822	structure, returning a pointer to an inner element. Because of this,
				3823	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3824
				3825	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3826	define i32* %foo(%ST* %s) {
				3827	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3828	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3829	%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]	3830	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3831	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3832	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3833	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3834	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3835
Chris Lattner	8c0e62c	2009-03-09 20:55:18 +0000	[diff] [blame]	3836	<p>Note that it is undefined to access an array out of bounds: array
				3837	and pointer indexes must always be within the defined bounds of the
				3838	array type when accessed with an instruction that dereferences the
				3839	pointer (e.g. a load or store instruction). The one exception for
				3840	this rule is zero length arrays. These arrays are defined to be
				3841	accessible as variable length arrays, which requires access beyond the
				3842	zero'th element.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3843
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3844	<p>The getelementptr instruction is often confusing. For some more insight
				3845	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3846	FAQ</a>.</p>
				3847
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3848	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3849
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3850	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3851	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3852	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3853	<i>; yields i8*:vptr</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3854	%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]	3855	<i>; yields i8*:eptr</i>
				3856	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta	9f805c2	2009-04-25 07:27:44 +0000	[diff] [blame]	3857	<i>; yields i32*:iptr</i>
Sanjiv Gupta	16ffa80	2009-04-24 16:38:13 +0000	[diff] [blame]	3858	%iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3859	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3860	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3861
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3862	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3863	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3864	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3865	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3866	<p>The instructions in this category are the conversion instructions (casting)
				3867	which all take a single operand and a type. They perform various bit conversions
				3868	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3869	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3870
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3871	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3872	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3873	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3874	</div>
				3875	<div class="doc_text">
				3876
				3877	<h5>Syntax:</h5>
				3878	<pre>
				3879	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3880	</pre>
				3881
				3882	<h5>Overview:</h5>
				3883	<p>
				3884	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3885	</p>
				3886
				3887	<h5>Arguments:</h5>
				3888	<p>
				3889	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3890	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]	3891	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]	3892	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3893	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3894
				3895	<h5>Semantics:</h5>
				3896	<p>
				3897	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]	3898	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3899	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3900	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3901
				3902	<h5>Example:</h5>
				3903	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3904	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3905	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3906	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3907	</pre>
				3908	</div>
				3909
				3910	<!-- _______________________________________________________________________ -->
				3911	<div class="doc_subsubsection">
				3912	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3913	</div>
				3914	<div class="doc_text">
				3915
				3916	<h5>Syntax:</h5>
				3917	<pre>
				3918	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3919	</pre>
				3920
				3921	<h5>Overview:</h5>
				3922	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3923	<tt>ty2</tt>.</p>
				3924
				3925
				3926	<h5>Arguments:</h5>
				3927	<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]	3928	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3929	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]	3930	<tt>value</tt> must be smaller than the bit size of the destination type,
				3931	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3932
				3933	<h5>Semantics:</h5>
				3934	<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]	3935	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]	3936
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3937	<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]	3938
				3939	<h5>Example:</h5>
				3940	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3941	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3942	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3943	</pre>
				3944	</div>
				3945
				3946	<!-- _______________________________________________________________________ -->
				3947	<div class="doc_subsubsection">
				3948	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3949	</div>
				3950	<div class="doc_text">
				3951
				3952	<h5>Syntax:</h5>
				3953	<pre>
				3954	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3955	</pre>
				3956
				3957	<h5>Overview:</h5>
				3958	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3959
				3960	<h5>Arguments:</h5>
				3961	<p>
				3962	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]	3963	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3964	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]	3965	<tt>value</tt> must be smaller than the bit size of the destination type,
				3966	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3967
				3968	<h5>Semantics:</h5>
				3969	<p>
				3970	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3971	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]	3972	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3973
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3974	<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]	3975
				3976	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3977	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3978	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3979	%Y = sext i1 true to i32 <i>; yields i32:-1</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	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3985	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3986	</div>
				3987
				3988	<div class="doc_text">
				3989
				3990	<h5>Syntax:</h5>
				3991
				3992	<pre>
				3993	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3994	</pre>
				3995
				3996	<h5>Overview:</h5>
				3997	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3998	<tt>ty2</tt>.</p>
				3999
				4000
				4001	<h5>Arguments:</h5>
				4002	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				4003	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				4004	cast it to. The size of <tt>value</tt> must be larger than the size of
				4005	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				4006	<i>no-op cast</i>.</p>
				4007
				4008	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4009	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				4010	<a href="#t_floating">floating point</a> type to a smaller
				4011	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				4012	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	4013
				4014	<h5>Example:</h5>
				4015	<pre>
				4016	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				4017	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				4018	</pre>
				4019	</div>
				4020
				4021	<!-- _______________________________________________________________________ -->
				4022	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4023	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				4024	</div>
				4025	<div class="doc_text">
				4026
				4027	<h5>Syntax:</h5>
				4028	<pre>
				4029	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				4030	</pre>
				4031
				4032	<h5>Overview:</h5>
				4033	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				4034	floating point value.</p>
				4035
				4036	<h5>Arguments:</h5>
				4037	<p>The '<tt>fpext</tt>' instruction takes a
				4038	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4039	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				4040	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4041
				4042	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4043	<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]	4044	<a href="#t_floating">floating point</a> type to a larger
				4045	<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]	4046	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]	4047	<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]	4048
				4049	<h5>Example:</h5>
				4050	<pre>
				4051	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				4052	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				4053	</pre>
				4054	</div>
				4055
				4056	<!-- _______________________________________________________________________ -->
				4057	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	4058	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4059	</div>
				4060	<div class="doc_text">
				4061
				4062	<h5>Syntax:</h5>
				4063	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4064	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4065	</pre>
				4066
				4067	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4068	<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]	4069	unsigned integer equivalent of type <tt>ty2</tt>.
				4070	</p>
				4071
				4072	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4073	<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]	4074	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4075	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4076	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4077	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]	4078
				4079	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4080	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4081	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4082	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				4083	the results are undefined.</p>
				4084
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4085	<h5>Example:</h5>
				4086	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4087	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	4088	%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]	4089	%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]	4090	</pre>
				4091	</div>
				4092
				4093	<!-- _______________________________________________________________________ -->
				4094	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4095	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4096	</div>
				4097	<div class="doc_text">
				4098
				4099	<h5>Syntax:</h5>
				4100	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4101	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4102	</pre>
				4103
				4104	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4105	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4106	<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]	4107	</p>
				4108
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4109	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4110	<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]	4111	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4112	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4113	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4114	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]	4115
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4116	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4117	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4118	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4119	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				4120	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4121
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	4122	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4123	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4124	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	4125	%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]	4126	%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]	4127	</pre>
				4128	</div>
				4129
				4130	<!-- _______________________________________________________________________ -->
				4131	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4132	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4133	</div>
				4134	<div class="doc_text">
				4135
				4136	<h5>Syntax:</h5>
				4137	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4138	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4139	</pre>
				4140
				4141	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4142	<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]	4143	integer and converts that value to the <tt>ty2</tt> type.</p>
				4144
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4145	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4146	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				4147	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4148	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4149	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4150	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]	4151
				4152	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4153	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4154	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4155	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]	4156
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4157	<h5>Example:</h5>
				4158	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4159	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4160	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4161	</pre>
				4162	</div>
				4163
				4164	<!-- _______________________________________________________________________ -->
				4165	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4166	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4167	</div>
				4168	<div class="doc_text">
				4169
				4170	<h5>Syntax:</h5>
				4171	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4172	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4173	</pre>
				4174
				4175	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4176	<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]	4177	integer and converts that value to the <tt>ty2</tt> type.</p>
				4178
				4179	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4180	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				4181	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4182	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4183	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4184	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]	4185
				4186	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4187	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4188	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4189	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]	4190
				4191	<h5>Example:</h5>
				4192	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4193	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4194	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4195	</pre>
				4196	</div>
				4197
				4198	<!-- _______________________________________________________________________ -->
				4199	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4200	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				4201	</div>
				4202	<div class="doc_text">
				4203
				4204	<h5>Syntax:</h5>
				4205	<pre>
				4206	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				4207	</pre>
				4208
				4209	<h5>Overview:</h5>
				4210	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				4211	the integer type <tt>ty2</tt>.</p>
				4212
				4213	<h5>Arguments:</h5>
				4214	<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]	4215	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]	4216	<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]	4217
				4218	<h5>Semantics:</h5>
				4219	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				4220	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				4221	truncating or zero extending that value to the size of the integer type. If
				4222	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				4223	<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]	4224	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				4225	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4226
				4227	<h5>Example:</h5>
				4228	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4229	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				4230	%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]	4231	</pre>
				4232	</div>
				4233
				4234	<!-- _______________________________________________________________________ -->
				4235	<div class="doc_subsubsection">
				4236	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				4237	</div>
				4238	<div class="doc_text">
				4239
				4240	<h5>Syntax:</h5>
				4241	<pre>
				4242	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				4243	</pre>
				4244
				4245	<h5>Overview:</h5>
				4246	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				4247	a pointer type, <tt>ty2</tt>.</p>
				4248
				4249	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4250	<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]	4251	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]	4252	<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4253
				4254	<h5>Semantics:</h5>
				4255	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				4256	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				4257	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				4258	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				4259	the size of a pointer then a zero extension is done. If they are the same size,
				4260	nothing is done (<i>no-op cast</i>).</p>
				4261
				4262	<h5>Example:</h5>
				4263	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4264	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				4265	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				4266	%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]	4267	</pre>
				4268	</div>
				4269
				4270	<!-- _______________________________________________________________________ -->
				4271	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4272	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4273	</div>
				4274	<div class="doc_text">
				4275
				4276	<h5>Syntax:</h5>
				4277	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4278	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4279	</pre>
				4280
				4281	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4282
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4283	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4284	<tt>ty2</tt> without changing any bits.</p>
				4285
				4286	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4287
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4288	<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]	4289	a non-aggregate first class value, and a type to cast it to, which must also be
				4290	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				4291	<tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	4292	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]	4293	type is a pointer, the destination type must also be a pointer. This
				4294	instruction supports bitwise conversion of vectors to integers and to vectors
				4295	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4296
				4297	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4298	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4299	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				4300	this conversion. The conversion is done as if the <tt>value</tt> had been
				4301	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				4302	converted to other pointer types with this instruction. To convert pointers to
				4303	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				4304	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4305
				4306	<h5>Example:</h5>
				4307	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4308	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4309	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4310	%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]	4311	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4312	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4313
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4314	<!-- ======================================================================= -->
				4315	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				4316	<div class="doc_text">
				4317	<p>The instructions in this category are the "miscellaneous"
				4318	instructions, which defy better classification.</p>
				4319	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4320
				4321	<!-- _______________________________________________________________________ -->
				4322	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				4323	</div>
				4324	<div class="doc_text">
				4325	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4326	<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]	4327	</pre>
				4328	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4329	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				4330	a vector of boolean values based on comparison
				4331	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4332	<h5>Arguments:</h5>
				4333	<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]	4334	the condition code indicating the kind of comparison to perform. It is not
				4335	a value, just a keyword. The possible condition code are:
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4336	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4337	<ol>
				4338	<li><tt>eq</tt>: equal</li>
				4339	<li><tt>ne</tt>: not equal </li>
				4340	<li><tt>ugt</tt>: unsigned greater than</li>
				4341	<li><tt>uge</tt>: unsigned greater or equal</li>
				4342	<li><tt>ult</tt>: unsigned less than</li>
				4343	<li><tt>ule</tt>: unsigned less or equal</li>
				4344	<li><tt>sgt</tt>: signed greater than</li>
				4345	<li><tt>sge</tt>: signed greater or equal</li>
				4346	<li><tt>slt</tt>: signed less than</li>
				4347	<li><tt>sle</tt>: signed less or equal</li>
				4348	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	4349	<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]	4350	<a href="#t_pointer">pointer</a>
				4351	or integer <a href="#t_vector">vector</a> typed.
				4352	They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4353	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4354	<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]	4355	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4356	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]	4357	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4358	<ol>
				4359	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				4360	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				4361	</li>
				4362	<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]	4363	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4364	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4365	<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]	4366	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4367	<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]	4368	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4369	<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]	4370	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4371	<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]	4372	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4373	<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]	4374	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4375	<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]	4376	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4377	<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]	4378	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4379	<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]	4380	</ol>
				4381	<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]	4382	values are compared as if they were integers.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4383	<p>If the operands are integer vectors, then they are compared
				4384	element by element. The result is an <tt>i1</tt> vector with
				4385	the same number of elements as the values being compared.
				4386	Otherwise, the result is an <tt>i1</tt>.
				4387	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4388
				4389	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4390	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				4391	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				4392	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				4393	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				4394	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				4395	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4396	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4397
				4398	<p>Note that the code generator does not yet support vector types with
				4399	the <tt>icmp</tt> instruction.</p>
				4400
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4401	</div>
				4402
				4403	<!-- _______________________________________________________________________ -->
				4404	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				4405	</div>
				4406	<div class="doc_text">
				4407	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4408	<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]	4409	</pre>
				4410	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4411	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				4412	or vector of boolean values based on comparison
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4413	of its operands.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4414	<p>
				4415	If the operands are floating point scalars, then the result
				4416	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				4417	</p>
				4418	<p>If the operands are floating point vectors, then the result type
				4419	is a vector of boolean with the same number of elements as the
				4420	operands being compared.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4421	<h5>Arguments:</h5>
				4422	<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]	4423	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]	4424	a value, just a keyword. The possible condition code are:</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4425	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4426	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4427	<li><tt>oeq</tt>: ordered and equal</li>
				4428	<li><tt>ogt</tt>: ordered and greater than </li>
				4429	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4430	<li><tt>olt</tt>: ordered and less than </li>
				4431	<li><tt>ole</tt>: ordered and less than or equal</li>
				4432	<li><tt>one</tt>: ordered and not equal</li>
				4433	<li><tt>ord</tt>: ordered (no nans)</li>
				4434	<li><tt>ueq</tt>: unordered or equal</li>
				4435	<li><tt>ugt</tt>: unordered or greater than </li>
				4436	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4437	<li><tt>ult</tt>: unordered or less than </li>
				4438	<li><tt>ule</tt>: unordered or less than or equal</li>
				4439	<li><tt>une</tt>: unordered or not equal</li>
				4440	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4441	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4442	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4443	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	4444	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4445	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4446	either a <a href="#t_floating">floating point</a> type
				4447	or a <a href="#t_vector">vector</a> of floating point type.
				4448	They must have identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4449	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4450	<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]	4451	according to the condition code given as <tt>cond</tt>.
				4452	If the operands are vectors, then the vectors are compared
				4453	element by element.
				4454	Each comparison performed
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4455	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]	4456	<ol>
				4457	<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]	4458	<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]	4459	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4460	<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]	4461	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4462	<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]	4463	<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]	4464	<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]	4465	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4466	<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]	4467	<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]	4468	<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]	4469	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4470	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4471	<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]	4472	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4473	<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]	4474	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4475	<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]	4476	<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]	4477	<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]	4478	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4479	<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]	4480	<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]	4481	<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]	4482	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4483	<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]	4484	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4485	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4486
				4487	<h5>Example:</h5>
				4488	<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]	4489	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4490	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4491	<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]	4492	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4493
				4494	<p>Note that the code generator does not yet support vector types with
				4495	the <tt>fcmp</tt> instruction.</p>
				4496
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4497	</div>
				4498
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4499	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4500	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4501	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4502	</div>
				4503
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4504	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4505
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4506	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4507
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4508	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4509	<h5>Overview:</h5>
				4510	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4511	the SSA graph representing the function.</p>
				4512	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4513
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4514	<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]	4515	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4516	as arguments, with one pair for each predecessor basic block of the
				4517	current block. Only values of <a href="#t_firstclass">first class</a>
				4518	type may be used as the value arguments to the PHI node. Only labels
				4519	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4520
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4521	<p>There must be no non-phi instructions between the start of a basic
				4522	block and the PHI instructions: i.e. PHI instructions must be first in
				4523	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4524
Jay Foad	d244909	2009-06-03 10:20:10 +0000	[diff] [blame]	4525	<p>For the purposes of the SSA form, the use of each incoming value is
				4526	deemed to occur on the edge from the corresponding predecessor block
				4527	to the current block (but after any definition of an '<tt>invoke</tt>'
				4528	instruction's return value on the same edge).</p>
				4529
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4530	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4531
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4532	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4533	specified by the pair corresponding to the predecessor basic block that executed
				4534	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4535
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4536	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4537	<pre>
				4538	Loop: ; Infinite loop that counts from 0 on up...
				4539	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4540	%nextindvar = add i32 %indvar, 1
				4541	br label %Loop
				4542	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4543	</div>
				4544
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4545	<!-- _______________________________________________________________________ -->
				4546	<div class="doc_subsubsection">
				4547	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4548	</div>
				4549
				4550	<div class="doc_text">
				4551
				4552	<h5>Syntax:</h5>
				4553
				4554	<pre>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4555	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4556
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4557	<i>selty</i> is either i1 or {<N x i1>}
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4558	</pre>
				4559
				4560	<h5>Overview:</h5>
				4561
				4562	<p>
				4563	The '<tt>select</tt>' instruction is used to choose one value based on a
				4564	condition, without branching.
				4565	</p>
				4566
				4567
				4568	<h5>Arguments:</h5>
				4569
				4570	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4571	The '<tt>select</tt>' instruction requires an 'i1' value or
				4572	a vector of 'i1' values indicating the
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4573	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]	4574	type. If the val1/val2 are vectors and
				4575	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4576	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4577	</p>
				4578
				4579	<h5>Semantics:</h5>
				4580
				4581	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4582	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]	4583	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4584	</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4585	<p>
				4586	If the condition is a vector of i1, then the value arguments must
				4587	be vectors of the same size, and the selection is done element
				4588	by element.
				4589	</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4590
				4591	<h5>Example:</h5>
				4592
				4593	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4594	%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]	4595	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4596
				4597	<p>Note that the code generator does not yet support conditions
				4598	with vector type.</p>
				4599
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4600	</div>
				4601
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4602
				4603	<!-- _______________________________________________________________________ -->
				4604	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4605	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4606	</div>
				4607
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4608	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4609
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4610	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4611	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4612	<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]	4613	</pre>
				4614
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4615	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4616
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4617	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4618
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4619	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4620
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4621	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4622
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4623	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4624	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4625	<p>The optional "tail" marker indicates whether the callee function accesses
				4626	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]	4627	function call is eligible for tail call optimization. Note that calls may
				4628	be marked "tail" even if they do not occur before a <a
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4629	href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4630	</li>
				4631	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4632	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4633	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]	4634	to using C calling conventions.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4635	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4636
				4637	<li>
				4638	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4639	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4640	and '<tt>inreg</tt>' attributes are valid here.</p>
				4641	</li>
				4642
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4643	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4644	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4645	the type of the return value. Functions that return no value are marked
				4646	<tt><a href="#t_void">void</a></tt>.</p>
				4647	</li>
				4648	<li>
				4649	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4650	value being invoked. The argument types must match the types implied by
				4651	this signature. This type can be omitted if the function is not varargs
				4652	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]	4653	</li>
				4654	<li>
				4655	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4656	be invoked. In most cases, this is a direct function invocation, but
				4657	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]	4658	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4659	</li>
				4660	<li>
				4661	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4662	function signature argument types. All arguments must be of
				4663	<a href="#t_firstclass">first class</a> type. If the function signature
				4664	indicates the function accepts a variable number of arguments, the extra
				4665	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4666	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4667	<li>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4668	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4669	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4670	'<tt>readnone</tt>' attributes are valid here.</p>
				4671	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4672	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4673
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4674	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4675
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4676	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4677	transfer to a specified function, with its incoming arguments bound to
				4678	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4679	instruction in the called function, control flow continues with the
				4680	instruction after the function call, and the return value of the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4681	function is bound to the result argument.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4682
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4683	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4684
				4685	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4686	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4687	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4688	%X = tail call i32 @foo() <i>; yields i32</i>
				4689	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4690	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4691
				4692	%struct.A = type { i32, i8 }
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4693	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	4694	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4695	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	85a350f	2008-10-08 06:26:11 +0000	[diff] [blame]	4696	%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]	4697	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4698	</pre>
				4699
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4700	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4701
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4702	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4703	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4704	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4705	</div>
				4706
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4707	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4708
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4709	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4710
				4711	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4712	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4713	</pre>
				4714
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4715	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4716
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4717	<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]	4718	the "variable argument" area of a function call. It is used to implement the
				4719	<tt>va_arg</tt> macro in C.</p>
				4720
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4721	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4722
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4723	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4724	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4725	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]	4726	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4727
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4728	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4729
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4730	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4731	type from the specified <tt>va_list</tt> and causes the
				4732	<tt>va_list</tt> to point to the next argument. For more information,
				4733	see the variable argument handling <a href="#int_varargs">Intrinsic
				4734	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4735
				4736	<p>It is legal for this instruction to be called in a function which does not
				4737	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4738	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4739
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4740	<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]	4741	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4742	argument.</p>
				4743
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4744	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4745
				4746	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4747
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	4748	<p>Note that the code generator does not yet fully support va_arg
				4749	on many targets. Also, it does not currently support va_arg with
				4750	aggregate types on any target.</p>
				4751
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4752	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4753
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4754	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4755	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4756	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4757
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4758	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4759
				4760	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4761	well known names and semantics and are required to follow certain restrictions.
				4762	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4763	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]	4764	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]	4765
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4766	<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]	4767	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4768	begin with this prefix. Intrinsic functions must always be external functions:
				4769	you cannot define the body of intrinsic functions. Intrinsic functions may
				4770	only be used in call or invoke instructions: it is illegal to take the address
				4771	of an intrinsic function. Additionally, because intrinsic functions are part
				4772	of the LLVM language, it is required if any are added that they be documented
				4773	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4774
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4775	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4776	a family of functions that perform the same operation but on different data
				4777	types. Because LLVM can represent over 8 million different integer types,
				4778	overloading is used commonly to allow an intrinsic function to operate on any
				4779	integer type. One or more of the argument types or the result type can be
				4780	overloaded to accept any integer type. Argument types may also be defined as
				4781	exactly matching a previous argument's type or the result type. This allows an
				4782	intrinsic function which accepts multiple arguments, but needs all of them to
				4783	be of the same type, to only be overloaded with respect to a single argument or
				4784	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4785
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4786	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4787	encoded into its function name, each preceded by a period. Only those types
				4788	which are overloaded result in a name suffix. Arguments whose type is matched
				4789	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4790	take an integer of any width and returns an integer of exactly the same integer
				4791	width. This leads to a family of functions such as
				4792	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4793	Only one type, the return type, is overloaded, and only one type suffix is
				4794	required. Because the argument's type is matched against the return type, it
				4795	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4796
				4797	<p>To learn how to add an intrinsic function, please see the
				4798	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4799	</p>
				4800
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4801	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4802
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4803	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4804	<div class="doc_subsection">
				4805	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4806	</div>
				4807
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4808	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4809
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4810	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4811	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]	4812	intrinsic functions. These functions are related to the similarly
				4813	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4814
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4815	<p>All of these functions operate on arguments that use a
				4816	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4817	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4818	transformations should be prepared to handle these functions regardless of
				4819	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4820
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4821	<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]	4822	instruction and the variable argument handling intrinsic functions are
				4823	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4824
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4825	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4826	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4827	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4828	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4829	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4830	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4831	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4832
				4833	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4834	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4835
				4836	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4837	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4838	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4839	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4840	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4841
				4842	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4843	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4844	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4845	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4846
				4847	declare void @llvm.va_start(i8*)
				4848	declare void @llvm.va_copy(i8, i8)
				4849	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4850	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4851	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4852
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4853	</div>
				4854
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4855	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4856	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4857	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4858	</div>
				4859
				4860
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4861	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4862	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4863	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4864	<h5>Overview:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4865	<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4866	<tt>*<arglist></tt> for subsequent use by <tt><a
				4867	href="#i_va_arg">va_arg</a></tt>.</p>
				4868
				4869	<h5>Arguments:</h5>
				4870
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4871	<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]	4872
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4873	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4874
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4875	<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]	4876	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4877	<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]	4878	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4879	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]	4880	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]	4881
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4882	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4883
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4884	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4885	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4886	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4887	</div>
				4888
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4889	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4890	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4891	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4892	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4893
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4894	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4895	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]	4896	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]	4897
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4898	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4899
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4900	<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]	4901
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4902	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4903
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4904	<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]	4905	macro available in C. In a target-dependent way, it destroys the
				4906	<tt>va_list</tt> element to which the argument points. Calls to <a
				4907	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4908	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4909	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4910
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4911	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4912
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4913	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4914	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4915	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4916	</div>
				4917
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4918	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4919
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4920	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4921
				4922	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4923	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4924	</pre>
				4925
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4926	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4927
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4928	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4929	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4930
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4931	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4932
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4933	<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]	4934	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]	4935
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4936
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4937	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4938
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4939	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4940	macro available in C. In a target-dependent way, it copies the source
				4941	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4942	intrinsic is necessary because the <tt><a href="#int_va_start">
				4943	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4944	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4945
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4946	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4947
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4948	<!-- ======================================================================= -->
				4949	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4950	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4951	</div>
				4952
				4953	<div class="doc_text">
				4954
				4955	<p>
				4956	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	4957	Collection</a> (GC) requires the implementation and generation of these
				4958	intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4959	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]	4960	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4961	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]	4962	Front-ends for type-safe garbage collected languages should generate these
				4963	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4964	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4965	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4966
				4967	<p>The garbage collection intrinsics only operate on objects in the generic
				4968	address space (address space zero).</p>
				4969
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4970	</div>
				4971
				4972	<!-- _______________________________________________________________________ -->
				4973	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4974	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4975	</div>
				4976
				4977	<div class="doc_text">
				4978
				4979	<h5>Syntax:</h5>
				4980
				4981	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4982	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4983	</pre>
				4984
				4985	<h5>Overview:</h5>
				4986
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4987	<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]	4988	the code generator, and allows some metadata to be associated with it.</p>
				4989
				4990	<h5>Arguments:</h5>
				4991
				4992	<p>The first argument specifies the address of a stack object that contains the
				4993	root pointer. The second pointer (which must be either a constant or a global
				4994	value address) contains the meta-data to be associated with the root.</p>
				4995
				4996	<h5>Semantics:</h5>
				4997
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	4998	<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]	4999	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5000	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				5001	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				5002	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5003
				5004	</div>
				5005
				5006
				5007	<!-- _______________________________________________________________________ -->
				5008	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5009	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5010	</div>
				5011
				5012	<div class="doc_text">
				5013
				5014	<h5>Syntax:</h5>
				5015
				5016	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5017	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5018	</pre>
				5019
				5020	<h5>Overview:</h5>
				5021
				5022	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				5023	locations, allowing garbage collector implementations that require read
				5024	barriers.</p>
				5025
				5026	<h5>Arguments:</h5>
				5027
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5028	<p>The second argument is the address to read from, which should be an address
				5029	allocated from the garbage collector. The first object is a pointer to the
				5030	start of the referenced object, if needed by the language runtime (otherwise
				5031	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5032
				5033	<h5>Semantics:</h5>
				5034
				5035	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				5036	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5037	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				5038	may only be used in a function which <a href="#gc">specifies a GC
				5039	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5040
				5041	</div>
				5042
				5043
				5044	<!-- _______________________________________________________________________ -->
				5045	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5046	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5047	</div>
				5048
				5049	<div class="doc_text">
				5050
				5051	<h5>Syntax:</h5>
				5052
				5053	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5054	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5055	</pre>
				5056
				5057	<h5>Overview:</h5>
				5058
				5059	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				5060	locations, allowing garbage collector implementations that require write
				5061	barriers (such as generational or reference counting collectors).</p>
				5062
				5063	<h5>Arguments:</h5>
				5064
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5065	<p>The first argument is the reference to store, the second is the start of the
				5066	object to store it to, and the third is the address of the field of Obj to
				5067	store to. If the runtime does not require a pointer to the object, Obj may be
				5068	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5069
				5070	<h5>Semantics:</h5>
				5071
				5072	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				5073	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5074	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				5075	may only be used in a function which <a href="#gc">specifies a GC
				5076	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5077
				5078	</div>
				5079
				5080
				5081
				5082	<!-- ======================================================================= -->
				5083	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5084	<a name="int_codegen">Code Generator Intrinsics</a>
				5085	</div>
				5086
				5087	<div class="doc_text">
				5088	<p>
				5089	These intrinsics are provided by LLVM to expose special features that may only
				5090	be implemented with code generator support.
				5091	</p>
				5092
				5093	</div>
				5094
				5095	<!-- _______________________________________________________________________ -->
				5096	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5097	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5098	</div>
				5099
				5100	<div class="doc_text">
				5101
				5102	<h5>Syntax:</h5>
				5103	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5104	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5105	</pre>
				5106
				5107	<h5>Overview:</h5>
				5108
				5109	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5110	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				5111	target-specific value indicating the return address of the current function
				5112	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5113	</p>
				5114
				5115	<h5>Arguments:</h5>
				5116
				5117	<p>
				5118	The argument to this intrinsic indicates which function to return the address
				5119	for. Zero indicates the calling function, one indicates its caller, etc. The
				5120	argument is <b>required</b> to be a constant integer value.
				5121	</p>
				5122
				5123	<h5>Semantics:</h5>
				5124
				5125	<p>
				5126	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				5127	the return address of the specified call frame, or zero if it cannot be
				5128	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5129	for arguments other than zero, so it should only be used for debugging purposes.
				5130	</p>
				5131
				5132	<p>
				5133	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5134	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]	5135	source-language caller.
				5136	</p>
				5137	</div>
				5138
				5139
				5140	<!-- _______________________________________________________________________ -->
				5141	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5142	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5143	</div>
				5144
				5145	<div class="doc_text">
				5146
				5147	<h5>Syntax:</h5>
				5148	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5149	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5150	</pre>
				5151
				5152	<h5>Overview:</h5>
				5153
				5154	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5155	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				5156	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5157	</p>
				5158
				5159	<h5>Arguments:</h5>
				5160
				5161	<p>
				5162	The argument to this intrinsic indicates which function to return the frame
				5163	pointer for. Zero indicates the calling function, one indicates its caller,
				5164	etc. The argument is <b>required</b> to be a constant integer value.
				5165	</p>
				5166
				5167	<h5>Semantics:</h5>
				5168
				5169	<p>
				5170	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				5171	the frame address of the specified call frame, or zero if it cannot be
				5172	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5173	for arguments other than zero, so it should only be used for debugging purposes.
				5174	</p>
				5175
				5176	<p>
				5177	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5178	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]	5179	source-language caller.
				5180	</p>
				5181	</div>
				5182
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5183	<!-- _______________________________________________________________________ -->
				5184	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5185	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5186	</div>
				5187
				5188	<div class="doc_text">
				5189
				5190	<h5>Syntax:</h5>
				5191	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5192	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5193	</pre>
				5194
				5195	<h5>Overview:</h5>
				5196
				5197	<p>
				5198	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]	5199	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5200	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				5201	features like scoped automatic variable sized arrays in C99.
				5202	</p>
				5203
				5204	<h5>Semantics:</h5>
				5205
				5206	<p>
				5207	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]	5208	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5209	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				5210	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				5211	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				5212	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				5213	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				5214	</p>
				5215
				5216	</div>
				5217
				5218	<!-- _______________________________________________________________________ -->
				5219	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5220	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +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 void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5228	</pre>
				5229
				5230	<h5>Overview:</h5>
				5231
				5232	<p>
				5233	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				5234	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]	5235	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5236	useful for implementing language features like scoped automatic variable sized
				5237	arrays in C99.
				5238	</p>
				5239
				5240	<h5>Semantics:</h5>
				5241
				5242	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5243	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]	5244	</p>
				5245
				5246	</div>
				5247
				5248
				5249	<!-- _______________________________________________________________________ -->
				5250	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5251	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5252	</div>
				5253
				5254	<div class="doc_text">
				5255
				5256	<h5>Syntax:</h5>
				5257	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5258	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5259	</pre>
				5260
				5261	<h5>Overview:</h5>
				5262
				5263
				5264	<p>
				5265	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]	5266	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				5267	no
				5268	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	5269	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5270	</p>
				5271
				5272	<h5>Arguments:</h5>
				5273
				5274	<p>
				5275	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				5276	determining if the fetch should be for a read (0) or write (1), and
				5277	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	5278	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]	5279	<tt>locality</tt> arguments must be constant integers.
				5280	</p>
				5281
				5282	<h5>Semantics:</h5>
				5283
				5284	<p>
				5285	This intrinsic does not modify the behavior of the program. In particular,
				5286	prefetches cannot trap and do not produce a value. On targets that support this
				5287	intrinsic, the prefetch can provide hints to the processor cache for better
				5288	performance.
				5289	</p>
				5290
				5291	</div>
				5292
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5293	<!-- _______________________________________________________________________ -->
				5294	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5295	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5296	</div>
				5297
				5298	<div class="doc_text">
				5299
				5300	<h5>Syntax:</h5>
				5301	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5302	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5303	</pre>
				5304
				5305	<h5>Overview:</h5>
				5306
				5307
				5308	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5309	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]	5310	(PC) in a region of
				5311	code to simulators and other tools. The method is target specific, but it is
				5312	expected that the marker will use exported symbols to transmit the PC of the
				5313	marker.
				5314	The marker makes no guarantees that it will remain with any specific instruction
				5315	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]	5316	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5317	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5318	</p>
				5319
				5320	<h5>Arguments:</h5>
				5321
				5322	<p>
				5323	<tt>id</tt> is a numerical id identifying the marker.
				5324	</p>
				5325
				5326	<h5>Semantics:</h5>
				5327
				5328	<p>
				5329	This intrinsic does not modify the behavior of the program. Backends that do not
				5330	support this intrinisic may ignore it.
				5331	</p>
				5332
				5333	</div>
				5334
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5335	<!-- _______________________________________________________________________ -->
				5336	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5337	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5338	</div>
				5339
				5340	<div class="doc_text">
				5341
				5342	<h5>Syntax:</h5>
				5343	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5344	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5345	</pre>
				5346
				5347	<h5>Overview:</h5>
				5348
				5349
				5350	<p>
				5351	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5352	counter register (or similar low latency, high accuracy clocks) on those targets
				5353	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5354	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5355	should only be used for small timings.
				5356	</p>
				5357
				5358	<h5>Semantics:</h5>
				5359
				5360	<p>
				5361	When directly supported, reading the cycle counter should not modify any memory.
				5362	Implementations are allowed to either return a application specific value or a
				5363	system wide value. On backends without support, this is lowered to a constant 0.
				5364	</p>
				5365
				5366	</div>
				5367
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5368	<!-- ======================================================================= -->
				5369	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5370	<a name="int_libc">Standard C Library Intrinsics</a>
				5371	</div>
				5372
				5373	<div class="doc_text">
				5374	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5375	LLVM provides intrinsics for a few important standard C library functions.
				5376	These intrinsics allow source-language front-ends to pass information about the
				5377	alignment of the pointer arguments to the code generator, providing opportunity
				5378	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5379	</p>
				5380
				5381	</div>
				5382
				5383	<!-- _______________________________________________________________________ -->
				5384	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5385	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5386	</div>
				5387
				5388	<div class="doc_text">
				5389
				5390	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5391	<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
				5392	width. Not all targets support all bit widths however.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5393	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5394	declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>,
				5395	i8 <len>, i32 <align>)
				5396	declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>,
				5397	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5398	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5399	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5400	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5401	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5402	</pre>
				5403
				5404	<h5>Overview:</h5>
				5405
				5406	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5407	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]	5408	location to the destination location.
				5409	</p>
				5410
				5411	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5412	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5413	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5414	</p>
				5415
				5416	<h5>Arguments:</h5>
				5417
				5418	<p>
				5419	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]	5420	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5421	specifying the number of bytes to copy, and the fourth argument is the alignment
				5422	of the source and destination locations.
				5423	</p>
				5424
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5425	<p>
				5426	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]	5427	the caller guarantees that both the source and destination pointers are aligned
				5428	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5429	</p>
				5430
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5431	<h5>Semantics:</h5>
				5432
				5433	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5434	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]	5435	location to the destination location, which are not allowed to overlap. It
				5436	copies "len" bytes of memory over. If the argument is known to be aligned to
				5437	some boundary, this can be specified as the fourth argument, otherwise it should
				5438	be set to 0 or 1.
				5439	</p>
				5440	</div>
				5441
				5442
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5443	<!-- _______________________________________________________________________ -->
				5444	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5445	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5446	</div>
				5447
				5448	<div class="doc_text">
				5449
				5450	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5451	<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
				5452	width. Not all targets support all bit widths however.</p>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5453	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5454	declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>,
				5455	i8 <len>, i32 <align>)
				5456	declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>,
				5457	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5458	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5459	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5460	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5461	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5462	</pre>
				5463
				5464	<h5>Overview:</h5>
				5465
				5466	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5467	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5468	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5469	'<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]	5470	</p>
				5471
				5472	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5473	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5474	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5475	</p>
				5476
				5477	<h5>Arguments:</h5>
				5478
				5479	<p>
				5480	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]	5481	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5482	specifying the number of bytes to copy, and the fourth argument is the alignment
				5483	of the source and destination locations.
				5484	</p>
				5485
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5486	<p>
				5487	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]	5488	the caller guarantees that the source and destination pointers are aligned to
				5489	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5490	</p>
				5491
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5492	<h5>Semantics:</h5>
				5493
				5494	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5495	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]	5496	location to the destination location, which may overlap. It
				5497	copies "len" bytes of memory over. If the argument is known to be aligned to
				5498	some boundary, this can be specified as the fourth argument, otherwise it should
				5499	be set to 0 or 1.
				5500	</p>
				5501	</div>
				5502
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5503
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5504	<!-- _______________________________________________________________________ -->
				5505	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5506	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5507	</div>
				5508
				5509	<div class="doc_text">
				5510
				5511	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5512	<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
				5513	width. Not all targets support all bit widths however.</p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5514	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5515	declare void @llvm.memset.i8(i8 * <dest>, i8 <val>,
				5516	i8 <len>, i32 <align>)
				5517	declare void @llvm.memset.i16(i8 * <dest>, i8 <val>,
				5518	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5519	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5520	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5521	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5522	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5523	</pre>
				5524
				5525	<h5>Overview:</h5>
				5526
				5527	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5528	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]	5529	byte value.
				5530	</p>
				5531
				5532	<p>
				5533	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5534	does not return a value, and takes an extra alignment argument.
				5535	</p>
				5536
				5537	<h5>Arguments:</h5>
				5538
				5539	<p>
				5540	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]	5541	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5542	argument specifying the number of bytes to fill, and the fourth argument is the
				5543	known alignment of destination location.
				5544	</p>
				5545
				5546	<p>
				5547	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]	5548	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5549	</p>
				5550
				5551	<h5>Semantics:</h5>
				5552
				5553	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5554	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5555	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5556	destination location. If the argument is known to be aligned to some boundary,
				5557	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5558	1.
				5559	</p>
				5560	</div>
				5561
				5562
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5563	<!-- _______________________________________________________________________ -->
				5564	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5565	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5566	</div>
				5567
				5568	<div class="doc_text">
				5569
				5570	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5571	<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]	5572	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]	5573	types however.</p>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5574	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5575	declare float @llvm.sqrt.f32(float %Val)
				5576	declare double @llvm.sqrt.f64(double %Val)
				5577	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5578	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5579	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5580	</pre>
				5581
				5582	<h5>Overview:</h5>
				5583
				5584	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5585	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]	5586	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]	5587	<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]	5588	negative numbers other than -0.0 (which allows for better optimization, because
				5589	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5590	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5591	</p>
				5592
				5593	<h5>Arguments:</h5>
				5594
				5595	<p>
				5596	The argument and return value are floating point numbers of the same type.
				5597	</p>
				5598
				5599	<h5>Semantics:</h5>
				5600
				5601	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5602	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]	5603	floating point number.
				5604	</p>
				5605	</div>
				5606
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5607	<!-- _______________________________________________________________________ -->
				5608	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5609	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5610	</div>
				5611
				5612	<div class="doc_text">
				5613
				5614	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5615	<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]	5616	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]	5617	types however.</p>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5618	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5619	declare float @llvm.powi.f32(float %Val, i32 %power)
				5620	declare double @llvm.powi.f64(double %Val, i32 %power)
				5621	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5622	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5623	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5624	</pre>
				5625
				5626	<h5>Overview:</h5>
				5627
				5628	<p>
				5629	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5630	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5631	multiplications is not defined. When a vector of floating point type is
				5632	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5633	</p>
				5634
				5635	<h5>Arguments:</h5>
				5636
				5637	<p>
				5638	The second argument is an integer power, and the first is a value to raise to
				5639	that power.
				5640	</p>
				5641
				5642	<h5>Semantics:</h5>
				5643
				5644	<p>
				5645	This function returns the first value raised to the second power with an
				5646	unspecified sequence of rounding operations.</p>
				5647	</div>
				5648
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5649	<!-- _______________________________________________________________________ -->
				5650	<div class="doc_subsubsection">
				5651	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5652	</div>
				5653
				5654	<div class="doc_text">
				5655
				5656	<h5>Syntax:</h5>
				5657	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5658	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]	5659	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5660	<pre>
				5661	declare float @llvm.sin.f32(float %Val)
				5662	declare double @llvm.sin.f64(double %Val)
				5663	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5664	declare fp128 @llvm.sin.f128(fp128 %Val)
				5665	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5666	</pre>
				5667
				5668	<h5>Overview:</h5>
				5669
				5670	<p>
				5671	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5672	</p>
				5673
				5674	<h5>Arguments:</h5>
				5675
				5676	<p>
				5677	The argument and return value are floating point numbers of the same type.
				5678	</p>
				5679
				5680	<h5>Semantics:</h5>
				5681
				5682	<p>
				5683	This function returns the sine of the specified operand, returning the
				5684	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]	5685	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5686	</div>
				5687
				5688	<!-- _______________________________________________________________________ -->
				5689	<div class="doc_subsubsection">
				5690	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5691	</div>
				5692
				5693	<div class="doc_text">
				5694
				5695	<h5>Syntax:</h5>
				5696	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5697	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]	5698	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5699	<pre>
				5700	declare float @llvm.cos.f32(float %Val)
				5701	declare double @llvm.cos.f64(double %Val)
				5702	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5703	declare fp128 @llvm.cos.f128(fp128 %Val)
				5704	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5705	</pre>
				5706
				5707	<h5>Overview:</h5>
				5708
				5709	<p>
				5710	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5711	</p>
				5712
				5713	<h5>Arguments:</h5>
				5714
				5715	<p>
				5716	The argument and return value are floating point numbers of the same type.
				5717	</p>
				5718
				5719	<h5>Semantics:</h5>
				5720
				5721	<p>
				5722	This function returns the cosine of the specified operand, returning the
				5723	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]	5724	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5725	</div>
				5726
				5727	<!-- _______________________________________________________________________ -->
				5728	<div class="doc_subsubsection">
				5729	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5730	</div>
				5731
				5732	<div class="doc_text">
				5733
				5734	<h5>Syntax:</h5>
				5735	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5736	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]	5737	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5738	<pre>
				5739	declare float @llvm.pow.f32(float %Val, float %Power)
				5740	declare double @llvm.pow.f64(double %Val, double %Power)
				5741	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5742	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5743	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5744	</pre>
				5745
				5746	<h5>Overview:</h5>
				5747
				5748	<p>
				5749	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5750	specified (positive or negative) power.
				5751	</p>
				5752
				5753	<h5>Arguments:</h5>
				5754
				5755	<p>
				5756	The second argument is a floating point power, and the first is a value to
				5757	raise to that power.
				5758	</p>
				5759
				5760	<h5>Semantics:</h5>
				5761
				5762	<p>
				5763	This function returns the first value raised to the second power,
				5764	returning the
				5765	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]	5766	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5767	</div>
				5768
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5769
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5770	<!-- ======================================================================= -->
				5771	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5772	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5773	</div>
				5774
				5775	<div class="doc_text">
				5776	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5777	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5778	These allow efficient code generation for some algorithms.
				5779	</p>
				5780
				5781	</div>
				5782
				5783	<!-- _______________________________________________________________________ -->
				5784	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5785	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5786	</div>
				5787
				5788	<div class="doc_text">
				5789
				5790	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5791	<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]	5792	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]	5793	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5794	declare i16 @llvm.bswap.i16(i16 <id>)
				5795	declare i32 @llvm.bswap.i32(i32 <id>)
				5796	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5797	</pre>
				5798
				5799	<h5>Overview:</h5>
				5800
				5801	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5802	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]	5803	values with an even number of bytes (positive multiple of 16 bits). These are
				5804	useful for performing operations on data that is not in the target's native
				5805	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5806	</p>
				5807
				5808	<h5>Semantics:</h5>
				5809
				5810	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5811	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]	5812	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5813	intrinsic returns an i32 value that has the four bytes of the input i32
				5814	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]	5815	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5816	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5817	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5818	</p>
				5819
				5820	</div>
				5821
				5822	<!-- _______________________________________________________________________ -->
				5823	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5824	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5825	</div>
				5826
				5827	<div class="doc_text">
				5828
				5829	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5830	<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]	5831	width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5832	<pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5833	declare i8 @llvm.ctpop.i8(i8 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5834	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5835	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5836	declare i64 @llvm.ctpop.i64(i64 <src>)
				5837	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5838	</pre>
				5839
				5840	<h5>Overview:</h5>
				5841
				5842	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5843	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5844	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5845	</p>
				5846
				5847	<h5>Arguments:</h5>
				5848
				5849	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5850	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]	5851	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5852	</p>
				5853
				5854	<h5>Semantics:</h5>
				5855
				5856	<p>
				5857	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5858	</p>
				5859	</div>
				5860
				5861	<!-- _______________________________________________________________________ -->
				5862	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5863	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5864	</div>
				5865
				5866	<div class="doc_text">
				5867
				5868	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5869	<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]	5870	integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5871	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5872	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5873	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5874	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5875	declare i64 @llvm.ctlz.i64(i64 <src>)
				5876	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5877	</pre>
				5878
				5879	<h5>Overview:</h5>
				5880
				5881	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5882	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5883	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5884	</p>
				5885
				5886	<h5>Arguments:</h5>
				5887
				5888	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5889	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]	5890	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5891	</p>
				5892
				5893	<h5>Semantics:</h5>
				5894
				5895	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5896	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5897	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]	5898	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5899	</p>
				5900	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5901
				5902
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5903
				5904	<!-- _______________________________________________________________________ -->
				5905	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5906	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5907	</div>
				5908
				5909	<div class="doc_text">
				5910
				5911	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5912	<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]	5913	integer bit width. Not all targets support all bit widths however.</p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5914	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5915	declare i8 @llvm.cttz.i8 (i8 <src>)
				5916	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5917	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5918	declare i64 @llvm.cttz.i64(i64 <src>)
				5919	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5920	</pre>
				5921
				5922	<h5>Overview:</h5>
				5923
				5924	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5925	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5926	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5927	</p>
				5928
				5929	<h5>Arguments:</h5>
				5930
				5931	<p>
				5932	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]	5933	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5934	</p>
				5935
				5936	<h5>Semantics:</h5>
				5937
				5938	<p>
				5939	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5940	in a variable. If the src == 0 then the result is the size in bits of the type
				5941	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5942	</p>
				5943	</div>
				5944
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	5945	<!-- _______________________________________________________________________ -->
				5946	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5947	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5948	</div>
				5949
				5950	<div class="doc_text">
				5951
				5952	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5953	<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]	5954	on any integer bit width.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5955	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5956	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5957	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5958	</pre>
				5959
				5960	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5961	<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]	5962	range of bits from an integer value and returns them in the same bit width as
				5963	the original value.</p>
				5964
				5965	<h5>Arguments:</h5>
				5966	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5967	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]	5968	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]	5969
				5970	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5971	<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]	5972	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5973	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5974	operates in forward mode.</p>
				5975	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5976	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]	5977	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5978	<ol>
				5979	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5980	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5981	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5982	to determine the number of bits to retain.</li>
				5983	<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]	5984	<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]	5985	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	5986	<p>In reverse mode, a similar computation is made except that the bits are
				5987	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5988	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5989	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5990	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5991	</div>
				5992
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5993	<div class="doc_subsubsection">
				5994	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5995	</div>
				5996
				5997	<div class="doc_text">
				5998
				5999	<h5>Syntax:</h5>
				6000	<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]	6001	on any integer bit width.</p>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6002	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	6003	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				6004	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]	6005	</pre>
				6006
				6007	<h5>Overview:</h5>
				6008	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				6009	of bits in an integer value with another integer value. It returns the integer
				6010	with the replaced bits.</p>
				6011
				6012	<h5>Arguments:</h5>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6013	<p>The first argument, <tt>%val</tt>, and the result may be integer types of
				6014	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]	6015	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				6016	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				6017	type since they specify only a bit index.</p>
				6018
				6019	<h5>Semantics:</h5>
				6020	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				6021	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				6022	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				6023	operates in forward mode.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6024
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6025	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				6026	truncating it down to the size of the replacement area or zero extending it
				6027	up to that size.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6028
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6029	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				6030	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				6031	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]	6032	to the <tt>%hi</tt>th bit.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6033
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	6034	<p>In reverse mode, a similar computation is made except that the bits are
				6035	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]	6036	<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]	6037
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6038	<h5>Examples:</h5>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6039
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6040	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	6041	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	6042	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				6043	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				6044	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	6045	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	6046	</pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6047
				6048	</div>
				6049
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6050	<!-- ======================================================================= -->
				6051	<div class="doc_subsection">
				6052	<a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
				6053	</div>
				6054
				6055	<div class="doc_text">
				6056	<p>
				6057	LLVM provides intrinsics for some arithmetic with overflow operations.
				6058	</p>
				6059
				6060	</div>
				6061
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6062	<!-- _______________________________________________________________________ -->
				6063	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6064	<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]	6065	</div>
				6066
				6067	<div class="doc_text">
				6068
				6069	<h5>Syntax:</h5>
				6070
				6071	<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]	6072	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6073
				6074	<pre>
				6075	declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
				6076	declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6077	declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
				6078	</pre>
				6079
				6080	<h5>Overview:</h5>
				6081
				6082	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6083	a signed addition of the two arguments, and indicate whether an overflow
				6084	occurred during the signed summation.</p>
				6085
				6086	<h5>Arguments:</h5>
				6087
				6088	<p>The arguments (%a and %b) and the first element of the result structure may
				6089	be of integer types of any bit width, but they must have the same bit width. The
				6090	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6091	and <tt>%b</tt> are the two values that will undergo signed addition.</p>
				6092
				6093	<h5>Semantics:</h5>
				6094
				6095	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6096	a signed addition of the two variables. They return a structure — the
				6097	first element of which is the signed summation, and the second element of which
				6098	is a bit specifying if the signed summation resulted in an overflow.</p>
				6099
				6100	<h5>Examples:</h5>
				6101	<pre>
				6102	%res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6103	%sum = extractvalue {i32, i1} %res, 0
				6104	%obit = extractvalue {i32, i1} %res, 1
				6105	br i1 %obit, label %overflow, label %normal
				6106	</pre>
				6107
				6108	</div>
				6109
				6110	<!-- _______________________________________________________________________ -->
				6111	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6112	<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]	6113	</div>
				6114
				6115	<div class="doc_text">
				6116
				6117	<h5>Syntax:</h5>
				6118
				6119	<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]	6120	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6121
				6122	<pre>
				6123	declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
				6124	declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6125	declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
				6126	</pre>
				6127
				6128	<h5>Overview:</h5>
				6129
				6130	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6131	an unsigned addition of the two arguments, and indicate whether a carry occurred
				6132	during the unsigned summation.</p>
				6133
				6134	<h5>Arguments:</h5>
				6135
				6136	<p>The arguments (%a and %b) and the first element of the result structure may
				6137	be of integer types of any bit width, but they must have the same bit width. The
				6138	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6139	and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
				6140
				6141	<h5>Semantics:</h5>
				6142
				6143	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6144	an unsigned addition of the two arguments. They return a structure — the
				6145	first element of which is the sum, and the second element of which is a bit
				6146	specifying if the unsigned summation resulted in a carry.</p>
				6147
				6148	<h5>Examples:</h5>
				6149	<pre>
				6150	%res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6151	%sum = extractvalue {i32, i1} %res, 0
				6152	%obit = extractvalue {i32, i1} %res, 1
				6153	br i1 %obit, label %carry, label %normal
				6154	</pre>
				6155
				6156	</div>
				6157
				6158	<!-- _______________________________________________________________________ -->
				6159	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6160	<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]	6161	</div>
				6162
				6163	<div class="doc_text">
				6164
				6165	<h5>Syntax:</h5>
				6166
				6167	<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]	6168	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6169
				6170	<pre>
				6171	declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
				6172	declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6173	declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
				6174	</pre>
				6175
				6176	<h5>Overview:</h5>
				6177
				6178	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6179	a signed subtraction of the two arguments, and indicate whether an overflow
				6180	occurred during the signed subtraction.</p>
				6181
				6182	<h5>Arguments:</h5>
				6183
				6184	<p>The arguments (%a and %b) and the first element of the result structure may
				6185	be of integer types of any bit width, but they must have the same bit width. The
				6186	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6187	and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
				6188
				6189	<h5>Semantics:</h5>
				6190
				6191	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6192	a signed subtraction of the two arguments. They return a structure — the
				6193	first element of which is the subtraction, and the second element of which is a bit
				6194	specifying if the signed subtraction resulted in an overflow.</p>
				6195
				6196	<h5>Examples:</h5>
				6197	<pre>
				6198	%res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6199	%sum = extractvalue {i32, i1} %res, 0
				6200	%obit = extractvalue {i32, i1} %res, 1
				6201	br i1 %obit, label %overflow, label %normal
				6202	</pre>
				6203
				6204	</div>
				6205
				6206	<!-- _______________________________________________________________________ -->
				6207	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6208	<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]	6209	</div>
				6210
				6211	<div class="doc_text">
				6212
				6213	<h5>Syntax:</h5>
				6214
				6215	<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]	6216	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6217
				6218	<pre>
				6219	declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
				6220	declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6221	declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
				6222	</pre>
				6223
				6224	<h5>Overview:</h5>
				6225
				6226	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6227	an unsigned subtraction of the two arguments, and indicate whether an overflow
				6228	occurred during the unsigned subtraction.</p>
				6229
				6230	<h5>Arguments:</h5>
				6231
				6232	<p>The arguments (%a and %b) and the first element of the result structure may
				6233	be of integer types of any bit width, but they must have the same bit width. The
				6234	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6235	and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
				6236
				6237	<h5>Semantics:</h5>
				6238
				6239	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6240	an unsigned subtraction of the two arguments. They return a structure — the
				6241	first element of which is the subtraction, and the second element of which is a bit
				6242	specifying if the unsigned subtraction resulted in an overflow.</p>
				6243
				6244	<h5>Examples:</h5>
				6245	<pre>
				6246	%res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6247	%sum = extractvalue {i32, i1} %res, 0
				6248	%obit = extractvalue {i32, i1} %res, 1
				6249	br i1 %obit, label %overflow, label %normal
				6250	</pre>
				6251
				6252	</div>
				6253
				6254	<!-- _______________________________________________________________________ -->
				6255	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6256	<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]	6257	</div>
				6258
				6259	<div class="doc_text">
				6260
				6261	<h5>Syntax:</h5>
				6262
				6263	<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]	6264	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6265
				6266	<pre>
				6267	declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
				6268	declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6269	declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
				6270	</pre>
				6271
				6272	<h5>Overview:</h5>
				6273
				6274	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6275	a signed multiplication of the two arguments, and indicate whether an overflow
				6276	occurred during the signed multiplication.</p>
				6277
				6278	<h5>Arguments:</h5>
				6279
				6280	<p>The arguments (%a and %b) and the first element of the result structure may
				6281	be of integer types of any bit width, but they must have the same bit width. The
				6282	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6283	and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
				6284
				6285	<h5>Semantics:</h5>
				6286
				6287	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6288	a signed multiplication of the two arguments. They return a structure —
				6289	the first element of which is the multiplication, and the second element of
				6290	which is a bit specifying if the signed multiplication resulted in an
				6291	overflow.</p>
				6292
				6293	<h5>Examples:</h5>
				6294	<pre>
				6295	%res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6296	%sum = extractvalue {i32, i1} %res, 0
				6297	%obit = extractvalue {i32, i1} %res, 1
				6298	br i1 %obit, label %overflow, label %normal
				6299	</pre>
				6300
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6301	</div>
				6302
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	6303	<!-- _______________________________________________________________________ -->
				6304	<div class="doc_subsubsection">
				6305	<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
				6306	</div>
				6307
				6308	<div class="doc_text">
				6309
				6310	<h5>Syntax:</h5>
				6311
				6312	<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
				6313	on any integer bit width.</p>
				6314
				6315	<pre>
				6316	declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
				6317	declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6318	declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
				6319	</pre>
				6320
				6321	<h5>Overview:</h5>
				6322
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	6323	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6324	a unsigned multiplication of the two arguments, and indicate whether an overflow
				6325	occurred during the unsigned multiplication.</p>
				6326
				6327	<h5>Arguments:</h5>
				6328
				6329	<p>The arguments (%a and %b) and the first element of the result structure may
				6330	be of integer types of any bit width, but they must have the same bit width. The
				6331	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6332	and <tt>%b</tt> are the two values that will undergo unsigned
				6333	multiplication.</p>
				6334
				6335	<h5>Semantics:</h5>
				6336
				6337	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6338	an unsigned multiplication of the two arguments. They return a structure —
				6339	the first element of which is the multiplication, and the second element of
				6340	which is a bit specifying if the unsigned multiplication resulted in an
				6341	overflow.</p>
				6342
				6343	<h5>Examples:</h5>
				6344	<pre>
				6345	%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6346	%sum = extractvalue {i32, i1} %res, 0
				6347	%obit = extractvalue {i32, i1} %res, 1
				6348	br i1 %obit, label %overflow, label %normal
				6349	</pre>
				6350
				6351	</div>
				6352
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	6353	<!-- ======================================================================= -->
				6354	<div class="doc_subsection">
				6355	<a name="int_debugger">Debugger Intrinsics</a>
				6356	</div>
				6357
				6358	<div class="doc_text">
				6359	<p>
				6360	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				6361	are described in the <a
				6362	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				6363	Debugging</a> document.
				6364	</p>
				6365	</div>
				6366
				6367
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6368	<!-- ======================================================================= -->
				6369	<div class="doc_subsection">
				6370	<a name="int_eh">Exception Handling Intrinsics</a>
				6371	</div>
				6372
				6373	<div class="doc_text">
				6374	<p> The LLVM exception handling intrinsics (which all start with
				6375	<tt>llvm.eh.</tt> prefix), are described in the <a
				6376	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				6377	Handling</a> document. </p>
				6378	</div>
				6379
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6380	<!-- ======================================================================= -->
				6381	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6382	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6383	</div>
				6384
				6385	<div class="doc_text">
				6386	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6387	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6388	the <tt>nest</tt> attribute, from a function. The result is a callable
				6389	function pointer lacking the nest parameter - the caller does not need
				6390	to provide a value for it. Instead, the value to use is stored in
				6391	advance in a "trampoline", a block of memory usually allocated
				6392	on the stack, which also contains code to splice the nest value into the
				6393	argument list. This is used to implement the GCC nested function address
				6394	extension.
				6395	</p>
				6396	<p>
				6397	For example, if the function is
				6398	<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]	6399	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]	6400	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6401	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				6402	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				6403	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				6404	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6405	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	6406	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				6407	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]	6408	</div>
				6409
				6410	<!-- _______________________________________________________________________ -->
				6411	<div class="doc_subsubsection">
				6412	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				6413	</div>
				6414	<div class="doc_text">
				6415	<h5>Syntax:</h5>
				6416	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6417	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6418	</pre>
				6419	<h5>Overview:</h5>
				6420	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6421	This fills the memory pointed to by <tt>tramp</tt> with code
				6422	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6423	</p>
				6424	<h5>Arguments:</h5>
				6425	<p>
				6426	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				6427	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				6428	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]	6429	intrinsic. Note that the size and the alignment are target-specific - LLVM
				6430	currently provides no portable way of determining them, so a front-end that
				6431	generates this intrinsic needs to have some target-specific knowledge.
				6432	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]	6433	</p>
				6434	<h5>Semantics:</h5>
				6435	<p>
				6436	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]	6437	dependent code, turning it into a function. A pointer to this function is
				6438	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6439	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6440	before being called. The new function's signature is the same as that of
				6441	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				6442	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				6443	of pointer type. Calling the new function is equivalent to calling
				6444	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				6445	missing <tt>nest</tt> argument. If, after calling
				6446	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				6447	modified, then the effect of any later call to the returned function pointer is
				6448	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6449	</p>
				6450	</div>
				6451
				6452	<!-- ======================================================================= -->
				6453	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6454	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				6455	</div>
				6456
				6457	<div class="doc_text">
				6458	<p>
				6459	These intrinsic functions expand the "universal IR" of LLVM to represent
				6460	hardware constructs for atomic operations and memory synchronization. This
				6461	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]	6462	is aimed at a low enough level to allow any programming models or APIs
				6463	(Application Programming Interfaces) which
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6464	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				6465	hardware behavior. Just as hardware provides a "universal IR" for source
				6466	languages, it also provides a starting point for developing a "universal"
				6467	atomic operation and synchronization IR.
				6468	</p>
				6469	<p>
				6470	These do <em>not</em> form an API such as high-level threading libraries,
				6471	software transaction memory systems, atomic primitives, and intrinsic
				6472	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				6473	application libraries. The hardware interface provided by LLVM should allow
				6474	a clean implementation of all of these APIs and parallel programming models.
				6475	No one model or paradigm should be selected above others unless the hardware
				6476	itself ubiquitously does so.
				6477
				6478	</p>
				6479	</div>
				6480
				6481	<!-- _______________________________________________________________________ -->
				6482	<div class="doc_subsubsection">
				6483	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				6484	</div>
				6485	<div class="doc_text">
				6486	<h5>Syntax:</h5>
				6487	<pre>
				6488	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				6489	i1 <device> )
				6490
				6491	</pre>
				6492	<h5>Overview:</h5>
				6493	<p>
				6494	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				6495	specific pairs of memory access types.
				6496	</p>
				6497	<h5>Arguments:</h5>
				6498	<p>
				6499	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				6500	The first four arguments enables a specific barrier as listed below. The fith
				6501	argument specifies that the barrier applies to io or device or uncached memory.
				6502
				6503	</p>
				6504	<ul>
				6505	<li><tt>ll</tt>: load-load barrier</li>
				6506	<li><tt>ls</tt>: load-store barrier</li>
				6507	<li><tt>sl</tt>: store-load barrier</li>
				6508	<li><tt>ss</tt>: store-store barrier</li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6509	<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]	6510	</ul>
				6511	<h5>Semantics:</h5>
				6512	<p>
				6513	This intrinsic causes the system to enforce some ordering constraints upon
				6514	the loads and stores of the program. This barrier does not indicate
				6515	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				6516	which they occur. For any of the specified pairs of load and store operations
				6517	(f.ex. load-load, or store-load), all of the first operations preceding the
				6518	barrier will complete before any of the second operations succeeding the
				6519	barrier begin. Specifically the semantics for each pairing is as follows:
				6520	</p>
				6521	<ul>
				6522	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				6523	after the barrier begins.</li>
				6524
				6525	<li><tt>ls</tt>: All loads before the barrier must complete before any
				6526	store after the barrier begins.</li>
				6527	<li><tt>ss</tt>: All stores before the barrier must complete before any
				6528	store after the barrier begins.</li>
				6529	<li><tt>sl</tt>: All stores before the barrier must complete before any
				6530	load after the barrier begins.</li>
				6531	</ul>
				6532	<p>
				6533	These semantics are applied with a logical "and" behavior when more than one
				6534	is enabled in a single memory barrier intrinsic.
				6535	</p>
				6536	<p>
				6537	Backends may implement stronger barriers than those requested when they do not
				6538	support as fine grained a barrier as requested. Some architectures do not
				6539	need all types of barriers and on such architectures, these become noops.
				6540	</p>
				6541	<h5>Example:</h5>
				6542	<pre>
				6543	%ptr = malloc i32
				6544	store i32 4, %ptr
				6545
				6546	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				6547	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				6548	<i>; guarantee the above finishes</i>
				6549	store i32 8, %ptr <i>; before this begins</i>
				6550	</pre>
				6551	</div>
				6552
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6553	<!-- _______________________________________________________________________ -->
				6554	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6555	<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]	6556	</div>
				6557	<div class="doc_text">
				6558	<h5>Syntax:</h5>
				6559	<p>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6560	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				6561	any integer bit width and for different address spaces. Not all targets
				6562	support all bit widths however.</p>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6563
				6564	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6565	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				6566	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				6567	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				6568	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]	6569
				6570	</pre>
				6571	<h5>Overview:</h5>
				6572	<p>
				6573	This loads a value in memory and compares it to a given value. If they are
				6574	equal, it stores a new value into the memory.
				6575	</p>
				6576	<h5>Arguments:</h5>
				6577	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6578	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]	6579	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				6580	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				6581	this integer type. While any bit width integer may be used, targets may only
				6582	lower representations they support in hardware.
				6583
				6584	</p>
				6585	<h5>Semantics:</h5>
				6586	<p>
				6587	This entire intrinsic must be executed atomically. It first loads the value
				6588	in memory pointed to by <tt>ptr</tt> and compares it with the value
				6589	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				6590	loaded value is yielded in all cases. This provides the equivalent of an
				6591	atomic compare-and-swap operation within the SSA framework.
				6592	</p>
				6593	<h5>Examples:</h5>
				6594
				6595	<pre>
				6596	%ptr = malloc i32
				6597	store i32 4, %ptr
				6598
				6599	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6600	%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]	6601	<i>; yields {i32}:result1 = 4</i>
				6602	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6603	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6604
				6605	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6606	%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]	6607	<i>; yields {i32}:result2 = 8</i>
				6608	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				6609
				6610	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				6611	</pre>
				6612	</div>
				6613
				6614	<!-- _______________________________________________________________________ -->
				6615	<div class="doc_subsubsection">
				6616	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				6617	</div>
				6618	<div class="doc_text">
				6619	<h5>Syntax:</h5>
				6620
				6621	<p>
				6622	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				6623	integer bit width. Not all targets support all bit widths however.</p>
				6624	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6625	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				6626	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				6627	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				6628	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6629
				6630	</pre>
				6631	<h5>Overview:</h5>
				6632	<p>
				6633	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				6634	the value from memory. It then stores the value in <tt>val</tt> in the memory
				6635	at <tt>ptr</tt>.
				6636	</p>
				6637	<h5>Arguments:</h5>
				6638
				6639	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6640	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6641	<tt>val</tt> argument and the result must be integers of the same bit width.
				6642	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				6643	integer type. The targets may only lower integer representations they
				6644	support.
				6645	</p>
				6646	<h5>Semantics:</h5>
				6647	<p>
				6648	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				6649	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				6650	equivalent of an atomic swap operation within the SSA framework.
				6651
				6652	</p>
				6653	<h5>Examples:</h5>
				6654	<pre>
				6655	%ptr = malloc i32
				6656	store i32 4, %ptr
				6657
				6658	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6659	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6660	<i>; yields {i32}:result1 = 4</i>
				6661	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6662	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6663
				6664	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6665	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6666	<i>; yields {i32}:result2 = 8</i>
				6667
				6668	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				6669	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6670	</pre>
				6671	</div>
				6672
				6673	<!-- _______________________________________________________________________ -->
				6674	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6675	<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]	6676
				6677	</div>
				6678	<div class="doc_text">
				6679	<h5>Syntax:</h5>
				6680	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6681	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]	6682	integer bit width. Not all targets support all bit widths however.</p>
				6683	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6684	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6685	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6686	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6687	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6688
				6689	</pre>
				6690	<h5>Overview:</h5>
				6691	<p>
				6692	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6693	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6694	</p>
				6695	<h5>Arguments:</h5>
				6696	<p>
				6697
				6698	The intrinsic takes two arguments, the first a pointer to an integer value
				6699	and the second an integer value. The result is also an integer value. These
				6700	integer types can have any bit width, but they must all have the same bit
				6701	width. The targets may only lower integer representations they support.
				6702	</p>
				6703	<h5>Semantics:</h5>
				6704	<p>
				6705	This intrinsic does a series of operations atomically. It first loads the
				6706	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6707	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6708	</p>
				6709
				6710	<h5>Examples:</h5>
				6711	<pre>
				6712	%ptr = malloc i32
				6713	store i32 4, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6714	%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]	6715	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6716	%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]	6717	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6718	%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]	6719	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6720	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6721	</pre>
				6722	</div>
				6723
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6724	<!-- _______________________________________________________________________ -->
				6725	<div class="doc_subsubsection">
				6726	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6727
				6728	</div>
				6729	<div class="doc_text">
				6730	<h5>Syntax:</h5>
				6731	<p>
				6732	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]	6733	any integer bit width and for different address spaces. Not all targets
				6734	support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6735	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6736	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6737	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6738	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6739	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]	6740
				6741	</pre>
				6742	<h5>Overview:</h5>
				6743	<p>
				6744	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6745	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6746	</p>
				6747	<h5>Arguments:</h5>
				6748	<p>
				6749
				6750	The intrinsic takes two arguments, the first a pointer to an integer value
				6751	and the second an integer value. The result is also an integer value. These
				6752	integer types can have any bit width, but they must all have the same bit
				6753	width. The targets may only lower integer representations they support.
				6754	</p>
				6755	<h5>Semantics:</h5>
				6756	<p>
				6757	This intrinsic does a series of operations atomically. It first loads the
				6758	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6759	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6760	</p>
				6761
				6762	<h5>Examples:</h5>
				6763	<pre>
				6764	%ptr = malloc i32
				6765	store i32 8, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6766	%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]	6767	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6768	%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]	6769	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6770	%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]	6771	<i>; yields {i32}:result3 = 2</i>
				6772	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6773	</pre>
				6774	</div>
				6775
				6776	<!-- _______________________________________________________________________ -->
				6777	<div class="doc_subsubsection">
				6778	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6779	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6780	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6781	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6782
				6783	</div>
				6784	<div class="doc_text">
				6785	<h5>Syntax:</h5>
				6786	<p>
				6787	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6788	<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]	6789	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6790	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6791	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6792	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6793	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6794	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6795	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]	6796
				6797	</pre>
				6798
				6799	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6800	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6801	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6802	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6803	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]	6804
				6805	</pre>
				6806
				6807	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6808	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6809	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6810	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6811	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]	6812
				6813	</pre>
				6814
				6815	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6816	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6817	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6818	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6819	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]	6820
				6821	</pre>
				6822	<h5>Overview:</h5>
				6823	<p>
				6824	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6825	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6826	at <tt>ptr</tt>.
				6827	</p>
				6828	<h5>Arguments:</h5>
				6829	<p>
				6830
				6831	These intrinsics take two arguments, the first a pointer to an integer value
				6832	and the second an integer value. The result is also an integer value. These
				6833	integer types can have any bit width, but they must all have the same bit
				6834	width. The targets may only lower integer representations they support.
				6835	</p>
				6836	<h5>Semantics:</h5>
				6837	<p>
				6838	These intrinsics does a series of operations atomically. They first load the
				6839	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6840	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6841	value stored at <tt>ptr</tt>.
				6842	</p>
				6843
				6844	<h5>Examples:</h5>
				6845	<pre>
				6846	%ptr = malloc i32
				6847	store i32 0x0F0F, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6848	%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]	6849	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6850	%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]	6851	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6852	%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]	6853	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6854	%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]	6855	<i>; yields {i32}:result3 = FF</i>
				6856	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6857	</pre>
				6858	</div>
				6859
				6860
				6861	<!-- _______________________________________________________________________ -->
				6862	<div class="doc_subsubsection">
				6863	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6864	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6865	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6866	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6867
				6868	</div>
				6869	<div class="doc_text">
				6870	<h5>Syntax:</h5>
				6871	<p>
				6872	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6873	<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]	6874	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6875	address spaces. Not all targets
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6876	support all bit widths however.</p>
				6877	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6878	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6879	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6880	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6881	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]	6882
				6883	</pre>
				6884
				6885	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6886	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6887	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6888	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6889	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]	6890
				6891	</pre>
				6892
				6893	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6894	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6895	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6896	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6897	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]	6898
				6899	</pre>
				6900
				6901	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6902	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6903	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6904	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6905	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]	6906
				6907	</pre>
				6908	<h5>Overview:</h5>
				6909	<p>
				6910	These intrinsics takes the signed or unsigned minimum or maximum of
				6911	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6912	original value at <tt>ptr</tt>.
				6913	</p>
				6914	<h5>Arguments:</h5>
				6915	<p>
				6916
				6917	These intrinsics take two arguments, the first a pointer to an integer value
				6918	and the second an integer value. The result is also an integer value. These
				6919	integer types can have any bit width, but they must all have the same bit
				6920	width. The targets may only lower integer representations they support.
				6921	</p>
				6922	<h5>Semantics:</h5>
				6923	<p>
				6924	These intrinsics does a series of operations atomically. They first load the
				6925	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6926	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6927	the original value stored at <tt>ptr</tt>.
				6928	</p>
				6929
				6930	<h5>Examples:</h5>
				6931	<pre>
				6932	%ptr = malloc i32
				6933	store i32 7, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6934	%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]	6935	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6936	%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]	6937	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6938	%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]	6939	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6940	%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]	6941	<i>; yields {i32}:result3 = 8</i>
				6942	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6943	</pre>
				6944	</div>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6945
				6946	<!-- ======================================================================= -->
				6947	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6948	<a name="int_general">General Intrinsics</a>
				6949	</div>
				6950
				6951	<div class="doc_text">
				6952	<p> This class of intrinsics is designed to be generic and has
				6953	no specific purpose. </p>
				6954	</div>
				6955
				6956	<!-- _______________________________________________________________________ -->
				6957	<div class="doc_subsubsection">
				6958	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6959	</div>
				6960
				6961	<div class="doc_text">
				6962
				6963	<h5>Syntax:</h5>
				6964	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6965	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]	6966	</pre>
				6967
				6968	<h5>Overview:</h5>
				6969
				6970	<p>
				6971	The '<tt>llvm.var.annotation</tt>' intrinsic
				6972	</p>
				6973
				6974	<h5>Arguments:</h5>
				6975
				6976	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6977	The first argument is a pointer to a value, the second is a pointer to a
				6978	global string, the third is a pointer to a global string which is the source
				6979	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6980	</p>
				6981
				6982	<h5>Semantics:</h5>
				6983
				6984	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6985	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6986	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]	6987	annotations. These have no other defined use, they are ignored by code
				6988	generation and optimization.
				6989	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6990	</div>
				6991
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6992	<!-- _______________________________________________________________________ -->
				6993	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	6994	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6995	</div>
				6996
				6997	<div class="doc_text">
				6998
				6999	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	7000	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				7001	any integer bit width.
				7002	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7003	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	7004	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				7005	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				7006	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				7007	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				7008	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]	7009	</pre>
				7010
				7011	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	7012
				7013	<p>
				7014	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7015	</p>
				7016
				7017	<h5>Arguments:</h5>
				7018
				7019	<p>
				7020	The first argument is an integer value (result of some expression),
				7021	the second is a pointer to a global string, the third is a pointer to a global
				7022	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]	7023	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7024	</p>
				7025
				7026	<h5>Semantics:</h5>
				7027
				7028	<p>
				7029	This intrinsic allows annotations to be put on arbitrary expressions
				7030	with arbitrary strings. This can be useful for special purpose optimizations
				7031	that want to look for these annotations. These have no other defined use, they
				7032	are ignored by code generation and optimization.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	7033	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7034	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	7035
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	7036	<!-- _______________________________________________________________________ -->
				7037	<div class="doc_subsubsection">
				7038	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				7039	</div>
				7040
				7041	<div class="doc_text">
				7042
				7043	<h5>Syntax:</h5>
				7044	<pre>
				7045	declare void @llvm.trap()
				7046	</pre>
				7047
				7048	<h5>Overview:</h5>
				7049
				7050	<p>
				7051	The '<tt>llvm.trap</tt>' intrinsic
				7052	</p>
				7053
				7054	<h5>Arguments:</h5>
				7055
				7056	<p>
				7057	None
				7058	</p>
				7059
				7060	<h5>Semantics:</h5>
				7061
				7062	<p>
				7063	This intrinsics is lowered to the target dependent trap instruction. If the
				7064	target does not have a trap instruction, this intrinsic will be lowered to the
				7065	call of the abort() function.
				7066	</p>
				7067	</div>
				7068
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	7069	<!-- _______________________________________________________________________ -->
				7070	<div class="doc_subsubsection">
Misha Brukman	dccb025	2008-11-22 23:55:29 +0000	[diff] [blame]	7071	<a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	7072	</div>
				7073	<div class="doc_text">
				7074	<h5>Syntax:</h5>
				7075	<pre>
				7076	declare void @llvm.stackprotector( i8* <guard>, i8** <slot> )
				7077
				7078	</pre>
				7079	<h5>Overview:</h5>
				7080	<p>
				7081	The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
				7082	it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
				7083	it is placed on the stack before local variables.
				7084	</p>
				7085	<h5>Arguments:</h5>
				7086	<p>
				7087	The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
				7088	first argument is the value loaded from the stack guard
				7089	<tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
				7090	has enough space to hold the value of the guard.
				7091	</p>
				7092	<h5>Semantics:</h5>
				7093	<p>
				7094	This intrinsic causes the prologue/epilogue inserter to force the position of
				7095	the <tt>AllocaInst</tt> stack slot to be before local variables on the
				7096	stack. This is to ensure that if a local variable on the stack is overwritten,
				7097	it will destroy the value of the guard. When the function exits, the guard on
				7098	the stack is checked against the original guard. If they're different, then
				7099	the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
				7100	</p>
				7101	</div>
				7102
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7103	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7104	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7105	<address>
				7106	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7107	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]	7108	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7109	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]	7110
				7111	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	7112	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7113	Last modified: $Date$
				7114	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	7115
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	7116	</body>
				7117	</html>